摘要
西湖凹陷中央反转带中北部花港组砂岩储层埋深跨度大,不同层位储层质量存在差异。基于铸体薄片、扫描电镜、X衍射和物性数据等资料,结合区域地质背景和埋藏史,系统分析了不同层位储层基本特征及其成岩差异演化过程。研究结果表明:花港组砂岩储层纵向上以埋深4100 m为界线,其上、下储层物性和孔隙发育类型存在明显差异。埋深4100 m以上为H3—H4砂组储层,埋藏相对较浅且火山岩岩屑含量相对较高,较弱的压实、压溶作用和普遍发育的绿泥石包膜共同抑制了石英次生加大,有效保存了原生孔隙,为后期有机酸规模溶蚀提供了条件,因此原生孔隙和次生孔隙都发育较好,存在相对高孔隙发育区;埋深4100 m以下为H5—H6砂组储层,埋藏相对较深且更富变质岩岩屑,绿泥石包膜发育较差,难以有效抑制石英次生加大,同时强烈的压实、压溶作用使其在快速埋藏阶段丧失了大量孔隙,不利于后期的有机酸溶蚀增孔作用,且由于较长时期处于碱性成岩环境,大量自生矿物胶结充填孔隙,导致储层相对致密。
Huagang Formation sandstone has a great buried depth range in the north-central part of the central reversal structural belt in Xihu Sag,and different layers differ in reservoir quality.In virtue of the data such as mold thin sections,scanning electron microscopes(SEM),X-ray diffraction(XRD),and physical properties,this paper systematically analyzed the fundamental features and the diagenetic differential evolution of different layers of sandstone reservoirs by referring to the regional geological background and burial history.The study shows that the physical properties and pore types of Huagang Formation sandstone reservoirs are distinctly different above and below the vertical demarcation line with a buried depth of 4100 m.The part above 4100 m matches H3-H4 reservoirs,which are buried shallowly and relatively rich in volcanic rock debris.The weak compaction and pressure dissolution and the common chlorite coat jointly inhibit the secondary enlargement of quartz and effectively preserve the primary pores,providing conditions for later large-scale organic acid dissolution.As a result,both primary and secondary pores are well developed,and highly porous zones exist in the reservoirs.The part below 4100 m mainly corresponds to H5-H6 reservoirs,which are buried deeply and rich in metamorphic rock debris.The poorly-developed chlorite coats fail to effectively inhibit the secondary enlargement of quartz.In addition,strong compaction and pressure dissolution result in the large loss of pores in the rapid burial stage,which is inconducive to the pore increasing by organic acid dissolution in the later stage.Exposed to the alkaline diagenetic environment for a long time,pores are filled by a large amount of authigenic mineral cement,which makes the reservoirs relatively dense.
作者
黄鑫
林承焰
黄导武
段冬平
林建力
何贤科
刘彬彬
HUANG Xin;LIN Chengyan;HUANG Daowu;DUAN Dongping;LIN Jianli;HE Xianke;LIU Binbin(Shanghai Branch of CNOOC Ltd.,Shanghai City,200335,China;School of Geosciences,China University of Petroleum(East China),Qingdao City,Shandong Province,266580,China;Shandong Provincial Key Laboratory of Reservoir Geology,Qingdao City,Shandong Province,266580,China)
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2022年第2期1-14,共14页
Petroleum Geology and Recovery Efficiency
基金
国家科技重大专项“东海厚层非均质性大型气田有效开发关键技术”(2016ZX05027-004)
国家自然科学基金项目“东海深层低渗-致密气储层体系质量差异性成因机制及演化模式”(41672129&41602135)
中海石油(中国)有限公司重大科技项目“西湖凹陷在生产油气田中后期综合调整关键技术研究与实践”(CNOOC-KJ135ZDXM39SH03)。
关键词
储层质量
成岩作用
有机酸溶蚀
绿泥石包膜
石英次生加大
花港组
西湖凹陷
reservoir quality
diagenesis
organic acid dissolution
chlorite coat
secondary enlargement of quartz
Huagang Formation
Xihu Sag
作者简介
黄鑫(1988-),男,江苏泰州人,工程师,硕士,从事地震沉积学和储层地质学方面的研究。E-mail:huangxin19@cnooc.com.cn。
