滨里海盆地Д南石炭系碳酸盐岩储层类型及分布特征

Types and Distribution of Carboniferous Carbonate Reservoirs in Southern Д Area of Pre-Caspian Basin

在滨里海盆地东缘Д南石炭系碳酸盐岩KT-II含油层系Д层岩心和录井资料稀缺的情况下,针对该区油气发现多年但储量一直未有效动用,导致碳酸盐岩储层钻井结果见效差、单井初始产能差异大的生产矛盾。通过井筒资料精细对比分析,确定Д南难动用储量区Д层复杂储层的有利层段为Д1底部鲕粒白云质灰岩所在的白云岩化带,该储层主要为孔洞缝复合型和孔隙-裂缝型。结合古构造和沉积相特征,确定储层有利分布相带为开阔台地相浅滩亚相滩微相,原始沉积环境和白云岩化作用控制着储层的发育。在有利相带约束下,优选地震属性并进行叠前叠后储层反演,根据储层厚度、孔隙度、裂缝发育程度及含烃指示等因素综合评价,预测Д1层复杂碳酸盐岩储层发育区为近NE SW向带状分布,为该区提高储量动用程度和钻井见效提供地质参考依据。

Given the shortage of core and mud logging data on the Д zone of Carboniferous KT-II of the southern of Д area in the eastern edge of Pre-Caspin basin,The oolitic dolomitic limestone on the lower of Д1 layer was defined as favorable reservoir layer in Carboniferous KT-II by the detailed analysis on borehole data in the southern of Д area in the eastern margin of Pre-Caspin basin.This favorable reservoir in Д1 layer are pore-vug-fracture composite and pore-fracture.The favorable sedimentary faciesbelt with beach miscorfacies of shoal subfacies in open platform facies is determined combined with the paleostructure and sedimentary facies.The carbonate rock reservoir in Д1 layer was controlled with both original depositional environments and dolomitization.Based on the sedimentary facies constraints and the optional seismic attributes selection with the pre-stack and post stack inversion,the advantageous reservoirs distribution with NE SW belts on Д1 layer is predicted considering the thickness,porosity, fracture and hydrocarbon indicator on carbonate rock reservoir.All these provide the effective and prospective geological references for drilling and production for KT-II.