涪陵页岩气田返排特征研究  

Research on Back Row Characteristics of Fuling Shale Gas Field

作　　者：袁小玲 黄灿[1] 

机构地区：[1]中国石化江汉油田分公司

出　　处：《非常规油气》2017年第5期66-70,共5页Unconventional Oil & Gas

基　　金：中国石油化工股份有限公司2015年度“十条龙”科技攻关项目“涪陵区块页岩油气勘探开发关键技术”(ZKD0213002);中国石油化工股份有限公司科研项目“涪陵区块页岩油气有效开发技术研究”(P13053)联合资助

摘　　要：涪陵页岩气藏通常需要进行大规模的水力压裂才具有工业开采价值,但是页岩气井压裂后返排率普遍较低。针对这一返排特征,采用页岩储层三孔隙裂缝—基质模型表示,裂缝在井的压裂过程中形成相互连通的网络连续区,而有机基质和无机基质会嵌入这种裂缝网络连续区。模型中考虑了基质润湿性、毛细管压力、相对渗透率和渗透压力等潜在的化学特性的影响。从机理上分析了页岩气井压后返排困难的原因。结果表明：水通过毛细管自吸作用进入微裂缝,注入水存在于比表面积极大、形态极为复杂的裂缝网络中,以致无法返排。页岩气井压后返排率的高低受多种因素的影响,页岩气井返排率低,产量一般较高。Fuling shale gas reservoir usually requires large-scale hydraulic fracturing to be of industrial value, but shale gas well flowback rate is generally low. According to the characteristics of flowbaek, the three porosity fractures of shale reservoir were used to represent the matrix model, continuous network zone connected to each other in the formation of fracturing wells in the crack, and the organic and inorganic matrix should been embedded in the fracture network continuum. The effects of substrate wettability, capillary pressure, relative permeability, and osmotic pressure on the chemical properties of the substrate were considered in the model. The reasons for the difficulty of backflow of shale gas well were analyzed from the mechanism. The results showed that the water was injected into the micro cracks by capillary imbibition, which was found to be in a large and complex crack network and could not be returned. Shale gas wells flowback rate is affected by many factors, the low yield of shale gas wells flowback rate is generally higher.

关 键 词：页岩气 水力压裂 三孔隙度 返排率 自吸 

分 类 号：TE377[石油与天然气工程—油气田开发工程]