珠江口盆地白云凹陷西南部珠海组储层成岩特征及其对储层物性的影响  

Characteristics of reservoir diagenesis in the Zhuhai Formation in the southwestern Baiyun Depression,Pearl River Mouth Basin,and its influence on reservoir physical properties

作　　者：张向涛 彭光荣 谢世文 卫哲 单玄龙[3] 贺文同[3] 郝国丽[3] ZHANG Xiangtao;PENG Guangrong;XIE Shiwen;WEI Zhe;SHAN Xuanlong;HE Wentong;HAO Guoli(CNOOC Deepwater Development Limited,Shenzhen 518067,China;Shenzhen Branch of CNOOC Ltd.,Shenzhen 518067,China;The College of Earth Sciences,Jilin University,Changchun 130061,China)

机构地区：[1]中海石油深海开发有限公司,广东深圳518067 [2]中海石油(中国)有限公司深圳分公司,广东深圳518067 [3]吉林大学地球科学学院,吉林长春130061

出　　处：《天然气地球科学》2024年第3期379-392,共14页Natural Gas Geoscience

基　　金：中国海洋石油有限公司“十四五”重大科技项目(编号:KJGG2021-0100)资助。

摘　　要：珠江口盆地白云凹陷西南部通过新钻井发现优质储层,但是目前关于该区域珠海组储层孔隙演化与成岩作用过程的相关研究很少,制约着深水区优质储层的评价与潜在甜点区的有效预测。首先选取白云凹陷珠海组最新深海钻井岩心作为研究对象,结合大量薄片、铸体薄片、X射线衍射以及岩石物理性质测试等资料,对其岩石特征、孔隙演化、成岩作用以及对储层物性的影响等方面进行了系统研究。结果表明:珠海组砂岩储层主要为长石砂岩和长石岩屑砂岩。储层孔隙类型以原生孔隙和次生溶解孔隙为主,原生孔隙大多受到改造,溶蚀孔隙比较多见。珠海组砂岩储层经历了强烈的成岩作用改造,包括压实作用、胶结作用、溶蚀作用和交代作用。系统总结了白云凹陷西南珠海组存在4种典型的成岩相:中—细粒砂岩机械压实相、中—细粒砂岩硅质胶结相、细—粉粒砂岩碳酸盐胶结相与中—细粒砂岩胶结—溶解混合相,并分析了成岩作用、成岩阶段与孔隙演化之间的耦合关系。通过对影响优质储层发育成岩因素的分析,发现压实作用是控制储层质量的主要因素,胶结作用和溶解作用是影响储层岩石物理性质的次要控制因素;碳酸盐含量和黏土矿物含量与物性呈明显的负相关;靠近生烃中心区域的储层接受大量酸性流体,引起的溶解作用进而形成的次生孔隙也能提高储层的物性。研究成果既有益于丰富白云凹陷珠海组储层研究理论体系,也能为类似深水油气勘探工作提供科学依据。High-quality reservoirs have been discovered in the southwestern part of Baiyun Depression in the Pearl River Mouth Basin of the South China Sea through new drilling wells,but there are few studies on the pore evolution and diagenetic processes of the reservoirs of the Zhuhai Formation in this region,which restricts the evaluation of high-quality reservoirs and the effective prediction of potential sweet spot zones.In this paper,the latest deep-sea drilling core of the Zhuhai Formation in Baiyun Depression was selected as the research ob⁃ject,and then based on a large number of thin sections,cast thin sections,X-ray diffraction,and rock physical property tests,a systematic study was carried out to investigate the rock characteristics,pore evolution,diagen⁃esis,and the impact on reservoir properties.It is found that the sandstone reservoirs of the Zhuhai Formation are mainly feldspathic sandstone and feldspathic clastic sandstone.The pore types of the reservoir are mainly prima⁃ry and secondary dissolution pores,and the primary pores are mostly modified,while the dissolution pores are more common.The sandstone reservoirs of the Zhuhai Formation in the target area have experienced strong dia⁃genetic modification,including compaction,cementation,dissolution,and accountable action.This paper sum⁃marizes the existence of four typical diagenetic phases in the Zhuhai Formation in the southwestern Baiyun De⁃pression,the mechanically compacted phase of medium-fine-grained sandstone,the siliceous cementation phase of medium-fine-grained sandstone,the carbonate cementation phase of fine-fine-grained sandstone,and the mixed cementation-dissolution phase of medium-fine-grained sandstone,and analyzes the coupling relationship between diagenesis,diagenetic phase and pore evolution.Through the analysis of the factors affecting the devel⁃opment of high-quality reservoirs,it is found that compaction is the main factor controlling the quality of reser⁃voirs,and it controls the physical properties of reservoirs at di

关 键 词：白云凹陷 珠海组 储层 成岩作用 孔隙演化 

分 类 号：TE122.23[石油与天然气工程—油气勘探]