Dissertations / Theses: 'Drilling Engineering'

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Sigurjonsson, Kjartan Örn. "Dual gradient drilling simulations." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18362.

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The system studied in this thesis is called the Low Rise Return system and uses a partly filled marine drilling riser with a variable mud level which is used control the bottom holes pressure.Initially main components of the Low Riser Return System are listed and explained. Then the performance characteristics of the system are explored. Level movements in riser during level increase and decrease at constant mud pump rates are explained along with the effect of mud pump rate on maximum level increase and decrease rates.A simple simulator is then presented that calculates the bottom hole pressure when pump rates are changed. The simulator includes a function that enables it to simulate lost circulation scenarios.The simulator is used to simulate some preferred scenarios. First a pressure increase and decrease at constant mud pump rates are simulated. Then it is shown how a faster pressure decrease can be achieved by temporarily lowering the mud pump rate. Next simulations are shown where changes in mud level are used to compensate for changes in equivalent circulation density as mud pump rates are changed. Finally simulations are run that demonstrate how mud level can be reduced to cure lost circulation scenarios. Results and lessons learned are then discussed.

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Ozer, Ceren. "Hydraulics Optimization Of Foam Drilling In Drilling Operations." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12611059/index.pdf.

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ABSTRACT HYDRAULICS OPTIMIZATION OF FOAM DRILLING IN DRILLING OPERATIONS Ö
zer, Ceren M. Sc., Department of Petroleum and Natural Gas Engineering Supervisor: Assoc. Prof. Dr. Evren Ö
zbayoglu September 2009, 72 pages In drilling, drilling fluid affects every single step of operation. If rig system is thought as the human body, drilling mud can be defined as the blood system of it. Drilling fluid carries the cuttings, cools the bit, it conditions the hole and so on. Some special kinds of drilling fluids are used for special purposes such as underbalanced drilling. Underbalanced drilling is generally used to prevent formation damage, lost circulation and to increase the penetration rate.Since 1980&rsquo
s foam is used as drilling fluid for underbalanced drilling purposes and there are some models for bit hydraulic optimizations. In this study, mathematical model has been derived considering not the volumetric flow rate but the mass flow rate of the foams. Maximum hydraulic horse power at the bit is determined as a function of mass flow rate. Using this concept, optimum volumetric flow rates for liquid and gas phases as well as optimum nozzle size are determined.Using this mathematical model, a computer program is developed for comparing the results with the existing data available in the literature. It accounts for the compressibility of foam and pressure losses inside the drill string, bit and annulus.Hole size, drill-string properties, formation temperature and pressure, maximum inlet pressure are used as input parameters. Program calculates static back pressure,pressure losses in the whole system, bottom hole foam properties such as quality and velocity and optimum liquid and gas flow rates which are the key parameters of foamdrilling optimization. Results show that liquid and gas rates should be increased with increasing hole sizeand formation pressure. Increasing temperature gradient causes a minimal decrease on foam rate properties. In addition, pressure losses due to friction increases with increasing hole size and formation pressure. Decrease in formation temperature also decreases the foam quality. Changes in temperature gradient causes minimal changes on foam rate properties. Comparisons of the proposed model with other models from the literature also gave good match. The optimization criteria and assumptions are differing from the existing models. As a result the comparison does not have to one to one match with the others. The results from this study may be used for optimization of flow rate of foam as drilling fluid based on mass flow.

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Xia, Tian. "INVESTIGATION OF DRILLING PERFORMANCE IN CRYOGENIC DRILLING ON CFRP COMPOSITE LAMINATES." UKnowledge, 2014. http://uknowledge.uky.edu/me_etds/36.

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In recent years, there has been a substantial growth in the application of carbon fiber reinforced plastic (CFRP) composite materials in automobile and aerospace industries due to their superior properties such as lightweight, high strength, excellent corrosion resistance, and minimal fatigue concerns. The present study evaluates the drilling performance of woven carbon fiber reinforced plastics under both dry and cryogenic cooling conditions using uncoated solid carbide drill with a through-hole for coolant application. The effects of the cooling conditions and the cutting parameters on drilling performance in drilling CFRP were evaluated in terms of generated thrust force, torque, cutting edge radius, outer corner flank wear, hole quality (including surface roughness, diameter error, roundness, delamination, burr formation, sub-surface quality). Both cooling conditions and cutting parameters were found to influence the thrust force and torque at different levels. The thrust force and the torque are higher in cryogenic cooling under all cutting parameters. In most of the cases, cryogenic drilling gives better bore-hole quality with lower surface roughness, more accurate diameter, less burr generation, better sub-surface quality, etc. Also, the tool-wear rates measured in drilling shows that cryogenic drilling produces less tool-wear than dry drilling does.

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McLaughlin, Jim. "ORTHOPEDIC DRILLING & THERMAL INJURY ANALYSIS." Master's thesis, Temple University Libraries, 2018. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/512272.

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Mechanical Engineering
M.S.M.E.
In orthopedic surgery, fixation pins are used to provide stability of bone segments to ensure proper healing. The drilling process to implant these pins can generate a considerable amount of heat. Raising the temperature of bone tissue above 47°C for a prolonged amount of time can cause cell death in a process called thermal osteonecrosis. Should bone tissue surrounding implants like fixation pins die and begin to break-down, the stability of said implants becomes at risk for failure. The failure of a surgical implant can be costly, resulting in additional surgery for repairs and prolonged recovery time. Reducing the amount of heat generated during drilling can greatly lessen the potential for thermal injury. This study aims to evaluate the effect of varying drilling parameters on heat generation, namely examining if internal temperatures be reduced by varying the rotational velocity and feed rate in orthopedic drilling, and thus reduce the probability of thermal osteonecrosis. Experiments were performed comparing combinations of feed rates and spindle speeds for the drilling process parameters, specifically feed rates of 1.5, 3.0, 5.0, 9.0, and 12.0 mm⁄s and spindle speeds of 1000, 2000, and 3000 rpm. The tests used traditional smooth-shaft fixation pins, with trocar tips, that were drilled into 20 PCF synthetic bone. A Flir T440 infrared camera was used to record thermal video of the drilling process. Data acquired from the infrared camera shows that lower spindle speeds resulted in lower maximum temperatures while varying feed rates had only a moderate effect. With these results orthopedic drilling can be optimized for reduced heat generation and the prevention of thermal osteonecrosis.
Temple University--Theses

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Fasheloum, Mohammed. "Investigation of drilling parameters indicators." Thesis, University of Nottingham, 1997. http://eprints.nottingham.ac.uk/11885/.

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The factors which influence the performance characteristics of diamond impregnated core bits and roller cone bits are examined, and actual field drilling data are analysed to determine these factors. Methods for selecting the appropriate bit type for optimised drilling are also highlighted. The importance of core drilling to the exploration and exploitation of the earth's natural resources and to the integrity of engineering structures is highlighted. An investigation of the slim hole continuous core drilling system and its application in the oil and gas exploration is analysed. The highly successful integration of oilfield, mining and geotechnical exploration technologies in a special investigation programme includes several elements which are important in the application of slim hole methods for oil and gas exploration are analysed. Many of the technical issues associated with a slim hole approach have been addressed in the development and application of the drilling, and coring equipment and systems. The project has given an opportunity to evaluate the advantages and disadvantages, merits and limitations for applying different drilling and associated technologies for deep hole construction to safety.

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Muelhoefer, Jay A. (Jay Allan). "Flexible shaft drilling for cased well exploration." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/37543.

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Rowsell, Philip J. "The automatic optimisation of drilling performance." Thesis, University of Nottingham, 1991. http://eprints.nottingham.ac.uk/11909/.

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The drilling industry, along with many others, is becoming increasingly competitive, demanding greater efforts to improve safety and reduce costs. For this reason, companies are progressively looking towards computerised automation to enhance performance. Unlike most industries however, the drilling industry has been slow to take advantage of the advances in computer and automation technology. Only recently have automatic operations such as tubular handling been placed under computer control. These activities relate to peripheral mechanical handling problems which are relatively easy to solve. The concept of an automatic intelligent drill, capable of making its own or assisted decisions about drilling parameters such as weight on bit or rotational speed, may seem remote and far into the future. Research in drilling automation, at the University of Nottingham, has the ultimate objective of achieving computerized drill control through the the application of an intelligent knowledge induction system. At the University, a laboratory rig has been developed with such a system installed. Decisions for optimal performance are based on either maximum penetration or minimum cost drilling. The system has a self-learning capability, allowing a progressive improvement in performance. The prototype system is currently undergoing trials, using real data collected while the laboratory rig is drilling and artificial data. The results are very encouraging and demonstrate the feasibility and advantages of optimised drill performance. This thesis describes the design and development of this drill optimisation scheme produced by the author. Both the theory behind the optimisation system, and the results of the initial phase of Laboratory testing are included.

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8

DeSilva, Sirilath. "Transient axisymmetric model for laser drilling." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/289927.

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A transient axisymmetric model is developed to study the laser drilling phenomenon. Governing equations are the transient axisymmetric 3-D heat conduction equation for the solid substrate and for the liquid molten part, the thin layer model (TLM) equations are utilized. Boundary element method (BEM) is used for the region encompassing the moving boundary and finite difference method (FDM) is utilized for the remainder. BEM and FDM are coupled using flux and temperature at their interface. TLM is obtained using simplified free surface, mass, momentum and energy equations in body intrinsic coordinates. They are simplified by integrating across the layer using profiles for velocity and temperature thus obtaining a 1-D transient hyperbolic system. This is solved by a space-time flux conservation method. The TLM is coupled to the BEM-FDM by the common interface matching conditions. The constitutive equations governing laser interaction with material are used at the liquid-vapor interface.

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Will, Maja, and Linn Krüger. "Automatic drilling of holes for wing- and fin interface : A theoretic idea of how the drilling could be automated." Thesis, Linköpings universitet, Industriell Produktion, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-139784.

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Year 2024 U.S. Air Force will replace their current Northrop T-38 Talon aircraft trainer for pilots, and therefore they have designed the T-X program where several aircraft manufactures competes about the first order of 350 aircrafts. Boeing and Saab AB have in cooperation produced a new aircraft trainer, Boeing T-X, where Saab AB produces the rear part of the fuselage. Today two prototypes have been produced and tested to fly, but if Boeing and Saab wins the order the production has to be more effective to manage the production volume. The aircraft has two wings and two fins which are assembled via an interface with several larger holes which were partially drilled manually during the prototype manufacturing. The purpose with this thesis was to examine if the drilling of the interfaces could be automated in order to increase the production volume, regarding to economy and high tolerance - and flatness requirements. The purpose was also to determine how much of the drilling should be done in an earlier stage and how much should be done where the fuselage is assembled. To manage the time limit, delimitations were set to only make a pre-study and examine which path Saab should take when selecting a suitable solution, the time limit will not be enough for a ready solution. Different drilling methods and different machines and robots suitable for drilling were examined. Concept selection matrices were used in the work process to reach a result, where different concepts were developed and compared with each other based on the requirements. The result was to develop the CNC gantry machine concept.
År 2024 kommer U.S. Air Force byta ut sina nuvarande skolflygplan Northrop T-38 Talon, och har därför startat T-X programmet där olika företag är med och tävlar om första ordern på 350 flygplan. Boeing och Saab AB har i samarbete tagit fram ett nytt skolflygplan, Boeing T-X, där Saab AB tillverkar bakre delen av flygkroppen. I dagsläget har två prototyper tillverkats och provflugits, men om Boeing och Saab får ordern måste produktionen effektiviseras för att klara av produktionshastigheten. Flygplanet har två vingar och två fenor vilka fästs via ett interface med ett fåtal större hål vilka under prototyptillverkningen till viss del har borrats manuellt. Syftet med det här exjobbet var att undersöka om borrningen av interfacen gick att automatisera för att kunna öka produktionshastigheten, med avseende på ekonomi samt höga tolerans- och planhetskrav. Syftet var också att avgöra hur mycket av borrningen som skulle göras i ett tidigare skede och hur mycket som skulle göras där flygkroppen byggs samman. För att hinna under tio veckor gjordes avgränsningar till att endast göra en förstudie och ett vägval åt Saab, och inte ta fram en färdig lösning. Olika borrningsmetoder samt maskiner och robotar lämpade för borrning undersöktes. För att komma fram till ett resultat användes under arbetet konceptutvecklingsmatriser, där olika koncept togs fram och jämfördes med varandra utifrån de krav som identifierats. Resultatet blev att utveckla CNC gantry maskin konceptet.

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Aboujaoude, Claude E. "Feedback control of vibrations in surface rotary blasthole drilling." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ29867.pdf.

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Kasaeyan, Mohammad. "A novel engineering framework for risk assessment of Mobile Offshore Drilling Units." Thesis, Liverpool John Moores University, 2015. http://researchonline.ljmu.ac.uk/4542/.

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Natural oil and gas has become one of mankind’s most fundamental resources. Hence, the performance of mobile offshore drilling units (MODUs) under various conditions has received considerable attention. MODUs are designed, constructed, operated, and managed for harsh geographical environments, thus they are unavoidably exposed to a wide range of uncertain threats and hazards. Ensuring the operational safety of an MODU’s system is often a complex problem. The system faces hazards from many different sources which dynamically threaten its integrity and can cause catastrophic consequences at time of failure. The main purpose of this thesis is to propose a methodology to improve the current procedures used in the risk assessment of MODUs. The aim is to prevent a critical event from occurring during drilling rather than on measures that mitigate the consequences once the undesirable event has occurred. A conceptual framework has been developed in this thesis to identify a range of hazards associated with normal operational activities and rank them in order to reduce the risks of the MODU. The proposed methodology provides a rational and systematic approach to an MODU’s risk assessment; a comprehensive model is suggested to take into consideration different influences of each hazard group (HG) of an offshore system. The Fuzzy- analytic hierarchy process (AHP) is used to determine the weights of each HG. Fault tree analysis (FTA) is used to identify basic causes and their logical relationships leading to the undesired events and to calculate the probability of occurrence of each undesirable event in an MODU system. The BBN technique is used to express the causal relationships between variables in order to predict and update the occurrence probability of each undesirable event when any new evidence becomes available. Finally, an integrated Fuzzy multiple criteria decision making (MCDM) model based on the Fuzzy-AHP and a Fuzzy techniques for order preference by similarity to an ideal solution (TOPSIS) is developed to offer decision support that can help the Decision maker to set priorities for controlling the risk and improving the MODU’s safety level. All the developed models have been tested and demonstrated with case studies. An MODU’s drilling failure due to its operational scenario has been investigated and focus has been on the mud circulation system including the blowout preventer (BOP).

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Ali, Naseer A. (Naseer Ahmad). "Adaptive control of robots for cutting and drilling processes." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61094.

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Drilling and cutting operations are required in many industrial applications. For example an advanced flexible manufacturing system using robotics technologies may be required to perform such operations. Variation in the mechanical properties of a material to be processed, and compliance add complexity to the already nonlinear robotic system. Thus, these tasks are difficult to perform. For cutting and drilling processes, it is often desirable to maintain a constant cutting force to maintain productivity and also to maintain the quality of the finished workpiece. To counter the effect of the material variations while maintaining a constant cutting force, a controller mechanism is necessary which will react to these variations, and adjust the robot controller's parameters to minimize the effects of the variations on the system's performance.
A single-input/single-output (SISO) model-reference adaptive control (MRAC) scheme to cope with varying material hardness, sensor compliance, and non-rigid body dynamics in the control of cutting forces is presented. The controller is formulated to maintain stable, damped, force control when rigid body and rigid contact assumptions are not valid, and when material hardness is variable, in discrete-time and Cartesian-space. It is suited to super-position on a Cartesian-space hybrid control scheme, and implementation on a multiprocessor control system.

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Park, Junho. "Nonlinear Model Predictive Control for a Managed Pressure Drilling with High-Fidelity Drilling Simulators." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/6792.

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The world's energy demand has been rapidly increasing and is projected to continue growing for at least the next two decades. With increasing global energy demand and competition from renewable energy, the oil and gas industry is striving for more efficient petroleum production. Many technical breakthroughs have enabled the drilling industry to expand the exploration to more difficult drilling such as deepwater drilling and multilateral directional drilling. For example, managed pressure drilling (MPD) offers ceaseless operation with multiple manipulated variables (MV) and wired drill pipe (WDP) provides two-way, high-speed measurements from bottom hole and along-string sensors. These technologies have maximum benefit when applied in an automation system or as a real-time advisory tool. The objective of this study is to investigate the benefit of nonlinear model-based control and estimation algorithms with various types of models. This work presents a new simplified flow model (SFM) for bottomhole pressure (BHP) regulation in MPD operations. The SFM is embedded into model-based control and estimation algorithms that use model predictive control (MPC) and moving horizon estimation (MHE), respectively. This work also presents a new Hammerstein-Wiener nonlinear model predictive controller for BHP regulation. Hammerstein-Wiener models employ input and output static nonlinear blocks before and after linear dynamics blocks to simplify the controller design. The control performance of the new Hammerstein-Wiener nonlinear controller is superior to conventional PID controllers in a variety of drilling scenarios. Conventional controllers show severe limitations in MPD because of the interconnected multivariable and nonlinear nature of drilling operations. BHP control performance is evaluated in scenarios such as drilling, pipe connection, kick attenuation, and mud density displacement and the efficacy of the SFM and Hammerstein-Wiener models is tested in various control schemes applicable to both WDP and mud pulse systems. Trusted high-fidelity drilling simulators are used to simulate well conditions and are used to evaluate the performance of the controllers using the SFM and Hammerstein-Wiener models. The comparison between non-WDP (semi-closed loop) and WDP (full-closed loop) applications validates the accuracy of the SFM under the set of conditions tested and confirms comparability with model-based control and estimation algorithms. The SFM MPC maintains the BHP within ± 1 bar of the setpoint for each investigated scenario, including for pipe connection and mud density displacement procedures that experience a wider operation range than normal drilling.

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Amjad, Muhammad. "Control of ITH percussive longhole drilling in hard rock." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37697.

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This thesis aims to develop a comprehensive strategy for automatic control of the ITH percussive drilling process. Such automation would provide the benefits of improved productivity and quality in terms of penetration rate and hole deviation, as well as enhanced hole quality and machine life.
Analysis of field data acquired from drilling experiments performed at INCO's Little Stobie Mine is presented. As a result of this analysis, a control algorithm is formulated to enhance the drilling process efficiency. This algorithm calculates the specific energy (SE) of the rock and adjusts the applied feed force based on this SE value, using a relationship obtained from the field data analysis.
A model of the percussive drilling process is developed and simulated in software. The proposed control algorithm is tested through simulations on this simulated drilling process. The results of the simulation show a significant increase in efficiency of the drilling process.
As a result of vibration data analysis it is concluded that vibration should be controlled through an improved design of the shock-absorber, rather than through drilling variables. A detailed shock-absorber test data analysis is therefore presented. Recommendations for design changes in the shock-absorber are also given.
Deviation analysis is also presented in the thesis, which shows a poor correlation between the machine variables and the hole deviation data. Hence, it is recommended that deviation be controlled by steering. An innovative guided drilling mechanism for controlling the hole deviation is also proposed. This mechanism consists of an eccentric ITH percussive hammer with controlled rotational speed, which can be employed as an actuator to steer the drill string in a desired direction without using any down hole instrumentation. Modelling and simulation analysis of this system is also presented.

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Shyha, Islam Saad Elsayed Mohamed. "Drilling of carbon fibre reinforced plastic composites." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1353/.

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Following an extensive literature survey focusing on the machinability of carbon fibre reinforced plastics (CFRP), three main phases of experimental work were undertaken to evaluate the drilling of CFRP and associated stack materials. Phase 1 and 2 involved small diameter holes (1.5 mm) in thin CFRP laminates (3 mm thick) while Phase 3 addressed the feasibility of one-shot drilling (6.35 mm diameter holes) in multilayer workpiece stacks comprising titanium, CFRP and aluminium. Machinability was assessed in terms of tool life/wear, force/torque, hole size and geometrical accuracy, workpiece surface integrity and chip morphology.

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Gyasi, Evans Akwasi. "A Bayesian approach to cost estimation for offshore deepwater drilling projects." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/97927/.

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The global offshore oil and gas industry is constantly challenged with complex operational activities, increasing uncertainties, strict regulations and delicate health, safety and environmental issues. That has made offshore deepwater drilling operation the most time sensitive activity in the upstream oil and gas industry with high probabilities of cost and time overrun. Unfortunately, the current cost estimation models are not robust enough to deal with the multi-variables associated with cost overrun in the offshore deepwater drilling industry in the Sub-Sahara Africa. This study therefore developed a mathematical model that can give accurate estimations with limited data, precisely capture risk elements and factor probability results of all the possible cost variables in the offshore deep-water drilling operations. The study combined Bayesian approach with Activity-based costing (ABC) model to address the limitations of most existing models using primary data collected and secondary data extrapolated from past literatures, published official drilling data and companies’ financial and operational reports. The integrated model showed promising results when tested against three offshore fields’ data across three different countries (Erha-Nigeria, Jubilee-Ghana and Luanda-Angola). Findings from the analysis of the three fields showed cost estimates to be 10% more accurate than the estimates from existing cost estimation models in Sub-Sahara Africa. Further analysis also demonstrated the ability of the model to reduce the regional cost overrun from about 40% to 20%, thereby underlining the efficacy of the model in estimating offshore drilling cost. The strengths, weaknesses as well as the implications of using the model were also discussed. Additionally, the study developed an improved elicitation framework and guidelines to help facilitate cost estimation in the offshore deep-water drilling operations based on the Bayesian approach. The developed elicitation process was used to collect the primary data for this work and generated probabilistic response on the known unknowns and unknown unknowns’ variables in the oil and gas industry Finally, the research analysed and produced findings on cost reduction techniques for the offshore drilling industry.

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Lehman, Ted Eugene. "EFFICIENT, HIGH ASPECT RATIO MICROHOLE DRILLING WITH RAPIDLY REPEATED PULSES." NCSU, 2009. http://www.lib.ncsu.edu/theses/available/etd-11042009-101354/.

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The necessity for micro holes spans across a wide range of industrial applications with nearly endless boundaries. From electronics and X-Ray apertures to micro fluidics and heat transfer phenomenon, the advancement of precision ablation will undoubtedly be of benefit. Currently, three major techniques are employed in the fabrication of micro-holes: Conventional drilling methods, electrical discharge machining (EDM), and laser drilling. The flexibility to drill a wide range of materials with a single device in combination with high consistency and accuracy lead many applications to the necessity of laser drilling. Major drawbacks of laser ablation are low material removal rates and heat affected zones around the holes. Much research has been performed in the pico- and femtosecond paradigm with less insight into longer pulse durations. Investigation was conducted into four variables affecting microsecond pulses on the material removal of steel: pulse length, high power density spikes, pulsing frequency, as well as group multiple pulsing. The optimal pulse length of 3 Âµs created unblocked holes with aspect ratios of 6 and depths of 196 Âµm. Multiple pulsing increased the aspect ratio to 10, deepening the cavity to 236 Âµm. Optimum depth occurred with the maximum number of pulses tested, 10; producing an aspect ratio of 12 and a depth of 295 Âµm. A major drawback produced by 10 pulses was the signs of hole blockage. A process anatomy of hole creation explains causes of the blockage. The second variable, high power density spike exhibited by the laser increased hole depth 5% over instances lacking this spike. Major improvements in depth were demonstrated as the pulsing frequency was increased to a laser capable maximum of 48.7 kHz. Holes created under this condition experienced major blockage near the exit. Group multiple pulsing deepened the hole to 438 Âµm with three sets of ten pulses at 48.7 kHz. Holes exhibited extreme blockage throughout their depths.

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Song, Jinze. "Limit of Horizontal Wellbore in Extended Reach Drilling with Gas." Thesis, University of Louisiana at Lafayette, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1585874.

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The limit of drilling ERD comes from the excessive friction between the drill string and borehole. This study investigates the potential of increasing the limit of horizontal displacement through optimization of drilling fluid and bottom hole assemblies. We conclude that lubricating bottom hole with water can significantly increase the maximum permissible WOB. This effect is more pronounced in drilling tight sands than shales with gas. Cooling the bottom hole with gas expansion after bit nozzles can greatly increase the maximum permissible WOB in drilling formations with geothermal temperatures above 200 °C. Three mathematical methods have been developed for calculating the limit of horizontal displacement in extended drilling with gas. The Rigorous Method is recommended because it gives conservative result. Among several factors affecting the ERD with gas, friction coefficient and the weight of pipe in the horizontal section are the two controlling factors. Adequate weight of BHA in the curve section should be used to overcome the friction.

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Tripuraneni, Gopi Chand. "Performance Analysis of Enhanced Activated Sludge as Drilling Mud Additive." Thesis, University of Louisiana at Lafayette, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10268960.

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The use of drilling fluids alone is not sufficient to reduce friction substantially, so a suitable lubricant has to be added to the drilling fluid so as to reduce the friction to an acceptable range. The lubricant reduces friction of fluid by producing a thin film of liquid that separates the solid surfaces in contact.

The primary objective of this research is to evaluate the performance of enhanced activated sludge (EAS) as a lubricant in drilling fluids. Enhanced activated sludge is composed of mixed consortium of microorganisms grown under conditions that promote lipid accumulation. Experiments were conducted to evaluate (EAS) with different lipid contents. Performance of EAS as drilling fluid additive was compared with commercial lubricants in terms of lubricity and flow properties. Lubricants are evaluated using water-based drilling mud at lubricant concentrations of 1.78, 3.11, 4.43, and 6.17 pounds per barrel (ppb). Experiments were carried out in a standard lubricity meter. The Lubricity meter tests the ability of the lubricant in the drilling mud to reduce friction. Other parameters measured re plastic viscosity, gel strength, fluid loss, mud cake thickness, sand content, methylene blue test (MBT), alkalinity, and chlorides.

All the lubricants studied (including EAS) lowered the coefficient of friction and significant torque reduction. EAS reduced the torque and fluid loss better than raw sludge. However, the top performers in terms of reducing the torque were the commercial lubricants. Bio Add was the best performer in the presence of both barite and bentonite. HDL+ resulted in the least coefficient of friction when the mud was prepared with only bentonite. A cost analysis was prepared to show the economics involved in using sludge (raw and EAS) as additive in drilling fluids. These findings show the potential of activated sludge for improving the properties of water-based drilling mud.

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Åman, Robin. "Design of an End Effector for Drilling in Automated Processes." Thesis, Linköping University, Department of Mechanical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7323.

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In an attempt to solve a problem concerning drilling, a project was started at the universities in Linköping and Lund. As a part of the project this thesis aims to help solve the drilling problem. The goal of this thesis is to design an end effector that will help avoid slipping when drilling. The methods used were taken from David G. Ullman’s book The Mechanical Design Process. Members involved in the project were interviewed to get an understanding of the task. With that done the concept generation phase began, resulting in several concepts. With the use of evaluation methods, such as feasibility judgment and Go/No-Go screening, a final concept emerged. All of the parts and details of the concept were designed with respect for the customers’ requirements and demands.

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El-Wahab, Abo B. I. A. "The influence of tool geometry on the performance of drilling tools." Thesis, Aston University, 1985. http://publications.aston.ac.uk/11869/.

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The main objective of the work presented in this thesis is to investigate the two sides of the flute, the face and the heel of a twist drill. The flute face was designed to yield straight diametral lips which could be extended to eliminate the chisel edge, and consequently a single cutting edge will be obtained. Since drill rigidity and space for chip conveyance have to be a compromise a theoretical expression is deduced which enables optimum chip disposal capacity to be described in terms of drill parameters. This expression is used to describe the flute heel side. Another main objective is to study the effect on drill performance of changing the conventional drill flute. Drills were manufactured according to the new flute design. Tests were run in order to compare the performance of a conventional flute drill and non conventional design put forward. The results showed that 50% reduction in thrust force and approximately 18% reduction in torque were attained for the new design. The flank wear was measured at the outer corner and found to be less for the new design drill than for the conventional one in the majority of cases. Hole quality, roundness, size and roughness were also considered as a further aspect of drill performance. Improvement in hole quality is shown to arise under certain cutting conditions. Accordingly it might be possible to use a hole which is produced in one pass of the new drill which previously would have required a drilled and reamed hole. A subsidiary objective is to design the form milling cutter that should be employed for milling the foregoing special flute from drill blank allowing for the interference effect. A mathematical analysis in conjunction with computing technique and computers is used. To control the grinding parameter, a prototype drill grinder was designed and built upon the framework of an existing cincinnati cutter grinder. The design and build of the new grinder is based on a computer aided drill point geometry analysis. In addition to the conical grinding concept, the new grinder is also used to produce spherical point utilizing a computer aided drill point geometry analysis.

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Joshi, Sandesh Surendra. ". Drilling Parameters and Their Effect on Chip Clogging and Surface Roughness." NCSU, 2000. http://www.lib.ncsu.edu/theses/available/etd-19991220-172709.

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In the woodworking industry, drilling (boring) is one of the most extensively used processes. Due to the traditional nature of the woodworking industry, not much data on machining has been recorded, only a fraction of this on drilling. This lack of information hinders the understanding and thus improvement in the process of drilling. The objective of this research is to provide a pilot study on chip clogging and the surface finish generated while drilling wood and also to examine the surface breakout at the point of drill entry and exit while drilling. This will help the industry by giving an insight into the drilling of wood for furthering research in focused areas. Experiments on chip clogging were carried out with two sizes of standard twist drills and the effect of feed (in/rev), spindle speed (rpm), passage of air jet, pecking cycle and rotational tool were studied on chip clogging. For the study of surface finish, a full factorial experimental design was implemented to evaluate the effect of factor level combinations of four wood types, four drill types, grain directions (along and across the grain), spindle speed (rpm) and feed (in/rev) and their interactions with respect to the surface quality of the machined workpiece. These 128 factor level combinations were replicated three times for a total of 384 experiments. The data obtained was statistically tested by using the analysis of variance techniques to prove the level of significance for each factor and interaction with respect to the surface finish. Work on chip clogging shows promise and needs further investigation for the benefit of the industry. Results on the surface finish study show trends in the behavior of parameters and future work should include developing mathematical models for accurately predicting responses with respect to the input parameters.

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Rao, V. N. Rama. "The radiation and vibration of drilling tubulars in fluid-filled boreholes." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/11277.

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Jin, Kenichiro 1979. "Thermal analysis of directional drilling tool in high heat flux environment." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/89354.

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PICARD, NICOLAS. "DEVELOPMENT OF NOVEL HYDRAULICS FOR OIL WELL DRILLING." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1025637714.

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26

Zhu, Yaoxuan, and Xiaoting Huang. "IMPROVEMENT OF COMPACTED GRAPHITE IRON DRILLING OPERATIONS WITH CUSTOMIZED CUTTING FLUID." Thesis, KTH, Industriell produktion, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-226315.

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With its higher strength, Compacted Graphite Iron (CGI) is widely used in automotive industry. However, the machinability of CGI is challenging, mostly due to the high temperature in the cutting zone and the higher cutting force. This paper studies the influence of the different cutting fluids on the machinability of CGI material in drilling operations. The investigation compared a few customized cutting fluids having alkaline phase and oil phase, to a conventional cutting fluid. The oil phase of customized cutting fluid can help reduce the friction force in the machining process. The flank wear measurements showed there is no significant difference among the fluids. The thrust force measurements, however, showed that the customized cutting fluids could effectively reduce the cutting force by nearly 20%. By using the customized cutting fluid, the machining of CGI materials could either use higher feed rate to reduce cycle time when keeping the cutting force same, or use the same process data while reducing energy consumption.
Inom bilindustrin används ofta kompaktgrafitjärn eftersom det har hög hållfasthet. Att bearbeta kompaktgrafitjärn är utmanade främst pga att det krävs hög temperatur och mycket kraft för att skära/borra materialet. I den här avhandlingen undersöks hur olika skärvätskor påverkar bearbetning av kompaktgrafitjärn under borrning. Skärvätskor där proportionerna mellan den alkaliska delen och oljedelen har anpassats, jämfördes mot traditionella emulsionsvätskor. Oljan i den kundanpassade skärvätskan kan hjälpa till att minska friktionskraften i bearbetningsoperationen. Fasförslitningsmätningen visade att det inte finns någon signifikant skillnad mellan skärvätskorna. Tryckraftsmätningarna visade emellertid att det kundanpassade skärvätskorna effektivt kunde reducera skärkraften med nästan 20%. Genom att använda de anpassade skärvätskorna kan man köra med högre mattningshastighet, reducera cykeltiden eller använda samma processparametrar men med mindre energianvändning.

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Abdelhafeez, Hassan Ali Mohamed. "Burr formation and effects when drilling metallic/composite stack assemblies." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7679/.

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Burr formation and poor hole quality can be detrimental to fatigue life as well as hinder the assembly and functionality of drilled components, particularly those made from metallic-composite stacks. Following a detailed literature review, four phases of experimental work were carried out to evaluate the effects of varying cutting parameters, tool geometries/coatings, workpiece configuration and machining strategies on hole quality/integrity, burr formation and subsequent workpiece fatigue performance, following drilling of several 2-layer stack configurations (CFRP/AA2024, AA2024/AA7010 and CFRP/Ti-6A1-4V). This was complemented by the development of numerical models to predict burr formation when drilling metallic alloys. Key contributions of the research were: (i) improved understanding with regard to the influence of cutting speed and feed rate on burr formation and hole quality when drilling individual Ti-6A1-4V, AA2024 and AA7010 alloys together with various stack assemblies; (ii) identification of appropriate tool type and cutting conditions in addition to possible alternative burr suppression methods; (iii) understanding of the significance of burr formation on fatigue life of individual metallic materials and; (iv) derivation of an analytical model for entrance and interlayer burrs as well as formulation of an FE model for enhanced burr formation (entrance and exit) predictions when drilling individual metallic materials.

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Harrysson, Ralph. "Laser drilling of ceramic materials : energy distribution and crack development." Licentiate thesis, Luleå tekniska universitet, 1991. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26686.

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Hamodi, Hussan. "Reliability and Life Cycle Cost Modelling of Mining Drilling Rigs." Doctoral thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17353.

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In the context of mining, drilling is the process of making holes in the face and walls of underground mine rooms, to prepare those rooms for the subsequent operation, which is the charging process. Due to the nature of the task, drilling incurs a high number of drilling rig failures. Through a combination of a harsh environment (characterised by dust, high humidity, etc.), the operating context, and reliability and maintainability issues, drilling rigs are identified as a major contributor to unplanned downtime.The purpose of the research performed for this thesis has been to develop methods that can be used to identify the problems affecting drilling rig downtime and to identify the economic lifetime of drilling rigs. New models have been developed for calculating the optimum replacement time of drilling rigs. These models can also be used for other machines which have repairable or replaceable components. Based on an analysis performed in a case study, a life cycle cost (LCC) optimization model has been developed, taking the most important factors affecting the economic replacement time of drilling rigs into consideration. To this end, research literature studies, case studies, and simulation studies have been performed, interviews have been held, observations have been made and data have been collected. For the data analysis, theories and methodologies within reliability, maintainability, ergonomics and optimization have been combined with the best practices from the related industries.Firstly, this thesis analyses the downtime of the studied drilling rigs, with the precision and uncertainty of the estimation at a given confidence level, along with the factors influencing the failures. Secondly, the thesis identifies components that significantly contribute to the downtime and the reason for that downtime (maintainability and/or reliability problems). Based on the failure analysis, some minor suggestions have been made as to how to improve the critical components of the drilling rig. Thirdly, a new method is proposed that can help decision makers to identify the replacement time of reparable equipment from an economic point of view. Finally, the thesis proposes a method using the artificial neural network (ANN) for predicting the economic lifetime of drilling rigs through a series of basic weights and response functions. This ANN-based method can be made available to engineers without the use of complicated software.Most of the results are related to specific industrial and scientific challenges, such as planning for cost-effectiveness. The results of the case study are promising for the possibility of making a significant reduction in the LCC by optimizing the lifetime. The results have been verified through interaction with experienced practitioners from both the manufacturer and the mining company using the drilling rig in question.
Godkänd; 2014; Bibliografisk uppgift: Hussan Al-Chalabi received a B.Sc.Eng. degree in mechanical engineering from Mosul University, Iraq, in 1994 and an M.Sc degree in mechanical engineering in thermal power from Mosul University, Iraq, in 2008. Then he joined the Department of Mechanical Engineering at Mosul University as a lecturer. In October 2010, he joined the Division of Operation, Maintenance and Acoustics at Lule°a University of Technology as a doctoral student.; 20141009 (hasham); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Hussan Al-Chalabi Ämne: Drift och underhållsteknik/Operation and Maintenance Uppsats: Reliability and Life Cycle Cost Modelling of Mining Drilling Rigs Opponent: Professor emeritus Jan-Gunnar Persson, Institutionen för maskinkonstruktion, Kungliga tekniska högskolan, Stockholm Ordförande: Professor Jan Lundberg, Avd för drift, underhåll och akustik, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Fredag den 12 december 2014 kl 10.00 Plats: F1031, Luleå tekniska universitet

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Taylor, Robin P. "Development and deployment of an autonomous micro-drilling system for cochleostomy." Thesis, Aston University, 2008. http://publications.aston.ac.uk/15396/.

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This thesis describes the design and development of an autonomous micro-drilling system capable of accurately controlling the penetration of complaint tissues and its application to the drilling of the cochleostomy; a key stage in the cochlea implant procedure. The drilling of the cochleostomy is a precision micro-surgical task in which the control of the burr penetration through the outer bone tissue of the cochlea is vital to prevent damage to the structures within and requires a high degree of skill to perform successfully. The micro-drilling system demonstrates that the penetration of the cochlea can be achieved consistently and accurately. Breakthrough can be detected and controlled to within 20µm of the distal surface and the hole completed without perforation of the underlying endosteal membrane, leaving the membranous cochlea intact. This device is the first autonomous surgical tool successfully deployed in the operating theatre. The system is unique due to the way in which it uses real-time data from the cutting tool to derive the state of the tool-tissue interaction. Being a smart tool it uses this state information to actively control the way in which the drilling process progresses. This sensor guided strategy enables the tool to self-reference to the deforming tissue and navigate without the need for pre-operative scan data. It is this capability that enables the system to operate in circumstances where the tissue properties and boundary conditions are unknown, without the need to restrain the patient.

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31

Ezekiel, Ekerette Elijah. "EXPERIMENTAL STUDY OF DRILLING MUD RHEOLOGY AND ITS EFFECT ON CUTTINGS TRANSPORT." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19792.

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Rawat, Sanjay. "The characterization of drilling process of woven composites using machinability maps approach /." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99533.

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Woven carbon fiber composites are being extensively used in aerospace, automotive and civil applications, owing to their high specific strength, higher fracture toughness, and drapeability as compared to unidirectional composites. The processing phase of composite manufacturing has a high added value to the processed laminate, so any damage during machining has a significant economical impact. However, the characteristic attributes like non-homogeneous structure, anisotropy and high abrasiveness of fibers coupled with non-optimized cutting parameters and tool wear can result in damage to the laminate. This experimental research involves quantifying the effect of processing parameters i.e. spindle speed, feed, and tool wear on hole quality during the drilling of a quasi-isotropic woven graphite fiber epoxy laminate. Drilling tests were conducted for wide range of spindle speeds (1,500 rpm to 15,000 rpm) and feed rates (20 μm/rev to 800 μm/rev) with a 5 mm diameter standard point tungsten carbide twist drill. This investigation extended the drilling approach to evaluate the benefits of high speed (12,000 rpm and 15,000 rpm) and high feed (600-800 μm/rev) regimes, which were not explored or reported in the open literature. Dependence of damage mechanisms; namely, delamination, fiber pull out, thermal damage, surface roughness deterioration, hole circularity and hole diameter errors, on cutting conditions was established. A strong correlation between different types of damages and cutting forces and temperature was also identified. High speed drilling approach produced contrasting results as spindle speed of 15,000 rpm was found to reduce delamination damage and improve surface roughness but increase the hole circularity and diameter errors. Machinability maps were designed to illustrate the affect of cutting parameters on delamination damage, hole circularity, hole diameter error and hole surface roughness. The application of machinability maps as an aid for process engineers to avoid damage and optimize the process is demonstrated. Finally, it was concluded that the process could be controlled and delamination be eliminated by increasing the spindle speed up to 15,000 rpm and feed rate up to 100 mum/rev. It results a higher productivity if a compromise on hole circularity and diameter tolerances is accepted. Having established the benefits of high speed and low feed drilling, tool wear was evaluated at 12,000 rpm and 15,000 rpm and optimal feed rate of 100 mum/rev. Chipping, abrasion and adhesion of carbon were found to be the main wear mechanisms. Abrasion at the flank face of the drills was identified to be the main wear process that controls the deterioration of the drill at high speeds. The three wear regimes i.e. primary, secondary, and tertiary, were found to strongly influence the thrust force, delamination damage, hole circularity, diameter error and hole surface roughness. Finally, the tool wear analysis revealed that a tool change strategy could be devised by monitoring the thrust force, rather than measuring the progression of flank wear.

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Augustine, Chad R. "Hydrothermal spallation drilling and advanced energy conversion technologies for Engineered Geothermal Systems." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/51671.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2009.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references.
The purpose of this research was to study the various factors affecting the economic and technical feasibility of Engineered Geothermal Systems, with a special emphasis on advanced drilling technologies. The first part of the thesis was devoted to modeling and analysis of the technologies used to develop EGS projects. Since the cost of completing wells is a major factor in determining the economic feasibility of EGS projects, it is vital to be able to accurately predict in determining the economic feasibility of EGS projects, it is vital to be able to accurately predict their costs. Historic well cost data was analyzed to identify trends, and a drilling cost index for updating historic geothermal well costs to present day costs was developed. The effects of different advanced drilling technologies on drilling costs were estimated and incorporated into a techno-economic model to estimate their impact, as well as the impact of advanced reservoir stimulation technologies, on EGS levelized electricity costs. A technical analysis of geothermal binary Rankine cycle surface power plants was also performed to determine the effect of novel working fluids on plant efficiency for both sub- and supercritical binary cycles. The objective of the second part of the thesis was the application of thermal spallation drilling to deep boreholes. Thermal spallation is the fragmentation of a brittle solid into small, disc-like flakes by rapidly heating a confined fraction of the rock. It was proposed that the necessary temperatures and heat fluxes needed to induce thermal spallation in the high pressure, high density deep borehole environment could be achieved using hydrothermal flame technologies. An autoclave reaction system was designed and constructed to create flame jets in water at a pressure of 250 bar. The temperatures of these flames were measured, and attempts were made to use the flames to spall small rock samples. The experimental system was modified to study the centerline temperature decay of supercritical water jets injected at temperatures up to 525 °C into ambient temperature water. A device for measuring the heat flux from these jets was designed, constructed, and used to determine the heat transfer coefficients of the jets impinging against a flat surface. Together, these studies indicate that the necessary temperatures and heat fluxes required to induce thermal spallation in rocks can be achieved in a deep borehole.
by Chad R. Augustine.
Ph.D.

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Moghaddas, Mohamad Amin. "On the Mechanism of the Ultrasonic-Assisted Drilling Process." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1534723108853497.

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Dahnel, Aishah Najiah. "Conventional and ultrasonic assisted drilling of carbon fibre reinforced polymer/Titanium alloy stacks." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/97565/.

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Drilling through Carbon Fibre Reinforced Polymer (CFRP)/Titanium (Ti) stacks is important for mechanical assembly of aircraft, however, there are concerns over rapid tool failure and part damage, which lead to reduced productivity and hole quality. Limited research has shown that Ultrasonic Assisted Drilling (UAD) has potential to improve hole quality when drilling CFRP and Ti individually. This has attracted the attention of aircraft manufacturers to evaluate the performance of UAD for CFRP/Ti stacks applications. This thesis presents three main studies of experimental work, which investigate tool wear mechanisms that govern tool life and hole quality when drilling CFRP/Ti stacks in a single continuous operation (one-shot) using carbide (WC-Co) drills. Study 1 involved conventional drilling of CFRP/Ti stacks as opposed to drilling CFRP and Ti individually using constant cutting parameters (cutting speed = 50 m/min; feed rate = 0.05 mm/rev). Study 2 and 3 investigate the effect of cutting parameters (cutting speeds = 25, 50, and 75 m/min; feed rates = 0.025, 0.05, and 0.075 mm/rev) during conventional drilling and UAD of CFRP/Ti stacks, and the performance of UAD was also evaluated. The hole quality was assessed in terms of hole diameter, CFRP damage (delamination and pull-out) and Ti surface integrity (burr formation, roughness, and hardness). The rapid tool failure when drilling CFRP/Ti stacks was found to be due to complex tool wear mechanisms, i.e. strong Ti adhesion on the abraded cutting edges and hence cutting edge fragmentation as the adhered Ti detached. Holes with inconsistent diameters, 22% – 62% more CFRP entrance delamination, 170% – 530% more CFRP pull-out and 720% higher Ti burr (after 80 holes) were observed when one-shot drilling of CFRP/Ti stacks compared to the case of drilling the materials individually (Study 1). It was shown (in Study 2 and 3) that using a low cutting speed and a high feed rate is important for better tool life during both conventional and UAD of CFRP/Ti stacks, although this does not completely resolve hole quality issues. Ti adhesion reduced, hence cutting edges wore uniformly and gradually, which resulted in a longer tool life, consistent hole diameter and reduced Ti burr when drilling CFRP/Ti stacks with reduced cutting speed and increased feed rate due to lower heat generation and contact time. However, CFRP damage when drilling CFRP/Ti stacks was not significantly affected by cutting parameters and tool wear, rather it was found to be substantially influenced by Ti chips evacuating through the CFRP. The application of UAD on CFRP/Ti stacks did not provide any significant advantage in tool wear / life compared to conventional drilling within the range of cutting parameters and cutting tool used, although there was slight improvement in hole quality. The cutting force profiles and Ti chip morphology indicated that UAD exhibited continuous cutting, i.e. the tool did not disengage from the workpiece during drilling. Even though the use of UAD was beneficial to produce more consistent hole diameter (between CFRP and Ti of the stacks), 33% lower machined Ti surface roughness and a marginal increase in Ti hardness compared to conventional drilling, there was no significant improvement in CFRP damage and Ti burr height. When drilling CFRP/Ti stacks, tool life and productivity could not be improved by the application of ultrasonic assistance using the range of parameters investigated, and finishing operations would still be needed to improve the hole quality. UAD could be more advantageous for drilling titanium individually than CFRP/Ti stacks.

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Tahchiev, Galin Valentinov. "Numerical prediction of mobile offshore drilling unit drift during hurricanes." Thesis, [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1355.

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Gupta, Aniruddha. "Study of cutting speed on ultrasonic assisted drilling of carbon fibre reinforced plastics." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/81993/.

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Workpiece damage generated during conventional drilling (CD) of carbon fibre reinforced plastics (CFRP) (such as delamination, matrix cracking, fibre pull out etc.) results in reduced fatigue strength, poor assembly tolerance and compromised structural integrity of the component. Avoidance of such damage during drilling of CFRP is a challenge for the aircraft and aerospace industries. At present, it requires a lot of resources and huge cost in order to generate damage free holes in CFRP in the industries. Therefore, the industries (such as BAE Systems) are looking for alternative hole producing processes for damage free drilling. It has been reported that thrust force during drilling should be reduced in order to reduce exit delamination. Ultrasonic assisted drilling (UAD) has been found to reduce the cutting and thrust forces during drilling of metals when compared to CD. Although limited attempts employing UAD indicate a reduction in thrust and cutting forces and damage when machining CFRP, this process has not been examined in detail with respect to optimising machining parameters in relation to machining theory. In addition, there has been limited research regarding the effect of the UAD process on overall workpiece damage as a result of drilling of CFRP. The focus of this research was the identification of the mechanism responsible for thrust force reduction in UAD in comparison to CD during drilling of CFRP which would help in selecting the machining parameters resulting in minimum workpiece damage. Consequently, the cutting speeds resulting in reduced forces and damage were investigated. As a fundamental concept in machining theory, higher rake angles result in lower cutting forces and improved surface roughness. Calculations of effective normal rake angle at the cutting edge of a twist drill in UAD revealed a maximum of 62° and 49° effective rake angle at 10 and 100 m/min (40160 Hz, 7.3 μm peak-to-peak amplitude) respectively for a new tool. Employing knowledge of the effective rake angle, experiments were performed at specific cutting speeds in order to examine the effects of UAD on forces and damage during drilling of CFRP and compared to CD. Further work employed a pilot hole to remove the contribution of chisel edges so that influence of effective rake angles at the cutting edges could be examined. Through-hole drilling tests, comparing UAD and CD, employing a constant feed rate of 0.05 mm/rev and two cutting speeds (10 and 100 m/min) were carried out. At 10 m/min, there was a reduction in thrust force and torque of 55 % and 45 %, respectively when utilising UAD with a new tool. 40 % reduction in thrust force and 46 % in torque with 52 μm of tool wear corresponded to 36 % reduction in entrance delamination and 22 % reduction in exit delamination at 10 m/min. At 100 m/min, 20 % reduction in thrust force and 30 % in torque was obtained respectively; however, this did not yield a significant reduction in entrance or exit delamination. Analysis of internal damage did, however, reveal a 55 % reduction in internal damage (i.e. fibre pull-out and fibre disorientation) at 100 m/min. Thus, the key contribution of this research is that low cutting speed is required in UAD in order to achieve the greatest reduction in machining forces (and hence, delamination) at entrance and exit of a hole in comparison to CD. The reason for this was discovered to be higher effective rake angle at low cutting speed in UAD causing the reduction in thrust force and torque. Furthermore, reduction of internal damage in a hole required higher cutting speed in UAD. The results imply that the cutting speed should be varied during drilling a hole in CFRP. In UAD, the cutting speed should be lower at entrance and exit of a hole and higher for drilling the intermediate part. Whereas in CD, the cutting speed should be higher at entrance and exit and lower during drilling of intermediate part keeping the feed rate constant in order to achieve the minimum workpiece damage during drilling of CFRP. The proposed variation of cutting speed during drilling of a hole is possible in the machine used in the present research.

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Schunnesson, Håkan. "Drill process monitoring in percussive drilling : a multivariate approach to data analysis." Licentiate thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 1990. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17591.

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39

Rahim, Ryan. "Rapid deployment of oil-drilling tools utilizing distribution network and inventory strategies." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61185.

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Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 73-76).
DTS is an oil and gas services company that delivers drilling tools to six major customer districts in the continental U.S. After the tools are used at a rig, they are transported to the closest repair and maintenance (MTC) facility in either Colorado (CO) or Oklahoma (OK) where they are disassembled and reconditioned for use on a future job. The tools are modular and require custom assembly and programming, depending on the requirements of the well. On occasion, DTS receives urgent orders for drilling tools to replace failed tools or to cater to unexpected demand. These urgent orders are expected to be delivered to customer sites in less than 24 hours from when an order is received. DTS wants to analyze the supply chain impact of consolidating MTC activities to a single facility for operational efficiencies. The rationalization of MTC activities to the CO facility affects DTS's ability to deliver tools within 24 hours due to the longer transportation times to customer districts. How can this longer transportation time be mitigated? Our research shows that using the OK facility as a postponement and distribution hub allows DTS to continue servicing expedited orders within 24 hours and results in a 28% logistics cost savings over a direct shipment method. The postponement strategy entails staging reconditioned inventory at both the OK and CO facility where they can be configured for use within 4 hours of receiving an order. By simulating the movement of inventory around the closed inventory loop, we determined that the total number of tools in the network and the MTC capacity are two important levers of control that affect the availability of reconditioned inventory to service demand. We found that we were able to fulfill a target item fill rate by calculating capital inventory required using an "order up to" inventory policy and setting facility capacity at one standard deviation above average demand.
by Ryan Rahim.
M.Eng.in Logistics

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Peker, Merter. "Economical Impact Of A Dual Gradient Drilling System." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614381/index.pdf.

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Dual Gradient Drilling (DGD) system is a promising technology that was developed to overcome the deep water drilling problems occurred due to narrow operating window between pore pressure and fracture pressure. In conventional drilling practice, single mud weight exists from drilling unit to TVD (True Vertical Depth) which creates big hydrostatic pressure in bottom hole ,moreover, minor changes in mud weight results a big pressure changes proportional to the length of hydrostatic column increase with water depth. On the other hand, DGD allows using two different mud weights to get same bottom hole pressure
low gradient drilling fluid from drilling unit to the sea floor and high gradient drilling fluid form the sea floor to TVD, to decrease the effect of water column on mud hydrostatic pressure in TVD. In this thesis, a conventionally drilled deepwater well was redesigned considering the DGD system and drilled virtually to determine the changes of cost of services and materials on total operation budget to prove the positive impact of system on total operation cost. This study not only proved the technical advantages of the DGD system, but also showed economical impact of the system on total drilling cost, by decreasing around 19%.

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Rauenzahn, Rick Meier. "Analysis of rock mechanics and gas dynamics of flame-jet thermal spallation drilling." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/14884.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1986.
MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE
Bibliography: v.2, leaves 574-583.
by Rick Meier Rauenzahn.
Ph.D.

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Cai, Xiao. "An Analytical Method for Predicting Wellbore Temperature Profile During Drilling Gas Hydrates Reservoirs." Thesis, University of Louisiana at Lafayette, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10163276.

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Production of natural gas from unconventional gas-hydrate reservoirs faces kinds of challenges and uncertainties. One of the main and most common problems in gas-hydrates drilling is the dissociated gas from gas hydrates with decrease of pressure, increase of temperature, or combination of them. A reliable method that can be applied to predict the temperature profile of fluid during circulating in the drilling pipe and the annulus is needed. An analytical model was developed in this study for predicting temperature profiles in drilling gas-hydrate deposits. A case study is provided and indicates a good consistency between model-implications and field observations. According to the sensitivity analyses, the temperature profile of fluid in the drill pipe can be affected by the thickness of drill pipe, density and heat capacity of drill mud, pumping rate of drill mud, geo-thermal gradient, and the surface geo-temperature. The bottom hole temperature is dominated by the temperature and flow rate of the injected drilling fluid, thermal conductivity of cement, heat capacity and density of drill mud, geo-thermal gradient and geothermal temperature at surface, thickness of drill pipe, and cement sheath. Higher geothermal gradient and surface geothermal temperature can lead to a higher temperature profile of fluid in the annulus. The Joule-Thomason cooling effect below the drill bit nozzles will rapidly diminish in a short interval above the bottom hole by the heating effect of geo-thermal gradient. The rate of penetration of drill bit has negligible effect on the fluid temperature profile due to the low percentage of heat flow contributed by the drill cuttings.

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Erazo, Fabio Ivan. "Effect of different drill bit geometries on the stability of the drilling process." FIU Digital Commons, 2004. http://digitalcommons.fiu.edu/etd/3241.

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The purpose of this study was to determine the effects of different drill bit geometries on the stability of the drilling process, based on a torsional-axial coupling model. Parameters such as number of cutting edges, helix angle and length were varied for this purpose. The analysis was performed using a mathematical model, where the coefficients of the model were obtained experimentally by calculating the cutting forces and using modal analysis. This provided stability lobes for the four types of drill bits used, where free chatter zones were identified. These results, in conjunction with simulations performed in Matlab®, were used to run drilling experiments and validate the model. The results of this study showed that increasing the number of cutting edges or the helix angle, allowed increments in the removal rate of material. On the other hand, increasing the drill bit length has the opposite effect and reduces the removal rate of material. The model was successful predicting axial vibrations close to the blimit.

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Akrouh, Ettaghadouini Samy. "Metamodelling of a Finite Element Analysis of a Drilling Process with Replaceable Inserts." Thesis, Högskolan i Skövde, Institutionen för ingenjörsvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-16780.

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The aim of this project is to create a metamodel from a drilling tool with replaceable inserts from FEA of the machining process using MATLAB and ABAQUS. This report contains research in drilling and in metamodeling using neural networks and the work from the design of the CAD, through FEA and simulations, to the metamodeling, excluding the optimization. The work has resulted in a framework where a base FE model of the drill with two inserts that works, but due to time issues and given high cutting speed and feed the results of the FEA and the metamodeling are not very accurate. Therefore, the optimization analysis could not be done. However, it has been shown that feed has a major influence on the inserts temperature than the cutting speed, despite the higher range of this last one.

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Kobaslic, Endi. "A parameter study when drilling holes in flanges." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-12738.

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Stabilitet och vibrationer inom invändiga svarvningsprocesser är ett område som kräver mer forskning. Tidigare studier visar att problem med stabilitet och utböjning är vanligt vid dessa processer och att de orsakar oönskade vibrationer i processen. Vibrationerna har en negativ effekt på bland annat ytjämnheten, som har visat sig vara en viktig parameter vid invändig svarvning. Syftet med den här studien var därför bland annat varit att undersöka utifrån vilka olika skärparametrar en konstruktions stabilitet kan säkerställas för att uppnå kravspecificerad ytjämnhet. Utöver det skapades en rörkonstruktion med 3D-programmet Autodesk Inventor 2017.Studien påbörjades genom att undersöka problematiken inom området, innan beräkningar på skärparametrar påbörjades parallellt med konceptframtagning.Beräkningarna i resultatet visar att utböjningen som uppstår i processen, är högre med den framtagna rörkonstruktionen än utan den. Dessutom krävs optimering av vissa skärdata för att kunna uppnå kravspecificerat värde på ytjämnhet.Beräkningarna fick baseras på en del approximationer vilket innebär att resultatet inte är tillförlitligt och att syftet inte uppnåtts helt.Den framtagna rörkonstruktionen är inte optimalt monterad på svarvmaskinen vilket betyder att monteringssätt måste optimeras. Utöver det är beräkningarna baserade på teori och approximationer och är därför inte lika tillförlitliga som exempelvis fysiska tester hade varit.
Stability and vibrations in internal turning processes is a field that requires more research. Current studies show that stability and deflection is a common problem with these processeses and that they cause unwanted vibrations in the process. The vibrations have a negative impact on the surface roughness, which has shown to be a crucial parameter in internal turning.The purpose of this thesis has therefore been to investigate by which cutting parameters a constructions stability can be ensured to achieve a required surface roughness. Furthermore a construction was designed with the 3D-program Autodesk Inventor 2017.The study started with an information investigation about the problems within the area of internal turning, before calculations and investigations of cutting parameters began. Parallel to the calculations of cutting parameters, a development of a construction began.The calculations in the result show that the deflection that occurs in the process is greater with the developed construction than without it. Besides this, an optimization of some cutting parameters are needed to obtain the required surface roughness.The calculation are had to be based on some approximations which means that the result is not reliable and therefore the purpose is not completely achieved.The designed construction is not optimally placed on the turning machine which indicates that the placement of the construction needs optimization. In addition to this, the calculations are based on theory and approximations and is therefore not as reliable as physical tests would have been.

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Tercan, Erdem. "Managed Pressure Drilling Techniques, Equipment &amp." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611824/index.pdf.

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In the most of the drilling operations it is obvious that a considerable amount of money is spent for drilling related problems
including stuck pipe, lost circulation, and excessive mud cost. In order to decrease the percentage of non-productive time (NPT) caused by these kind of problems, the aim is to control annular frictional pressure losses especially in the fields where pore pressure and fracture pressure gradient is too close which is called narrow drilling window. If we can solve these problems, the budget spent for drilling the wells will fall, therefore enabling the industry to be able to drill wells that were previously uneconomical. Managed Pressure Drilling (MPD) is a new technology that allows us to overcome these kinds of drilling problems by controlling the annular frictional pressure losses. As the industry remains relatively unaware of the full spectrum of benefits, this thesis involves the techniques used in Managed Pressure Drilling with an emphasis upon revealing several of its lesser known and therefore less appreciated applications.

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Montgomery, Justin B. (Justin Bruce). "Characterizing shale gas and tight oil drilling and production performance variability." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98600.

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Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 137-147).
Shale gas and tight oil are energy resources of growing importance to the U.S. and the world. The combination of horizontal drilling and hydraulic fracturing has enabled economically feasible production from these resources, leading to a surge in domestic oil and gas production. This is providing an economic boon and reducing reliance on foreign sources of energy in the U.S., but there are still a number of environmental, economic, and technical challenges that must be overcome to unlock the resource's full potential. One key challenge is understanding variability in individual well performance-in terms of both drilling time (a key driver of well cost) and well productivity-which has led to greater than anticipated economic risk associated with shale gas and tight oil development. Thus far, more reliable forecasting has remained elusive due to its prohibitive cost and the poorly understood nature of the resource. There is an opportunity to make use of available drilling and production data to improve the characterization of variability. For my analysis, I use publicly-available well production data and drilling reports from a development campaign. In order to characterize variability, I use a combination of graphical, statistical, and data analytics methods. For well productivity, I use probability plots to demonstrate a universality to the distribution shape, which can accurately be described as lognormal. Building on this distributional assumption, I demonstrate the utility of Bayesian statistical inference for improving estimates of the distribution parameters, which will allow companies to better anticipate resource variability and make better decisions under this uncertainty. For drilling, I characterize variability in operations by using approximate string matching to compare drilling activity sequences, leading to a metric for operational variability. Activity sequences become more similar over time, consistent with the notion of standardization. Finally, I investigate variability of drilling times as they progress along the learning curve, using probability plots again. I find some indication of lognormality, with implications for how learning in drilling should be measured and predicted. This thesis emphasizes the relevance of data analytics to characterizing performance variability across the spectrum in shale gas and tight oil. The findings also demonstrate the value of such an approach for identifying patterns of behavior, estimating future variability, and guiding development strategies.
by Justin B. Montgomery.
S.M. in Technology and Policy

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48

Cong, Weilong. "Drilling of high-performance materials: experimental, numerical, and theoretical investigations." Diss., Kansas State University, 2013. http://hdl.handle.net/2097/15476.

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Doctor of Philosophy
Department of Industrial & Manufacturing Systems Engineering
Zhijian Pei
High-performance materials, such as silicon, aerospace stainless steels, titanium alloys, and carbon fiber reinforced plastic (CFRP) composites, have a variety of engineering applications. However, they usually have poor machinability and are classified as hard-to-machine materials. Drilling is one of the important machining processes for these materials. Industries are always under tremendous pressure to meet the ever-increasing demand for lower cost and better quality of the products made from these high-performance materials. Rotary ultrasonic machining (RUM) is a non-traditional machining process that combines the material removal mechanisms of diamond grinding and ultrasonic machining. It is a relatively low-cost, environment-benign process that easily ﬁts in the infrastructure of the traditional machining environment. Other advantages of this process include high hole accuracy, superior surface ﬁnish, high material removal rate, low tool pressure, and low tool wear rate. The goal of this research is to provide new knowledge of machining these high performance materials with RUM for further improvement in the machined hole quality and decrease in the machining cost. A thorough research in this dissertation has been conducted by experimental, numerical, and theoretical investigations on output variables, including cutting force, torque, surface roughness, tool wear, cutting temperature, material removal rate, edge chipping (for silicon), power consumption (for CFRP), delamination (for CFRP), and feasible regions (for dry machining of CFRP). In this dissertation, an introduction of workpiece materials and RUM are discussed first. After that, two literature reviews on silicon drilling and dry drilling are presented. Then, design of experiment and finite element analysis on edge chipping in RUM of silicon, experimental investigations and finite element analysis on RUM of aerospace stainless steels, an ultrasonic vibration amplitude measurement method and a cutting temperature measurement method for RUM using titanium alloys as workpiece, experimental and theoretical investigations on RUM of CFRP composites, and experimental studies on CFRP/Ti stacks are presented, respectively. Finally, conclusions and contributions on RUM drilling are discussed.

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Guttenkunst, Emy. "Study of the wear mechanisms for drill bits used in core drilling." Thesis, Uppsala universitet, Tillämpad materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-355399.

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The thesis work was made in cooperation with the I-EDDA project who evaluates the drill equipment used in core drilling. The aim of this work was to determine how and why the drill bits are worn. The work consisted of two parts; investigate drill bits used in field tests and develop a lab scale method to be able to change one drill parameter at a time and see how it affects the wear. During the field tests the rotational speed and the pressure on the drill bits were changed between the three boreholes drilled. In the lab test one parameter at a time was changed; the rotational speed, the water flow and the load. The lab test was developed to attempt to replicate the core drilling and was performed by pressing a piece of a drill bit against a rotating stone cylinder. The drill bits from the field tests and lab test were analysed with the same methods on both macro- and microscale for easier comparison. The results indicate that the lab scale test can be used to evaluate the wear of drill bits. The analyses show rock present on the matrix of all the drill bits, in various amounts. The load has the largest impact on the wear of the drill bits and cause a change in mechanism. A high pressure leads to a higher amount of damaged diamonds and three body abrasive wear on the matrix. Lower pressure leads to polished diamonds and erosive wear on the matrix.

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50

Schlegelmilch, Tye (Tye Anthony). "The design of a coiled tubing cutter for use in subsea oil drilling applications." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/38278.

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Thesis (S.M. and S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999.
Includes bibliographical references (leaves 82-83).
A cutting device has been developed which can be used in conjunction with Schlumberger's SenTree product line to insure proper disconnect of an offshore system from a subsea wellhead during the testing of the well. Design requirements for the device were established by the requirements of the SenTree tool. Additional force requirements for the prototype were established through theoretical models and experimental tests. These goals were met with a prototype based upon a linear piston arrangement. This piston arrangement offers an advantage over other conventional methods of cutting because of its predictability and ease of use. This thesis explores issues relevant to the design including material considerations, cutting blade optimization, and the examination of prior work. In this thesis, the proposed prototype was manufactured and verified through experimental testing. Furthermore, the guidelines developed in this thesis can be used to design the future generations of subsea cutting tools.
by Tye Schlegelmilch.
S.M.and S.B.

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Dissertations / Theses on the topic 'Drilling Engineering'

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