特低渗透—致密砂岩成岩作用特征及其差异性分析——以鄂尔多斯盆地陇东地区延长组为例  

Diagenesis characteristics and difference analysis of ultra‑low permeability and tight sandstone:Taking Yanchang Formation in Longdong area of Ordos Basin as an example

作　　者：庞军刚 李文厚[3] 国吉安 马治国 东玉 常梁杰 Pang Jungang;Li Wenhou;Guo Ji'an;Ma Zhiguo;Dong Yu;Chang Liangjie(School of Earth Science and Engineering,Xi'an Shiyou University,Xi'an 710065;Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xi'an Shiyou University,Xi'an 710065;Geological Department,State Key Laboratory of Continental Dynamics,Northwest University,Xi'an 710069;No.2 Comprehensive Geophysical Prospecting Brigade Shaanxi Geological Mining CO.,Ltd.,Xi'an 710016;Kela Oil and Gas Development,PetroChina Tarim Oilfield Company,Korla,Xinjiang 841000)

机构地区：[1]西安石油大学,地球科学与工程学院,西安710065 [2]陕西省油气成藏地质学重点实验室,西安710065 [3]西北大学,地质学系/大陆动力学国家重点实验室,西安710069 [4]陕西地矿第二综合物探大队有限公司,西安710016 [5]中国石油塔里木油田公司克拉油气开发部,新疆库尔勒841000

出　　处：《地质科学》2021年第1期121-135,共15页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国地质调查局矿产资源调查评价项目(编号:121201011000150014);地质矿产调查评价项目(编号:21201011000150014);“十三五”国家科技重大专项(编号:2016ZX05050006);国家科技重大专项(编号:2017ZX05005⁃002⁃04);西安石油大学科研创新团队项目(编号:2013KYCXTD03)资助。

摘　　要：根据大量岩石薄片观察、扫描电镜和X⁃衍射分析,研究陇东地区典型区块三叠系延长组长6—长8段特低渗透—致密砂岩的岩石学特征、孔隙成因等,探讨成岩作用类型及主要控制因素,剖析延长组长6与长8成岩作用的差异性。研究表明:该区砂岩经历的成岩作用主要有压实作用、胶结作用、溶解作用等,建立了三角洲和重力流成岩演化模式序列,研究区目前处于中成岩A⁃B期;并从储层形成的物源、沉积环境、古气候等方面的差异性,探讨了华庆区块长63和马岭区块长81成岩作用差异性的成因。由于长6较长8粒度细、杂基含量较高,其压实作用强,原生粒间孔保存较少,早期绿泥石膜胶结不发育,含铁碳酸盐胶结物及自生伊利石含量高,砂岩储层物性较差。Based on plenty of rock thin section observation,scanning electron microscopy(SEM)and X⁃ray diffraction analysis,such characteristics of petrology and pore formation of low permeable⁃tight sandstone petrology members Chang⁃6 and Chang⁃8 of Yanchang Formation,furthermore,the diagenesis and its main controlling factors are discussed,thus the difference of sandstone reservoir in members Chang⁃6 and Chang⁃8 of Yanchang Formation are analyzed.The research results indicate that the diagenesis sandstone experienced includes compaction,cementation,dissolution and so on,the sequence model of diagenetic evolution of sedimentary setting of delta and sediment gravity flow was established,the rock record of the study area is experiencing the phase A⁃B of medium⁃term diagenesis.Forthermore,the difference of sandstone reservoir in Chang⁃63 sub⁃member of Yanchang Formation in Huaqing area and Chang⁃81 sub⁃member of Yanchang Formation in Maling area in Ordos Basin are discussed,primarily in the terms of the provenance,sedimentary environment,the palaeoclimate of reservoir formation.Comparing the sandstone reservoirs of member Chang⁃6 with that of Chang⁃8 of Yanchang Formation,such differences,i.e.,the finer granularity,higher proportion of matrix content,stronger compaction,less primary intergranular pore,less early chlorite membrane cementation,higher content of iron carbonate cement and authigenic illite content,result to the poor reservoir physical property.

关 键 词：致密砂岩 成岩作用 差异性 鄂尔多斯 马岭 华庆延长组 

分 类 号：TE127.1[石油与天然气工程—油气勘探]