Self-distribution seepage-regulation water-controlling acidifying technology

Abstract

The invention comprises the preparation of a self-distribution seepage-regulation polymer and a self-distribution seepage-regulation water-controlling acidifying technology. The preparation of the regulation polymer comprises the steps of: adding 5-15 parts by mass of dimethyl diallyl ammonium chloride monomer, 2-8 parts by mass of acrylate monomer, 1-8 parts by mass of crylamide monomer, and the balance deionized water into a reaction vessel in turn; stirring the mixture; keeping the mixture at a constant temperature; introducing nitrogen to remove oxygen; adding a solid initiator which accounts for 0.2-0.8% by weight of the total mass; and allowing the obtained mixture to react for 7-9 hours under normal pressure. The self-distribution seepage-regulation water-controlling acidifying technology comprises the steps of preparation of a pad fluid, preparation of a cleaning agent, and performance of water-controlling acidifying construction. The preparation of the pad fluid comprises the steps of adding 0.2%-5% by weight of the self-distribution seepage-regulation polymer, 3%-15% by weight of hydrochloric acid or mud acid, and 0.5%-2% by weight of a corrosion inhibitor to clear water; and stirring the mixture uniformly under normal temperature and pressure. The preparation of the cleaning agent comprises the step of adding 2%-3% by weight of KCl brine to 20m3 of 1% by weight of a nonionic surfactant. The performance of water-controlling acidifying construction comprises the steps of washing a well in forward and reverse directions by running a tubing string; washing an oil reservoir wherein the pad fluid is injected under the pressure of less than70% of an oil reservoir fracture pressure; injecting a routine acidifying liquid and closing the well.

Description

technical field [0001] The invention relates to a method for water-controlled acidification of water-bearing oil wells in oilfield development, in particular to a self-distributed seepage regulation water-control acidification process. Background technique [0002] The key to the success of acid liquid temporary plugging in acidizing process in oilfield development is uniform acid distribution, especially for horizontal wells. The currently used foam acid plugging removal has played a role in the acidizing process, but at the same time there are the following shortcomings or deficiencies: ①Because the conditions of most production wells are different, there are also differences in permeability between layers, and it is difficult to distribute acid uniformly; ② The water saturation of different layers has a great influence on the cloth acid; ③The construction process is complex, requiring the use of nitrogen-making vehicles, foam liquid, etc., the construction cost is high, a...

AI Technical Summary

Problems solved by technology

The currently used foam acid plugging removal has played a role in the acidizing process, but at the same time there are the following shortcomings or deficiencies: ①Because the conditions of most production wells are different, there are also differences in permeability between layers, and it is difficult to distribute acid uniformly; ② The water saturation of different layers has a great influence on the cloth acid; ③The construction process is complex, requiring the use of nitrogen-making vehicles, foam liquid, etc., the construction cost is high, and the construction time is too long; ④There is an increase in water output after acidification