西湖凹陷中央反转带花港组储层成岩演化南北差异及其影响因素分析  

Analysis on the difference of diagenetic evolution and its influencing factors between north and south of Huagang Formation reservoir in central inversion zone of Xihu Sag

作　　者：刘创新 高红艳 刘彬彬 李文俊 黄志龙 屈童[2,3] 杨易卓 夏瑜 单理军 LIU Chuangxin;GAO Hongyan;LIU Binbin;LI Wenjun;HUANG Zhilong;QU Tong;YANG Yizhuo;XIA Yu;SHAN Lijun(Shanghai Branch of CNOOC Ltd.,Shanghai,200335;National Key Laboratory of Petroleum Resources and Engineering,Beijing,102249;College of Geosciences,China University of Petroleum(Beijing),Beijing,102249)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335 [2]油气资源与工程全国重点实验室,北京102249 [3]中国石油大学(北京)地球科学学院,北京102249

出　　处：《地质论评》2024年第4期1353-1365,共13页Geological Review

基　　金：中海石油(中国)有限公司上海分公司综合科研“某区低渗—特低渗气藏高气饱富集区分布规律研究与实践”项目(编号:KJ2022-JYZJ-SH01)的成果。

摘　　要：东海盆地西湖凹陷花港组砂岩储层作为西湖凹陷的重要勘探目的层,储层非均质性研究至关重要,笔者等基于储层成岩作用和成岩演化分析,明确中央反转带南北差异,进一步分析其差异成因。研究结果表明,北部地区具有更强的压实作用和溶蚀作用,纵向上以3500 m和4000 m为界划分为酸性、酸碱过渡和碱性3个成岩带,经历两期硅质胶结和三期钙质胶结;而南部地区埋深浅、地温低,仅具有两期钙质胶结,纵向上以4000 m为界划分为酸性和碱性两个成岩带;由于北部地区具有更多的岩浆岩母源贡献使得储层抗压实能力较差,遭受压实更强,但烃源岩较强的生烃强度使得储层遭受溶蚀作用更强,因此北部地区花港组储层具有低孔高渗的特征。该研究对优质储层发育研究和甜点预测具有重要意义。Objectives:The Huagang Formation sandstone reservoir is an important exploration target in thr Xihu Sag,East China Sea Basin,and the study of reservoir heterogeneity is crucial.Based on the analysis of reservoir diagenesis and diagenetic evolution,this paper clarifies the difference between the north and south of the central inversion zone,and further analyzes the causes of the difference.Methods:In this study,one type of thin sections were made,including casting thin sections and the production process was all in accordance with the Chinese Oil and Gas Industry Standard(Y/T5162-2014).All the thin sections could be used to analyze the mineral composition and pore geometry.The casting thin sections were stained with blue epoxy resin to identify the pore type and size distribution,and a Leica DM4500P/DFC450C high-precision microscope was used for the observation.SEM is a common electronic imaging technique,which is mainly used to observe the pore structure of rocks at micro/nano scale.This study adopted two methods to observe SEM,one was to use Quanta-200F field emission SEM(with X-ray energy spectrometer)with a minimum resolution of 1.2 nm to observe the pore type,mineral composition,diagenesis,and pore connectivity.The XRD experiment could be used to analyze the mineral composition.Before the experiment,samples need to be crushed in an agate container to a particle size of<200 mesh.Take 100~200 g of the original sample,bake until dry,then weigh it,take an appropriate amount of sediment sample into a container,add water to diffuse,and use a 63~125μm copper sieve for sorting.After screening out the particle size,it is weighed dry and its mass fraction is calculated;take 1~2 grams of sorted samples,separate them with tribromomethane heavy liquid,dry and weigh them,and calculate the mass fraction of heavy minerals.Results:The northern region has stronger compaction and dissolution,and can be divided into three diagenetic zones,acid,acid-base transition and alkaline,with two stages of siliceous cementation and three

关 键 词：成岩演化 影响因素 花港组 中央反转带 西湖凹陷 

分 类 号：P618.13[天文地球—矿床学]