层状各向异性孔隙介质裂缝扩展模拟研究

The fracture network of oil-and gas-bearing pore reservoir not only has the possibility of opening and expanding, but also the possibility of closure. The size and scope of the fracture network can influence oil-gas developing effect. Furthermore, for sandstone-mudstone interbedding and developed beddings reservoir, it is very necessary to study the layered properties of these kinds of reservoirs. Therefore, it’s very important for the efficient development of oil and gas resources in China to study the behaviors of the opening, expanding and closure of the fractures in the multilayered porous media and to analyze the coupling effects between the seepage-stress-displacement of porous media and the propagation of fractures.. Multilayered anisotropic porous media is taken as the object of this project. Based on the theoretical, numerical and experimental methods, the Green function solution for the point flow source or the point dislocation of the multilayered porous media will be deduced; A displacement discontinuity method for multilayered anisotropic porous media will be established, in which the opening, expansion and closure of fractures all can be simulated, and the experimental results will be used to verify the accuracy of the numerical method; The interaction between the propagation of fractures and the seepage-stress-deformation fields in porous media will be carefully investigated with the combined effect of the fluid flow in fractures and fluid in pores in consideration. The project will provide a powerful means to study the interaction between the seepage-deformation of the reservoir and the fractures.

含油气的孔隙储层内压裂缝网既有开启、扩展的可能性，也有闭合的可能性，而缝网的大小和范围直接影响了油气开发的效果。此外，对于有砂泥互层或者层理发育的储层，研究其层状特性也是十分必要的。因而，研究层状孔隙介质内压裂裂缝的起裂、扩展、闭合，分析介质渗流-应力变形、缝内流体流动以及裂缝的扩展行为的相互作用，对我国的油气资源的高效开发具有重要的意义。. 本项目以层状各向异性孔隙介质作为研究对象，以理论分析、数值模型和试验验证相结合的手段，推导半无限空间内孔隙介质点流源和点位错的Green函数；建立模拟层状孔隙介质裂缝的起裂、扩展、闭合过程的位移不连续数值方法，验证其合理性；分析缝内流体、孔隙内流体共同作用下，裂缝扩展与孔隙介质内渗流-变形的相互作用。该项目的顺利进行，为研究油气藏储层的渗流、变形与裂缝的相互作用提供了有力的手段。

本项目以层状各向异性介质作为研究对象，以理论分析、数值模型和试验验证相结合的手段，推导有限空间内孔隙介质点流源的Green函数；分析缝内流体、孔隙内流体的共同作用；研究了层状各向异性材料的多物理场耦合行为，并给出相应的解析解；建立模拟层状孔隙介质裂缝的扩展过程的数值方法。目前已正式发表论文16篇，其中SCI检索14篇，EI不重复检索1篇，申请专利1项，授权软件著作权2项，培养研究生1名。项目主持人获2019年教育部科技成果一等奖，2019年辽宁省自然科学三等奖。完成了计划书中的预定研究目标。. 本项目建立了完整、实用的层状各向异性结构的力学模型，发展了精度和效率更高、适用范围更广的新方法。通过理论分析、数值模拟和实验检测相结合，建立层状结构的界面力学模型，深化对含界面的各向异性材料的力学行为的研究。通过对有限空间内点源的Green函数和裂纹扩展行为的研究，为研究油气藏储层的渗流、变形与裂缝的相互作用提供了有力的手段。