特高含水期水驱油效率计算新方法

A new method suitable for water-oil displacement efficiency calculation in extra-high water cut period

特高含水期是油田开发的重要阶段,水驱油效率研究在该阶段具有十分重要的意义。水驱油效率计算是以油水相渗比与含水饱和度的关系为理论基础的,传统方法认为该关系呈线性,而矿场实践表明,这种关系仅适用于中—高含水阶段,在特高含水阶段则表现为非线性;因此,文中在深入研究相渗曲线特征的基础上,对油水相渗比与含水饱和度的关系表达式进行修正,并以修正公式为基础,重新推导出新的适用于特高含水期的驱油效率计算公式。实践证明,该公式符合特高含水期的开发规律,能满足油田实际生产的需要。

Extra-high water cut period is an important stage in oilfield development. It is significant to research the displacement efficiency of oilfiehls at this stage. The basis of the traditional theoretical calculation formula of displacement efficiency is that the linear relationship between oil-water relative permeability ratio and water saturation. Fiehl practice shows that this linear relationship is applicable at medium to high water cut stage. But at extra-high water cut stage, the relationship is not linear any more. Therefore, based on the research of the eharactefistics of relative permeability curve, it is necessary to correct the relationship between oil-water relative permeability ratio and water saturation. Then, the calculation formula of displacement efficiency is deduced to suit the development laws at extra-high water cut stage and meet the needs of oilfield production.