Method of regulating water sucking sectino of deep oil layer

Abstract

The water injection profile regulation method for further raising crude recovery efficiency is characterized by that in the course of injecting crosslinked polymer solution into water injection well the described crosslinked polymer solution is a dispersion system which is formed from cross-linking agent solution and polymer solution in water and has elastic solid and / or non-solid particles or a dispersion system formed from polymer coil made up by cross-linking cross-linking agent solution and polymer solution, and the diameter of elastic solid and / or non-solid particles or cross-linked polymer coil in the dispersion system is 10-2000 nm, and the viscosity of said dispersion system is 0.6-8.9 mPa.s.

Description

field of invention [0001] The present invention relates to the field of petroleum exploitation, in particular to a method that can realize the adjustment of the deep water absorption profile of the oil reservoir in the oilfield, so that the unproduced crude oil can be driven out in the process of water flooding or polymer flooding, and the crude oil recovery can be further improved. yield method. Background of the invention [0002] In the process of oil recovery, oil displacement is an important part of enhanced oil recovery. The traditional methods include water flooding and chemical flooding. Looking at the traditional oil flooding process, it can be found that due to the heterogeneity of the formation, the effect of this oil flooding method is that the crude oil in the rock formation with higher permeability can be driven out smoothly, while the crude oil in the rock formation with lower permeability can be driven out smoothly. Crude oil remains in the ground. For oilf...

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Problems solved by technology

[0005] The adjustment of the deep water absorption profile of the reservoir in each period is completed by injecting the profile control agent. During the injection process of the profile control agent, the traditional methods include: 1. Inject the pre-prepared profile control agent from the water injection well. Traditional profile control agents pursue high viscosity or high strength (such as polymer gel), and the polymer concentration used is high to form a network structure, resulting in high injection pressure and difficult injection; 2. "Double liquid method" injection , this method is to inject the polymer solution from the water injection well first, and then inject the cross-linking agent from the same water injection well after a period of time (usually a few days). It is hoped that the polymer and the cross-linking agent will meet and cross-link in the deep formation. However, due to the influence of factors such as the adsorption loss of the cross-linking agent in the formation and the slow diffusion into the polymer solution, it is difficult for the polymer and the cross-linking agent to form a gel in the formation, so it is not as expected 3. Using the "delayed cross-linking method", this method is to wrap the cross-linking agent in "capsules", mix the capsules in the polymer solution, and inject the mixture of the capsules and the polymer solution After the formation, the capsule is gradually broken, releasing the cross-linking agent, making it cross-linked with the polymer to form a polymer gel, which plays the role of deep profile control

However, due to the difficulty in controlling the preparation and rupture time of capsules, this method has not been successfully recorded in field tests.

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