A kind of hydrophobic association zwitterionic polymer and preparation method thereof

Abstract

The invention relates to a hydrophobic association zwitterionic polymer and a preparation method thereof. The preparation method comprises the following steps: adding acrylamide, acrylic acid and cationic monomers containing quaternary ammonium groups sequentially into a reactor; adding water and dissolving; adjusting the pH value of a system to be 6 to 9 by using NaOH; supplementing deionized water to enable the total monomer mass percentage of the reaction system to be 10 to 30%; adding surfactant lauryl sodium sulfate and stirring uniformly; adding an acrylamide hydrophobic monomers containing capsaicin functional groups; introducing N2 for 20 minutes; and adding a water-soluble initiator and performing polymerization reaction to obtain the hydrophobic association zwitterionic polymer. The positive charge content and the negative charge content of the hydrophobic association zwitterionic polymer prepared with the method are equal, a solution of the polymer has an antipolyelectrolyte effect, and the hydrophobic association zwitterionic polymer has excellent salt resistance. The introduced hydrophobic units containing the capsaicin functional groups have bioactivity and adopts a rigid benzene ring structure, so that the polymer has excellent tackifying property, temperature resistance, salt resistance and anti-microbial property, high dissolution speed and low price, and has an excellent application prospect in petroleum reservoir exploitation under the conditions of high temperature, high salt and bacteria in existence.

Description

【Technical field】 [0001] The invention belongs to the field of functional polymers. More specifically, the present invention relates to a hydrophobically associating zwitterionic polymer and a method for its preparation. 【Background technique】 [0002] Petroleum still plays a key role in today's period of rapid social and economic development. However, at present, the petroleum industry is facing two major problems: (1) There are fewer and fewer new oil fields; (2) There is still a large amount of crude oil in depleted oil reservoirs, and conventional oil recovery techniques can only recover about 30% of the underlying reserves. Therefore, research and development of enhanced oil recovery technology is a very urgent subject. Tertiary oil recovery technology is a high-tech developed in the past ten years. One of the most important and mature methods is polymer flooding technology, which plays an important role in improving crude oil recovery and stabilizing crude oil produc...

AI Technical Summary

Problems solved by technology

At present, the most commonly used polymer oil displacement agents in oilfields are biopolymer xanthan gum and synthetic polymer partially hydrolyzed polyacrylamide (HPAM), which have achieved good results in most blocks of the oilfield. There are insurmountable problems in high-temperature and high-salt reservoirs: although xanthan gum has good salt tolerance, its thermal stability and biological stability are poor, it is easy to degrade and block the oil layer, and the cost is high; HPAM Rely on high molecular weight and on-chain—COO - The electrostatic repulsion makes the molecular chain stretch, so as to achieve the effect of thickening, but under the conditions of high temperature, high salt, high shear, etc., HPAM is easy to hydrolyze, degrade, chain curling, etc., resulting in a sudden change in the performance of the solution and failing to achieve engineering construction. requirements

In the process of oil recovery, bacteria such as sulfate reducing bacteria and saprophytic bacteria may adhere to the pipeline wall for a long time and contact with continuously injected HAWP, which greatly improves the ability of bacteria to decompose polymers, resulting in a large loss of polymer solution viscosity. leading to a reduction in oil displacement efficiency

(5) The synthesis process of most modified hydrophobic monomers is cumbersome and expensive, which brings difficulties to large-scale industrial production, and large-scale application has no practical significance in oilfield exploitation

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