镇北油田长8段储集层孔隙类型与水驱油渗流特征

针对鄂尔多斯盆地镇北油田延长组长8段储集层微观孔隙类型复杂、水驱油规律认识薄弱等问题，应用砂岩微观水驱油模型，结合铸体薄片、扫描电镜等手段，对长8 油藏的微观孔隙类型及水驱油渗流特征进行研究。结果表明，研究区长8油藏储集空间以残余粒间孔、溶蚀孔和微裂缝为主；驱替类型主要为网状驱替和指状驱替，均匀驱替较少，不同驱替类型水驱油效率不同，均匀驱替效率最高，指状驱替效率最低。水驱油效率与渗透率相关性较高，相关系数为0.84，与孔隙度相关系数为0.51，储集层非均质性也是影响水驱油效率的重要因素。

Reservoir Pore Types and Flowing Characteristics of Oil Displacement by Water in the Chang-8 Member of Zhenbei Oilfield,Ordos Basin

Regarding the complex microscopic pore structures and the weak understanding on water flooding regularity, the paper studies the microscopic pore structures and the flowing characteristics of oil displacement by water in the reservoir of the Chang-8 member by using sandstone waterflooding model, cast thin section and SEM analysis in Zhenbei oilfield, Ordos basin. The results show that the accumulation spaces of the Chang-8 reservoir in the study area can be divided into residual intergranular pores, dissolved pores and microcracks; the displacement types are dominated by network displacement and finger-like displacement and even displacement seldom occurs. Different types of waterflooding have different displacement efficiencies, the efficiency of even displacement is the highest and that of finger-like displacement is the lowest. The waterflooding efficiency highly correlates with the permeability with the correlation coefficient of 0.84 and the correlation coefficient between the waterflooding efficiency and porosity is 0.51. Reservoir heterogeneity is also an important factor influencing the waterflooding efficiency.