伊拉克米桑油田群Mishrif组MB_2~1段碳酸盐岩储层特征及成因

Characteristics and genesis of carbonate reservoirs in the Mishrif MB_2~1 member in the Missan oil fields,Iraq

以岩心、录井、测井、地震及相关生产资料为基础,对伊拉克米桑（Missan）油田群Mishrif组MB_2~1段储层特征及其成因进行分析。结果表明,Mishrif组MB_2~1段储层沉积环境属于碳酸盐岩开阔台地,发育有台内滩、台内礁和开阔潮下亚相。岩石类型主要有生物礁灰岩、生屑颗粒灰岩、生屑似球粒颗粒灰岩及生屑似球粒泥粒灰岩。储集空间类型主要为原生粒间孔、次生粒间溶孔、铸模孔、基质微孔及少量小型溶蚀孔洞和微裂缝。受沉积作用和成岩作用控制,储层横向分布相对稳定,但纵向物性变化较大、层内非均质性严重,是制约原油采出程度的关键因素。

The characteristics and genesis of carbonate reservoirs in the Mishrif MB12 member in the Missan oil fields were studied based on core,well logging,seismic and production data. The reservoirs were mainly deposited in a carbonate open platform sedimentary environment,and developed several subfacies such as bioclastic shoals,bioherms and open subtidal deposits. Rudist grainstones,skeletal grainstones,skeletal peloidal grainstones and skeletal peloidal packstones were found. Primary intergranular pores,secondary dissolution pores,mouldic pores,micro-pores associated with matrix,a small quantity of micro-vuggy and micro-fractures provided space for hydrocarbon accumulation. Controlled by deposition and diagenesis,reservoir distribution was similar laterally,but varied obviously vertically and showed a strong heterogeneity,which restricted oil development.