Research on Refined Water Injection Technology for Medium and High Water Cut Reservoirs in Nanpu 4 Block

Abstract For water injection development reservoir, the key is to control the di-rection and flow field of the injected water in the reservoir to adjust the tapping of the remaining oil between wells. This paper presents that, by applying the comprehensive discrimination technique of inefficient cir-culation flow field, a flow field evaluation model containing permeabil-ity, overwater multiplier and water saturation seepage characteristics parameters is established and the small layer flow field distribution is quantitatively evaluated by numerical simulation. Based on the geo-logical characteristics, development characteristics and grid inefficient circulation coefficients, the flow field is qualitatively classified into three types: streamline not established, streamline primary and sec-ondary, and streamline fixed and difficult to adjust. Based on the re-search of domestic and foreign literature and numerical simulation, the management system of different types of flow fields is studied to clari-fy the reasonable development technology policy of reservoir flow field adjustment and tapping the remaining oil between wells, so as to achieve the purpose of controlling the reservoir water content rise rate, reducing the water content rate and improving the recovery rate. The mine field experiments conducted in Nanpu 4 block showed that the recovery rate of the block increased by 4 percentage points, indicating that the block development achieved significant results. This is an im-portant guideline for reservoir development in low recovery, medium to high water-bearing reservoirs with water injection development.