各向异性低渗透油藏菱形反九点井网压裂裂缝优化  

Optimization Study of Fracturing Length for Rhombus Inverse Nine-spot Diamond Reverse Well Pattern in Anisotropy Reservoirs

作　　者：王福顺 刘鹏程[1] 王文环[2] 郝明强[2] 庄永涛[3] WANG Fushun;LIU Pengcheng;WANG Wenhuan;HAO Mingqiang;ZHUANG Yongtao(School of Energy Resources,China University of Geosciences,Beijing100083,China;Research Institute of Petroleum Exploration and Development,CNPC,Beijing100083,China;Oil Production Technology Institute of Dagang Oilfield,Tianjin300280,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]中国石油勘探开发研究院,北京100083 [3]大港油田采油工艺研究院,天津300280

出　　处：《现代地质》2018年第3期547-553,共7页Geoscience

基　　金：国家科技重大专项"稠油;碳酸盐岩和致密油藏开发主体技术与应用潜力"(2016X05016-006);中国石油天然气股份有限公司项目"不同类型特低渗透油藏最佳开采方式研究"(RIPED-2016-JS-150)

摘　　要：在低渗透油藏开发中普遍采用菱形反九点井网,但采油井等缝长压裂将导致非均匀驱替,当油藏物性各向异性时,非均匀驱替现象更加明显。以往针对菱形反九点井网的研究主要基于等缝长压裂,未考虑利用不等缝长设计改善开发效果。根据某各向异性低渗透油藏基本参数建立数值模型,进行不等缝长设计,分析油藏渗透性各向异性及油水井压裂情况对菱形反九点井网水驱效果的影响。随着储层K_x∶K_y的增加,角井裂缝优化穿透比减小,而边井裂缝优化穿透比增大。在相等K_x∶K_y条件下,注水井是否压裂对角井裂缝优化穿透比影响较小,对边井裂缝优化穿透比影响较大。数值模拟结果表明,在各向异性低渗透油藏中进行不等缝长优化设计,能有效改善菱形反九点井网的开发效果,优化结果对于各向异性低渗透油藏的水力压裂设计以及井网布置具有一定的指导意义。Nine-point diamond reverse well pattern is widely applied in the development of low-permeability reservoirs,and the wells with hydraulic fracturing can significantly improve the oil recovery. The production wells with equal length of fractures,however,may cause non-uniform displacement. The impacts are more serious if the reservoir properties are inhomogeneous. The main focus of previous research is to study the effect of equal length fractured wells regarding to the nine-point diamond reverse well pattern,without the consideration of unequal length fractured wells. Consequently,we established a numerical simulation model based on parameters of a specific low-permeability inhomogeneous reservoir. Nine-point diamond reverse well pattern was used,and unequal fracture lengths were designed for each well. The anisotropic effects of permeability and fracture lengthson the water-flooding efficiency were analyzed in detail. The results indicate that the optimized fracture penetration ratios of corner wells decrease,and those of the edge wells increase with the increasing ratios of permeability in the x and y directions. When the permeability is uniform in the x and y directions,the influence of whether injection well is fractured or not on penetration ratios of corner wells is relatively small,compared to the influence on edge wells. Our results show that the development effect of nine-point diamond reverse well pattern in inhomogeneous low-permeability reservoirs will be boosted significantly by designing unequal length fractures.This has great significance on the design for fracturing of anisotropic low permeability reservoir and well pattern design.

关 键 词：各向异性 低渗透油藏 菱形反九点井网 压裂 不等缝长 

分 类 号：TE34[石油与天然气工程—油气田开发工程]