致密储层缝内暂堵转向压裂裂缝扩展规律数值模拟  

Numerical simulation of fracture propagation law of in-fracture temporary plugging and diverting fracturing in tight reservoirs

作　　者：唐述凯 郭天魁[2] 王海洋 陈铭 TANG Shukai;GUO Tiankui;WANG Haiyang;CHEN Ming(Dongsheng Jinggong Petroleum Development Group Co.,Ltd.,Sinopec Shengli Oilfield Company,Dongying 257000,Shandong,China;School of Petroleum Engineering,China University of Petroleum,Qingdao 266580,Shandong,China)

机构地区：[1]中国石化胜利油田分公司东胜精攻石油开发集团股份有限公司,山东东营257000 [2]中国石油大学(华东)石油工程学院,山东青岛266580

出　　处：《岩性油气藏》2024年第4期169-177,共9页Lithologic Reservoirs

基　　金：山东省优秀青年科学基金项目“储层压裂改造理论与方法”(编号:ZR2020YQ36)资助。

摘　　要：基于损伤力学理论,建立了储层渗流-应力-损伤耦合裂缝扩展数值模型,将模型结果与室内真三轴水力压裂物理模拟实验结果进行了对比,验证了模型的准确性,并基于该模型探讨了压裂液黏度、排量、水平地应力差以及储层岩石非均质性对缝内暂堵转向压裂效果的影响。研究结果表明:(1)储层渗流-应力-损伤耦合裂缝扩展数值模型是联合流体流动控制方程与岩石变形方程形成整体控制方程,通过在初始裂缝扩展路径上某一区域人为设置高强度的岩石物理力学参数和较小的储层渗透率值,实现缝内暂堵的模拟。(2)缝内暂堵转向压裂裂缝扩展模型数值模拟的分支缝数量、主裂缝面积、主裂缝延伸方向等与室内真三轴水力压裂物理模拟实验的结果基本一致,该模型可实现缝内暂堵后基质的破裂与新裂缝扩展模拟,对缝内暂堵转向压裂裂缝扩展情况也具有较好的模拟效果。(3)压裂液的黏度和排量越大,缝内暂堵转向压裂裂缝长度、改造面积及偏转角度均明显增大,且逐渐由单一裂缝向复杂裂缝转变。当水平地应力差小于7.5 MPa时,缝内暂堵转向压裂的效果较好;当水平地应力差为10~15 MPa时,压裂效果变差;当水平地应力差大于15 MPa时,裂缝几乎不偏转;储层非均质性会影响裂缝局部的扩展路径,但对裂缝总体扩展趋势影响甚微。Based on the theory of damage mechanics,a numerical model of reservoir flow-stress-damage cou‐pling fracture propagation was established,and it was verified by comparing with inddor true triaxial hydraulic fracturing physical simulation experiment results.What’s more,the influences of fracturing fluid viscosity,dis‐placement,horizontal stress difference and reservoir rock heterogeneity on in-fracture temporary plugging and di‐verting fracturing were discussed.The results show that:(1)The numerical model of reservoir flow-stress-damage coupling fracture propagation is a combination of fluid flow control equation and rock deformation equa‐tion to form an overall control equation,and the temporary plugging in the fracture can be simulated by artifi‐cially setting high-strength rock physical and mechanical parameters and small reservoir permeability values in a certain area along the initial fracture propagation path.(2)The numbers of branch fractures,area of main frac‐tures,and extension direction of main fracture in numerical simulation of in-fracture temporary plugging and di‐verting fracturing fracture propagation model are basically consistent with the results of indoor true triaxial hy‐draulic fracturing physical simulation experiment results.This model can achieve the simulation of matrix frac‐ture and new fracture extension after temporary plugging in fractures,and also has a good simulation effect on the situation of in-fracture temporary plugging and diverting fracturing fracture propagation.(3)The larger the viscosity and displacement of fracturing fluid,the greater the length,reconstruction area and deflection angle of in-fracture temporary plugging and diverting fracturing fracture,and single fractures gradually transition to com‐plex fractures.When the horizontal stress difference is less than 7.5 MPa,the effect of in-fracture temporary plugging and diverting fracturing is better.When the horizontal stress difference is 10-15 MPa,the fracturing ef‐fect deteriorates.When the horiz

关 键 词：致密储层 缝内暂堵转向压裂 裂缝扩展数值模型 真三轴水力压裂物理模拟 裂缝偏转 损伤力学 水平地应力差 非均质性 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程] P618.13[天文地球—矿床学]