渤海XX29-2油田中深层优质储层成因分析

Origin Analysis of the Intermediate-deep High Quality Reservoir in XX29-2 Oil Field,Bohai Sea

为研究XX29-2油田沙河街组中深层储层特征,运用薄片镜下观察、岩心描述、物性分析、扫描电镜等手段对其岩性、物性进行精细分析。结果表明,XX29-2油田沙河街组中深层储层砂岩类型以含砾中—粗粒岩屑长石砂岩和长石岩屑砂岩为主,孔隙类型以粒间孔为主,储集性好,为中孔高渗优质储层。按一般的理论分析,中深层的储层因受成岩作用影响,物性多为低一中孔渗,为了解这种中深层优质储层的成因,从影响中深层优质储层成因的七个因素对其做了分析,最后得出CO_2热流体和粗粒砂岩是形成该区优质储层的主控因素。这一成果为下步渤海中深层有利目标的勘探提供了科学依据。

The reservoir characteristics and physical properties of medium-deep Paleogene Shahejie Fm in XX29-2 oil field have been studied by using thin sections observation, physical properties analysis, scanning electron microscope and core description. The study results showed that the reservoir sandstones are dominated by conglomeratic mesograin-macrograin lithic arkose and feldspath- ic lithic sandstone. The main pore types are intergranular pores in this area. The reservoir physical properties are good, with middle porosity and high permeability. According to the general theory, the physical property of mid-depth reservoirs is low-middle porosity and permeability due to the influence of diagenesis. To understand the origins of this kind of excellent mid-depth reservoir, analysis has been conducted on the seven factors influencing the high-quality reservoir. Through analysis, it is concluded that the main control factors for high-quality reservoirs are CO2 hot fluid and gritstone. The study results provide a scientific foundation for looking for high-quality reservoirs in Bohai bay.