A Method for Improving the Development Effect of Multilayer Reservoir After Polymer Flooding

Abstract

The invention relates to a method for improving the development effect of multi-layer reservoirs after polymer flooding. The method comprises the following steps: 1) according to the recovery degree of each production layer in the target oil reservoir, set a recovery degree average value, and reorganize the production layers whose recovery degree is lower than the recovery degree average value into low recovery unit, reorganize the production layers whose recovery degree is not lower than the average value of the recovery degree as a high recovery unit; 2) for a high recovery unit, extract by thinning the well pattern and changing the direction of liquid flow; for The low-production unit is mined by means of dense well pattern. This method utilizes different well patterns combined with changing the liquid flow direction to carry out targeted production of the main layer and the non-main layer, which can expand the water injection sweep of high-production units, increase the production degree of low-production units, and effectively alleviate the reservoir pressure. The planar and vertical contradictions in the development process can achieve the purpose of improving the water flooding development effect and increasing the recovery factor.

Description

technical field [0001] The invention belongs to the field of petroleum exploitation, and in particular relates to a method for improving the development effect of multi-layer oil reservoirs after polymer flooding. Background technique [0002] The development of domestic oil fields has generally gone through the stages of early water flooding, polymer flooding and subsequent water flooding development. [0003] In the early stage of water flooding, affected by the heterogeneity of the reservoir, the injected water bursts along the high-permeability interval in the plane and vertical direction, resulting in better production of the main layers with better physical properties in the vertical direction. Polymer flooding is mainly to inject high-viscosity polymer solution into the formation to reduce the mobility ratio and increase the sweep coefficient to achieve the purpose of enhancing the recovery factor. In the stage of polymer flooding, although the polymer has expanded t...

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Problems solved by technology

[0007] The purpose of the present invention is to provide a method for improving the development effect of multi-layer reservoirs after polymer flooding, so as to solve the problem that the water injection development effect of the existing method is poor after the development of multi-layer reservoirs after polymer flooding

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