Self-diverting agent for heterogeneous carbonate rock acidizing system

Abstract

The invention relates to a self-diverting agent for a heterogeneous carbonate rock acidizing system. The self-diverting agent is characterized by: taking erucic acid as an initiator, adding 3-dimethylaminopropylamine to make them undergo a reaction under oil bath conditions and under the action of a water carrying agent dimethylbenzene and a catalyst KOH; subjecting the reacted mixed solution to pressure reduced vacuum pumping and cooling, thus obtaining erucamide tertiary amine; mixing the erucamide tertiary amine with a sodium chloroacetate solution and leaving them to react under water bath conditions; dissolving the reacted mixed solution in an acetone solution, conducting cooling to room temperature, and carrying out standing and pumping filtration so as to obtain erucamidopropyl betaine, i.e. the self-diverting agent for the heterogeneous carbonate rock acidizing system involved in the invention. Along with the progression of an acid-rock reaction, the acid solution system prepared in the invention can realize automatic viscosity change to generate high flow resistance, thus realizing effective distribution of the acid solution in a reservoir. The self-diverting agent has the characteristics of reducing acid solution filter loss, increasing the acid solution penetration distance, and ensuring effective self-diverting of the acid solution system.

Description

Technical field: [0001] The invention relates to a self-steering agent for heterogeneous carbonate rock acidification system, which belongs to the technical field of oil field chemical agent design. Background technique: [0002] For now, acidizing is still one of the most widely used stimulation measures for oil and gas reservoirs. In the acidizing process of heterogeneous carbonate reservoirs, according to the principle of minimum permeability resistance, conventional acids such as gelled acid, emulsified acid, and cross-linked acid first enter the higher permeability layer, and it is difficult to enter the microscopic layer of the low permeability layer. The cracks and pores cause a large amount of acid fluid to be lost and quickly consumed, the effective distance of action is reduced, and the effect of acidification to increase production is not ideal; Injection pressure. At the same time, conventional acid only shows superiority in viscosity, which is characterized by...

AI Technical Summary

Problems solved by technology

In the acidizing process of heterogeneous carbonate reservoirs, according to the principle of minimum permeability resistance, conventional acids such as gelled acid, emulsified acid, and cross-linked acid first enter the higher permeability layer, and it is difficult to enter the microscopic layer of the low permeability layer. The cracks and pores cause a large amount of acid fluid to be lost and quickly consumed, the effective distance of action is reduced, and the effect of acidification to increase production is not ideal; Injection pressure

At the same time, due to the superiority of conventional acid only in viscosity, it is more viscous, and its shear resistance is limited, which means that the system is less elastic and the stability of the system is poor when it is acidified.

[0003] In order to obtain the effect of high-efficiency stimulation and transformation, not only a greater penetration depth of the acid solution is required, but also a better flow state and an appropriate acid etching position of the acid solution in the target layer are required, and the system is stable and the residual acid breaks the gel when the acidification is turned. Thoroughly, without polluting the reservoir; obviously, the existing conventional acid technology cannot meet the needs of actual production

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