摘要
目前页岩气水平井压裂后排采主要依靠现场经验,规律性不强。为此,通过挖掘气藏数值模型的功能,并结合井筒流动模型,初步研究了页岩气水平井分段压裂排采规律。基于正交设计原理,考虑了页岩基质参数、裂缝参数及生产参数等13个影响因素。结果表明,影响压后返排率的因素按影响程度排序依次为破胶液黏度、压力系数、井底流压、段数、单段注入量、裂缝半长、日排液量、返排时机、导流能力、束缚水饱和度、裂缝形态、裂缝支撑剖面和吸附气含量。为了取得最好的压裂后排采效果,上述不可控参数可作为选井、选段的重要依据,而可控参数可用来对压裂施工参数进行优化调整。该成果已在涪陵焦石坝区块的页岩气水平井压裂中成功应用,压裂后排采效果显著,多口应用井压裂后获得10×104 m3/d以上的产量,且稳产前景良好。
At present,ilowback management atter tracturmg ot shale gas horizontal WellS mainly aepends on field experience. By combining gas reservoir simulation model and wellbore flow model, multistage fracturing flowback pattern of shale gas horizontal wells was simulated preliminarily. Based on the orthogonal design method, 13 factors including rock matrix,fracture, and production are taken into consideration. The results indicate that the factors affecting flowback recovery rank in descending sequence as viscosity of gel breaking fluid, pressure coefficient, bottom hole flowing pressure, total stages, fluid volume injected per stage, half fracture length, flowback rate, flowback time, fracture conductivity, irreducible water saturation, fracture shape, propped fracture profile, and adsorption gas content. To optimize flowback effect, controllable factors among those mentioned above can be used to adjust fracture treatment parameters,and the uncontrollable factors can be used in well and interval candidate selection. The research results have been put into application in shale gas fracturing in Jiaoshiba Block of Fuling in Chongqing, the flowback and production effect after fracturing is very encouraging, where gas production of several horizontal wells reach more than 100,000 m3/d after fracturing,and the decline rate is very low.
出处
《石油钻探技术》
CAS
CSCD
北大核心
2013年第5期21-25,共5页
Petroleum Drilling Techniques
基金
中国石化科技攻关项目"页岩气网络压裂机理及设计方法研究"(编号:P11013)部分研究内容
关键词
页岩气
水平井
分段压裂
排采规律
数值模拟
shale gas
horizontal well
multi-stage fracturing
flowback pattern
numerical simulation
