Academic literature on the topic 'Non-water based slurry'

In the design of slurry transport equipment, the effects of solid particle concentration on hydraulic performance and wear have to be considered. This study involves examining the acoustic properties of slurry flows such as velocity, backscatter and attenuation as a function of volume fraction of solid particles. Ultrasound A-mode imaging method is developed to obtain particle concentration in a flow of soda lime glass particles (diameter of 200 micron) and water slurry in a 1″ diameter pipe. Based on the acoustic properties of the slurry a technique is developed to measure local solid particle concentrations. The technique is used to obtain concentration profiles in homogeneous (vertical flow) and non-homogeneous (horizontal flow) slurry flows with solid particle concentrations ranging from 1–10% by volume. The algorithm developed utilizes the power spectrum and attenuation measurements obtained from the homogeneous loop as calibration data in order to obtain concentration profiles in other (i.e. non-homogenous) flow regimes. A computational study using FLUENT was performed and a comparison is made with the experimental results. A reasonable agreement between the experimental and computational results is observed.

Slurries transport through circular pipelines is present in many industries: oil, mineral, water and others. There are many variables involved in slurry flows, causing the flow behavior of these slurry systems to vary over a wide range, and therefore, different approaches have been used to describe their behavior in various flow regimes. At some typical applications, the rheology of the base fluid is itself non-Newtonian. Due to the wide range of variables and their variations, the experimental approach is necessarily limited by geometric and physical scale factors. For a non-Newtonian base fluid, only some particular cases that cover a limited range of conditions have been reported. For these reasons, numerical simulation constitutes an ideal technique for predicting the general flow behavior of these systems. Models in this area can be divided in two different classes: Eulerian-Eulerian and Lagrangian-Eulerian. Lagrangian-Eulerian models calculate the path and motion of each particle, while Eulerian-Eulerian models treat the particle phase as a continuum and average out motion on the scale of individual particles. This work focuses on the Eulerian-Eulerian approach for modeling the flow of a mixture of sand particles and a non-Newtonian fluid in a horizontal pipe. The steady-state rheological behavior of the base fluid was expressed by the three-parameter Sisko model. Homogeneous and heterogeneous flow regimes are considered. For the present study, the widely used “k-ε model” is employed to model turbulent viscosity. The k-ε turbulence model introduces two additional variables: the kinetic energy of the fluid turbulence, k, and the dissipation rate of this kinetic energy, ε. These two variables are solved throughout the fluid domain via two additional differential transport equations. The k-ε model is therefore commonly referred to as a “two-equation” turbulence model. The turbulent viscosity is then determined as a function of k and ε. Additionally, closure of solid-phase momentum equations requires a description for the solid-phase stress. Constitutive relations for the solid-phase stress, considering the inelastic nature of particle collisions based on kinetic theory concepts, have been used. Governing equations were solved numerically using the control volume-based finite element method. An unstructured non-uniform grid was chosen to cover the entire computational domain. A second-order scheme in space was used. Precise numerical solutions in a fully developed turbulent flow were found. Flow behavior for different sand concentrations was simulated. Results for the mean pressure gradients were compared with experimental data. The results turned out to be in compliance with those from the experimental data, for a sand concentration of less than 5%. Numerical simulations of non-Newtonian slurry flows provide a method that can relate properties of the fluid and solid component of the slurry, and does not entail the time and expenses needed for empirical studies. This also might provide a further sight to develop correlations between mean pressure gradients and slurry mean velocity.

Abstract In some shale plays, insufficient formation breakdown and presence of near-wellbore tortuosity make it challenging to reach the designed pumping rate and lead to premature screen-outs. Screen-outs during a fracturing operation are a tremendous burden for operators as they diminish the well's total production and add cost to do a wellbore cleanout. In some cases, these issues could cause suboptimal perforation cluster efficiency and production loss. There is a critical need for an easy-to-implement solution that can help operators in achieving their desired fracture designs. This paper presents field case studies of a new microparticles-based slurry (MPS) technology that proves ease of operations and an improvement in production across four different US shale basins. Non-hazardous water-based slurry contains engineered glass microparticles with a median size of 550–625 mesh. It was implemented in the Rockies, Powder River, Permian, and SCOOP/STACK with over 10,000 stages stimulated so far. The slurry was usually deployed as an additive to the pad or as a pill before pumping the proppant-laden slurries. It is compatible with commonly used fracturing fluids. The MPS technology helps in scouring the perforations and lessening fracture entry restrictions. This results in better fracture initiation and lowers the screen-out potential. The technology also widens fracture openings, restricts fracture complexity, reduces near-wellbore tortuosity, and increases reservoir connectivity. The slurry can be used as a far-field diverter pill as well. Field studies in multiple challenging formations involving alternating stages between the microparticle slurry and the standard control showed a 12–25% reduction in pump time due to significant pressure relief. In another pad, the MPS reduced the screen-outs by over 6 folds. Production data showed up to 19% uplift within a 15-month period against control wells. The production improvement analysis is a subject of further study. Oil and water tracer tests confirmed the production improvement in stages that had the microparticle slurry. Overall, the success rate of the technology has been unprecedented and has been gaining significant ground over the past year. Realizing a treatment design is a critical step in maximizing the rate of return on a well. This new chemical slurry offers operators a simple, cost-effective, and field proven solution to alleviate operational issues and potentially be more aggressive in completion designs. The diverse case studies in this paper prove the efficacy of this innovative technology in solving the major day-to-day fracturing challenges faced by completion engineers.

Abstract A novel, non-ionic surfactant is presented that alters typical cement incompatibility with non-aqueous fluids, effectively removing synthetic/oil-based mud (SOBM) from the wellbore and changing wettability of casing and formation from oil-wet to water-wet. The change in wettability eliminates the need for cement spacers conventionally deployed between the preceding non-aqueous fluid and the ensuing cement slurry. The entirety of spacer fluid interface can therefore be removed from operation, improving operational safety and efficiency, reduce waste and simplify wellsite logistics. The paper discusses the selection and evaluation of the proprietary surfactant in various laboratory testing. The main characteristics of the surfactant is its non-foaming, non-retarding, compatible with SOBM, ability to change oil-wet surface to water-wet, stable while minimizing environmentally impact. Scaling up, a yard test and a field trial in an offshore rig was successfully performed to evaluate the mixing, compatibility and pumpability using rig equipment.

Liquid-solid two-phase flows are found in numerous operations in the chemical, petroleum, pharmaceutical and many other industries. In numerous cases, the mixture or slurry that flows is composed by a suspension of solid particles (dispersed phase) transported by a liquid (continuum phase). However, the large number and range of variables encountered in slurry flows, in the case of pipelines, cause the flow behavior of these slurry systems to vary over a wide range of conditions, and consequently, different approaches have been used to describe the behavior of different flow regimes. Therefore, there are numerous studies of particular cases that cover limited ranges of conditions. In consequence, the experimental approach is necessarily limited by geometric and physical scale factors. For these reasons, Computational Fluid Dynamics, CFD, constitutes an ideal technique for predicting the general flow behavior of these systems. CFD models in this area can be divided in two different classes: Eulerian-Eulerian and Lagrangian-Eulerian models. Differences between these models are related to the way the solid phase flow is represented. Lagrangian-Eulerian models calculate the path and motion of each particle, while Eulerian-Eulerian models treat the particle phase as a continuum and average out motion on the scale of individual particles. This work focuses on the Eulerian-Eulerian approach for modeling the flow of a mixture of sand particles and water in a horizontal pipe. Homogeneous and heterogeneous flow regimes are considered. The k-ε model was used for modeling turbulent effects. Additionally, closure of solid-phase momentum equations requires a description for the solid-phase stress. Constitutive relations for the solid-phase stress considering the inelastic nature of particle collisions based on the Gas Kinetic Theory concepts have been used. Governing equations are solved numerically using the control volume-based finite element method. An unstructured non-uniform grid was chosen to discretize the entire computational domain. A second-order scheme in space and time was used. Numerical solutions in fully developed turbulent flow were found. Results show that flow predictions are very sensitive to the restitution coefficient and pseudo-viscosity of the solid phase. The mean pressure gradients from numerical solutions were compared with results obtained using the correlations of Einstein, Thomas and Krieger for homogeneous cases and with experimental data found in the open literature for heterogeneous cases. The solutions were found to be in good agreement with both correlations and experimental data. In addition, these numerical results were closer to experimental data than results obtained using other numerical models.

Abstract Curing total losses of drilling fluids in fractured formations is one of the most challenging fluid loss scenarios to control. Loss zones are unpredictable due to large vugular zones, extended and connected fracture structures formations. However, based on proper evaluation of the offset wells data, losses events can be anticipated to customize a Lost Circulation Material (LCM) solution. Non-Conventional LCM solutions typically are used to go beyond and be more aggressive, aiming to cure the losses, reduce non-productive time and resume programmed operations. We worked to locally develop an Innovative Non-Conventional LCM solution, which involves pill trains combinations to cure the losses across fractured formations. After successful lab testing verification, those formulations were implemented at the field with satisfactory results. Well A was identified with total losses across fractured formation. Previously lab tested Non-Conventional LCM solution was recommended. At Well A location, the first pill was made with blend of organic polymers with super absorbent materials, specifically designed to impart viscosity and swell as it fills the fractures. producing a viscous slurry designed to flow into downhole loss zones, where it will swell and seal large fractures providing a base for the second pill pumped to rapidly de-water, leaving behind a drillable plug. The second pill pumped consisted on a blend of sealants which form a stable, high solids, high fluid loss LCM slurry. Upon contact with a thief zone, this second pill will rapidly de-water, leaving behind a drillable plug-in fracture, voids and vugular spaces across the loss zone. A soft squeeze was hold for several hours. The resulted plug was easy drilled through without the danger of unintentional sidetracking. As conclusion, we were able to customize an Innovative Non-Conventional LCM solution to regain the circulation on well A, allowing them to continue with the programmed operations and eliminating non-productive time in this well. This paper discusses how this innovative customized Non-Conventional LCM Solution was designed, lab and field tested with successful results curing total losses scenarios across fractured formations, resulting in considerable non-productive time mitigation while drilling across losses zones.

Now a days, Non-Conventional Machining process is gaining more attention by the researchers. Abrasive Water jet machining (AWJM) is one of such machining process where material is removed with abrasive slurry as cutting tool. The present work discuss about the development of an optimal solution for minimizing surface roughness using a response surface methodology (RSM) while machining of EN grade steel. The machining parameters considered for the study are Abrasive Grain Size (AGS) and Hydraulic Pressure (HP) and Stand Off Distance (SOD) and the Abrasive Flow Rate (AFR). The response parameter is surface roughness (Ra). The experiments are performed based on the Box-Behnken design. Additionally, the significance of the developed optimization design has been identified using analysis of variance (ANOVA). Finally, the validity and adequacy of the developed model are done through confirmation tests. Key Words: Abrasive Water jet Machining, Response Surface Methodology, Optimization, ANOVA

With the widespread adoption of the backfill mining method in metal mines, the barricade wall, as a crucial structure for stope stability control, has its drainage performance and spatial placement significantly influencing structural stability. This study utilizes a self-developed force simulation device for backfill walls to systematically conduct mechanical tests on non-cemented backfill walls under various installation positions and drainage conditions. The results indicate that non-cemented slurry conforms to the ideal fluid model under undrained conditions, with lateral pressure distribution closely matching the hydrostatic pressure theory. Optimized drainage design can reduce lateral pressure by 70% and accelerate the dissipation process of pore water pressure. For drainage walls, their installation position can significantly regulate lateral pressure; when adjacent to the stope (entry), the peak lateral pressure reaches 73.18 kPa (under 80 kPa loading pressure), which is a 35.43% increase compared to the condition at the end of the entry. This research reveals the load transfer mechanism and pressure evolution规律 of non-cemented walls, providing theoretical support for mine safety protection design.

Hydrofracking transfigured the concept of producing from unconventional reservoirs. The Fracking fluid used in fracturing has unlocked many tight reservoirs but in terms of an aquifer, it poses threats like consumption of large quantity of water and also, used water becomes polluted as well as recycling cost is uneconomic. This paper evaluates alternatives to water-based frac fluids and discusses their environmental & economic impact along with resource availability and commercial feasibility. Pure Propane Fracturing uses propane in combination with non-toxic man-made proppants (light glass & carbon fullerene microbeads) with desired properties. Pure Propane is fluorinated and carbonated without water or harmful additives, thereby eliminates the risk of catching fire. Pure Propane Fracturing eliminates the need for water completely and thus, a perfect option for fracturing in water scarcity regions. Fracture flow capacity of Pure Propane can be enhanced with the use of phase change chemical proppants in the slurry stage. CO2 Foam Fracturing predominantly comprises liquid carbon-dioxide which reduces the water requirement up to 80%. CO2 foam-based frac fluid uses relatively fewer chemical additives as compared to the water-based frac fluid which in-turn does minimal formation damage. Foam Fracturing fluids have high fluid recovery and clean-up efficiency. CO2 foam-based frac fluid is available in a wide range of viscosities and can also work in high pressure high temperature conditions at significantly low polymer loadings. Energized frac fluid comprises N2/CO2 (20-30%) which reduces water consumption and provides additional energy to aid in load recovery during the post-frac flow-back stage. N2 gas can propagate more easily into small pores and micro-fractures to get lower breakdown pressure and enhance fracture complexity & CO2 exists in dense phase at static bottom hole conditions, thus is less susceptible to dissipation and dissolves in crude oil which reduces its viscosity and improves cleanup and recovery.

Abstract The low permeability carbonate reservoir in central Iraq was discovered in the 80's, facing the acid stimulation demand of shut-in well reactivation and new drilling well high-efficiency production. Low permeability, poor pore connectivity and non-ideal production necessitate the shift from conventional acidizing and pad fracturing to integrated multistage acid fracturing techniques, which achieve better fracture conductivity and deep penetration to maximize the production potential. Petro-physically speaking, effective porosity, net pay and hydrocarbon pore volume are related to reservoir performance. In this low permeability carbonate reservoir, previous acid stimulation analysis shows that the factors affecting production capacity are far more than those above mentioned. The injection parameters, surface etching and conductivity were lab-tested and evaluated among the four techniques of matrix acidizing, pad fracturing, alternating injection with acid and linear gel and proppant-slurry acid fracturing. The proppant-slurry acid fracturing was the first-ever proposed to unlock the production potential. Comparing to the conventional acid stimulation, the parameters including the proportion of crosslinked gel and acid, concentration, size and total volume of proppant, multistage injection volume and rate, retardance and closed acidizing, have been optimized and designed successfully for the first pilot well on-site.After the lab tests, geomechanics and modeling and parameter simulation of proppant-slurry acid fracturing, the results show that the stress difference between the perforated layer and the upper rock layers is about 5 MPa, the geometry of the artificial fractures can be controlled in between oil layers. Water-based guar gel fracturing fluid with additives and 20% concentration HCL with retarded agents were selected, the maximum pumping rate was designed as 6.0 m3/min with 6862 Psi pumping pressure, and the volume of acid was double of fracturing fluid. After the pumping of 20 m3 20/40 proppant with maximum concentration of 583 kg/m3 and 400 m3 acid, the evaluation results showed that the propped half-length Xf = 116.4 m width Wf = 0.7 cm, and dimensionless conductivity is 2.6. The predicted production was 2.5 times greater than before stimulation, and the artificial fracture was initiated in the pad stage, and then a finite conductive channel was formed by dual support of surface etching and proppant.Many technical and operational challenges were faced and properly handled with lab tests, numerical simulation and evaluation, which will form the completion and stimulation strategies for the low permeability carbonate reservoir. Four jobs have been confirmed for proppant-slurry acid fracturing.