Modeling the Interaction Between Hydraulic and Natural Fractures Using Three Dimensional Finite Element Analysis

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ISBN 13 :
Total Pages : 202 pages
Book Rating : 4.:/5 (957 download)

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Book Synopsis Modeling the Interaction Between Hydraulic and Natural Fractures Using Three Dimensional Finite Element Analysis by : Aditya Balasaheb Nikam

Download or read book Modeling the Interaction Between Hydraulic and Natural Fractures Using Three Dimensional Finite Element Analysis written by Aditya Balasaheb Nikam and published by . This book was released on 2016 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Natural fractures are present in almost every formation and their size and density definitely affect the hydraulic fracturing job. Some of the analysis done in the past shed light on hydraulic fracture (HF) and natural fracture (NF) geometries. The interaction of the HF with existing NF in a formation results in a denser fracture network. The volume of rock covering this fracture network is called the stimulated reservoir volume (SRV). This SRV governs the hydrocarbon production and the ultimate revenue generation. Moreover, past studies show that a microseismic interpreted SRV can be different than the actual SRV. Additionally, there is always limited subsurface access, which makes it imperative to understand the HF – NF interaction to plan and execute a successful hydraulic fracturing job. A three layered, three dimensional complex geomechanical model is built using commercially available finite element analysis (FEA) software. A propagating HF approaching mainly orthogonal NF is studied and analyzed. Cohesive pore pressure elements in FEA software capable of modeling fluid continuity at HF – NF intersection are used to model the HF – NF interaction. Furthermore, a detailed sensitivity analysis considering the effect of stress contrast, job design parameters, NF properties, and properties of the formation is conducted. The sensitivity analysis of properties such as principal horizontal stress contrast, job design parameters, NF properties and properties of target formation reveals a broad variation in the impact of the sensitivity parameters on the HF, NF, and HF-NF geometry and interaction. The observations and the corresponding conclusions were based on broadly classified sensitivity parameters. The most important parameters solely for HF resultant geometry are observed to be a high stress contrast with stress reversal, highest injection rate, and farther NF distance from the injection point. The least important parameter is observed to be the scenario with almost equal horizontal stresses. However, the most important parameter solely for resulting NF geometry is only the high stress contrast with stress reversal. Conversely, for the considered sensitivity cases, the least important parameters are the injection rate, lower injection viscosity (10 cP), higher NF leak-off coefficient, target formation thickness, Young’s modulus, and lowest value of target formation Poisson’s ratio. Collective conclusions for considering HF-NF are also obtained.

3-D Modeling of Interaction Between a Hydraulic Fracture and Multiple Natural Fractures Using Finite Element Analysis

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ISBN 13 :
Total Pages : 184 pages
Book Rating : 4.:/5 (11 download)

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Book Synopsis 3-D Modeling of Interaction Between a Hydraulic Fracture and Multiple Natural Fractures Using Finite Element Analysis by : Debashish Talukder

Download or read book 3-D Modeling of Interaction Between a Hydraulic Fracture and Multiple Natural Fractures Using Finite Element Analysis written by Debashish Talukder and published by . This book was released on 2019 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three-layered, 3-D geo-mechanical model was developed using Finite Element Analysis (FEA) software (ABAQUS) to simulate single stage hydraulic fracturing treatment in a synthetic fractured model based on available shale information from literature. The main objectives of this study were- (i) to investigate the interaction between a hydraulic fracture (HF) orthogonally intersecting two parallel natural fractures (NF) and (ii) to identify significant parameters and their 2-factor interactions that affect HF propagation in the presence of multiple NFs. Based on literature review, an initial set of 20 parameters (a combination of geologic and drilling parameters) was selected. Those parameters were believed to affect the hydraulic fracture propagation in a naturally fractured model. Experiments were conducted in two stages. First-order order numerical experiments were conducted under the Plackett-Burman experimental design. Central Composite Design (CCD) was used to check curvature and to take care of non-linearity existing in the dataset. A stepwise sensitivity analysis and parametric study were conducted to identify significant parameters and their interactions. When the HF interacted with NFs, there were three possible outcomes- the HF either got arrested, dilated or crossed the NF. The overall hydraulic fracture geometry depended on the type of interaction behavior occurring at the intersection. The NF leakoff coefficient was the most significant factor in the 1st order experiments that affected the HF propagation in the presence of multiple NFs. CCD results suggested that NF strength at the bottom shale layer and injection fluid viscosity significantly influenced the HF opening in the presence of the natural fractures. The most significant two-factor interaction was the interaction between stress contrast and Young’s modulus of the overburden shale (Ytop). This study will help understand the interaction behavior between a HF and two pre-existing NFs. The parametric study will provide a valuable insight for hydraulic fracturing treatment in a naturally fractured formation.

Hydraulic Fracture Modeling

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Publisher : Gulf Professional Publishing
ISBN 13 : 0128129999
Total Pages : 568 pages
Book Rating : 4.1/5 (281 download)

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Book Synopsis Hydraulic Fracture Modeling by : Yu-Shu Wu

Download or read book Hydraulic Fracture Modeling written by Yu-Shu Wu and published by Gulf Professional Publishing. This book was released on 2017-11-30 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydraulic Fracture Modeling delivers all the pertinent technology and solutions in one product to become the go-to source for petroleum and reservoir engineers. Providing tools and approaches, this multi-contributed reference presents current and upcoming developments for modeling rock fracturing including their limitations and problem-solving applications. Fractures are common in oil and gas reservoir formations, and with the ongoing increase in development of unconventional reservoirs, more petroleum engineers today need to know the latest technology surrounding hydraulic fracturing technology such as fracture rock modeling. There is tremendous research in the area but not all located in one place. Covering two types of modeling technologies, various effective fracturing approaches and model applications for fracturing, the book equips today's petroleum engineer with an all-inclusive product to characterize and optimize today's more complex reservoirs. - Offers understanding of the details surrounding fracturing and fracture modeling technology, including theories and quantitative methods - Provides academic and practical perspective from multiple contributors at the forefront of hydraulic fracturing and rock mechanics - Provides today's petroleum engineer with model validation tools backed by real-world case studies

Mathematical Modeling and Finite Element Analysis of Three-dimensional Hydraulic Fractures in Layered Media

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ISBN 13 :
Total Pages : 382 pages
Book Rating : 4.:/5 (27 download)

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Book Synopsis Mathematical Modeling and Finite Element Analysis of Three-dimensional Hydraulic Fractures in Layered Media by : Tae Soo Lee

Download or read book Mathematical Modeling and Finite Element Analysis of Three-dimensional Hydraulic Fractures in Layered Media written by Tae Soo Lee and published by . This book was released on 1989 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Solving Three-dimensional Problems in Natural and Hydraulic Fracture Development

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ISBN 13 :
Total Pages : 312 pages
Book Rating : 4.:/5 (858 download)

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Book Synopsis Solving Three-dimensional Problems in Natural and Hydraulic Fracture Development by : Farrokh Sheibani

Download or read book Solving Three-dimensional Problems in Natural and Hydraulic Fracture Development written by Farrokh Sheibani and published by . This book was released on 2013 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although many fracture models are based on two-dimensional plane strain approximations, accurately predicting fracture propagation geometry requires accounting for the three-dimensional aspects of fractures. In this study, we implemented 3-D displacement discontinuity (DD) boundary element modeling to investigate the following intrinsically 3-D natural or hydraulic fracture propagation problems: the effect of fracture height on lateral propagation of vertical natural fractures, joint development in the vicinity of normal faults, and hydraulic fracture height growth and non-planar propagation paths. Fracture propagation is controlled by stress intensity factor (SIF) and its determination plays a central role in LEFM. The DD modeling is used to evaluate SIF in Mode I, II and III at the tip of an arbitrarily-shaped embedded crack by using crack-tip element displacement discontinuity. We examine the accuracy of SIF calculation is for rectangular, penny-shaped, and elliptical planar cracks. Using the aforementioned model for lateral propagation of overlapping fractures shows that the curving path of overlapping fractures is strongly influenced by the spacing-to-height ratio of fractures, as well as the differential stress magnitude. We show that the angle of intersection between two non-coincident but parallel en-echelon fractures depends strongly on the fracture height-to-spacing ratio, with intersection angles being asymptotic for "tall" fractures (large height-to-spacing ratios) and nearly orthogonal for "short" fractures. Stress perturbation around normal faults is three-dimensionally heterogeneous. That perturbation can result in joint development at the vicinity of normal faults. We examine the geometrical relationship between genetically related normal faults and joints in various geologic environments by considering a published case study of fault-related joints in the Arches National Park region, Utah. The results show that joint orientation is dependent on vertical position with respect to the normal fault, the spacing-to-height ratio of sub-parallel normal faults, and Poisson's ratio of the media. Our calculations represent a more physically reasonable match to measured field data than previously published, and we also identify a new mechanism to explain the driving stress for opening mode fracture propagation upon burial of quasi-elastic rocks. Hydraulic fractures may not necessarily start perpendicular to the minimum horizontal remote stress. We use the developed fracture propagation model to explain abnormality in the geometry of fracturing from misaligned horizontal wellbores. Results show that the misalignment causes non-planar lateral propagation and restriction in fracture height and fracture width in wellbore part.

Analysis of Interaction Between Hydraulic and Natural Fractures

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (115 download)

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Book Synopsis Analysis of Interaction Between Hydraulic and Natural Fractures by : Jaber Taheri-Shakib

Download or read book Analysis of Interaction Between Hydraulic and Natural Fractures written by Jaber Taheri-Shakib and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The behavior of natural fractures at the hydraulic fracturing (HF) treatment is one of the most important considerations in increasing the production from this kind of reservoirs. Therefore, considering the interaction between the natural fractures and hydraulic fractures can have great impact on the analysis and design of fracturing process. Due to the existence of such natural fractures, the perturbation stress regime around the tip of hydraulic fracture leads to some deviation in the propagation of path of hydraulic fracture. Increasing the ratio of transverse stress to the interaction stress results in a reduction in the deviation of hydraulic fracturing propagation trajectory in the vicinity of natural fracture. In this study, we modeled a hydraulic fracture with the extended finite element method (XFEM) using a cohesive-zone technique. The XFEM is used to discrete the equations, allowing for the simulation of induced fracture propagation; no re-meshing of domain is required to model the interaction between hydraulic and natural fractures. XFEM results reveal that the distance and angle of natural fracture with respect to the hydraulic fracture have a direct impact on the magnitude of tensile and shear debonding. The possibility of intersection of natural fracture by the hydraulic fracture will increase with increasing the deviation angle value. At the approaching stage of hydraulic fracture to the natural fracture, hydraulic fracture tip exerts remote compressional and tensile stress on the interface of the natural fracture, which leads to the activation and separation of natural fracture walls.

A 3D Hydro-mechanical Discrete Element Model for Hydraulic Fracturing in Naturally Fractured Rock

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (11 download)

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Book Synopsis A 3D Hydro-mechanical Discrete Element Model for Hydraulic Fracturing in Naturally Fractured Rock by : Efthymios Papachristos

Download or read book A 3D Hydro-mechanical Discrete Element Model for Hydraulic Fracturing in Naturally Fractured Rock written by Efthymios Papachristos and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydraulic fracturing is at the core of a number of naturally occurring and induced phenomena and crucial for a sustainable development of energy resource production. Given its crucial role this process has been given increasing attention in the last three decades from the academic world. Nonetheless a number of very significant aspects of this process have been systematically overlooked by the community. Two of the most notable ones are the inability of the vast majority of existing models to tackle at once the propagation of hydraulic fractures in realistic, fractured rocks-masses where hydraulic fracturing is a competing dipole mechanism between fracturing of the intact rock and re-activation of exiting fracture networks. Another essential aspect of this process is that it is intrinsically three-dimensional which is neglected by most models. To tackle this vital problem taking into account these pivotal aspects, a fully coupled hydro-mechanical model based on the discrete element method has been developed. The rock mass is here represented by a set of discrete elements interacting through elastic-brittle bonds that can break to form cracks inside the simulated medium. Theses cracks can coalesce to form fractures. A finite volume scheme is used to simulate the fluid flow in between these discrete elements. The flow is computed as a function of the pore space deformation in the intact medium and of the cracks' aperture in the fractures. Furthermore, the natural fractures are modelled explicitly and present mechanical and hydraulic properties different from the rock matrix. Employing this model in an intact numerical specimen, single fluid injection and multiple closely spaced sequential injections, enabled the description the full spatio-temporal evolution of HF propagation and its impact on quantitative indexes used in description of hydraulic fracturing treatments, such as fractured volume, fracture intensity and down-the-hole pressure for different control parameters and in-situ stress-fields. Moreover, injections from perforation slots which are not well aligned to the minimum stress plane showed possible creation of percolating non-planar hydraulic fractures of low connectivity, which can be troublesome for proppant placement. Also, strong interactions between closely spaced HF were highlighted by tracking the local principal stress rotation around the injection zones, emphasizing the importance of stress shadow effects. Optimization solutions are proposed for multiple treatments from a non-perfectly aligned wellbore. Finally, interaction between a single hydraulic fracture and a single natural fracture of varying properties and orientations was studied using the proposed model. The evolution of the hydraulic fracture and the global response of the specimen were recorded in a way comparable to existing experimental data to bridge the experimental and numerical findings. Persistent natural fractures appeared to be barriers for the hydraulic fracture if their conductance is high compared to the matrix conductivity or if their stiffness is significantly low compared to the rock matrix rigidity. Low stiffness in non-persistent defects might also cause a bifurcation of the main hydraulic fracture due to the local stress field perturbation around the defect and ahead of the hydraulic fracture tip. Furthermore, high approach angles and differential stresses seemed to favour crossing of the natural fracture while low angles enable shear slippage or dilation on the part of the plane which is not affected by the local stress perturbation.

Hydraulic Fracture Modeling in Naturally Fractured Reservoirs

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ISBN 13 :
Total Pages : 239 pages
Book Rating : 4.:/5 (114 download)

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Book Synopsis Hydraulic Fracture Modeling in Naturally Fractured Reservoirs by : Kaustubh Shrivastava

Download or read book Hydraulic Fracture Modeling in Naturally Fractured Reservoirs written by Kaustubh Shrivastava and published by . This book was released on 2019 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydraulic fracturing of horizontal wells is one of the key technological breakthroughs that has led to the shale revolution. Hydraulic fracturing models are used to engineer hydraulic fracture design and optimize production. Typically, hydraulic fracturing models treat hydraulic fractures as planar, bi-wing fractures. However, recent core-through investigations have suggested that during hydraulic fracturing in naturally fractured reservoirs, complex hydraulic fracture geometries can be created due to the interaction of the growing hydraulic fracture with natural fractures. This limits the application of planar fracture models for optimizing hydraulic fracturing design in naturally fractured reservoirs. In this research, we present a novel three-dimensional displacement discontinuity method based hydraulic fracturing simulator that allows us to model hydraulic fracture growth in the presence of natural fractures along with proppant transport in an efficient manner. The model developed in this dissertation is used to investigate the interaction of a hydraulic fracture with natural fractures and study the transport of proppant in the resulting complex fracture networks. This investigation gives us novel insight into the influence of fracture geometry and stress interference on the final distribution of proppant in fracture networks. Based on this investigation, suggestions are made to improve proppant transport in complex fracture networks. In order to correctly capture the effect of natural fractures on fracture growth, knowledge about the distribution of natural fractures in the reservoir is imperative. Typically, little is known about the in-situ natural fracture distribution, as direct observation of the reservoir is not possible. A novel technique of synthetic coring is developed to create a discrete fracture network (DFN) from core data, and it is used to create a DFN based on the Hydraulic Fracturing Test Site #1 data. Hydraulic fracture propagation is modeled in the created DFN, and the results are compared with field observations. As the reservoir may contain thousands of natural fractures, simulations in a realistic DFN can be computationally very expensive. In order to reduce the computational requirements of the simulator, we present a novel predictor step based on the local linearization method that provides a better initial guess for solving the fluid-solid interaction problem. This is shown to reduce computational time significantly. A novel technique, Extended Adaptive Integral Method, to speed up the simulator is developed. The method uses an effective medium to represent the interaction between displacement discontinuity elements and reduces the order of complexity of solving the geomechanical system of equations from O(N2) to O(NlogN). The novel formulation of this method is presented, and sensitivity studies are conducted to show the improvement in computational efficiency

The Combined Finite-Discrete Element Method

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Publisher : John Wiley & Sons
ISBN 13 : 0470020172
Total Pages : 348 pages
Book Rating : 4.4/5 (7 download)

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Book Synopsis The Combined Finite-Discrete Element Method by : Antonio A. Munjiza

Download or read book The Combined Finite-Discrete Element Method written by Antonio A. Munjiza and published by John Wiley & Sons. This book was released on 2004-04-21 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combined finite discrete element method is a relatively new computational tool aimed at problems involving static and / or dynamic behaviour of systems involving a large number of solid deformable bodies. Such problems include fragmentation using explosives (e.g rock blasting), impacts, demolition (collapsing buildings), blast loads, digging and loading processes, and powder technology. The combined finite-discrete element method - a natural extension of both discrete and finite element methods - allows researchers to model problems involving the deformability of either one solid body, a large number of bodies, or a solid body which fragments (e.g. in rock blasting applications a more or less intact rock mass is transformed into a pile of solid rock fragments of different sizes, which interact with each other). The topic is gaining in importance, and is at the forefront of some of the current efforts in computational modeling of the failure of solids. * Accompanying source codes plus input and output files available on the Internet * Important applications such as mining engineering, rock blasting and petroleum engineering * Includes practical examples of applications areas Essential reading for postgraduates, researchers and software engineers working in mechanical engineering.

A Generalized Finite Element Method for the Simulation of Non-planar Three-dimensional Hydraulic Fracture Propagation

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (988 download)

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Book Synopsis A Generalized Finite Element Method for the Simulation of Non-planar Three-dimensional Hydraulic Fracture Propagation by : Piyush Gupta

Download or read book A Generalized Finite Element Method for the Simulation of Non-planar Three-dimensional Hydraulic Fracture Propagation written by Piyush Gupta and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Modelling Rock Fracturing Processes

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Publisher : Springer Nature
ISBN 13 : 303035525X
Total Pages : 579 pages
Book Rating : 4.0/5 (33 download)

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Book Synopsis Modelling Rock Fracturing Processes by : Baotang Shen

Download or read book Modelling Rock Fracturing Processes written by Baotang Shen and published by Springer Nature. This book was released on 2020-05-06 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the second edition of the well-known textbook Modelling Rock Fracturing Processes. The new and extended edition provides the theoretical background of rock fracture mechanics used for modelling of 2-D and 3-D geomechanics problems and processes. Fundamentals of rock fracture mechanics integrated with experimental studies of rock fracturing processes are highlighted. The computer programs FRACOD 2D and 3D are used to analyse fracture initiation and propagation for the three fracture modes: Mode I, II and III. Coupled fracture modelling with other continuous and distinct element codes including FLAC, PFC, RFPA, TOUGH are also described. A series of applications of fracture modelling with importance for modern society is presented and discussed by distinguished rock fracture modelling experts.

Numerical Modeling of Nonlinear Problems in Hydraulic Fracturing

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (126 download)

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Book Synopsis Numerical Modeling of Nonlinear Problems in Hydraulic Fracturing by : Endrina Rivas

Download or read book Numerical Modeling of Nonlinear Problems in Hydraulic Fracturing written by Endrina Rivas and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydraulic fracturing is a stimulation technique in which fluid is injected at high pressure into low-permeability reservoirs to create a fracture network for enhanced production of oil and gas. It is the primary purpose of hydraulic fracturing to enhance well production. The three main mechanisms during hydraulic fracturing for oil and gas production which largely impact the reservoir production are: (1) fracture propagation during initial pad fluid injection, which defines the extent of the fracture; (2) fracture propagation during injection of proppant slurry (fluid mixed with granular material), creating a propped reservoir zone; and (3) shear dilation of natural fractures surrounding the hydraulically fractured zone, creating a broader stimulated zone. The thesis has three objectives that support the simulation of mechanisms that lead to enhanced production of a hydraulically-fractured reservoir. The first objective is to develop a numerical model for the simulation of the mechanical deformation and shear dilation of naturally fractured rock masses. In this work, a two-dimensional model for the simulation of discrete fracture networks (DFN) is developed using the extended finite element method (XFEM), in which the mesh does not conform to the natural fracture network. The model incorporates contact, cohesion, and friction between blocks of rock. Shear dilation is an important mechanism impacting the overall nonlinear response of naturally fractured rock masses and is also included in the model--physics previously not simulated within an XFEM context. Here, shear dilation is modeled through a linear dilation model, capped by a dilation limiting displacement. Highly nonlinear problems involving multiple joint sets are investigated within a quasi-static context. An explicit scheme is used in conjunction with the dynamic relaxation technique to obtain equilibrium solutions in the face of the nonlinear constitutive models from contact, cohesion, friction, and dilation. The numerical implementation is verified and its convergence illustrated using a shear test and a biaxial test. The model is then applied to the practical problem of the stability of a slope of fractured rock. The second objective is to develop a numerical model for the simulation of proppant transport through planar fractures. This work presents the numerical methodology for simulation of proppant transport through a hydraulic fracture using the finite volume method. Proppant models commonly used in the hydraulic fracturing literature solve the linearized advection equation; this work presents solution methods for the nonlinear form of the proppant flux equation. The complexities of solving the nonlinear and heterogeneous hyperbolic advection equation that governs proppant transport are tackled, particularly handling shock waves that are generated due to the nonlinear flux function and the spatially-varying width and pressure gradient along the fracture. A critical time step is derived for the proppant transport problem solved using an explicit solution strategy. Additionally, a predictor-corrector algorithm is developed to constrain the proppant from exceeding the physically admissible range. The model can capture the mechanisms of proppant bridging occurring in sections of narrow fracture width, tip screen-out occurring when fractures become saturated with proppant, and flushing of proppant into new fracture segments. The results are verified by comparison with characteristic solutions and the model is used to simulate proppant transport through a KGD fracture. The final objective is to develop a numerical model for the simulation of proppant transport through propagating non-planar fractures. This work presents the first monolithic coupled numerical model for simulating proppant transport through a propagating hydraulic fracture. A fracture is propagated through a two-dimensional domain, driven by the flow of a proppant-laden slurry. Modeling of the slurry flow includes the effects of proppant bridging and the subsequent flow of fracturing fluid through the packed proppant pack. This allows for the simulation of a tip screen-out, a phenomenon in which there is a high degree of physical interaction between the rock deformation, fluid flow, and proppant transport. Tip screen-out also leads to shock wave formation in the solution. Numerical implementation of the model is verified and the model is then used to simulate a tip screen-out in both planar and non-planar fractures. An analysis of the fracture aperture, fluid pressure, and proppant concentration profiles throughout the simulation is performed for three different coupling schemes: monolithic, sequential, and loose coupling. It is demonstrated that even with time step refinement, the loosely-coupled scheme fails to converge to the same results as the monolithic and sequential schemes. The monolithic and sequential algorithms yield the same solution up to the onset of a tip screen-out, after which the sequential scheme fails to converge. The monolithic scheme is shown to be more efficient than the sequential algorithm (requiring fewer iterations) and has comparable computational cost to the loose coupling algorithm. Thus, the monolithic scheme is shown to be optimal in terms of computational efficiency, robustness, and accuracy. In addition to this finding, a robust and more efficient algorithm for injection-rate controlled hydraulic fracturing simulation based on global mass conservation is presented in the thesis.

Three-dimensional Modeling of Hydraulic and Natural Fracture Interactions and Its Applications in Reservoir Stimulation

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ISBN 13 :
Total Pages : 231 pages
Book Rating : 4.:/5 (115 download)

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Book Synopsis Three-dimensional Modeling of Hydraulic and Natural Fracture Interactions and Its Applications in Reservoir Stimulation by : Amirhossein Kamali

Download or read book Three-dimensional Modeling of Hydraulic and Natural Fracture Interactions and Its Applications in Reservoir Stimulation written by Amirhossein Kamali and published by . This book was released on 2020 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Modeling of Complex Hydraulic Fractures in Naturally Fractured Formations

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (139 download)

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Book Synopsis Modeling of Complex Hydraulic Fractures in Naturally Fractured Formations by : Meng Cao (Ph. D.)

Download or read book Modeling of Complex Hydraulic Fractures in Naturally Fractured Formations written by Meng Cao (Ph. D.) and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation of complex fracture networks with nonplanar and multistranded shapes, due to the interaction between hydraulic and natural fractures, has been indicated by cores, mine-back experiments, and multiple numerous fracture diagnostic techniques. Having a better understanding of the mechanisms and implications of creating complex fracture networks would be a big step in improving hydrocarbon recovery and geothermal energy in naturally fractured formations. This dissertation presents the development of an integrated fracturing- production/geothermal simulator that can simulate multiple fracture propagation in naturally fractured reservoirs. It provides a new model for the interaction between hydraulic and natural fractures, dynamically distributes fluid and partitions proppant among multiple perforation clusters, simulates fluid flow and heat transfer in the coupled fracture-matrix system in an efficient manner, and speeds up the numerical computation for large-scale problems. This integrated fracturing-production/geothermal simulator enables a very computationally efficient solution by combining the displacement discontinuity method (DDM) for fracture propagation with a general Green’s function solution for fluid flow and heat transfer from the matrix to the fracture since there is no need to discretize the matrix domain. The fracturing model solves stresses and fluid pressure in a fully coupled manner by using DDM for rock deformation and a finite volume method for fluid flow inside fractures. In addition, the fluid distribution and proppant partitioning among multiple perforation clusters are solved dynamically. The production/geothermal simulator computes pressure and temperature using a fully implicit method for the fracture network domain, and solves the reservoir domain by using a semi-analytical solution. A fast, adaptive integral method (AIM) is used to reduce the computational time significantly when solving for the displacement field in a large complex fracture network. The key to the fast Fourier transform (FFT)-based adaptive integral method is the fast matrix-vector multiplication algorithm. The large dense matrix is decomposed into far- field and near-field components. The far-field component is computed by using the uniformly spaced Cartesian grid, and this component provides the foundation to perform discrete fast Fourier transform. The sparse near-field component is calculated by using the grid for fracture elements. Based on the split of the dense matrix into far-field and near- field components, FFT is applied to accelerate the multiplication of matrix and vector since no dense matrices are used. Finally, the new model is applied to two separate field studies, the Hydraulic Fracturing Test Site #2 (HFTS #2) and the Utah Frontier Observatory for Research in Geothermal Energy (FORGE)

Numerical Modeling of Complex Hydraulic Fracture Development in Unconventional Reservoirs

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (91 download)

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Book Synopsis Numerical Modeling of Complex Hydraulic Fracture Development in Unconventional Reservoirs by : Kan Wu

Download or read book Numerical Modeling of Complex Hydraulic Fracture Development in Unconventional Reservoirs written by Kan Wu and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Successful creations of multiple hydraulic fractures in horizontal wells are critical for economic development of unconventional reservoirs. The recent advances in diagnostic techniques suggest that multi-fracturing stimulation in unconventional reservoirs has often caused complex fracture geometry. The most important factors that might be responsible for the fracture complexity are fracture interaction and the intersection of the hydraulic and natural fracture. The complexity of fracture geometry results in significant uncertainty in fracturing treatment designs and production optimization. Modeling complex fracture propagation can provide a vital link between fracture geometry and stimulation treatments and play a significant role in economically developing unconventional reservoirs. In this research, a novel fracture propagation model was developed to simulate complex hydraulic fracture propagation in unconventional reservoirs. The model coupled rock deformation with fluid flow in the fractures and the horizontal wellbore. A Simplified Three Dimensional Displacement Discontinuity Method (S3D DDM) was proposed to describe rock deformation, calculating fracture opening and shearing as well as fracture interaction. This simplified 3D method is much more accurate than faster pseudo-3D methods for describing multiple fracture propagation but requires significantly less computational effort than fully three-dimensional methods. The mechanical interaction can enhance opening or induce closing of certain crack elements or non-planar propagation. Fluid flow in the fracture and the associated pressure drop were based on the lubrication theory. Fluid flow in the horizontal wellbore was treated as an electrical circuit network to compute the partition of flow rate between multiple fractures and maintain pressure compatibility between the horizontal wellbore and multiple fractures. Iteratively and fully coupled procedures were employed to couple rock deformation and fluid flow by the Newton-Raphson method and the Picard iteration method. The numerical model was applied to understand physical mechanisms of complex fracture geometry and offer insights for operators to design fracturing treatments and optimize the production. Modeling results suggested that non-planar fracture geometry could be generated by an initial fracture with an angle deviating from the direction of the maximum horizontal stress, or by multiple fracture propagation in closed spacing. Stress shadow effects are induced by opening fractures and affect multiple fracture propagation. For closely spaced multiple fractures growing simultaneously, width of the interior fractures are usually significantly restricted, and length of the exterior fractures are much longer than that of the interior fractures. The exterior fractures receive most of fluid and dominate propagation, resulting in immature development of the interior fractures. Natural fractures could further complicate fracture geometry. When a hydraulic fracture encounters a natural fracture and propagates along the pre-existing path of the natural fracture, fracture width on the natural fracture segment will be restricted and injection pressure will increase, as a result of stress shadow effects from hydraulic fracture segments and additional closing stresses from in-situ stress field. When multiple fractures propagate in naturally fracture reservoirs, complex fracture networks could be induced, which are affected by perforation cluster spacing, differential stress and natural fracture patterns. Combination of our numerical model and diagnostic methods (e.g. Microseismicity, DTS and DAS) is an effective approach to accurately characterize the complex fracture geometry. Furthermore, the physics-based complex fracture geometry provided by our model can be imported into reservoir simulation models for production analysis.

Advances in the study of natural fractures in deep and unconventional reservoirs

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Author :
Publisher : Frontiers Media SA
ISBN 13 : 2832514138
Total Pages : 393 pages
Book Rating : 4.8/5 (325 download)

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Book Synopsis Advances in the study of natural fractures in deep and unconventional reservoirs by : Lei Gong

Download or read book Advances in the study of natural fractures in deep and unconventional reservoirs written by Lei Gong and published by Frontiers Media SA. This book was released on 2023-05-08 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Development of a Three-dimensional, Semi-analytical Propagation Model for Non-symmetric Hydraulic Fractures

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Publisher :
ISBN 13 :
Total Pages : 278 pages
Book Rating : 4.:/5 (347 download)

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Book Synopsis Development of a Three-dimensional, Semi-analytical Propagation Model for Non-symmetric Hydraulic Fractures by : Jose Ignacio Rueda

Download or read book Development of a Three-dimensional, Semi-analytical Propagation Model for Non-symmetric Hydraulic Fractures written by Jose Ignacio Rueda and published by . This book was released on 1994 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: