有效累计注采比及其在注水开发效果评价中的应用——以吉林红岗油田大45区块超低渗透油藏为例

针对超低渗透砂岩油藏注采比高的问题,基于无效注水原因分析提出了有效累计注采比的概念。以吉林红岗油田大45区块为例,采用吸水剖面法和物质平衡法分别对有效累计注水量和有效累计注采比进行了计算并比较其结果,并利用油藏数值模拟予以验证。其结果合理地解释了超低渗透油藏有效累计注采比高的原因,同时也说明了以往累计注采比的局限性,该方法可用于同类超低渗透油藏注水开发效果评价。

Effective accumulative injection-production ratio and its application during the effect evaluation of water injection development—taking ultra-low permeability reservoir in Da 45 Block of Honggang Oilfield in Jilin Province for example

For the problem about the high injection-production ratio in ultra-low permeability reservoir, the concept of effective accumulative injection-production ratio is created based on the reason of inefficient water injection. Taking Da 45 Block of Jilin Honggang Oilfield in Jilin Province, water injection profile method and material balance method are used to respectively compute the effective accumulative water injection rate and the effective accumulative injection-production ratio and contrast the results, and numerical reservoir simulation is used for verification. The results reasonably demonstrate the reason of the high effective accumulative injection-production ratio in ultra-low permeability reservoir as well as the limitation of pervious accumulative injection-production ratio. Therefore this method can be applied to evaluate the water injection development effect in the similar ultra-low permeability reservoir.