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Anthony Peirce - One of the best experts on this subject based on the ideXlab platform.
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Proppant Transport in hydraulic fracturing : crack tip screen-out in KGD and P3D models
International Journal of Solids and Structures, 2015Co-Authors: Egor Dontsov, Anthony PeirceAbstract:Abstract The aim of this study is to develop a model for Proppant Transport in hydraulic fractures capable of capturing both gravitational settling and tip screen-out effects, while prohibiting the particles from reaching the crack tips by imposing a width restriction based on the particle size. First, the equations that govern the propagation of hydraulic fractures and the Proppant Transport inside them are formulated. They are based on the solution for the steady flow of a viscous fluid, mixed with spherical particles, in a channel, which is obtained assuming an empirical constitutive model. This Proppant Transport model is applied to two fracture geometries – Khristianovich–Zheltov–Geertsma–De Klerk (KGD) and pseudo-3D (P3D). Numerical simulations show that the proposed method makes it possible to capture Proppant plug formation and growth, as well as the gravitational settling for both geometries. A dimensionless parameter, whose magnitude reflects the intensity of the settling, is introduced for the P3D fracture.
Dongxiao Zhang - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of Proppant Transport in propagating fractures with the multi phase particle in cell method
Fuel, 2019Co-Authors: Junsheng Zeng, Dongxiao ZhangAbstract:Abstract In this work, the Proppant Transport process in large-scale propagating fractures is simulated using an Eulerian–Lagrangian method. Fracture propagation is solved using the Perkins–Kern–Nordgren (PKN) model, while the fluid-particle system is solved with the multi-phase particle-in-cell (MP-PIC) method. The fluid motion is governed by volume-averaged Navier–Stokes equations, and solved using the finite volume method, and the particle motion is solved by applying Newton’s second law in a Lagrangian manner. Based on the original MP-PIC method, an extended 2D system of governing equations for fluid-particle flow is derived to solve the moving boundary problems associated with fracture propagation. By means of this method, the fluid-particle interaction is fully coupled, and the propagating fracture is considered as a prior-known boundary for the fluid and particle phases. Several numerical experiments are performed to validate the method for simulating fluid motion and Proppant settling behaviors in a fracture through comparison with results in the literature. The simulation results of the 2D framework are also compared with those of 3D framework and show a good agreement. Large-scale problems of Proppant Transport in propagating fractures for different Proppant and fracturing fluid properties, including the leak-off effect, are then simulated using this method. The Lagrangian feature of the MP-PIC method allows for flexible design of Proppant injection, such as injection of Proppant with multi-densities and/or multi-sizes.
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Numerical simulation of Proppant Transport in hydraulic fracture with the upscaling CFD-DEM method
Journal of Natural Gas Science and Engineering, 2016Co-Authors: Junsheng Zeng, Dongxiao ZhangAbstract:Abstract In this study, the coupled CFD (Computational Fluid Dynamics)-DEM (Discrete Element Method) method is employed to simulate the Proppant Transport process in a hydraulic fracturing system. The particle-particle and particle-wall interactions can be captured precisely in the DEM, which could not be fully considered in other methods. However, the DEM is time-consuming if every single Proppant particle is considered as a discrete element. In order to reduce the computational efforts, the representative particle model (RPM) is adopted in this work for upscaling the CFD-DEM. Dynamic packing problems of both the uniform and bi-density cases are designed to illustrate the advantage of simulating Proppant Transport behaviors with the CFD-DEM, and the upscaling cases are performed with the RPM for comparison. In addition, upscaling issues regarding validation and large-scale applications of the RRM are also discussed. After upscaling, the main characteristics of the packing patterns can be captured, while the time cost is greatly reduced.
Imqam Abdulmohsin - One of the best experts on this subject based on the ideXlab platform.
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Proppant Transport Using High-Viscosity Friction Reducer Fracture Fluids at High-Temperature Environment (includes associated errata)
'Society of Petroleum Engineers (SPE)', 2021Co-Authors: Biheri Ghith, Imqam AbdulmohsinAbstract:The stimulation of unconventional reservoirs to improve oil productivity in tight formations of shale basins is a key objective in hydraulic fracturing treatments. Such stimulation can be made by reliable fracture fluids that have a high viscosity and elasticity to suspend the Proppant in the fracture networks. Recently, due to several operational and economic reasons, the oil industry began using high-viscosity friction reducers (HVFRs) as direct replacements for linear and crosslinked gels. However, some issues can limit the capability of HVFRs to provide effective sand Transport, including the high fluid temperature during fracture treatment inside the formations. This may lead to unstable fracture fluids caused by a decrease in the interconnective strength between the fluid chains, which results in reduced viscosity and elasticity. This study comprehensively investigated HVFRs in comparison with guar at various temperatures. An HVFR at 4 gallons per thousand gallons of water (gpt) and guar at 25 pounds per thousand gallons of water (ppt) were selected based on fluid rheology tests and hydraulic fracture execution field results. The rheological measurements of both fracture fluids were conducted at different temperature values (i.e., 25, 50, 75, and 100⁰C). Static and dynamic Proppant settling tests were also conducted at the same temperatures. The results showed that the HVFR provided better Proppant Transport capability than the guar. The HVFR had better thermal stability than guar, but its viscosity and elasticity decreased significantly when the temperature exceeded 75⁰C. An HVFR can carry and hold the Proppant more deeply inside the fracture than liner gel, but that ability decreases as the temperature increases. Therefore, using conditions that mimic field conditions to measure the fracture fluid rheology, Proppant static settling velocity, and Proppant dune development under a high temperature is crucial for enhancing the fracture treatment results
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Proppant Transport by High Viscosity Friction Reducer and Guar Linear Gel-Based Fracture Fluids
Scholars\u27 Mine, 2020Co-Authors: Biheri Ghith, Imqam AbdulmohsinAbstract:The enhancements to the oil production process produced by high viscosity friction reducers (HVFRs) has increased dramatically. The HVFR fluid improves processes during hydraulic fracture operations and provides a successful reduction in friction compared to the traditional treatment, which employs linear gel such as guar. The research aims to determine Proppant capability performance of HVFRs and linear gel by conducting intensive laboratory investigations. These investigations aim to elucidate the effects of rheological fluids and fracture geometry on the static and dynamic settling velocity of the Proppant inside fractures using HVFRs compared to linear gel fluids. Various concentrations of HVFR and guar were used for both the rheology and the Proppant test experiments. The rheology and settling measurements show greater improvement of HVFR to distribute the Proppant in the fracture compared to guar. Interestingly, a lower concentration of the HVFR (i.e., 2 gpt) provided improved viscosity and elastic properties than the standard concentration of linear gel (i.e., 20 ppt). This work will contribute to a better comprehension of HVFRs\u27 ability to Transport Proppant. Ultimately, this improved understanding can assist hydraulic fracturing companies to build better friction reducers
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Static Proppant Settling Velocity Characteristics in High Viscosity Friction Reducers Fluids for Unconfined and Confined Fractures
Scholars\u27 Mine, 2019Co-Authors: Mohammed Ba Geri, Imqam Abdulmohsin, Flori M. R., Shen L., Bogdan A.Abstract:Measuring Proppant settling velocity in high viscosity friction reducers (HVFRs) plays a critical key for evaluating Proppant Transport in hydraulic fracture treatment. Settling of particles is governed by several factors such as fluid rheology (viscosity and elasticity), Proppant size, retardation confining walls effect, and fracture orientation. The objective of this experimental study was to determine how these factors would influence particle settling velocity in hydraulic fracturing applications. The experiments were conducted in unconfined and confined fluid conditions. Fracture cell was designed in certain ways to capture the impact of fracture orientation by 45°, 60°, and 90° on settling velocity. Results showed HVFR provided better Proppant Transport capability than regular FRs used in slickwater. Proppant settling velocity using HVFR was decreased by 80%. Results obtained from confined fluid experiments showed that Proppant settling velocity decreased due to the confining walls exert retardation impact. The wall retardation was also reduced as the fracture width increased. Changing fracture orientation from vertical position (90 degree) to 45 degree led to high reduction in Proppant settling velocity
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Proppant Transport using High Viscosity Friction Reducer Fluids: Part I- Rheology and Static Settling Velocity Characterization
'Elsevier BV', 2019Co-Authors: Mohammed Ba Geri, Imqam AbdulmohsinAbstract:Measuring Proppant static settling velocity in high viscosity friction reducers (HVFRs) plays a critical key for evaluating Proppant Transport in hydraulic fracture treatment. Settling of particles is governed by several factors such as fluid rheology (viscosity and elasticity), Proppant size, retardation confining walls effect, and fracture orientation. The objective of this experimental study was to determine how these factors would influence particle settling velocity in hydraulic fracturing applications. The experiments were conducted in unconfined and confined fluid conditions. Fracture cell was designed in certain ways to capture the impact of fracture orientation on settling velocity. Results showed HVFR provided better Proppant Transport capability than regular frictional reducers concentrations used in slickwater. In most of the settling measurements, Proppant settling velocity using HVFR decreased significantly compare to the settling velocity measured using slickwater. HVFR with low loading of 2 gpt caused drag enhancement or Proppant settling velocity reduction across wide ranges of particle sizes due to the elasticity properties of fluid. Changing fracture orientation from vertical position to 45° led to a high reduction in Proppant settling velocity due to contact force or friction force from the inclined fracture sidewall. The importance of measuring Proppant static settling velocity and fracture fluid rheology is crucial to mimic the low shear rate conditions of fracture treatment after stop pumping the Proppant
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Investigate Proppant Transport with Varying Perforation Density and its Impact on Proppant Dune Development Inside Hydraulic Fractures
Scholars\u27 Mine, 2019Co-Authors: Ba Geri M., Imqam Abdulmohsin, Suhail M.Abstract:Proppant Transport adequately during hydraulic fracturing treatment assumes same perforation contribution through multi-perforation system. Proppant Transport performance into the different ordination fracture system using multi-entry perforation technique is still not fully understood. This experimental study was aimed to deeply investigate five factors that affect Proppant Transport performance: number of perforations, perforation opening size, shear rate, fracture orientation, and Proppant size distribution. The impact of these factors on Proppant Transport performance from different perspective was studied. Fracture slot model was designed and built to observe easily the effects of perforation density and fracture orientation. The results of this experimental work show that limited-entry perforation technique has significant impact on Proppant Transport within fractures where single top perforation had better Proppant placement than multi-perforation system. Fracture area was approximately propped with 66% and 48% using top perforation and multi-perforation system, respectively. Slurry with high shear rate has a negative effect on the Proppant equilibrium dune level (EDL) and fracture propped area (FPA). Fracturing treatment using high shear rate causes high pressure drop in the fracture that leads to decreasing EDL by 17% and fracture propped area by 23% comparing to using low shear rate. Using large Proppant size (20/40) leads to form high EDL and FPA compared to 100 mesh size. Proppant Transport dominated by four mechanisms and the vertexes near wellbore plays main mechanism to carry Proppant farther inside the fracture
A. P. Peirce - One of the best experts on this subject based on the ideXlab platform.
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implicit level set algorithms for modelling hydraulic fracture propagation
Philosophical Transactions of the Royal Society A, 2016Co-Authors: A. P. PeirceAbstract:Hydraulic fractures are tensile cracks that propagate in pre-stressed solid media due to the injection of a viscous fluid. Developing numerical schemes to model the propagation of these fractures is particularly challenging due to the degenerate, hypersingular nature of the coupled integro-partial differential equations. These equations typically involve a singular free boundary whose velocity can only be determined by evaluating a distinguished limit. This review paper describes a class of numerical schemes that have been developed to use the multiscale asymptotic behaviour typically encountered near the fracture boundary as multiple physical processes compete to determine the evolution of the fracture. The fundamental concepts of locating the free boundary using the tip asymptotics and imposing the tip asymptotic behaviour in a weak form are illustrated in two quite different formulations of the governing equations. These formulations are the displacement discontinuity boundary integral method and the extended finite-element method. Practical issues are also discussed, including new models for Proppant Transport able to capture ‘tip screen-out’; efficient numerical schemes to solve the coupled nonlinear equations; and fast methods to solve resulting linear systems. Numerical examples are provided to illustrate the performance of the numerical schemes. We conclude the paper with open questions for further research. This article is part of the themed issue ‘Energy and the subsurface’.
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A Lagrangian Approach to Modelling Proppant Transport with Tip Screen-Out in KGD Hydraulic Fractures
Rock Mechanics and Rock Engineering, 2015Co-Authors: E. V. Dontsov, A. P. PeirceAbstract:This study introduces a continuum approach to model Proppant Transport in hydraulic fractures in a Lagrangian frame of reference. The model for the Proppant Transport is based on the recently obtained slurry flow solution inside a channel, where the latter utilizes a phenomenological constitutive relationship for a slurry. This approach allows us to describe the transition from Poiseuille flow with an effective viscosity to Darcy flow as the particle concentration increases towards the maximum value. The algorithm is presented for the one-dimensional case, for which propagation of a symmetric Kristinovich–Zheltov–Geertsma–De Klerk fracture is considered. To examine the effectiveness of the Lagrangian approach for Proppant Transport modelling, a set of parameters, for which Proppant particles reach the fracture tip and cause the development of a Proppant plug is selected. In this situation, the coupling between the hydraulic fracture propagation and Proppant Transport is the most significant. To estimate the accuracy of the Lagrangian Proppant Transport model, the results are compared to the predictions of an Eulerian Proppant Transport model, which utilizes the same algorithm for hydraulic fracture propagation. It is shown that, although both approaches have the same convergence rate, the error of the Lagrangian approach is three to five times smaller, which depends on the number of Proppant elements used in the Lagrangian approach. This permits us to use a coarser mesh for hydraulic fracture propagation, and to obtain results with similar accuracy up to a hundred times faster.
Egor Dontsov - One of the best experts on this subject based on the ideXlab platform.
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Proppant Transport in hydraulic fracturing : crack tip screen-out in KGD and P3D models
International Journal of Solids and Structures, 2015Co-Authors: Egor Dontsov, Anthony PeirceAbstract:Abstract The aim of this study is to develop a model for Proppant Transport in hydraulic fractures capable of capturing both gravitational settling and tip screen-out effects, while prohibiting the particles from reaching the crack tips by imposing a width restriction based on the particle size. First, the equations that govern the propagation of hydraulic fractures and the Proppant Transport inside them are formulated. They are based on the solution for the steady flow of a viscous fluid, mixed with spherical particles, in a channel, which is obtained assuming an empirical constitutive model. This Proppant Transport model is applied to two fracture geometries – Khristianovich–Zheltov–Geertsma–De Klerk (KGD) and pseudo-3D (P3D). Numerical simulations show that the proposed method makes it possible to capture Proppant plug formation and growth, as well as the gravitational settling for both geometries. A dimensionless parameter, whose magnitude reflects the intensity of the settling, is introduced for the P3D fracture.
