四川盆地龙马溪组页岩孔隙度控制因素及演化规律

发布时间：2018-03-27 15:10

本文选题：页岩孔隙度　切入点：有机质丰度　出处：《石油学报》2017年02期

【摘要】：为查明四川盆地龙马溪组页岩储层孔隙控制因素及演化规律,利用场发射扫描电子显微镜和氮气吸附实验等方法对页岩储层孔隙类型及孔隙结构进行研究。页岩储层孔隙类型包括有机孔、晶间孔、晶内溶孔和粒间孔,有机孔是主要孔隙类型之一,且有机孔中微孔所占的孔体积和比表面积大,是页岩气储集的主要空间。通过对有机质丰度(TOC)、有机质成熟度(Ro)、成岩作用和构造作用对页岩孔隙度的影响研究,结果表明:1有机质丰度对孔隙度的影响可以分为4个阶段:快速增大(TOC为0%~2%)、缓慢减小(TOC为2%~3%)、快速增大(TOC为3%~4%或6%)、快速减小(TOC4%或6%);2四川盆地页岩成熟度对孔隙度的影响可分为3个阶段:快速减小(Ro为1.5%~2.2%)、快速增大(Ro为2.2%~2.7%)、快速减小(Ro2.7%);3高热演化阶段有机成岩作用强于无机成岩作用;4构造作用对孔隙度影响较大,构造作用越强烈的区域孔隙度越小。四川盆地龙马溪组页岩孔隙度演化经历5个阶段:未熟快速压实阶段(Ro0.7%)、成熟生烃溶蚀阶段(Ro为0.7%~1.3%)、高成熟孔隙封闭阶段(Ro为1.3%~2.2%)、过成熟二次裂解阶段(Ro为2.2%~2.7%)、过成熟缓慢压实阶段(Ro2.7%),其中成熟生烃溶蚀阶段和过成熟二次裂解阶段是最有利的页岩孔隙发育阶段。
[Abstract]:In order to find out the pore control factors and evolution law of shale reservoir in Longmaxi formation, Sichuan Basin, The pore types and pore structure of shale reservoir are studied by means of field emission scanning electron microscope and nitrogen adsorption experiment. The pore types of shale reservoir include organic pore, intergranular pore, intragranular dissolved pore and intergranular pore. Organic pore is one of the main pore types, and the pore volume and specific surface area of organic pores are large. Through the study of the abundance of organic matter, the maturity of organic matter and the influence of diagenesis and tectonism on the porosity of shale, The results show that the effect of organic matter abundance on porosity can be divided into four stages: rapidly increasing TOC = 0, slowly decreasing TOC to 2 / 2, rapidly increasing TOC = 3 / 4% or 6 / 5, and rapidly decreasing the porosity of shale maturity in Sichuan Basin by 4% or 6 / 2 respectively. The influence can be divided into three stages: the rapid reduction of Ro is 1.5 / 2.2a, the rapid increase of Ro is 2.2and 2.7a, and the rapid reduction of organic diagenesis is stronger than that of inorganic diagenesis during the high thermal evolution stage, and the porosity is greatly affected by tectonism. The evolution of shale porosity in Longmaxi formation, Sichuan Basin, experienced five stages: immature rapid compaction stage, mature hydrocarbon generation solution stage, Ro = 0.7 ~ 1.33%, and high mature pore sealing stage, respectively. The Ro of the secondary cracking stage is 2.2 and that of the overmature and slowly compacted stage is 2.7.The mature hydrocarbon generation dissolution stage and the over-mature secondary cracking stage are the most favorable stage for the development of shale pores.
【作者单位】：中国石油西南油气田公司勘探开发研究院;页岩气评价与开采四川省重点实验室;中国石油西南油气田公司;
【基金】：国家自然科学基金青年科学基金项目(No.41502150) 四川省科技支撑计划项目(2015SZ0001) 中国科学院战略性先导科技专项(B类)(XDB10010504)资助
【分类号】：P618.13

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