五峰组-龙马溪组页岩孔隙结构与非均质特征研究
Study on pore structure and heterogeneous features of shale in Wufeng Formation-Longmaxi Formation
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摘要: 为探究五峰组-龙马溪组页岩储层孔隙特征与微观非均质特征,以重庆南川、綦江的五峰组-龙马溪组页岩样品为例,通过氩离子抛光-场发射扫描电镜、高压压汞、低温氮吸附等实验技术手段,总结出孔隙的结构特征,进而揭示储层在微观尺度上的非均质性。结果表明:储层发育为多种孔隙类型,特征具有较大差异;孔隙在连通性、形态、孔径、分布特征上的微观非均质性较强;储集能力、渗流能力的差异受控于储层孔隙-微裂隙的非均质性;分形维数可作为孔隙非均质程度的定量评价标准。对页岩储层纳米孔和非均质性的研究,可以为储层评价提供新的思路。Abstract: in order to detect and study the pore features and micro heterogeneous features of the shale reservoir in wireng Formation-LongmnaxiFormation,basedon the samples from Wwufeng Formation-Longmaxi Formation in Chongging Nanchuan and aijing as the exampes the argon ion fgurn -rfed emiss io scamning electon microcopy.high pressure mercury,cryogenic nitrogen adsorption and other experiment techrica means were appied to the obsenvtion and analys s n the pore features of the shale reservoir. The pore structre develogment and distrbution features were sumarzed and the micro-scale heterogeneity of th shale reservoir was revealed. The results showed that there were multi pore types developed in the reservoir and the features were in bi oifference.The micro he erogenety of he pore vasstrong on the connecivityshape,pore diameter and distribution features. The diferences of the reservoir capacity and seepage fovw capacity were controled by the heterogeneity of the reservoir pore- microcrack.The fractal dimension value would be the quantiaive evaluation standard of the pore heterogeneity degree The study on he nanopore and heterogeneity of the shale reservir could provide a new ldeaof the resevir evaluLation and the micro heterogeneou features coud be appied to characterize the reservoir property.