低品位砂岩气藏压裂技术研究及应用——以DF109H井为例  

Fracturing technologies for low-grade sandstone gas reservoirs and their application to DF109H well

作　　者：钟森[1] 赵祚培[1] 王淑静 杜杰[1] ZHONG Sen;ZHAO Zuopei;WANG Shujing;DU Jie(Sinopec Southwest Oil&Gas Company,Chengdu,Sichuan 610041,China)

机构地区：[1]中国石化西南油气分公司,四川成都610041

出　　处：《天然气技术与经济》2024年第4期32-36,72,共6页Natural Gas Technology and Economy

基　　金：中国石油化工集团有限公司重大科技攻关项目“川西中浅层致密砂岩气藏体积压裂关键技术”(编号:P22047)。

摘　　要：四川盆地中部东峰场地区上三叠统须家河组气藏孔隙度、渗透率特低,含水饱和度高,常压,前期采用常规压裂后天然气增产及稳产效果差。为了动用该区须家河组低品位天然气储量,在新井DF109H开展了压裂技术系统化攻关,通过对减小地层伤害、加快返排、增大改造体积、支撑剂高效铺置等开展研究,形成了地质工程一体化紧密结合的高效压裂技术。研究结果表明:①前置液氮气体增能及水性降阻剂工作液体系,在常压致密气藏能增加返排能量,加快排液,降低储层伤害,实现天然气产能快速突破;②优选测录井甜点射孔,差异化高密度布缝,通过大排量、复合暂堵等提升人造裂缝体积,降低渗流距离,提升远端供给能力;③提升裂缝长期有效性是稳产的关键,加砂阶段伴注纤维+分散剂,采用脉冲段塞注入模式,使支撑剂铺置更为均匀。结论认为,该技术体系应用后天然气产量大幅度提升,在致密气藏显示了较好适应性,成为该区致密砂岩气藏有效开发的重要技术措施。Gas reservoirs of Xujiahe Formation,Dongfengchang area,central Sichuan Basin,are characterized by extra low porosity and permeability,high water saturation and normal pressure,leading to terrible effects in their stimulation and stable production after the early regular fracturing.Thus,we discussed fracturing technologies via an example from the new DF109H well in order to draw on the low-grade gas reserves in this formation.Geology-engineering integration technologies were appeared through a series of research to reduce reservoir damage,speed up flowback,enlarge stimulated bulk,and realize efficient proppant placement.Results show that(i)one system of working fluid which is composed of energized prepad liquid nitrogen and water-based drag reducer can increase flowback energy in tight gas reservoirs with normal pressure,so as to advance liquid drainage and cut down reservoir damage,and to make a rapid breakthrough in deliverability;(ii)sweet spots of both mud and well logging are selected for perforating,and differential high-density fracture arrangement is conducted.Large displacement and composite temporary plugging are used to enlarge the size of hydraulic fractures,decrease flow distance and raise distal supply capacity;and(iii)that fractures remain effective for a long time is the key to stable production.Fiber and dispersing agent are injected through pulse plug during sand fracturing so that proppant is placed more uniformly.In conclusion,with fine fitness in the tight gas reservoirs,these technologies may increase the production substantially and become considerable measures for the efficient reservoir development in Dongfengchang area.

关 键 词：砂岩气藏 水性降阻剂 高密度裂缝 支撑剂高效铺置 压裂 

分 类 号：TE377[石油与天然气工程—油气田开发工程]