Investigate effects of weak bedding interfaces on fracture geometry in unconventional reservoirs

2018 ◽  
Vol 165 ◽  
pp. 992-1009 ◽  
Author(s):  
Jizhou Tang ◽  
Kan Wu ◽  
Bo Zeng ◽  
Haoyong Huang ◽  
Xiaodong Hu ◽  
...  
Keyword(s):  
Unconventional Reservoirs ◽  
Fracture Geometry

An Efficient Hydraulic Fracture Geometry Calibration Workflow Using Microseismic Data, Geomechanics, DFN Models, and History Matching

2021 ◽  
Author(s):  
Joseph Alexander Leines-Artieda ◽  
Chuxi Liu ◽  
Hongzhi Yang ◽  
Jianfa Wu ◽  
Cheng Chang ◽  
...  
Keyword(s):  
Hydraulic Fracture ◽  
History Matching ◽  
Fracture Propagation ◽  
Natural Fracture ◽  
Unconventional Reservoirs ◽  
Production Data ◽  
Fracture Geometry ◽  
Microseismic Data ◽  
Fracture Models ◽  
Microseismic Events

Abstract Reliable estimates of hydraulic fracture geometry help reduce the uncertainty associated with estimated ultimate recovery (EUR) forecasts and optimize field developing planning in unconventional reservoirs. For these reasons, operators gather information from different sources with the objective to calibrate their hydraulic fracture models. Microseismic data is commonly acquired by operators to estimate hydraulic fracture geometry and to optimize well completion designs. However, relying solely on estimates derived from microseismic information may lead to inaccurate estimates of hydraulic fracture geometry. The objective of this study is to efficiently calibrate hydraulic fracture geometry by using microseismic data, physics-based fracture propagation models, and the embedded discrete fracture model (EDFM). We first obtain preliminary estimates of fracture geometry based on microseismic events’ spatial location and density with respect to the perforation cluster location. We then tune key completion parameters using an in-house fracture propagation model to provide hydraulic fracture geometries that are constrained by the microseismic cloud. In the history matching process, we included the effect of natural fractures, using the microseismic events location as natural fracture initiation points. Finally, we used cutoff coefficients to further reduce hydraulic fracture geometries to match production data. The results of this work showed a fast and flexible method to estimate fracture half-lengths and fracture heights, resulting in a direct indicator of the completion design. Additionally, hydraulic-natural fracture interactions were assessed. We concluded that the inclusion of cutoff coefficients as history matching parameters allows to derive realistic hydraulic and natural fracture models calibrated with microseismic and production data in unconventional reservoirs.

scholarly journals Hydraulic Fracture Geometry Modeling Techniques for Extracting Unconventional Reservoirs

2020 ◽  
pp. 1-5
Author(s):  
Mohamed Ali Khalil ◽  
Abdunaser Omar Susi
Keyword(s):  
Hydraulic Fracturing ◽  
Oil Recovery ◽  
Hydraulic Fracture ◽  
3D Models ◽  
Unconventional Reservoirs ◽  
Fracture Geometry ◽  
Geometry Modeling ◽  
Advantages And Disadvantages ◽  
Modeling Techniques ◽  
Enhance Oil Recovery

This study aims to provide a comprehensive review of all hydraulic fracture geometry modeling techniques available in the conventional and unconventional reservoirs. We are introducing a comparison study between major available hydraulic fracture modeling techniques, advantages, and disadvantages of each one according to the latest related studies. The study includes the three general families of models: 2D models, pseudo-3D models, and fully 3D models. Consequently, the results of this work can be used for selecting the proper model to simulate or stimulate the reservoir to enhance oil recovery using hydraulic fracturing. Also, these results can be used for any future updates related to hydraulic fracturing stimulation based on the comparisons that were conducted.

Development of Efficiently Coupled Fluid-Flow/Geomechanics Model To Predict Stress Evolution in Unconventional Reservoirs With Complex-Fracture Geometry

SPE Journal ◽  
2018 ◽  
Vol 23 (03) ◽  
pp. 640-660 ◽  
Author(s):  
Anusarn Sangnimnuan ◽  
Jiawei Li ◽  
Kan Wu
Keyword(s):  
Fluid Flow ◽  
Stress Distribution ◽  
Unconventional Reservoirs ◽  
Stress Evolution ◽  
Principal Stresses ◽  
Fracture Geometry ◽  
Discrete Fracture Model ◽  
Complex Fracture ◽  
Split Method ◽  
Stress Changes

Summary Stress changes associated with reservoir depletion are often observed in the field. Stress evolution within and surrounding drainage areas can greatly affect further reservoir developments, such as completion of infill wells and refracturing. Previous studies mainly focus on biwing planar-fracture geometry, which limits the possibility of investigating stress evolution caused by complex-fracture geometry. In this paper, we have developed a novel and efficient coupled fluid-flow/geomechanics model with an embedding-discrete-fracture model (EDFM) to characterize stress evolution associated with depletion in unconventional reservoirs with complex-fracture geometry. Coupled geomechanics/fluid flow was developed using the well-known fixed-stress-split method, which is unconditionally stable and computationally efficient to simulate how stress changes during reservoir depletion. EDFM was coupled to the model to gain capability of simulating complex-fracture geometries using structured grids. The model was validated against the classical Terzaghi (1925) and Mandel (1953) problems. Local grid refinement was used as a benchmark when comparing results from EDFM for fractures with 0 and 45° angles of inclination. After that, the model was used to analyze stress distribution and reorientation in reservoirs with three different fracture geometries: planar-fracture (90° angle of inclination), 60° inclination, and nonplanar-fracture geometries. As the pressure decreases, reservoir stresses tend to change anisotropically depending on depletion area. The principal stress parallel to the initial fracture reduces faster than the orthogonal one as a function of time. The decrease rate of principal stresses is distinct for different shapes of depleted areas created by different fracture geometries. The rectangular shape produced by the planar-fracture geometry yields the largest stress-reorientation area for a variety of differential-stress (DS) values (difference between two horizontal principal stresses). The squared shape produced by nonplanar-fracture geometry yields stress reorientation only for low DS. The results indicate that created fracture geometry has a significant effect on stress distribution and reorientation induced by depletion. To the best of our knowledge, this is the first time a coupled fluid-flow/geomechanics model incorporated with EDFM has been developed to efficiently calculate stress evolution in reservoirs with complex-fracture geometry. Characterization of stress evolution will provide critical guidelines for optimization of completion designs and further reservoir development.

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