摘要
阿联酋X油田下白垩统哈布桑组上段为主力生产层段。根据岩心及镜下观察、物性测试及毛细管压力曲线等资料,分析哈布桑组上段储层特征、成岩作用及储层成因机制。结果表明:哈布桑组上段发育5种类型(LM1、LM2、LM3、LM4、LM5)灰岩和3种类型(DL1、DL2、DL3)白云岩,储集空间以粒间溶孔、铸模孔、晶间孔为主,其他孔隙类型少见。储层以中低孔中低渗为主,孔隙结构可划分为大孔喉型、中孔喉型、细孔喉型及微孔喉型4种类型,储层整体喉道半径小。沉积相为哈布桑组上段储层的发育提供基础,多期溶蚀作用、白云岩化作用及裂缝等因素是优质储层形成的关键。哈布桑组上段沉积时期水动力条件弱,岩性较细,基质含量高;优越的气候条件有利于古生物的繁殖,为准同生期大量铸模孔的形成奠定基础;高能相带发育原生粒间孔和粒间溶孔,受整体占比较小及“孔隙尺寸控制沉淀”现象的影响,对渗透率的贡献很小,导致哈布桑组上段储层表现为低渗特征。该结果对中东地区储层成因及分类评价研究具有参考意义。
Habshan Formation upper member of Lower Cretaceous in United Arab Emirates is the main production zone of X Oilfield.Reservoir characteristics,diagenesis and the genetic mechanism were studied by cores and cast thin section observation,physical property testing and mercury injection experiments.There are five types(LM1,LM2,LM3,LM4,LM5)of limestone and three types(DL1,DL2,DL3)of dolomite developed in the upper member of Habshan Formation.The reservoir space was dominated by intergranular pores,moldic pores and inter-crystalline pores,while other pore types were rare.The reservoir is mainly characterized by medium and low porosity and low permeability,the pore structure can be divided into four types:large-pore throat type,medium-pore throat type,fine-pore throat type and micro-pore throat type,the reservoir with small throat radius.Sedimentary environment provides the foundation for the development of reservoirs in the upper member of Habshan Formation,and the multi-stage dissolution,dolomitization and fractures are the key factors for the formation of high-quality reservoirs.The Habshan Formation upper member has weak hydrodynamic conditions,which caused fine lithology and high matrix content.The favorable climatic conditions during the sedimentary period were conducive to the reproduction of paleontology,which provided a foundation for the moldic pores formed by syngenetic selective dissolution.The primary intergranular pores and intergranular dissolution pores developed in the high-energy facies zone have little contribution to permeability due to the relatively small overall proportion,and the phenomenon of"pore-size controlled precipitation".All these caused the reservoirs characterized by low permeability.The study is of great reference significance for the study of the formation and classification of such reservoirs in the Middle East.
作者
陈培元
CHEN Peiyuan(International Company Limited,CNOOC,Beijing 100028,China)
出处
《东北石油大学学报》
CAS
北大核心
2021年第4期1-14,I0001,共15页
Journal of Northeast Petroleum University
基金
国家科技重大专项(2017ZX05032-004-001)。
关键词
低渗储层
成因机制
孔隙结构
海相碳酸盐岩
哈布桑组
阿联酋
low permeability reservoir
genetic mechanism
pore structure
marine carbonate reservoir
Habshan Formation
United Arab Emirates
