一组平行裂缝变形特征及动态渗透率模型

Deformation characteristics of a set of parallel fractures and dynamic permeability model

冯月丽 刘月田 丁祖鹏 陈健 毛小龙 周月波3

中国石油大学（北京）油气资源与探测国家重点实验室，北京102249 中海油研究总院，北京 100028 中国石化中原油田分公司石油工程研究院，河南 濮阳 457001

State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China CNOOC Research Institute, Beijing 100028, China Petroleum Engineering Institute, Zhongyuan Oilfield Company, SINOPEC, Puyang 457001, China

为了解裂缝性储层中复杂裂缝网络的变形特征及其对整个渗流介质渗透率的影响，假设岩石基质为各向同性线弹性体，建立了一组平行裂缝变形计算模型，并研究了流体压力及基质、裂缝的弹性参数、几何参数对裂缝变形、裂缝渗透率的影响，研究了整个渗流介质渗透率张量的变化规律，最后通过物理模拟实验验证了该模型的准确性。研究结果表明：裂缝变形量随孔隙流体压力增大而增大，随弹性模量增大而减小；裂缝渗透率随裂缝间距增大而减小；裂缝倾角在0°~90°变化时，裂缝渗透率呈先增大后减小的趋势；渗流介质的渗透率最大主值方向始终沿着裂缝发育方向。

In order to obtain the deformation characteristics of complex fracture networks in fractured reservoir and their effects on the permeability of seepage medium, assuming the rock matrix as an isotropic linear elastomer, a model for calculation of a set of parallel fractures deformation was established. The influences of fluid pressure, elastic and geometric parameters on fracture deformation and permeability, and the variation of permeability tensor throughout the seepage medium were studied. Finally, the accuracy of the model was verified by physical simulation experiments. The results show that the fracture deformation increases with the increase of fluid pressure and decreases with the increase of elastic modulus. Fracture permeability decreases with the increasing of fracture spacing. When fracture angle changes from 0° to 90°, the fracture permeability increases first and then decreases. The direction of the maximum principal value of permeability is always along the fracture direction.

10.6056/dkyqt201806010