板桥-合水地区长8油层微观渗流特征及驱油效率分析

Study on Micro-seepage Characteristics and Oil Displacement Efficiency Factors of Chang 8 Reservoir in Banqiao-Heshui Area

通过观察大量岩心、铸体薄片、扫描电镜对储层岩石学,沉积等特征分析的基础上,对研究区长8储层的微观孔隙结构作分析,利用水驱油实验分析储层微观的驱替类型及驱油效率的影响因素。分析表明:长8储层微观驱替方式主要有均匀水道驱替型,指状绕流驱替型,网状驱替型3种类型,流体渗流效果的不同受微观孔隙结构特征,储层物性,微观非均质性等诸多因素的影响。其中渗透率较孔隙度能够更加有效提高驱油效率;最大孔喉半径、最大进汞饱和度均是储层孔喉连通性的重要参数,直接反应孔喉的储集和渗流能力;储层孔喉的连通程度越高,孔喉半径越大,储层渗流能力越强,驱油效率越高。

Based on the observation of a large number of cores,castings and scanning electron microscopy（ SEM） on reservoir petrology and sedimentary characteristics,the microscopic pore structure of Chang 8 reservoir was studied,and analysis the micro-displacement types and factors of oil displacement efficiency by water flooding experiment.Analysis shows： the Chang 8 reservoirs have 3 displacement methods,including uniform waterway displacement,finger around flow displacement,reticular displacement. The effect of fluid seepage is affected by micro-pore structure,reservoir physical properties,micro-heterogeneity and many other factors. The permeability is more efficient to increase the oil displacement efficiency than the porosity. Maximum throat radius and Maximum mercury saturationare the important parameters of reservoir pore throat connectivity,they directly respond to the reservoir and seepage capacity of the pore throat. The connection degree of reservoir pore throat,throat radius and reservoir seepage capacity areall have positive effects on oil displacement efficiency.