高含水期储集层物性和润湿性变化规律研究

随着大庆油田水驱程度的不断提高,各类储集层的物性和润湿性发生明显变化,影响开发调整措施的制定。为此,利用大庆油田历年检查井水洗分析资料、不同时期同井场测井资料及室内岩心实验分析资料,开展储集层物性(孔隙度、渗透率)和润湿性等参数变化规律研究,并对影响储集层物性和润湿性参数变化的诸多因素进行分析。研究认为,油层水淹后孔隙度变化幅度不大,而渗透率的变化相对比较大,并随油层厚度增加,渗透率变化幅度逐渐变大;油层水淹后岩石润湿性由原始的偏亲油非均质润湿性变为偏亲水非均质润湿性,而且随着油层含水饱和度的增大,岩石亲水程度明显增强。图6参4

Variation of physical characteristics and wettability of the reservoir in high water-cut stage

The physical characteristics and wettability of different reservoir varies evidently with the increasing of water flooding re-covery in Daqing Oilfield. The variations influence the development and adjustment measures of the oilfield. Using the cored wells data of past years, well logging data in different period of same well sites and the laboratory core data, the variation of physical characteristics (porosity and permeability) and wettability of the reservoir are studied. The elements that influence the physical characteristics and wettability are also studied. After the water flood of the reservoir, the variation of porosity is not obvious, whereas the change of permeability isapparent. The variation of the permeability increases with the increase of thickness of the reservoir. The wettability of the rocks changes from the original slightly heterogeneous oil wet to slightly heteroge-neous water wet.