Method for improving oil field recovery rate

Abstract

The invention relates to a method for improving the oil field recovery rate. The method for improving the oil field recovery rate is characterized by using profile control and deep flow diversion dual functional blasting type pre-cross-linked gel particles for improving the oil field recovery rate, wherein the profile control and deep flow diversion dual functional blasting type pre-cross-linked gel particles are gel particles formed by initiating polymerization cross-linking of a monomer, a stable cross-linking agent and an unstable cross-linking agent by an initiator, and drying and grinding the obtained main gel. In reservoir production operation, when the method for improving the oil field recovery rate by pre-cross-linked gel particles for profile control and deep flow diversion, provided by the invention, is used, dual effects of profile control and deep flow diversion can be realized, and simultaneously, the blasting time of the pre-cross-linked gel particles can be controlled by adjusting the concentrations of the stable cross-linking agent and the unstable cross-linking agent, thereby achieving the purpose of controlling the operation period.

Description

technical field [0001] The invention relates to a method for increasing oil recovery, in particular to a method for improving oil recovery by utilizing profile control and deep liquid flow diversion dual-function blasting pre-crosslinked gel particles, which belongs to the technical field of oil exploitation. Background technique [0002] With the continuous development of oilfields, the heterogeneity of reservoirs is becoming more and more serious. A large amount of injected water scours, swelling and dissolution of clay and cement in oil layers, migration of particles, and aggravation of sand production will cause further deterioration of geological heterogeneity. . During the development process, the following problems often appear: prominent plane contradictions, plane injection water rushes along the high-permeability zone to form water channels; prominent interlayer contradictions, uneven production and suction profiles, and single-layer breakthroughs in the vertical d...

AI Technical Summary

Problems solved by technology

During the development process, the following problems often appear: prominent plane contradictions, plane injection water rushes along the high-permeability zone to form water channels; prominent interlayer contradictions, uneven production and suction profiles, and single-layer breakthroughs in the vertical direction; high viscosity of underground crude oil, oil-water High viscosity ratio, serious viscous fingering phenomenon, etc.

In recent years, although tertiary oil recovery measures such as polymer flooding have achieved good results, there are still problems such as high cost of oil displacement and difficulty in field implementation; In oil reservoirs, there are still serious problems of channeling in some wells, which affects the effect of polymer injection. Moreover, due to the limitations of the polymer itself, the effective viscosity loss in high-temperature and high-salinity formations is very large, which often cannot be reached. to the intended purpose

ASP flooding technology has gradually been widely used in Daqing and other old oilfields. The use of surfactants to reduce interfacial tension greatly reduces capillary force, and oil and water achieve miscible flow, thus starting the low permeability reservoir. Residual oil, but ASP flooding technology and polymer flooding have similar problems: shear thinning, affected by reservoir conditions, and both polymer flooding and ASP flooding will pollute oil-bearing low-permeability layers, making subsequent water flooding unable to achieve best results

Flexible particles can form dynamic plugging in deep reservoirs, but for fractures and ultra-high permeability layers caused by high-intensity water scour near the wellbore, high-strength plugging agents must be used for anti-channeling operations, otherwise flexible diverting agents will not improve recovery The effect cannot be maximized

[0007] To sum up, so far, profile control and deep liquid flow diversion cannot be carried out simultaneously in the water plugging and profile control technology of oil production, and no existing technology can solve this problem.

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