伊拉克鲁迈拉油田白垩系Mishrif组碳酸盐岩生物碎屑和成岩作用特点  

DIAGENESIS OF BIOCLASTIC CARBONATES OF THE CRETACEOUS MISHRIF FORMATION IN THE RUMAILA OIL FIELD,IRAQ

作　　者：田泽普 刘波[1] 高计县[1,2] 

机构地区：[1]北京大学地球与空间科学学院,北京100871 [2]中国石油勘探开发研究院,北京100083

出　　处：《地层学杂志》2016年第1期41-50,共10页Journal of Stratigraphy

基　　金：中国石油天然气股份有限公司科研项目“伊拉克鲁迈拉油田Mishrif组碳酸盐岩储层非均质性研究”资助

摘　　要：中东地区白垩系Mishrif组主要由富含生物碎屑的颗粒泥晶灰岩及泥晶颗粒灰岩组成。基于薄片研究了伊拉克鲁迈拉油田Mishrif组碳酸盐岩中生物碎屑特征及其成岩作用的相异性特点,并总结了生屑成岩作用差异性特征对储层的影响。该区Mishrif组重要的生物碎屑有三大类,即双壳类、棘皮类和有孔虫类。这些生物碎屑主要经历了同生阶段的泥晶化和大气淡水溶蚀作用,中-浅埋藏期的压实压溶、充填胶结、新生变形等多期成岩作用。泥晶化作用主要发生在有孔虫壳体外壁;溶蚀作用更易发生在双壳类和有孔虫壳体中。胶结作用在不同类别生物碎屑上的表现形式不同,且对储层中早期孔隙的破坏强烈。不同类别生物碎屑的结构、大小、成分的差异造成了成岩作用的差异并进而影响储层物性。The Cretaceous Mishrif Formation in the Middle East mainly consists of bioclastic packstone or wackestone.Based on a detailed study of thin sections,the diagenetic history of Mishrif Formation of the Rumaila Oil Field,Southern Iraq,was analyzed.This paper also discusses the impact of bioclasts on reservoir quality.In the study area,three types of of bioclastic can be identified：they were derived from bivalves,echinoderms,and foraminifers.These bioclasts underwent micritization and meteoric dissolution in early diagenesis,and then experienced compaction,cementation,and neomorphism during the burial stage.Micritization mainly occurred on the exterior surfaces of foraminifer shells,whereas meteoric dissolution occurred in bivalve and foraminifer shells.Different bioclasts are characterized by different styles and different degrees of cementation,and these cements strongly damaged early dissolution porosities.Therefore,the texture,size,and composition of different types of bioclastics controlled the diagenetic processes and affected reservoir properties.

关 键 词：资源地层学 岩石地层学 碳酸盐岩 生物碎屑 成岩作用 Mishrif组 白垩系 鲁迈拉油田 伊拉克 

分 类 号：P539[天文地球—古生物学与地层学] P534.53[天文地球—地质学]