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。
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.
作者
乔玲茜
王本强
陈雨松
何启越
蔡金赤
续化蕾
江厚顺
QIAO Lingxi;WANG Benqiang;CHEN Yusong;HE Qiyue;CAI Jinchi;XU Hualei;JIANG Houshun(Project Manager Department of Shale Gas Exploration and Development,Chuanqing Drilling Engineering Co.,Ltd.,CNPC,Chengdu 610056,China;School of Petroleum Engineering,Yangtze University,Wuhan 430100,China;Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering,Yangtze University,Wuhan 430100,China)
出处
《断块油气田》
CAS
CSCD
北大核心
2024年第2期241-245,265,共6页
Fault-Block Oil & Gas Field
基金
国家自然科学基金面上项目“页岩气藏压窜形成机理及暂堵转向对策研究”(52274028)。
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
shale gas reservoir
temporary plugging and diverting
true triaxial large physical model
numerical simulation
horizontal stress difference
