摘要
为了进一步认识浅层致密砂岩油气储层分布规律与成因,以四川盆地川中地区侏罗系沙溪庙组致密砂岩为例,综合物性表征、岩石学、地球化学等多种分析测试手段,系统表征致密岩储层的物质组成、储集物性、孔喉结构、成岩作用等特征。结果表明:川中地区侏罗系沙溪庙组致密砂岩以岩屑长石砂岩为主,孔隙度分布在1.99%~18.52%之间,渗透率分布在(0.002~191.340)×10^(-3)μm^(2)之间,低孔致密储层体积分数达77.93%。储集空间以次生孔隙为主,发育4种类型孔喉结构,各类储层的渗透能力均由体积分数较小、半径较大的喉道控制,储集能力则由体积分数较大、半径较小的孔喉主导。破坏性化学成岩作用是研究区储层物性致密的主要控制因素,主要包括浊沸石胶结、方解石胶结、硅质胶结、硬石膏胶结、钠长石胶结、黏土矿物胶结作用等。不同成岩胶结物差异分布引发的强烈成岩非均质性,是研究区储层孔渗差异显著的主要原因;受成岩非均质性控制,不同埋深和不同地区储层的成岩演化过程会存在显著差异,这是造成研究区储层整体致密并发育部分相对优质储层的主要原因。
To analysis the characteristics and formation mechanisms of shallow tight sandstones oil and gas reservoirs,taking the Jurassic Shaximiao Formation tight sandstone in the central Sichuan basin as an example,the material composition,storage properties,pore-throats characteristics and diagenesis of tight sandstone were systematically studied by using comprehensive physical property characterization,petrography,geochemistry,and other analysis and testing methods so as to further explore the genesis of tight reservoirs.The tight sandstones of Jurassic Shaximiao Formation in Central Sichuan are dominated by lithic feldspar sandstones,with porosity ranging from 1.99%to 18.52%,permeability ranging from 0.002×10μm~2 to 191.340×10^(-3)μm^(2),and low-porosity tight reservoirs with a content of 77.93%in volume.Secondary pores and four types of pore-throat structures are mainly developed.The permeability of various reservoirs is controlled by a small volume of throats with larger radius,and the storage capacity is dominated by a large volume of pore throats with smaller radius.The extensive development of destructive chemical diagenesis is the main controlling factor for the compactness of the reservoirs in the study area,mainly including laumontite cementation,calcite cementation,siliceous cementation,anhydrite cementation,albite cementation,and clay mineral cementation,etc.The strong diagenetic heterogeneity caused by the differential distribution of different diagenetic cements is the main reason for the significant differences in the physical properties of the reservoirs in the study area.Controlled by the diagenetic heterogeneity,the diagenetic evolution process of the reservoirs in different depths and regions will be significantly different.This is the main reason for the overall tight reservoirs in the study area and the development of some relatively high-quality reservoirs in the tight background.
作者
王小娟
洪海涛
吴长江
刘敏
关旭
陈双玲
张少敏
梁庆韶
杨田
Wang Xiaojuan;Hong Haitao;Wu Changjiang;Liu Min;Guan Xu;Chen Shuangling;Zhang Shaomin;Liang Qingshao;Yang Tian(Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu 610041,China;State Key Laboratory of oil and Gas Reservior Geology and Exploitation(Chengdu University of Technology),Chengdu 610059,China)
出处
《吉林大学学报（地球科学版）》
CAS
CSCD
北大核心
2022年第4期1037-1051,共15页
Journal of Jilin University：Earth Science Edition
基金
自然资源部沉积盆地与油气资源重点实验室开放基金项目(cdcgs2020003)
国家自然科学基金项目(41906188)
关键词
致密砂岩
储层特征
成岩作用
储层成因
沙溪庙组
四川盆地
tight sandstone
reservoir characteristics
diagenesis
reservoir formation mechanism
Shaximiao Formation
Sichuan basin
作者简介
王小娟(1982—),女,高级工程师,主要从事油气勘探方面的研究,E-mail:wxj_82@petrochina.com.cn;通信作者:杨田(1989—),男,研究员,博士生导师,主要从事沉积学和油气储层地质学方面的研究,E-mail:yangtian9645@126.com
