油水同层生产井注水效果评价指标修正方法

Modification Method of Evaluation Index for Water Injection Effect of Production Wells in Oil-water Layer

常规用于评价注水效果的计算公式(如水驱指数、存水率、耗水率等)在评价油水同层生产井时出现严重失真。研究发现,失真原因是油水同层生产井开井即产出伴生水,拥有较高的含水率,造成计算公式中产水量偏高的假象。将油井产水量区分为“产出伴生水量”和“产出注入水量”,并根据油井见水时间区分二者大小,提出了将计算公式中的“产水量”修订为“产出注入水量”,并将修正后的计算公式用于F井区油水同层生产井的开发效果评价。目前区块采出程度18%,存水率为80%,耗水率为0.98,水驱指数为1.24,注水利用率较高。该修正方法对其他油水同层井注水效果评价也有一定的借鉴意义。

The calculation formulas that are conventionally used to evaluate the effect of water injection(such as water flooding index,water storage rate,water consumption rate,etc.)are seriously distorted when evaluating production wells in oil-water layer.In order to solve this problem,the production wells in F well area are studied.It is found that the reason for the distortion is that the associated water is produced when the well is opened,and the water content is high,which causes the false appearance of high water production in the calculation formula.In this paper,the water production of oil wells is divided into“associated water”and“injected water”,and the two volumes are distinguished according to the water breakthrough time of oil wells.The“water production”in the calculation formula is revised to“injected water”,and the revised calculation formula is used to evaluate the development effect of oil-water production wells in F well area.At present,the extraction rate of the block is 18%,the water storage rate is 80%,the water consumption rate is 0.98,the water flooding index is 1.24,and the water injection utilization rate is high.This corrected method also provides significant reference for water injection effect evaluation of other oil-water wells.