Oligomeric betanine type foam drainage agent and preparation method

Abstract

The invention relates to an oligomeric betanine type foam drainage agent for foam drainage gas recovery in the later period of oil and gas well development and a preparation method. The agent can improve the foaming performance and stability of a foaming agent in electrolytes and hydrocarbons. The technical scheme is as follows: the chemical name of the foam drainage agent is N,N,N''-alkyl sodium diethyletriaminepentaacetate named NDDTP; firstly, sodium hydroxide and an isopropyl alcohol aqueous solution are added to a three-neck bottle, and the solution is stirred for dissolution; then diethylenetriaminepentaacetic acid is added, the mixture reacts at the temperature of 65-75 DEG C for 15 min, and an intermediate product,namely, sodium diethylenetriaminepentaacetate, is obtained; then a bromoalkanol solution is added to the intermediate product solution while stirring, and the mixture reacts at the temperature of 75-85 DEG C for 6-8 h; finally, a coarse product is obtained through distillation of a reaction liquid, and a solid product is obtained through desalinzation with ethanol and recrystallization with acetone. A foam drainage solution is prepared through compound of the foam drainage agent and ethylene glycol, has good foaming performance and foam stability and is used for increasing gas recovery ratio.

Description

technical field [0001] The invention relates to an oligomeric betaine-type foam drainage agent used for foam drainage and gas recovery in the later stage of exploitation of natural gas wells, coalbed gas wells and shale gas wells, and a preparation method thereof, which is suitable for high temperature resistance, high salinity and high condensate oil in deep wells For foam drainage. Background technique [0002] Foam drainage gas recovery is to improve the liquid-carrying capacity of the gas flow through the injection of foam agents, so as to relieve the blockage of gas-water flow and achieve the purpose of stabilizing and increasing production of gas wells. Its production-aiding effect is through the foam effect (injecting foam agent or foam drainage agent into the wellbore, under the agitation of the air flow, the foam agent is miscible in the gas-water mixed phase, and in the form of foam, the bottom-hole fluid brought out by the wellbore), dispersion effect, drag reduc...

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Problems solved by technology

Patent CN102851015 has developed a high-temperature, high-condensation, and high-salinity oil foam drainage agent, which has a good drainage and gas recovery effect, but the mass fraction of the surfactant used is as high as 0.90-0.95, and the cost is too high to be used at all. implementation, and the site has to be prepared with a reactor and then react for 30 minutes, which brings inconvenience to the construction

Patent CN102676142A has developed a condensate oil foaming agent suitable for natural gas development, which solves the phenomenon of wellbore fluid accumulation caused by water and condensate oil, but the mass fraction of surfactant is still high, reaching 0.37-0.70, and the cost is high ,Uneconomical

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