莫索湾地区清水河组储层特征及优质储层控制因素分析

Analysis of Reservoir Characteristics and Controlling Factors of High Quality Reservoir of Qingshuihe Formation in Mosuowan Area

莫索湾地区清水河组油气资源丰富,但埋深较大,储层非均质性较强,优质储层分布规律较复杂。本次研究以岩心、镜下薄片、压汞、物性及地层测试资料为基础,结合储集砂体沉积条件,深入分析储层特征及优质储层发育的控制因素,结果表明,储层整体储集条件较为优越,孔隙类型以原生孔隙为主,且孔隙结构多为中孔粗喉型;储层平均孔隙度为15.26%,平均渗透率为35.99×10^(-3)μm^2,属中孔中渗型。其中优质储层发育主要受控于沉积微相、成岩作用和异常高压3方面。沉积微相控制砂体的宏观分布、成分成熟度和结构成熟度,决定储层原始物性的好坏。沟槽带的水下分流河道砂体和低凸带的滩坝砂体物性最优越。成岩作用决定着对储层物性的后期改造及次生孔隙的发育程度。普遍存在的地层超压对于深部储层物性的保存具关键作用。

The Qingshuihe Formation in Mosuowan area is rich in hydrocarbon resources.But the reservoir is deeply buried,and the heterogeneity is strong.Thus,it is significant for hydrocarbon exploration to analyze reservoir characters and its controlling factors.Based on cores,thin slice,mercury intrusion data,physical property data and strata test data,sedimentary and diagenesis characteristics of the reservoir are analyzed and the main controlling factors which affect the development of high quality reservoir are determined.The results show that the reservoirs are mainly composed of primary pores,and the average porosity is 15.26%,the average permeability is 35.99×10-3μm2.The structure type of the pores is medium porosity and coarse throat.On the whole,the reservoir belongs to middle porosity and middle permeability,with a favorable pore structures.The sedimentary microfacies determine the distribution of sand bodies and reservoir composition maturity and structure maturity which in turn determine the original physical property.Sand bodies of underwater distributary channel and beach bar have better physical properties.In addition,the diagenesis processes determine the transformation of the reservoirs in the later evolution period.The widespread distribution of overpressure plays a significant role in the formation of dissolution pores and in porosity preservation of deeply buried reservoirs.