水驱砂岩油藏开发后期确定合理注采比的一种方法

A NEW METHOD USED TO DETERMINE THE SUITABLE INJECTION-PRODUCTION RATIO FOR WATER-FLOODING RESERVOIRS AT LATER STAGES

确定水驱开发油藏的合理注采比是现代油藏管理的重要任务之一.水驱开发油藏的注采比是否合理直接影响着油藏地层压力保持水平及生产能力.利用物质平衡方程,依据注采平衡原理,推导出在油藏稳定生产时地层压降与注采比的关系,由实际矿场资料拟合出相关系数,通过合理地层压降来确定合理注采比,为油藏开发后期生产管理提供依据.双河油田437块、438块、Ⅴ上、Ⅶ上等4个开发单元的实例证明,这是一种计算简便、行之有效的方法.在宏观油藏管理上,该方法对于指导高含水期开发阶段油田的注水调整有一定的指导意义和实用价值.

It is one of most important tasks in modern reservoir menagement to determine the suitable injection-production ratio. Injection-production ratio （IPR） directly affects the pressure maintenance and the productivity of reservoirs. Based on the material-balance equation and the theory of injection-production balance, we derived the relationship between the pressure decline and the injection-production ratio from when the reservoir has a stable production Then we proposed the suitable injection-production ratio for the production management at later stages of reservoir development with the correlation factor derived from regression analysis. Instances of four developing units in Shuanghe oilfield, including Block 437, Block 438, Block Ⅴ and Block Ⅶ, show that this method is a simple and effective one. It should be meaningful and useful for the adjustment of water injection in oilfields at high water-cut stage of production.