杏六区薄差储层水驱油特征

Water Flooding Characteristics of Thin and Poor Reservoirs in Xing 6 Area

通过对杏六区薄差储层典型相对渗透率曲线进行筛选,采用流动系数作为权重系数对单层归一化后的曲线进行复合,得到复合相对渗透率曲线。由复合相对渗透率曲线可知,杏六区薄差储层具有残余油饱和度、束缚水饱和度小,驱油效率低,共渗区范围较窄的相渗特征。根据相对渗透率曲线计算含水率和采出程度,得出含水率与采出程度的关系曲线分为"凸"型和"S"型两种。通过研究杏六区薄差储层的驱油效率与渗透率、原油黏度、驱替压力梯度的关系曲线可知,驱油效率随渗透率、驱替压力梯度的增加而增加,随地层原油黏度的增加而降低。对驱油效率与微观结构孔隙参数进行相关性分析。结果表明,孔隙半径与驱油效率之间的相关系数最小,仅仅为0.090,驱油效率和喉道半径之间的相关性最大,相关系数为0.437;另外,微观孔隙结构参数中孔隙半径对驱油效率的影响较小,喉道半径与孔喉比对驱油效率的影响较大。

After screening the typical relative permeability curves of thin and poor reservoirs in Xing 6 area,the flow coefficient is used as the weight coefficient to compound the normalized curves of single layer,and the composite relative permeability curves are obtained.The study of composite relative permeability curve shows that thin and poor reservoirs in Xing 6 area have the characteristics of residual oil saturation,low irreducible water saturation,low oil displacement efficiency and narrow common permeability area.According to the relative permeability curve,the water cut and recovery degree are calculated.The results show that the relationship curve between water cut and recovery degree can be divided into two types:convex and S.By studying the relationship curves between displacement efficiency and permeability,crude oil viscosity and displacement pressure gradient of thin and poor reservoirs in Xing6 area,it can be seen that displacement efficiency increases with the increase of permeability and displacement pressure gradient,and decreases with the increase of formation crude oil viscosity.The correlation analysis between oil displacement efficiency and micro⁃pore parameters shows that the correlation coefficient between pore radius and oil displacement efficiency is the smallest,only 0.090.The correlation coefficient between displacement efficiency and throat radius is 0.437.The results show that the effect of pore radius on oil displacement efficiency is small in micro pore structure parameters,and the effect of throat radius and pore throat ratio on oil displacement efficiency is greater.