岩石脆性对水力压裂裂缝影响的数值模拟实验  

Numerical simulation experiment of the effect of rock brittleness on fracture propagation of hydraulic fracturing

作　　者：延新杰[1] 李连崇[1] 张潦源[2] 李明[2] 黄波[2] 左家强[2] Yan Xinjie;Li Lianchong;Zhang Liaoyuan;Li Ming;Huang Bo;Zuo Jiaqiang(School of Civil Engineering,Dalian University of Technology,Dalian City,Liaoning Province,116024,China;Research Institute of Petroleum Engineering,Shengli Oilfield Company,SINOPEC,Dongying City,Shandong Province,257000,China)

机构地区：[1]大连理工大学土木工程学院,辽宁大连116024 [2]中国石化胜利油田分公司石油工程技术研究院,山东东营257000

出　　处：《油气地质与采收率》2017年第3期116-121,共6页Petroleum Geology and Recovery Efficiency

基　　金：国家自然科学基金项目"软硬间互地层水力压裂裂缝三维延伸机理研究"(51479024);安徽省科技攻关计划项目"煤矿动力灾害事故智能预警防控技术与示范"(1604a0802109)

摘　　要：水力压裂裂缝起裂与拓展轨迹对致密油气储层水力压裂改造效果的影响至关重要。基于胜利油区某区块埋深为3200m的致密砂岩储层岩石试样的单轴压缩物理实验结果,应用数值模拟软件RFPA^(2D),对单轴压缩数值模拟实验中的岩石力学参数进行标定,建立数值模拟模型,研究岩石脆性指数及残余应力水平对水力压裂裂缝拓展轨迹的影响。研究结果表明:岩石脆性指数越大,越有利于水力压裂裂缝的拓展,并且产生的裂缝越宽,起裂压力越小,形成有效复杂裂缝网络的面积越大,水力压裂改造的效果越好;岩石残余应力水平越低,水力压裂产生裂缝的发育程度越高,并且压裂裂缝的宽度越宽,起裂压力越低,水力压裂改造的效果越明显。The fracture initiation and propagation of hydraulic fracturing are important to post-fracturing performance of tight oil and gas reservoirs. Based on uniaxial compression experiment results of rock specimens taken from tight sandstone reservoir at 3 200 meters depth in certain block of Shengli oilfield,rock mechanics parameters used in the numerical simulation of uniaxial compression experiment were calibrated,and the effect of brittleness index and residual stress on hydraulic fracture propagation was investigated by using numerical simulation software RFPA2D. The results show that higher brittleness index is more favorable for hydraulic fracturing propagation,and hydraulic fracture with larger width and smaller initial stress can lead to larger area of effective complex fracture network and better hydraulic fracturing effects. When the residual stress is lower,the degree of development of hydraulic fracture is higher with wider fracture width and smaller initial stress and the effects of hydraulic fracturing are better.

关 键 词：水力压裂 岩石脆性 残余应力 裂缝拓展 数值模拟 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]