Abstract: With the application of the thought of integrated geology study and engineering in the exploration and development of shale gas, the importance of the 3D geostress study is more prominent. It is of great significance to establish a reliable and adaptable geostress model for rock mechanics evaluation for shale gas formation. Considering the constraints of the finite element simulated mechanical boundary conditions, a new method of 3D geostress modeling for shale gas is proposed in this paper, which is based on the single well geostress model, and the theories and methods related to density integration, under compaction, effective stress ratio and geostatistics. A 3D model describing the various elements of the earth stress is obtained by the  method. Through the research work on Well Pad Ning 209 in deep shale gas at Changning block area, it is proved that the modeling method has is highly reliable and practicable in the study of the 3D geostress law of shale gas.

摘要： 地质工程一体化研究思路是页岩气勘探开发的有效手段，而地应力是地质工程一体化研究思路中的重要考虑因素，如何建立可靠且适应页岩气地层岩石力学评价的地应力模型有重要意义。文章考虑传统三维地应力建模方法受到有限元模拟力学边界条件的制约，提出了一种新的页岩气三维地应力建模方法—以单井地应力模型为基础，综合考虑密度积分、欠压实作用、有效应力比及地质统计学等相关理论和方法，获取描述地应力各个要素的三维模型，通过在长宁区块宁 ２０９井区深层的研究工作，证实了建模方法在页岩气三维地应力规律研究中具有很好的可靠性和实用性。

关键词: 页岩气, 地质工程一体化, 长宁, 三维, 地应力建模