Acidification preflushing fluid with seepage regulatory function

Abstract

An acidification preflushing fluid with a seepage regulatory function comprises a seepage regulatory agent and an acidification preflushing fluid. The preparation technology for the seepage regulatory agent comprises: adding 5-15 parts by weight of acrylic acid monomer, 2-8 parts by weight of acrylic acid ester, 1-8 parts by weight of acrylamide and 2-5 parts by weight of coupling agent KH570, and the balance deionized water successively to a reaction vessel, stirring to uniform, heating to 90 DEG C and keeping constant temperature, stirring as feeding nitrogen for 30min to remove oxygen in the solution, and adding a solid initiator with a mass percentage content of 0.2%-0.8% to initiate the solution to carry out a polymerization reaction at normal pressure for 7-9 h. A preparation method for the acidification preflushing fluid is that: the preflushing fluid is formed by adding a phase permeability modifier with a mass percent of 0.2%-5% to deionized water or clear water and stirring to uniform at normal temperature and pressure, or adding the phase permeability modifier with a mass percentage of 0.2%-5%, a corrosion inhibitor with a mass percentage of 0.5%-2% and hydrochloric acid or mud acid with a mass percentage of 5%-20% to deionized water or clear water and stirring to uniform at normal temperature and pressure.

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 an acidification pre-fluid with seepage regulation function. Background technique [0002] During the implementation of conventional acidizing process in oil field development, the traditional pre-fluid is generally deionized water or deionized water with active agent added. This pre-fluid plays a role in the acidizing treatment of production wells, but at the same time there are the following problems Disadvantages or deficiencies: ① When acidizing oil wells with heterogeneity and interlayer permeability differences, the acid liquid first enters the high permeability layer, and often the subsequent acid liquid is ineffective or inefficient, resulting in insufficient acidification of the production layer and affecting Acidizing effect; ②Acidizing often has the phenomenon that the water content rises rapidly after con...

AI Technical Summary

Problems solved by technology

[0002] During the implementation of conventional acidizing process in oil field development, the traditional pre-fluid is generally deionized water or deionized water with active agent added. This pre-fluid plays a role in the acidizing treatment of production wells, but at the same time there are the following problems Disadvantages or deficiencies: ① When acidizing oil wells with heterogeneity and large interlayer permeability differences, the acid liquid first enters the high permeability layer, and often the subsequent acid liquid is ineffective or inefficient, resulting in insufficient acidification of the production layer and affecting Acidizing effect; ②Acidizing often has the phenomenon that the water content rises rapidly after construction, which seriously affects the productivity of oil wells; ③For horizontal wells or production wells with thick oil layers or high water-cut production wells in the middle and late stages of development, the acidizing effect is even worse; ④Treatment The effect is poor, and repeated construction is often required, resulting in a waste of financial, material and manpower