摘要
油气勘探逐步向中深层拓展是当前的一个重要趋势。在柴达木盆地西北部地区,为开辟勘探新领域,以及对国内外同类研究提供参考,以碱山构造为重点研究对象,基于显微镜下岩石学精细鉴定、储集空间分析和物性测试等方法,研究储层基本特征,并结合地质背景讨论储层成因,结果表明:中深层岩性以泥岩和泥质、钙质粉砂岩为主,储集空间基本类型为裂缝、次生溶蚀孔隙和剩余粒间孔隙,并以前两者为主,物性总体较差,孔隙度在5%左右,渗透率大多小于1×10-3μm2,属于低孔特低渗储层;储层成因可归纳为沉积和成岩作用的叠合影响,其中,沉积作用是低渗透储层发育的基础,压实作用和胶结作用是储层致密化的关键,而裂缝作用和溶蚀作用是储层形成的必要条件。
Petroleum exploration is increasingly extending to middle-deep strata worldwide.In the northwestern Qaidam basin,to provide references for finding new regional exploration field and similar studies worldwide,this article analyzed reservoir characteristics and its genesis based on a case study in the middle-deep strata of the Jianshan structure.The basic reservoir characteristics were obtained by combined methods including detailed microscope observation,reservoir space characterization and physical property analyses.The results show that the lithology is mainly composed of mudstone and argillaceous and calcareous siltstone.The basic type of reservoir space includes fracture and secondary dissolution pore.Residual intergranular pore was also observed.The physical property is of relatively low-quality with porosity and permeability being approximately 5% and less than 1×10-3 μm2,respectively.This indicates that the reservoir belongs to the type of low porosity and especially low permeability.Combined with geological setting,the reservoir genesis was summarized and concluded as an integrated influence of sedimentary and diagenetic processes.The sedimentary process is the basis for the development of low-permeability reservoir,compaction and cementation is key for the densification of reservoir,while fracture and dissolution is necessary condition for the reservoir formation.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2012年第5期820-825,共6页
Natural Gas Geoscience
关键词
柴达木盆地
碱山构造
储层
中深层
裂缝
溶蚀
Qaidam basin
Jianshan structure
Reservoir
Middle-deep strata
Fracture
Dissolution
