为提高四川盆地页岩气产能，以威远页岩气田202和204两个区块为目标区

为提高四川盆地页岩气产能，以威远页岩气田202和204两个区块为目标区块，采取地质工程一体化研究思路，提出地应力场三维精细有限元数值模拟计算流程并给出两个区块的地应力场数值计算结果。首先运用地震波提供的层位信息建立地质模型以及有限元模型，其次结合单井地质力学分析结果建立目标区块的三维地应力场，从而对目标区块三维地应力场进行精细化有限元建模，最终获得区块地应力的三维空间分布数值解。研究得到的主要结论有：1）获得威202区块的三维精细地应力场数值解。发现应力格式呈较明显的‘走滑断层应力格式’；最大水平主应力从西北/左上部位的130°，逐渐过渡到东南/右下部位的接近90°。2）获得威204区块的三维精细地应力场数值解。地应力场的三个主应力中，最大水平主应力和竖向应力接近，差别仅有0.9MPa，储层局部应力呈正断层应力模式和走滑断层应力模式并存。所得结果可为下一步进行水平井轨迹设计及水力压裂工程提效提供比解析计算和单井地质力学分析更准确的参考依据。

In order to improve the shale gas production capacity in Sichuan Basin, taking blocks 202 and 204 of Weiyuan shale gas field as the target blocks and adopting the idea of geological engineering integration, the three-dimensional fine finite element numerical simulation calculation process of in-situ stress field is proposed, and the numerical calculation results of in-situ stress field in the two blocks are given. Firstly, the geological model and finite element model are established by using the horizon information provided by seismic waves. Secondly, combined with the results of single well geomechanical analysis, the three-dimensional in-situ stress field of the target block is established, so as to carry out fine finite element modeling of the three-dimensional in-situ stress field of the target block, and finally obtain the numerical solution of three-dimensional spatial distribution of in-situ stress in the block. The main conclusions are as follows: 1) the numerical solution of three-dimensional fine in-situ stress field in Wei 202 block is obtained. It is found that the stress pattern shows an obvious' strike slip fault stress pattern '; The maximum horizontal principal stress gradually transits from 130 ° in the Northwest / upper left part to nearly 90 ° in the Southeast / lower right part. 2) The numerical solution of three-dimensional fine in-situ stress field in Wei 204 block is obtained. Among the three principal stresses in the in-situ stress field, the maximum horizontal principal stress is close to the vertical stress, and the difference is only 0.9mpa. The local stress of the reservoir is positive, and the fault stress mode and strike slip fault stress mode coexist. The results obtained can provide more accurate reference basis than analytical calculation and single well geomechanical analysis for horizontal well trajectory design and hydraulic fracturing engineering efficiency improvement in the next step.

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