页岩气藏暂堵转向压裂裂缝扩展规律模拟
Fracture propagation laws simulation of temporary plugging and diverting fracturing in shale gas reservoir
乔玲茜 1王本强 1陈雨松 1何启越 1蔡金赤 1续化蕾 2江厚顺2
作者信息
- 1. 中国石油川庆钻探工程有限公司页岩气勘探开发项目经理部,四川成都 610056
- 2. 长江大学石油工程学院,湖北武汉 430100;长江大学油气钻采工程湖北省重点实验室,湖北武汉 430100
- 折叠
摘要
暂堵转向压裂技术是提高非常规油气产能的重要方法之一,在非常规油气藏储层改造中已经得到了广泛应用.为进一步认识威远地区页岩气藏暂堵转向压裂裂缝扩展特征,文中通过真三轴大物模实验研究了暂堵转向压裂压力响应与岩样破裂形态,验证了暂堵产生复杂缝网结构的可行性,明确了在不同应力差条件下的暂堵后裂缝起裂规律;同时采用ABAQUS软件黏结单元模拟裂缝的起裂与扩展,研究了不同水平应力差、不同偏转角下暂堵转向压裂裂缝扩展规律.研究结果表明:水平应力差对初次裂缝与暂堵转向裂缝的开启与扩展均具有显著的影响,水平应力差越小时,一次和二次压裂时岩样的破裂压力就越大,岩样越不容易被压碎.裂缝扩展阻力的不断增加,提升了缝内净压力与裂缝宽度;相交缝二次扩展后开启的新裂缝与一次压裂夹角越小,新裂缝扩展效果越好.该研究对威远地区现场压裂和缝网形态预测具有一定的理论指导和借鉴意义.
Abstract
Temporary plugging and diverting fracturing technology is one of the important methods to improve unconventional oil and gas productivity,and has been widely used in the stimulation of unconventional oil and gas reservoirs.In order to further understand the propagation characteristics of temporary plugging and diverting fracturing fractures in shale gas reservoirs in Weiyuan area,the pressure response of temporary plugging and diverting fracturing and the fracture morphology of rock samples were studied by true triaxial large physical model experiment,and the feasibility of complex fracture network by temporary plugging was vertified.The fracture initiation law after temporary plugging and diverting fracturing is clarified under different stress difference conditions.At the same time,the cohesive unit of ABAQUS software is used to simulate the initiation and propagation of fractures,and the propagation laws of temporary plugging and diverting fracturing under different horizontal stress differences and different deflection angles are studied.The research results show that the horizontal stress difference has a significant effect on the opening and propagation of the primary fracture and the temporary plugging and diverting fracture.The smaller the horizontal stress difference,the greater the fracture pressure of the rock sample during the primary and secondary fracturing,and the less easily the rock is crushed.With the increasing resistance of fracture propagation,the in-fracture net pressure and fracture width are increased.The smaller the angle between the new fracture opened after the secondary propagation of the intersecting fracture and the primary fracturing,the better the new fracture propagation effect This study has certain reference significance for on-site fracturing and fracture network shape prediction in Weiyuan area
关键词
页岩气藏/暂堵转向/真三轴大物模/数值模拟/水平应力差Key words
shale gas reservoir/temporary plugging and diverting/true triaxial large physical model/numerical simulation/horizontal stress difference引用本文复制引用
基金项目
国家自然科学基金面上项目(52274028)
出版年
2024
NETL
NSTL
万方数据