Small-molecular liquid anti-swelling agent, clay anti-swelling agent for fracturing and preparation method

Abstract

The invention discloses a small-molecular liquid anti-swelling agent, a clay anti-swelling agent for fracturing and a preparation method. The anti-swelling agent comprises the following components byweight percent: 10-65% of alkyl hydroxypropyl quaternary ammonium salt, 1-10% of guanidine hydrochloride, 1-10% of nonionic surfactant and the balance of water, wherein the nonionic surfactant is alkylphenol polyoxyethylene or fatty alcohol-polyoxyethylene ether with 8-18 alkyl carbon atoms and degree of polymerization within 8-20. The liquid anti-swelling agent disclosed by the invention is composed of small-molecular components, has the characteristics of low relative molecular weight, no harm to hydrocarbon reservoir and convenience in onsite preparation, and is low in dosage and high in anti-swelling rate; the anti-swelling rate of an anti-swelling rate aqueous solution can reach up to 71%; after the liquid anti-swelling agent is compounded with an inorganic salt, the anti-swelling rate can reach up to 79%; the small-molecular liquid anti-swelling agent is specially suitable for fracturing modification of low-permeability and water-sensitive stratum.

Description

technical field [0001] The invention relates to the field of well drilling, and more particularly relates to a small molecule liquid anti-swelling agent, a clay anti-swelling agent for fracturing and a preparation method. Background technique [0002] At present, most scholars' research on anti-swelling agents is focused on organic cationic polymers, such as CN101921366, which synthesizes three-branched cationic polymers from diallyl ammonium chloride and triallyl ammonium chloride, which are used to stabilize clay in the oil recovery process. . However, studies have shown that high-molecular-weight cationic polymers are not suitable for low-permeability formations, and they are easy to form plugs in the pore channels of formations, thereby blocking formations; at the same time, due to the long molecular chains of polymers, they contain a large number of cationic groups, and are easy to mix with anionic groups. The treatment agent reacts, which greatly affects the effect of...

AI Technical Summary

Problems solved by technology

[0003] Most of the commonly used anti-swelling agents are in solid form. Although the effect of stabilizing clay is good (high anti-swelling rate), it is difficult to meet the requirements of mass mixing and rapid dispersion at the fracturing site, so the liquid form is preferred

Yet the anti-swelling agent figure solid anti-swelling agent of liquid form compares, because effective content reduces, and anti-swelling effect is poor during its low dosage, so need increase dosage during application (as Chemical and Biological Engineering, 2010, 27 (12) Small molecule polyamine anti-swelling agent, the anti-swelling rate is 72-86% when the dosage is 1%-2%, and the anti-swelling rate is only 43% when the dosage is 0.5%)

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