四川盆地志留系龙马溪组页岩储层成岩作用  

Reservior Diagenesis Research of Silurian Longmaxi Formation in Sichuan Basin

作　　者：孔令明[1,2] 万茂霞[1,2] 严玉霞[1,2] 邹春艳[1,2] 刘文平[1,2] 田冲[1,2] 易力[1,2] 张鉴[1,2] 

机构地区：[1]中国石油西南油气田分公司勘探开发研究院,四川成都610051 [2]页岩气评价与开采四川省重点实验室,四川成都610051

出　　处：《天然气地球科学》2015年第8期1547-1555,共9页Natural Gas Geoscience

基　　金：国家重点基础研究发展计划项目"中国南方古生界页岩气赋存富集机理和资源潜力评价(编号:2012CB214706);国家重点基础研究发展计划项目"中国南方海相页岩气高效开发的基础研究"(编号:2013CB228006);国家科技重大专项"页岩气勘探开发关键技术--南方海相页岩气开采试验"(编号:2012ZX05018-006)联合资助

摘　　要：在大量岩石薄片鉴定、扫描电镜、X-射线衍射等分析实验基础上,对四川盆地志留系龙马溪组页岩储层成岩作用进行了研究。共识别出压实作用、胶结作用、黏土矿物转化作用、交代作用、溶蚀作用、有机质热成熟作用以及构造破裂作用共7类成岩作用。其中胶结作用又包括了硅质、碳酸盐和硫化物胶结,总结了硅质胶结物的物质来源以及钙质胶结物发育的主控因素。在N3井单井分析的基础上,指出龙马溪组优质页岩储层段、次优页岩储层段与非页岩储层段经受了不同成岩事件的改造,其中优质页岩储层段经历的主要无机成岩作用除压实作用外,均与有机质热成熟作用存在明显联系。通过多项成岩指标综合分析认为,龙马溪组页岩储层现今处于中成岩B亚期—晚成岩阶段。无机矿物成岩作用对于页岩储层具有重要的影响,它控制了储层孔隙的保存、发展和演化,同时也影响着岩石的力学性质和页岩储层的吸附能力;有机质热成熟过程中排出的天然气是页岩气的物质来源,同时其在热成熟过程中生成的大量有机质纳米孔隙增大了储层孔隙度并提高了储层吸附能力。Based on a large number of thin section identification,scanning electron microscopy analysis,Xray diffraction tests and some other experiments,the reservoir diagenesis of Silurian Longmaxi Formation in Sichuan Basin were studied.Seven diagenetic processes were identified,including compaction,cementation,clay mineral transformation,replacement,dissolution,organic matter thermal maturation and tectonic disruption.Three kinds of cements（quartz,carbonate and sulfide）were recognized,while the source material of quartz cements and the main factor of forming abandant carbonate cements were summed up.According to single well analysis of N3,it shows that the best,suboptimal and none shale reservoir sections were subjected to different diagenetic transformations.As to best shale reservoir,except for compaction,all the main inorganic diagenesis was significantly related to organic matter maturation.Through comprehensive analysis of diagentic indicators,it is indicated that the reservoir currently has already been in period B of middle diagenetic stage to late diagenetic stage.The inorganic diagenesis has a significant impact on shale reservoir,because it controls not only the conservation,development and evolution of porosity,but also the mechanical property and the adsorption capacity of rocks.However,the organic diagenesis is the source material of shale gas,and it generates a large number of nanoporosity in organic matter,which increase the total porosity and the adsorption capacity of the reservoir.

关 键 词：四川盆地 龙马溪组 页岩储层 成岩作用 

分 类 号：TE122.2[石油与天然气工程—油气勘探]