Formula of pure binary super low interface tension composite oil-displacement agent of surfactant and pdymer for triple oil production

Abstract

The composite oil-displacement agent consists of polymer 0-0.3 wt.%, surfactant 0.05-0.6 wt% and water 99.1-99.95 wt%, and is produced in kettle reactor with coagulated petroleum fraction from raw oil. It has surfactant concentration not higher than available systems, high interface tension reducing effect and stable performance. The ternary composite oil-displacement agent has no alkali and saltwhile reaching superlow interface tension and thus no alkali scale formed, no loss in polymer viscosity and viscolerasticity. In the compounding of the composite oil-displacement agent, common sewagemay be used and this produces certain environment protection effect.

Description

[0001] Involved areas [0002] The invention relates to a composite flooding formulation in tertiary oil recovery, in particular to a surfactant-polymer pure binary ultra-low interfacial tension composite flooding formulation used in tertiary oil recovery. Background technique [0003] After underground crude oil has undergone primary and secondary extraction, most of the crude oil remains in the formation. Tertiary oil recovery technology is a technology that uses chemical agents to enhance oil recovery. Composite flooding refers to a composite flooding technology that combines two or three of alkali-surfactant-polymer. The polymer increases the viscosity of the displacement fluid and improves Oil / water mobility ratio and water absorption profile, its viscoelasticity also has a certain oil washing effect, surfactants reduce oil / water interfacial tension, emulsify and solubilize crude oil; alkali reacts with acidic substances in crude oil to generate new surface in situ Activ...

AI Technical Summary

Problems solved by technology

[0004] The existing conventional ASP flooding system uses an alkali concentration of 1.0-1.5%, but some problems that directly restrict the industrial application of this technology have been exposed from field tests, such as (1) due to the high alkali concentration, Scaling in oil layers and oil wells has severely damaged the formations, and the pump barrel must be cleaned every 10 to 15 days, which increases the difficulty of oil production and additional costs, and even directly affects the normal production of oil wells; Alkali (such as NaOH) causes serious corrosion of equipment and pipelines; (3) Due to the high concentration of alkali, the viscosity and viscoelasticity of the polymer are seriously reduced. In order to achieve the required viscosity, the concentration of the polymer has to be greatly increased, which increases the cost a lot