Evaluation method of utilization status of injected water in reservoir

Abstract

The invention provides an evaluation method of usage status of reservoir flooding water. The evaluation method of the usage status of the reservoir flooding water includes: first, according to a permeability saturation curve of normalization of an oil reservoir, confirming a reservoir water-cut rising regularity description equation; secondly, according to an actual recovery percent of recoverable reserves at different stages of the oil reservoir, calculating corresponding theoretical water content by adopting the reservoir water-cut rising regularity description equation, and then according to a stage injection-production ratio of the oil reservoir, calculating theoretical stage water storage rate and stage water drive index deviation of the oil reservoir; thirdly, according to the stage injection-production ratio and actual water content of the oil reservoir, calculating actual stage water storage rate and stage water drive index deviation of the oil reservoir, and respectively drawing curves of the actual and theoretical stage water storage rate and the actual and theoretical stage water drive index deviation, which change along with time; finally, evaluating the usage status of the reservoir flooding water by comparing the theoretical curves with the actual curves. By using the evaluation method of the usage status of the reservoir flooding water, the usage status of the reservoir flooding water can be accurately evaluated, and a reliable decision basis is provided to development adjustment of the reservoir flooding water.

Description

technical field [0001] The invention relates to the technical field of reservoir water injection development, and more specifically, relates to an evaluation method for utilization status of reservoir injection water. Background technique [0002] Most of the oil reservoirs in our country adopt the water injection development method. For the water injection development oil reservoirs, it is usually necessary to evaluate the water injection development effect of the reservoir, so as to find the problems in the reservoir development in time and clarify the overall direction of the next development adjustment of the reservoir; Among them, the evaluation of the utilization status of injected water is an important part of the evaluation content system of water injection development effect. [0003] For water injection reservoirs, the water storage rate or water flooding index is usually used as the evaluation index to evaluate the utilization status of the injected water in the r...

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Problems solved by technology

[0004] However, the existing relationship between stage water storage ratio or stage water flooding index and water cut ignores the influence of formation water volume coefficient in the derivation process, and the derivation process is not rigorous enough, which makes the relationship form more complicated and the physical meaning between parameters Not clear enough

In addition, since the injection-production ratio in the actual stages of water-flooding development reservoirs is constantly changing, and the relationship curve between the stage water storage ratio or stage water flooding index and water cut in the theoretical relationship diagram is fixed injection-production ratio, the actual curve and the theoretical curve Correspondence is poor, so the utilization status of reservoir injection water cannot be well evaluated

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