页岩储层组构特征对自发渗吸的影响  

Effect of composition and structural characteristics on spontaneous imbibition of shale reservoir

作　　者：黄睿哲 姜振学[1,2,3] 高之业 李宜润 张昆[1,2,3] 张醒初 宁传祥 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)科学技术研究院,北京102249 [3]中国石油大学(北京)非常规油气协同创新中心,北京102249

出　　处：《油气地质与采收率》2017年第1期111-115,共5页Petroleum Geology and Recovery Efficiency

基　　金：国家"973"计划"中国东部古近系陆相页岩油资源潜力与分布规律"(2014CB239105);国家自然科学基金项目"页岩储层基质孔隙连通性及其定量评价方法"(41502125);国土资源部项目"南方富有机质页岩储集能力及其控制因素调查"(ZX20150274)

摘　　要：自发渗吸是利用水力压裂和水平钻井技术在开发页岩油气过程中出现的重要现象。孔隙结构和矿物组成是影响页岩储层自发渗吸的重要因素。通过对页岩样品进行自发渗吸实验,探讨其孔隙连通性、页理方向和矿物组成对页岩储层自发渗吸速率的影响,并利用自发渗吸曲线斜率评价页岩储层的孔隙连通性。结果表明,与常规油气储层相比,页岩储层孔隙连通性较差,自发渗吸曲线斜率明显低于理论值。页理方向也会对自发渗吸产生影响,顺层自发渗吸曲线斜率通常较高,但是也有样品表现为穿层自发渗吸曲线斜率与顺层自发渗吸曲线斜率相当,这可能是由于页岩储层中亲水性矿物含量较高,使水在页岩储层中对运移的方向依赖性减弱。自发渗吸与页岩矿物组成密切相关:当页岩中粘土矿物含量较高时,吸水膨胀使页岩储层中原有孔隙结构发生改变,导致重复实验时页岩储层自发渗吸的曲线斜率逐渐减小;当页岩中石英等脆性矿物含量较高时,自发渗吸曲线变化不大,说明实验的重复性较好。页岩储层的自发渗吸曲线斜率越大,其渗透性越好,越有利于页岩油气的开发。The spontaneous imbibition occurs during development of shale oil and gas by using technologies of horizontal drilling and hydraulic fracturing. Shale reservoir pore structure and mineral composition are the important factors that have an impact on shale spontaneous imbibition. The impact of pore structure,mineral composition and direction of lamination on shale spontaneous imbibition rate was studied through spontaneous imbibition experiments of shale samples,and the pore connectivity of shale reservoir was evaluated by using the slope of spontaneous imbibition curve. The results show that shale reservoir pore connectivity is poor and the slop of spontaneous imbibition curve is significantly lower than the theoretical value compared with conventional oil and gas reservoirs. Lamination direction will also have an impact on the spontaneous imbibition,and the slope of spontaneous imbibition curve tested along the lamination is usually higher than that tested against the lamination. But the experiment results of some samples also show that the slope of spontaneous imbibition curve tested along the lamination is comparable with that tested against the lamination,which is probably due to the fact that higher content of hydrophilic mineral in shale reservoirs can weaken the impact of lamination on the direction of water migration.Spontaneous imbibition behavior is closely related to the composition of the shale minerals. When the content of clay miner-als is high,the original pore structure of shale changes under the effect of water swelling,which would result in the de-crease of the slope of spontaneous imbibition curve if the experiment was repeated. When the content of brittle minerals,like quartz,in shale is high,the spontaneous imbibition curve would show little change in the repeated experiment,whichindicates a good repeatability. The greater the slope of spontaneous imbibition curve is,the better the permeability is,andthus it is more conducive to the development of shale oil and gas.

关 键 词：自发渗吸 页岩 孔隙连通性 页理 矿物组成 

分 类 号：TE311[石油与天然气工程—油气田开发工程]