In-situ stress distribution and its implication on coalbed methane development in Liulin area, eastern Ordos basin, China

2014 ◽  
Vol 122 ◽  
pp. 488-496 ◽  
Author(s):  
Yong Li ◽  
Dazhen Tang ◽  
Hao Xu ◽  
Tingxu Yu
Keyword(s):  
Stress Distribution ◽  
Coalbed Methane ◽  
Ordos Basin ◽  
In Situ Stress

scholarly journals In Situ Stress Distribution and Its Control on the Coalbed Methane Reservoir Permeability in Liulin Area, Eastern Ordos Basin, China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Peng Feng ◽  
Song Li ◽  
Dazhen Tang ◽  
Liangjun Wu ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Ordos Basin ◽  
In Situ Stress ◽  
Burial Depth ◽  
Lateral Stress ◽  
High Permeability ◽  
Depth Zone ◽  
Stress Coefficient ◽  
Lateral Stress Coefficient

Permeability is one of the important factors that affect the production efficiency of coalbed methane, and it is mainly controlled by in situ stress. Therefore, it is very essential to study the in situ stress and permeability for the extraction of coalbed methane. Based on the injection/falloff well test and in situ stress measurement of 35 coalbed methane wells in the Liulin area in the east of the Ordos basin, the correlations between initial reservoir pressure, in situ stress, lateral stress coefficient, permeability, and burial depth were determined. Finally, the distribution characteristics of in situ stress and its influence on permeability were analyzed systematically. The results show that with the increase of burial depth, the initial reservoir pressure and in situ stress both increase, while the lateral stress coefficient decreases. The permeability variation is related to the type of stress field in different burial depths, and its essence is the deformation and destruction of coal pore structures caused by stress. The distribution characteristics of in situ stress at different depths and its effect on permeability are as follows: at depths < 800   m , the horizontal principal stress is dominant ( σ H ≥ σ v > σ h ) and the permeability is a simple decreasing process with the increase of the depth; at depths > 800   m , the vertical stress is dominant ( σ v ≥ σ H > σ h ). The permeability of most coal is very small due to the large in situ stresses in this depth zone. However, because of the stress release at the syncline axis, coal with high permeability is still possible at this depth zone. Due to the existence of high permeability data points at burial depth (>800 m) and the fitting relationship between permeability and vertical stress, the maximum and minimum horizontal principal stress is poor. However, the coal permeability and lateral stress coefficient show a good negative exponential relationship. This indicates that the lateral stress coefficient can be used to predict permeability better.

scholarly journals A Workflow to Predict the Present-day in-situ Stress Field in Tectonically Stable Regions

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Wei Ju ◽  
Ke Xu ◽  
Jian Shen ◽  
Chao Li ◽  
Guozhang Li ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Stress Field ◽  
Ordos Basin ◽  
Simulation Method ◽  
In Situ Stress ◽  
Wellbore Stability ◽  
Central China ◽  
Geometric Framework ◽  
In Situ Stress Field

Knowledge of the present-day in-situ stress distribution is greatly important for better understanding of conventional and unconventional hydrocarbon reservoirs in many aspects, e.g., reservoir management, wellbore stability assessment, etc. In tectonically stable regions, the present-day in-situ stress field in terms of stress distribution is largely controlled by lithological changes, which can be predicted through a numerical simulation method incorporating specific mechanical properties of the subsurface reservoir. In this study, a workflow was presented to predict the present-day in-situ stress field based on the finite element method (FEM). Sequentially, it consists of: i) building a three-dimensional (3D) geometric framework, ii) creating a 3D petrophysical parameter field, iii) integrating the geometric framework with petrophysical parameters, iv) setting up a 3D heterogeneous geomechanical model, and finally, v) calculating the present-day in-situ stress distribution and calibrating the prediction with measured stress data, e.g., results from the extended leak-off tests (XLOTs). The approach was successfully applied to the Block W in Ordos Basin of central China. The results indicated that the workflow and models presented in this study could be used as an effective tool to provide insights into stress perturbations in subsurface reservoirs and geological references for subsequent analysis.

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