Preparation method and application of gel profile control oil-displacing agent

Abstract

The invention provides a preparation method and an application of a gel profile control oil-displacing agent. The preparation method comprises the following steps: mixing the following components by mass percent: 10% to 50% of cationic monomer, 5% to 20% of nonionic monomer, 0.01% to 0.1% of methylene bisacrylamide, 0.1% to 0.2% of ammonium persulfate and the balance of water, so as to prepare a solution; performing a polymerization reaction on the solution for 8 to 11 hours at the temperature of 60 DEG C to 90 DEG C so as to obtain the gel profile control oil-displacing agent. The preparation method is simple; the required synthetic materials are abundant in resource and easy to obtain. In addition, the prepared gel profile control oil-displacing agent has the advantages that the oil-displacing agent is small in particle diameter and can be split from sand grains and condensed with the sand grains to form gel groups under different pressure differences; the oil-displacing agent is more excellent in heat resistance and salt tolerance because an oil-displacing activator is fixed on the surface of each microsphere, and the like. Thus, the gel profile control oil-displacing agent can be favorably applied to the blocking and the oil displacement of rock layer cracks during the exploitation of oilfields of various types, and is low in cost and good in effect.

Description

technical field [0001] The invention belongs to the field of oil displacement agents, in particular to a preparation method and application of a gel profile control oil displacement agent. Background technique [0002] The oilfield recovery rate is determined by the efficiency of the injected fluid, which is reflected in the swept volume and oil washing efficiency. The complexity of the formation (such as heterogeneity) and the large flow channel formed by long-term water injection lead to a small swept volume of injected water, The recovery rate is low. In the high water-cut and ultra-high water-cut periods in the later stage of production, a large amount of injected water flows in series, and the middle and low permeability layers are not swept, and there is still a large amount of residual oil. At this time, the full profile control changes the seepage direction of the injected water and increases the swept volume of the injected water. It is an important method to impro...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a preparation method and application of a gel profile control and oil displacement agent, aiming to solve the existing problems of weak profile control and oil displacement, resistance to high temperature and high salt, too fast crosslinking speed, and high cost