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Journal articles on the topic 'CORE DRILLING THEORY'

Author: Grafiati

Published: 28 June 2021

Last updated: 29 July 2025

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1

Schwander, J., S. Marending, T. F. Stocker, and H. Fischer. "RADIX: a minimal-resources rapid-access drilling system." Annals of Glaciology 55, no. 68 (2014): 34–38. http://dx.doi.org/10.3189/2014aog68a015.

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AbstractDetermining the expected age at a potential ice-core drilling site on a polar ice sheet generally depends on a combination of information from remote-sensing methods, estimates of current accumulation and modelling. This poses irreducible uncertainties in retrieving an undisturbed ice core of the desired age. Although recently perfected radar techniques will improve the picture of the ice sheet below future drilling sites, rapid prospective drillings could further increase the success of deep drilling projects. Here we design and explore a drilling system for a minimum-size rapid-acces

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2

Li, Zhan Tao, Yong Zheng Ma, and Ken-ichi Itakura. "Development of a Rotary Drilling Mechanism for Impregnated Diamond Bits." Advanced Materials Research 989-994 (July 2014): 3136–39. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.3136.

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Impregnated diamond core bits are often used in core drilling for geological surveys. A tri-state theory is proposed to describe the three states in drilling processes for a diamond particle or a bit. These states are contacting state, cutting state, and ploughing state. Furthermore, the relations among thrust and other mechanical parameters are also summarized. The optimal value of the specific energy is in the cutting state. Several experiment results verified the proposed model. This mechanism is useful for selecting operation parameters in core drilling using impregnated diamond core bits.

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3

Talalay, P. G. "Perspectives for development of ice-core drilling technology: a discussion." Annals of Glaciology 55, no. 68 (2014): 339–50. http://dx.doi.org/10.3189/2014aog68a007.

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AbstractMore than 170 years ago, Louis Agassiz, one of the creators of glacial theory, made his first attempt to drill into the bed of Unteraargletscher, Swiss Alps. Since that time, various systems for thermal and mechanical drilling have been designed especially for boring into ice, and some conventional drill rigs been adopted for ice coring. Although contemporary ice-drilling knowledge and techniques are now familiar, there remain many problems to be solved by advanced modern technology. Specific challenges related to improving old drilling methods and developing new emerging technologies

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4

Zhu, Lun. "Experimental Study by Using Drilling Core Materials Inversion Formation Rock Fracture Toughness Test Research." Applied Mechanics and Materials 538 (April 2014): 315–18. http://dx.doi.org/10.4028/www.scientific.net/amm.538.315.

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On the basis of Cliftons, hydraulic fracturing is established under the condition of cylindrical specimen fracture toughness expression. Using a self-built laboratory equipment, drilling core specimen for the fracture toughness test and obtain the relevant data. Based on the rock parameters inversion theory to construct the formation rock fracture toughness inversion objective function and optimization function. according to the drilling core material fracture toughness test data and the application of Matlab programming presented the formation rock fracture toughness.

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5

Kurgansky, V. ""GEOPHYSICAL RESEARCHES OF MINING HOLES" – 50 YEARS AT TARAS SHEVCHENKO NATIONAL UNIVERSITY OF KYIV." Visnyk of Taras Shevchenko National University of Kyiv. Geology, no. 1 (84) (2019): 89–94. http://dx.doi.org/10.17721/1728-2713.84.13.

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Development of carotage (retrospective years 1969-2019) at Taras Shevchenko National University of Kyiv is described. Basic achievements are shown in educational and scientific directions. Carbonate rocks methodology study problems, petrophysical models which allowed building physically well-founded dependences of "core-core", "core-geophysics", "geophysics- geophysics" type are described. Petrophysical simulation, theory of probability and mathematical statistics methods allowed the author to work out a complex system of data processing and interpretation in welllogging. Current status and te

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6

Wei, Na, YingFeng Meng, Gao Li, et al. "Cuttings Transport Models and Experimental Visualization of Underbalanced Horizontal Drilling." Mathematical Problems in Engineering 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/764782.

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Aerated underbalanced horizontal drilling technology has become the focus of the drilling industry at home and abroad, and one of the engineering core issues is the horizontal borehole cleaning. Therefore, calculating the minimum injection volume of gas and liquid accurately is essential for the construction in aerated underbalanced horizontal drilling. This paper establishes a physical model of carrying cuttings and borehole cleaning in wellbore of horizontal well and a critical transport mathematical model according to gas-liquid-solid flow mechanism and large plane dunes particle transport

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7

Azuma, Nobuhiko, Ikuo Tanabe, and Hideaki Motoyama. "Heat generated by cutting ice in deep ice-core drilling." Annals of Glaciology 47 (2007): 61–67. http://dx.doi.org/10.3189/172756407786857848.

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AbstractIn order to understand and solve the ‘warm-ice problem’ in deep ice-core drilling, we applied the metal-cutting theory to ice and estimated the heat generated during ice coring taking into account the mechanical and thermal properties of the ice and cutters. We found that (1) most of the heat in cutting is generated by shear deformation at the shear plane of ice, and the heat could increase the chip temperature by several degrees; (2) the rake angle of the cutter has more influence on the temperature increase in chips than the barrel rotation speed and penetration pitch; (3) if the cut

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8

Sedaghatzadeh, Mostafa, Khalil Shahbazi, Mohammad Hossein Ghazanfari, and Ghasem Zargar. "The Impact of Nanoparticles Geometry and Particle Size on Formation Damage Induced by Drilling Nano-Fluid during Dynamic Filtration." Journal of Nano Research 43 (September 2016): 81–97. http://dx.doi.org/10.4028/www.scientific.net/jnanor.43.81.

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In this paper, the impact of three parameters including nanoparticles geometry, particles aggregation and borehole inclination on induced formation damage from water based drilling fluids were investigated by means of experimental studies. Accordingly, we designed a dynamic filtration setup capable to rotate and change well inclination. nanobased drilling fluids consisting of spherical, cubical and tubular shapes nanoparticles as fluid loss additives were used. Mud cake quality, core permeability impairment and degree of formation damage at various well inclinations were examined. The cluster

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9

Jiang, An Nan, and Zheng Wen Zeng. "Three Dimensional Numerical Simulation of Rock Core Discing Based on Strain Soft Model." Advanced Materials Research 187 (February 2011): 565–69. http://dx.doi.org/10.4028/www.scientific.net/amr.187.565.

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Aiming at the complexity of rock discing mechanics, and the theory being not mature, the paper carried out three-dimensional numerical simulation for rock core discing based on strain soft model. The strain soft theory is introduced firstly, then numerically simulated how the depth of lug boss and original stress affect the rock core destroy pattern(discing if occurs, the thickness of disk), obtained the characters of rock core discing. Along with the drilling depth increases, the stress concentration scope below lug boss also increases, as well as the pressure stress concentration degree of s

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10

Shen, Xing Quan, Zhen Ya Chen, and Jun Zhong Pang. "The Structure Optimization of Double Feeder System Core Components." Advanced Materials Research 472-475 (February 2012): 1091–96. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.1091.

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The work investigates the structure parameters of adjustable subatmospheric pumping scraps device and oil feeder, which have extremely significant impacts on double feeder system in the deep-hole drilling process. Equations for subatmospheric zone pressure are derived herein using the siphon principle, and experiments are performed the trends of pressure on the single factor condition, which provide reasonable structure parameters for adjustable subatmospheric pumping scraps device. Oil feeder is studied based on the Euler column theory, and it can be optimized that is intermediate support, pi

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11

Carvajal Jiménez, Jenny Mabel, Luz Carime Valera Lara, Alexander Rueda, and Néstor Fernando Saavedra Trujillo. "GEOMECHANICAL WELLBORE STABILITY MODELING OF EXPLORATORY WELLS – STUDY CASE AT MIDDLE MAGDALENA BASIN." CT&F - Ciencia, Tecnología y Futuro 3, no. 3 (2007): 85–102. http://dx.doi.org/10.29047/01225383.477.

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This paper presents the geomechanical wellbore stability model of an exploratory well sited at Middle Magdalena Basin (MMB), which is based on the validity of linear elastic deformational theory for porous media; the use of correlations and field tools such as well and image logs to indirect determination of mechanical properties and stress state. Additionally, it is shown the model calibration and validation using drilling events which occurred at other previously drilled wells in the study area, at the exploratory well itself and experimentally evaluated mechanical properties on outcrop and

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Cao, Pinlu, Miaomiao Liu, Zhuo Chen, Baoyi Chen, and Qi Zhao. "Theory calculation and testing of air injection parameters in ice core drilling with air reverse circulation." Polar Science 17 (September 2018): 23–32. http://dx.doi.org/10.1016/j.polar.2018.06.005.

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13

Yu, Bo, Heping Xie, Ling Chen, Wu Zhao, and Zhiqiang He. "Exploration of Digital Twin Design Mechanism of the Deep in Situ Rock Insulation Coring Device." Geofluids 2020 (September 22, 2020): 1–12. http://dx.doi.org/10.1155/2020/8835085.

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With the development of the resource exploration and environmental science drilling, strict and scientific requirements are put forward for the samples taken from drilling. It is significant to keep the original appearance of the core and obtain the in situ core for the analysis of deep geological fluid and the exploration of the law of geological disasters caused by large-scale geological exploitation. To achieve the high-fidelity in situ core of deep rock, the development of the corresponding deep in situ fidelity coring device should involve the insulation coring device. The development of

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14

Li, Jianan, Heping Xie, Ling Chen, Cong Li, and Zhiqiang He. "Exploring Deep-Rock Mechanics through Mechanical Analysis of Hard-Rock In Situ Coring System." Advances in Civil Engineering 2020 (September 7, 2020): 1–11. http://dx.doi.org/10.1155/2020/8899156.

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Exploration of deep-rock mechanics has a significant influence on the techniques of mining and rock mechanics. Rock coring technique is the basic method for all rock mechanics study. With the increase of the drilling depth and increasing strength of the hard rock, how to obtain high-quality rock core through various coring techniques is an eternal work. Here an innovative method is applied to design the new coring system to maximize the efficiency of operation. The stress conditions or parameters of rock core in the coring are analyzed, and the mechanism of the core with in situ stress is show

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15

Akhymbayeva, B. S., S. Z. Kabdulov, B. K. Mauletbekova, T. A. Kuandykov, and G. A. Mashatayeva. "Theoretical studies of the process of crack formation during rotational impact drilling." Neft i Gaz 140, no. 2 (2024): 93–106. http://dx.doi.org/10.37878/2708-0080/2024-2.09.

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This article is devoted to the study of the process of crack formation, which are actively manifested during rotational impact drilling. The studies conducted during the writing of the article show that simultaneously with the destruction of the bottom of the well, another process occurs – the formation of many cracks in the angular (peripheral) zones of the bottom and on the walls of the well, going to a depth of 5-10 mm. These cracks remain in the form of a dense network in the walls of wells and in the core (during its selection), and the depth of the cracks increases with increasing impact

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16

Liu, Wei Tao, Jian Jun Shen, and Yun Juan Liu. "Deterministic Method of Floor Rock Permeability Tensor of Mining over Confined Water and Application in Numerical Simulation." Applied Mechanics and Materials 204-208 (October 2012): 4840–44. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.4840.

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Based on equivalent continuum media theory of fractured rock mass, the author got the permeability tensor of floor strata in some mine according to core logging method, drilling imaging method and boring water injection method, and determined the floor rock permeability tensor using correction method. The author simulated the floor inrush problem by coupling fluid-solid theory and anisotropic flow model with FLAC3D software. The result shows that, the destroyed depth of floor and the confined water rising height are all slight when the coal mining workface is 150m apart from the fault, but the

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17

Cong, Lin, Yang Liu, Wen Long Li, and Hai Ou Fang. "Regional Estimation of Block Oilfield Rock Physical Parameters." Advanced Materials Research 734-737 (August 2013): 1425–28. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.1425.

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Based on getting block oilfield original drilling core data, the study established a geological physical parameters database and visual geological model of block oilfield, including block areas model, fault model, surface model and so on, by choosing several block oilfield oil parameters and using geological sections. The paper established block model by using hexahedral subdivision skills, estimated three-dimensional space physical parameters by using geostatistics theory and constraints of block areas and faults. It got block oilfield rock parameters spatial distribution and supplied a effec

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18

Lu, Fawei, Xincai Cheng, Guodong Zhang, Zhihu Zhang, Liangqing Tao, and Bin Zhao. "A Method for Calculating Permeability Based on the Magnitude of Resistivity Divergence." Processes 13, no. 4 (2025): 947. https://doi.org/10.3390/pr13040947.

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Low-permeability sandstone reservoirs have low permeability, but due to their high porosity and difficulty in development, the development difficulty is relatively high. They can fully tap into the high potential of oil and gas resources in low-permeability sandstone reservoirs and occupy an important position in the global energy supply The study area belongs to low-permeability dense sandstone reservoir, and the destination layer has complex lithology, strong physical inhomogeneity, and complicated pore–permeability relationship, so the conventional core pore–permeability regression method a

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19

Ren, Ziqiang, Feng Zhou, Hai Zhu, et al. "Analysis and Research on Mobile Drilling Rig for Deep Seabed Shallow Strata." Marine Technology Society Journal 55, no. 2 (2021): 81–93. http://dx.doi.org/10.4031/mtsj.55.2.7.

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Abstract Drilling rigs for deep seabed shallow strata are commonly used to explore ocean cobalt-rich crust resources and other fields. This paper mainly presents the structure and mechanism of a mobile drilling rig for use in acquiring seafloor cores that are up to 1.5 m in length. The software Simcenter Amesim is used to establish the mobile drilling rig's hydraulic propulsion system model, which is the basis and a core part of the rig. Moreover, closed-loop and PID (proportion-integral-differential) control methods are separately used to control the hydraulic propulsion system for simulation

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20

Liu, Yang, Cheng Zhi Liu, Hui Li, Xiao Jing Liu, and Yu Cong Li. "Research on Sedimentary Microfacies of Sandstone Group I in Putaohua Oil Reservoir of Gu83 Block in Gulong Oilfield." Advanced Materials Research 787 (September 2013): 618–21. http://dx.doi.org/10.4028/www.scientific.net/amr.787.618.

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The oil and gas reserves of Gu83 block in Gulong oilfield is very abundant, but the development is very difficult because the sand bodies are thin, scattered and lack of horizontal continuity. Guided by the theory of sequence stratigraphy and reservoir sedimentology, using drilling core, logging and seismic data, the researcher found that the interest area belongs to delta front subfacies deposition, which can be mainly classified by four miscrofacies types including underwater distributary channel, mouth, sheet sand and bay between distributary. The plane distribution of sedimentary microfaci

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21

Suryanarayana, P. V., Zhan Wu, John Ramalho, and Ronald Earl Himes. "Dynamic Modeling of Invasion Damage and Impact on Production in Horizontal Wells." SPE Reservoir Evaluation & Engineering 10, no. 04 (2007): 348–58. http://dx.doi.org/10.2118/95861-pa.

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Summary We present a novel approach that combines dynamic reservoir simulations and special core tests to model the extent of invasive damage and its impact on flowback during production. A radially adaptive 3D microsimulator is used to estimate the extent and impact of filtrate invasion on near-wellbore saturation and reservoir pressure. Time-varying reservoir exposure is used to simulate the acts of drilling, tripping, completions, and workovers. Extremely fine, core-scale grids are used to capture saturation and pressure in the invasion zone. Special core tests using a specially designed co

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22

LOBANOV, Konstantin V., Mikhail V. CHICHEROV, and Nikolay V. SHAROV. "The 50th Anniversary of the Start of Drilling the Kola Superdeep Well." Arctic and North, no. 44 (September 24, 2021): 267–84. http://dx.doi.org/10.37482/issn2221-2698.2021.44.267.

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The Kola Superdeep Well (SG-3) is an outstanding achievement of Soviet science and technology, drilled in Precambrian crystalline rocks and reached a depth of 12262 m. It was one of a series of super deep wells planned within the framework of the program “Earth's Interior Exploration and Superdeep Drilling”. In order to achieve record depths, unique domestic drilling equipment and materials capable of working at high temperatures and pressures were created. A fundamentally new technology for drilling wells using hydraulic downhole motors was developed. Despite difficult drilling conditions and

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23

Zhang, Qing Xiang, Hou Sheng Jia, Long Fan, Xi Dong Zhao, Zhi Gang Wang, and Jun Long Xing. "The Detection Research of Roadway Roof Strata Structure in Coal Seam." Advanced Materials Research 734-737 (August 2013): 677–81. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.677.

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Through the structure instability theory analysis of the coal roadway roof ,the author concluded that mechanical properties of rock, location, thickness and thickness ratio is the main factor affecting the instability and failure of rock structure. Capitalize on the roof caving hidden danger detector developed by the China university of mining and technology to synchronize, continuous and intensive monitor the rotational speed, thrust for synchronization and thrust. Based on the record ,the author inferred the coal seam roof lithology and rock structures of the different drilling location. Eng

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24

Sun, Yuping, Qiaojing Li, Cheng Chang, Xuewu Wang, and Xuefeng Yang. "NMR-Based Shale Core Imbibition Performance Study." Energies 15, no. 17 (2022): 6319. http://dx.doi.org/10.3390/en15176319.

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Shale gas reservoirs are unconventional resources with great potential to help meet energy demands. Horizontal drilling and hydraulic fracturing have been extensively used for the exploitation of these unconventional resources. According to engineering practice, some shale gas wells with low flowback rate of fracturing fluids may obtain high yield which is different from the case of conventional sandstone reservoirs, and fracturing fluid absorbed into formation by spontaneous imbibition is an important mechanism of gas production. This paper integrates NMR into imbibition experiment to examine

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25

Ahsan, Muhammad, Shah Fahad, and Muhammad Shoaib Butt. "Computational Fluid Dynamics Simulation and Analysis of Non-Newtonian Drilling Fluid Flow and Cuttings Transport in an Eccentric Annulus." Mathematics 13, no. 1 (2024): 101. https://doi.org/10.3390/math13010101.

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This study examines the flow behavior as well as the cuttings transport of non-Newtonian drilling fluid in the geometry of an eccentric annulus, accounting for what impacts drill pipe rotation might have on fluid velocity, as well as annular eccentricity on axial and tangential distributions of velocity. A two-phase Eulerian–Eulerian model was developed by using computational fluid dynamics to simulate drilling fluid flow and cuttings transport. The kinetic theory of granular flow was used to study the dynamics and interactions of cuttings transport. Non-Newtonian fluid properties were modeled

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26

Talsma, T. "Reevaluation of the well permeameter as a field method for measuring hydraulic conductivity." Soil Research 25, no. 4 (1987): 361. http://dx.doi.org/10.1071/sr9870361.

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Improved theory of steady outflow of water ponded to constant depth in holes drilled in unsaturated soil is used to re-evaluate the well permeameter method for measurement of in situ hydraulic conductivity, Kg. In particular, theory predicts that neglect of unsaturated flow into soil surrounding the saturated region around a borehole may lead to serious overestimation of K0, especially when using small holes in soils with high capillarity, i.e. the capillarity factor � = 0.1-1 m-l. Field studies on 12 soils gave a values from 6 to 35 m-l, resulting in theoretical overestimates of K0 by 10-40%,

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27

Dominy, Simon, Hylke Glass, and Saranchimeg Purevgerel. "Sampling for resource evaluation and grade control in an underground gold operation: a case of compromise." TOS Forum 2022, no. 11 (2022): 375. http://dx.doi.org/10.1255/tosf.165.

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The foundation of any resource evaluation and/or grade control programme is the collection of high-quality samples within a geological context. The requirement for quality samples has long been recognised, where they must be representative and fit-for-purpose. Correct application of the Theory of Sampling reduces sampling errors across the collection to assay process. This contribution presents a case study where small-sample based assays understate grade in geometrically simple, coarse gold-dominated veins. Drilling with whole core sampling and assaying is applied to estimate Inferred Mineral

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28

Xie, Daolei, Jing Han, Huide Zhang, Kai Wang, Zhongwen Du, and Tianyu Miao. "Risk Assessment of Water Inrush from Coal Seam Roof Based on Combination Weighting-Set Pair Analysis." Sustainability 14, no. 19 (2022): 11978. http://dx.doi.org/10.3390/su141911978.

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When exploiting Jurassic-era coal resources in Northwest China, there are risks of water inrush and sand burst disasters from coal seam roofs. To improve the safety of coal mining, it is imperative to accurately and objectively evaluate the water inrush risk of sandstone aquifers from coal seam roofs and to reasonably and effectively prevent and control water disasters. In this paper, the 221 mining area of the Shilawusu Coal Mine was considered. By combining the basic geological condition data, hydrogeological condition data, and drilling data in the area studied, four main control factors, i

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29

Yang, Chen, xiqiang Wang, Ling Li, and Zhaohu chun. "Study on reservoir heterogeneity of Chang 8 reservoir in Hongde Oilfield, western margin of Ordos Basin and knowledge of fine stratification development practice." Journal of Physics: Conference Series 2834, no. 1 (2024): 012160. http://dx.doi.org/10.1088/1742-6596/2834/1/012160.

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Abstract In view of the problems of reservoir heterogeneity and unclear understanding of main control factors in Chang8 reservoir of Hongde Oilfield in the middle part of Tianhuan, Ordos Basin, efficient development and stable production are restricted by a large number of drilling, core data and log comparative analysis, using core observation, microscopic rock slice identification, scanning electron microscopy, mercury injection and phase infiltration experiments, etc. Based on the understanding of sedimentary facies and diagenesis, the quantitative analysis of Chang 8 in the study area is c

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30

Che Senik, Zizah, Adlin Masood, Khairul Akmaliah Adham, Noreha Halid, Rosmah Mat Isa, and Norrana Khidil. "UMW Holdings: sustaining a centennial corporation." Emerald Emerging Markets Case Studies 3, no. 4 (2013): 1–13. http://dx.doi.org/10.1108/eemcs-07-2013-0161.

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Title – UMW Holdings: sustaining a centennial corporation. Subject area – Strategic Management and Organization Theory and Design. Study level/applicability – Advanced undergraduate and MBA students taking courses in Strategic Management and Organization Theory and Design. Case overview – By the end of 2011, five years short of its centennial anniversary, UMW Holdings was one of the biggest corporations in Malaysia, registering revenues of RM13.5 billion (US$4.5 billion), and net profit after tax of RM1 billion (US$0.33 billion). By that time, it had 110 subsidiaries, operating in four core bu

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Yue, Gaofan, Xi Zhu, Guiling Wang, and Feng Ma. "Mineral Reaction Kinetics during Aciding of the Gaoyuzhuang Carbonate Geothermal Reservoir in the Xiong’an New Area, Northern China." Water 14, no. 19 (2022): 3160. http://dx.doi.org/10.3390/w14193160.

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There are abundant geothermal resources in the Xiong’an New Area, China. Drilling has revealed a greater potential in the deep Gaoyuzhuang geothermal reservoir. However, the reservoir required acidification to increase its water production. In this study, three types of core samples with different mineral compositions from different depths in the target boreholes were selected for acid rock reaction experiments at the temperature of 40 °C, 60 °C, 80 °C and 100 °C, and pressure of 30 MPa. The kinetics of the acid rock reaction of the major minerals were modeled based on the transitional state t

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32

Ding, Chunyu, Yan Su, Shuguo Xing, et al. "Numerical Simulations of the Lunar Penetrating Radar and Investigations of the Geological Structures of the Lunar Regolith Layer at the Chang’E 3 Landing Site." International Journal of Antennas and Propagation 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/3013249.

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In the process of lunar exploration, and specifically when studying lunar surface structure and thickness, the established lunar regolith model is usually a uniform and ideal structural model, which is not well-suited to describe the real structure of the lunar regolith layer. The present study aims to explain the geological structural information contained in the channel 2 LPR (lunar penetrating radar) data. In this paper, the random medium theory and Apollo drilling core data are used to construct a modeling method based on discrete heterogeneous random media, and the simulation data are pro

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33

Živanović, Ivana, Zoran Poduška, Ljubinko Rakonjac, and Filip Jovanović. "Potentials of the evaluation of the wood quality in living trees by using semi-and non-destructive methods in order to reduce wood-processing costs." Sustainable Forestry: Collection, no. 79-80 (2019): 115–26. http://dx.doi.org/10.5937/sustfor1979115q.

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Being a natural, ecological and renewable resource, wood is increasingly replacing artificial and toxic materials in the manufacture of various types of packaging and other products; thus, its proper and economically justified use has become necessary. The best utilization of wood raw materials has been sought both in practice and theory, which led to the development of a number of non-destructive and semi-destructive methods for the wood quality assessments in various stages of wood exploitation. In this paper, two instruments for the inspection of the internal condition of standing trees wer

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34

Zhang, Yun, Shenggen Cao, Tong Wan, and Jijun Wang. "Field Measurement and Mechanical Analysis of Height of the Water Flowing Fracture Zone in Short-Wall Block Backfill Mining beneath the Aquifer: A Case Study in China." Geofluids 2018 (October 4, 2018): 1–12. http://dx.doi.org/10.1155/2018/7873682.

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Short-wall block filling mining (SBBM) technology has become an effective way to recover coal resources beneath the aquifer, which are unsuitable, or cannot be used by long-wall mining, such as corner coal pillars, industrial square pillars, and irregular coal blocks as well as the coal beneath buildings, railways, and water bodies. The SBBM method can not only enhance the recovery ratio but also provide a solution for the environment problems associated with gangues on the surface. However, whether the height of water flowing fractures will reach to the aquifer to cause water loss during SBBM

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35

Cheng, Hanlie, Jianfei Wei, and Zhaoyuan Cheng. "Study on Sedimentary Facies and Reservoir Characteristics of Paleogene Sandstone in Yingmaili Block, Tarim Basin." Geofluids 2022 (March 7, 2022): 1–14. http://dx.doi.org/10.1155/2022/1445395.

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Block Yingmai 7 is structurally located in the western segment of the southern margin of the Kuqa Depression in the Tarim Basin. In the foreland basin, huge continental Mesozoic and Cenozoic strata have been deposited. In recent years, the Paleogene bottom sandstone section has been the main oil and gas exploration horizon. In order to further improve the oil and gas exploration effect of the Paleogene bottom sandstone in the study area and improve the accuracy of reservoir prediction, based on the related theory of sedimentology and petrology, this paper analyzes and studies the cores obtaine

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36

Qian, Jin, Xiujuan Wang, Timothy S. Collett, et al. "Gas hydrate accumulation and saturations estimated from effective medium theory in the eastern Pearl River Mouth Basin, South China Sea." Interpretation 5, no. 3 (2017): SM33—SM48. http://dx.doi.org/10.1190/int-2016-0217.1.

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Pore- and fracture-filling gas hydrates were identified from the core samples at several sites during the second Guangzhou Marine Geological Survey (GMGS2) expedition. Well logs indicated that gas hydrate occurred in three distinct layers at site GMGS2-08. The gas hydrate saturations calculated from well-log data and the seismic responses for the three gas hydrate-bearing layers, especially within the middle carbonate layer, were poorly known. We estimated gas hydrate saturations using isotropic and anisotropic models based on the mineral composition of the sediments and the effective medium t

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Graue, Arne, B. Kvamme, Bernie Baldwin, et al. "MRI Visualization of Spontaneous Methane Production From Hydrates in Sandstone Core Plugs When Exposed to CO2." SPE Journal 13, no. 02 (2008): 146–52. http://dx.doi.org/10.2118/118851-pa.

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Summary Magnetic resonance imaging (MRI) of core samples in laboratory experiments showed that CO2 storage in gas hydrates formed in porous rock resulted in the spontaneous production of methane with no associated water production. The exposure of methane hydrate in the pores to liquid CO2 resulted in methane production from the hydrate that suggested the exchange of methane molecules with CO2 molecules within the hydrate without the addition or subtraction of significant amounts of heat. Thermodynamic simulations based on Phase Field Theory were in agreement with these results and predicted s

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Ren, Bo, Wenqiang Mu, Bingyou Jiang, et al. "Grouting Mechanism in Water-Bearing Fractured Rock Based on Two-Phase Flow." Geofluids 2021 (February 24, 2021): 1–18. http://dx.doi.org/10.1155/2021/5585288.

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Grouting is always used in mine water plugging, reinforcement, and other disaster prevention projects. The diffusion mechanism of slurry in fractured rock is affected by geological environment and slurry performance, which should be revealed and characterized better. Based on the two-phase flow diffusion theory, a slurry diffusion model considering flowing water condition was established for a blocking area of a fracture zone in one case from China. The feasibility of two-phase flow model in grouting diffusion calculation was analyzed. The diffusion model in dynamic water environment was studi

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Li, Bianhong, Yushuang Dong, and Hanjun Gao. "Numerical Simulation and Experiment of Stress Relief and Processing Deformation of 2219 Aluminum Alloy Ring." Metals 13, no. 7 (2023): 1187. http://dx.doi.org/10.3390/met13071187.

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Large aluminum alloy ring forgings are the core components of heavy-duty rocket fuel storage tanks, and the large residual stress inside the rings leads to poor shape accuracy of large thin-walled parts. The initial stress of the 2219 aluminum alloy ring blank was tested using the drilling method, and the creep constitutive coefficient of the 2219 aluminum alloy was determined through stress relaxation tests. The numerical simulation processes of thermal stress relief (TSR), vibration stress relief (VSR), and thermal–vibration stress relief (TVSR) were compared and established. Through the cor

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Liu, Shuguang, Jiayi Wang, and Yin Long. "Research into the Spatiotemporal Characteristics and Influencing Factors of Technological Innovation in China’s Natural Gas Industry from the Perspective of Energy Transition." Sustainability 15, no. 9 (2023): 7143. http://dx.doi.org/10.3390/su15097143.

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Promoting technological innovation in the natural gas industry is a feasible means of achieving energy transition. Guided by the geographic innovation theory, this article carries out research on the scale, technical fields, capabilities, and influencing factors of technological innovation in the natural gas industry of 312 Chinese prefecture-level cities, making use of the cusp catastrophe model, the center of gravity and standard deviational ellipse, exploratory spatial data analysis, and geographically and temporally weighted regression (GTWR). The research shows the following: (1) Technolo

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Yuan, Qingwu, Yuqiang Jiang, Zhujiang Liu, Xiangfeng Wei, and Yifan Gu. "Lacustrine Gravity-Flow Deposits and Their Impact on Shale Pore Structure in Freshwater Lake Basins: A Case Study of Jurassic Dongyuemiao Member, Sichuan Basin, SW China." Minerals 15, no. 5 (2025): 473. https://doi.org/10.3390/min15050473.

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In recent years, the successful application of gravity-flow deposit theory in major petroliferous basins in China had attracted extensive attention in the field of sedimentology and had become a key research frontier. This study utilized core, drilling, logging, and microphotograph data, along with low-temperature nitrogen adsorption and high-pressure mercury injection experiments. It discussed the characteristics of gravity-flow deposits, sedimentary microfacies, sedimentary models, and the significance of gravity-flow deposits to pore heterogeneity in shale reservoirs, focusing on the first

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Nes, O. M., R. M. Holt, and E. Fjær. "The Reliability of Core Data as Input to Seismic Reservoir Monitoring Studies." SPE Reservoir Evaluation & Engineering 5, no. 01 (2002): 79–86. http://dx.doi.org/10.2118/76641-pa.

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Summary There is a potential for improving the reliability of standard core tests for seismic monitoring studies. A primary concern is the ability to quantify and correct for core-damage effects, which significantly enhance the stress dependency of wave velocities. This problem is most relevant for relatively low-strength rocks cored in high-stress environments. We have used synthetic sandstones formed under stress to perform a systematic study of stress-release- induced core-damage effects. The results show that careful laboratory procedures and modeling efforts may reduce core damage effects

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Zhang, Zhiyao, Shang Xu, Qiyang Gou, and Qiqi Li. "Reservoir Characteristics and Resource Potential of Marine Shale in South China: A Review." Energies 15, no. 22 (2022): 8696. http://dx.doi.org/10.3390/en15228696.

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Many sets of Paleozoic marine organic-rich shale strata have developed in South China. However, the exploration and development results of these shale formations are quite different. Based on the data of core experiment analysis, drilling, fracturing test of typical wells, the reservoir differences and controlling factors of four sets of typical marine organic-rich shale in southern China are investigated. The four sets of shale have obvious differences in reservoir characteristics. Ordovician–Silurian shale mainly develops siliceous shale, mixed shale and argillaceous shale, with large pore d

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Della Nave, Esteban, and Eduardo Natalio Dvorkin. "On the modeling of oil well drilling processes." Engineering Computations 32, no. 2 (2015): 387–405. http://dx.doi.org/10.1108/ec-03-2013-0093.

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Purpose – The purpose of this paper is to present the development of a simulator of oil well drilling processes. Design/methodology/approach – The simulator incorporates the main variables that are used by drilling engineers in the definition of the drilling processes. The code is useful a priori, in the design of a drilling process, as a tool for comparing different design options and predicting their results and a posteriori of a failure to understand its genesis and therefore provide know-why to improve the drilling techniques. Findings – The developed finite element simulator uses a co-rot

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Will, Robert, Rosalind A. Archer, and William S. Dershowitz. "Integration of Seismic Anisotropy and Reservoir Performance Data for Characterization of Naturally Fractured Reservoirs Using Discrete Feature Network Models." SPE Reservoir Evaluation & Engineering 8, no. 02 (2005): 132–42. http://dx.doi.org/10.2118/84412-pa.

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Summary This paper proposes a method for quantitative integration of seismic(elastic) anisotropy attributes with reservoir-performance data as an aid in characterizing systems of natural fractures in hydrocarbon reservoirs. This method is demonstrated through application to history matching of reservoir performance using synthetic test cases. Discrete-feature-network (DFN) modeling is a powerful tool for developing fieldwide stochastic realizations of fracture networks in petroleum reservoirs. Such models are typically well conditioned in the vicinity of the wellbore through incorporation of c

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Tekinalp, O., and A. G. Ulsoy. "Modeling and Finite Element Analysis of Drill Bit Vibrations." Journal of Vibration and Acoustics 111, no. 2 (1989): 148–55. http://dx.doi.org/10.1115/1.3269835.

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Drill bit vibrations are modeled using the Euler-Bernoulli beam theory. The model includes the most important properties of drill bits and of the drilling operation. These are: the drill bit cross sectional geometry, the drill helix angle, rotational speed of the drill bit, the thrust force, torque, and cutting forces generated during drilling. Equations of motion are derived in an inertial frame and then transformed to a rotating fluted frame for convenience in the solution. The transformed equations are discretized using finite element techniques. The finite element code developed is capable

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Hvenegård-Lassen, Kirsten. "Journey to the centre of the ice: narrating ice-core drillings in northern Greenland." Studies in Travel Writing 20, no. 3 (2016): 237–48. http://dx.doi.org/10.1080/13645145.2016.1212505.

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Mandziy, Teodor, Iryna Ivasenko, Olena Berehulyak, et al. "Evaluation of the Degree of Degradation of Brake Pad Friction Surfaces Using Image Processing." Lubricants 12, no. 5 (2024): 172. http://dx.doi.org/10.3390/lubricants12050172.

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The improvement of drilling rig systems to ensure a reduction in unproductive time spent on lowering and lifting operations for replacing drilling tools and restoring the performance of drilling equipment units is an important task. At the same time, considerable attention is paid to the reliable and efficient operation of the braking systems of drilling rig winches. In the process of operation, the polymer pads periodically come into contact with the outer cylindrical surface of the metal pulley during braking, work in extreme conditions and wear out intensively, so they need periodic replace

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Khilov, V. S. "Identification of resistance torque on the roller cone bit in the drill rod rotation drive." IOP Conference Series: Earth and Environmental Science 1254, no. 1 (2023): 012066. http://dx.doi.org/10.1088/1755-1315/1254/1/012066.

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Abstract There is a problem of increasing the durability of the roller cone bit of the drilling rigs used in the quarries of Ukraine. One of the effective ways to solve it is to apply the control method of maintaining a constant flow of mechanical power in the bottom hole zone. The implementation of such a control method leads to the necessity of controlling and limiting the resistance torque on the roller cone bit. To solve the problem of determining the resistance torque, we used methods of parameter identification: the Luenberger observation device with adaptation to external influences; es

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Berlioz, A., J. Der Hagopian, R. Dufour, and E. Draoui. "Dynamic Behavior of a Drill-String: Experimental Investigation of Lateral Instabilities." Journal of Vibration and Acoustics 118, no. 3 (1996): 292–98. http://dx.doi.org/10.1115/1.2888180.

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This paper focuses on laboratory tests concerned with the lateral behavior of a rod representative of part of a drill-string in the area of rotary oil drilling. The original experimental set-up takes into account the curvature of the rod, mud, stabilizers and rotation speed. The lateral behavior of the drill-string subjected to the axial excitations of the bit is governed by time varying parameter equations due to torsion-lateral and longitudinal-lateral couplings. The experimental results highlight the different kinds of lateral instabilities and they are compared either with existing experim

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