沉积学报2011，Vol.29Issue(4)：744-751,8.
四川盆地川中地区中下侏罗统砂岩储层异常致密成因机理
Origin Mechanism of Anomalous Tightness of Middle and Lower Jurassic Sandstone Reservoirs in Central Sichuan Basin
刘占国 1斯春松 1寿建峰 1倪超 1潘立银 1刘群1
作者信息
- 1. 中国石油杭州地质研究院,杭州310023
- 折叠
摘要
Abstract
As unique tight reservoirs in China,the middle-upper Jurassic sandstones in central Sichuan basin occur at present-day burial depth of 1 500～3 000 m and they are characterized by ultra-low porosity（average below 5%） and ultra-low permeability（average below 1×10-3 μm2） that fail to match their burial depth.Microscopic observation and statistics of relative contribution of compaction and cementation to porosity loss indicate that intensive compaction is responsible for the anomalous tightness of these sandstones.Furthermore,utilizing the research method of sandstone dynamical diagenesis theory,based on the analysis of original sandstone components and basin diagenetic dynamic factors,the mechanism of intensive compaction of Middle and Lower Jurassic sandstones in the study area has been discussed.It is suggested that fine grain size and high ductile fragments content are the internal cause,while the basin diagenetic dynamics characteristics of deep paleo-burial,high paleo-geothermal field and late oil emplacement are considered as the external cause. Mechanisms of diagenesis and porosity evolution of some sandstone reservoirs are quite complex in superimposed basins in western China.In one of these complex cases,this study of origin mechanism of anomalous tightness of Middle and Lower Jurassic sandstone reservoirs in central Sichuan Basin shows that the sandstone dynamical diagenesis theory and method can integrally and systematically take original sandstone components and all basin diagenetic dynamics factors（structure,thermal flow,pore fluid,etc.） into account,and which can well resolve such difficult questions in complex sandstone reservoirs.关键词
四川盆地/致密砂岩储层/压实作用/动力成岩作用理论Key words
Sichuan basin/tight sandstone reservoir/compaction/dynamic diagenesis theory分类
能源科技引用本文复制引用
刘占国,斯春松,寿建峰,倪超,潘立银,刘群..四川盆地川中地区中下侏罗统砂岩储层异常致密成因机理[J].沉积学报,2011,29(4):744-751,8.
