摘要
以东营凹陷永安镇油田沙河街组二段河控三角洲前缘储层为研究对象,通过对岩心样品的分析化验、扫描电镜以及测井曲线等资料的综合统计和分析,明确了钙质胶结的垂向分布规律及其成因。研究表明:在河控三角洲前缘储层中,垂向上钙质胶结主要分布在反韵律砂体的顶部和中部,均质韵律砂体的顶底部,而薄层砂岩易被整体胶结;自陆地向湖盆方向,随着微相及岩性组合的过渡,钙质胶结也由不易发育向顶底及中部发育,再过渡到薄层整体钙质胶结。究其成因,是在早成岩B期,碎屑矿物的溶蚀和黏土矿物演化过程中形成的高浓度碳酸盐离子流体在不同微相、粒度及砂泥岩接触关系的控制下,形成的碳酸盐胶结程度的差异。
Through comprehensive and statistical analysis of core samples and laboratory analysis,as well as scanning electron microscopy and logging curves and other data,the vertical distribution of calcareous rock and its genesis were clarified by taking the reservoirs in fluvial-dominated delta front of the Second Member of Shahejie Formation in Yonganzhen Oilfield as a study area.Studies show that in the reservoirs of the fluvial-dominated delta front,vertically it is mainly distributed on the top and in the middle of inverted rhythm sand bodies,and on the top and bottom of the homogene-ous rhythm sand bodies,while thin sandstone is easily to be cemented.From the land to the lake,with the transition of microfacies and lithological association,calcite cementation witnesses a non-development to development on the top and in the mid,then transits to the overall calcite cementation in the thin layer of sandstone.The cause of this phenomenon is the carbonate cementation difference at the early stage of its diagenesis of Phase B,which is under control of different micro-phases,particle sizes,and contact between the sandstone and mudstone of the high concentration of carbonate ion fluid in the process of the detrital mineral dissolution and clay mineral evolution.
出处
《长江大学学报（自科版）（中旬）》
CAS
2015年第4期30-35,共6页
Journal of Yangtze University(Nature Science Edition)
基金
国家自然科学基金项目(41202106)
国家科技重大专项(2011ZX05010-001)
中国石油大学(北京)基金项目(KYJJ2012-01-19)
关键词
三角洲前缘
钙质胶结
岩性演化规律
钙质成因
delta front
calcite cementation
lithological evolution
calcite genesis
