摘要
四川盆地侏罗系沙溪庙组是重要的致密气储层。通过对川西地区侏罗系沙溪庙组储层特征的研究,探究南北双向物源条件下沙溪庙组储层砂岩孔隙的演化过程,对指导致密砂岩气的高效勘探开发具有重要意义。根据岩心和薄片观察结果,使用X射线衍射、阴极发光、扫描电镜、电子探针等实验技术手段对储层特征进行研究,从储层演化和储层成因机理方面讨论优质储层成因。研究发现:受物源方向影响,川西南在南向物源影响下,主要发育长石砂岩和岩屑砂岩,川西北地区受北向物源影响,主要为长石岩屑砂岩和岩屑长石砂岩;川西南地区平均孔隙度为10.52%,平均渗透率为0.1334×10^(-3)μm^(2),川西北地区,平均孔隙度9.74%,平均渗透率为0.5262×10^(-3)μm^(2);川西地区储集空间主要为原生粒间孔和次生粒内溶孔;压实作用在孔隙减少中占主导地位,导致川西北地区孔隙度减少了23.94%。相比之下,由于绿泥石包膜的保护作用,川西南地区孔隙度减少了22.75%;胶结作用在孔隙减少中发挥次要作用,川西北和川西南地区的孔隙度分别减少了9.2%和11.3%;与此相反,溶蚀作用在孔隙增加方面起到积极作用,分别使川西北和川西南地区的孔隙度增加了5.26%和4.32%。综合分析显示,川西地区沙溪庙组储层的现今孔隙特征是多种成岩作用共同作用的结果。
In this paper,X-ray diffraction,cathodoluminescence,scanning electron microscopy,electron microprobe,and other experimental techniques are used to study the characteristics of tight gas reservoirs in the Jurassic Shaximiao Formation in western Sichuan.The study explores the evolution of sandstone pores in the reservoir under bidirectional provenance conditions from the north and south.It discusses the formation of high-quality reservoirs from the perspectives of reservoir evolution and formation mecha-nisms,aiming to provide a reference for efficient exploration of tight sandstone gas in the area.The results reveal that under the influence of southward provenance,feldspar sandstone and lithic sandstone are pri-marily developed in southwest Sichuan,while under the influence of northward provenance,feldspar lithic sandstone and lithic feldspar sandstone are mainly developed in northwest Sichuan.The average porosity and permeability of sandstone in southwest Sichuan are 10.52%and 0.1334×10^(-3)μm^(2),respectively,while in northwest Sichuan,they are 9.74%and 0.5262×10^(-3)μm^(2),respectively.The reservoir space of sandstone in western Sichuan is mainly composed of primary intergranular pores and secondary intergranu-lar pores.Compaction plays a dominant role in the reduction of porosity,resulting in a 23.94%decrease in the porosity of sandstone.In contrast,due to the protective effect of chlorite coating,the porosity of sand-stone in southwest Sichuan is reduced by 22.75%,with cementation playing a secondary role in the reduc-tion of porosity.Overall,the porosity of sandstones in northwest and southwest Sichuan decreases by 9.2%and 11.3%,respectively.Conversely,dissolution plays a positive role in increasing porosity,lead-ing to a porosity increase of 5.26%in northwest Sichuan and 4.32%in southwest Sichuan.Comprehen-sive analysis reveals that the present pore characteristics of the Shaximiao Formation reservoir in western Sichuan are the result of multiple diagenetic processes.
作者
陈春宇
梁庆韶
田景春
余瑜
王旭丽
林小兵
CHEN Chunyu;LIANG Qingshao;TIAN Jingchun;YU Yu;WANG Xuli;LIN Xiaobin(Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu,Sichuan 610059,China;Northwest Sichuan Gas Field of PetroChina Southwest Oil and Gas Field Company,Jiangyou,Sichuan6621700,China)
出处
《矿物岩石》
CAS
CSCD
北大核心
2024年第2期108-121,共14页
Mineralogy and Petrology
基金
国家自然科学基金(项目批准号:42172135)
四川省科技计划项目-四川省自然科学基金(项目编号:2024NSFSC0831)。
关键词
四川盆地
侏罗系沙溪庙组
储层特征
主控因素
成岩作用
Sichuan Basin
Jurassic Shaximiao Formation
reservoir characteristics
main control factors
diagenesis
作者简介
第一作者:陈春宇,男,25岁,硕士研究生,地质学专业,研究方向:沉积学。E-mail:cdut_ccy@163.com;通信作者:梁庆韶,男,32岁,副教授(博士),沉积学专业,研究方向:储层沉积学与事件沉积学.E-mail:liangqs@cdut.edu.cn。
