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.