相互垂直裂缝应力阴影的影响因素及规律
汪道兵1,2,3,周福建1,葛洪魁1,Sergio Zlotnik2,杨向同4,彭金龙5

1)中国石油大学(北京)非常规天然气研究院,北京100249; 2)西班牙加泰罗尼亚理工大学土木工程学院,巴塞罗那E- 08034,西班牙; 3)中国石油勘探开发研究院采油工程研究所,北京100083; 4)中国石油塔里木油田分公司,新疆维吾尔自治区库尔勒841000; 5)中国石油大庆油田有限责任公司第二采油厂,黑龙江大庆163414

应力干扰; 缝网压裂; 垂直裂缝; 有限元方法; 转向剂; 可降解纤维; 流体压力; 流固耦合; 线弹性力学

The main factors and rules of stress shadow of perpendicular cracks
Wang Daobing1,2,3, Zhou Fujian1, Ge Hongkui1, Sergio Zlotnik2, Yang Xiangtong4, and Peng Jinlong5

Wang Daobing1,2,3, Zhou Fujian1, Ge Hongkui1, Sergio Zlotnik2, Yang Xiangtong4, and Peng Jinlong51)Unconventional Natural Gas Research Institute, China University of Petroleum, Beijing 102249, P.R.China2)School of Civil Engineering, Technical University of Catalonia, Barcelona E- 08034, Spain3)Institute of Oil Production Engineering, Research Institute of Exploration & Development, PetroChina, Beijing 100083, P.R.China4)Tarim Oilfield Company, PetroChina, Kuerle 841000, Xinjiang Uygur Autonomous Region, P.R.China5)The Second Oil Extraction Plant of Daqing Oilfield Company Limited, PetroChina, Daqing 163414, Heilongjiang Province, P.R.China

stress interference; fracture network fracturing; perpendicular crack; finite element method; diverting agent; degradable fiber; fluid pressure; fluid-solid coupling; linear elastic mechanics

DOI: 10.3724/SP.J.1249.2017.04344

备注

基于弹性力学理论,采用Galerkin有限元数值离散化方法,编制Matlab有限元程序,数值模拟两条相互垂直裂缝干扰时的“应力阴影”分布状态,其主应力与主方向分布具有关于交点(坐标原点)的对称性特征.分析了流压比值、孔隙压力、缝面流压及水平应力差值等因素对两缝间主应力及主方向的影响,通过改进变排量施工、改变压裂液黏度、油气井开采降低孔隙压力和增大注入液量等工艺,发挥应力阴影效应的优点,增加复杂缝网形成的可能性.

Based on elasticity theory, we use numerical Galerkin finite element discretization method and implement Matlab finite element code to simulate “stress shadow” distributions of mutual orthogonal fractures. The principal stress and principal distributions have the symmetry characteristic on the intersection(coordinate origin). The relationships between stress shadow and flow pressure ratio, pore pressure, fluid pressure and horizontal stress contract are analyzed, respectively. By these techniques of variable displacement construction, changing the viscosity of the fracturing fluid, exploitation of oil and gas wells changing pump rate and fracturing fluid viscosity, reducing pore pressure and increasing the injection volume, taking the advantages of shadow effect, it is likely to produce a complex fracture network.

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