Demulsifying agent, preparation method of demulsifying agent and application thereof to demulsification of binary compound flooding produced liquid

Abstract

The invention relates to the field of demulsification of binary compound flooding produced liquid, in particular to a demulsifying agent, a preparation method of the demulsifying agent and application thereof to demulsification of the binary compound flooding produced liquid. The preparation method of the demulsifying agent comprises the following steps that (1) under the existence of etherification catalysts, an initiator, ethylene oxide and epoxypropane react to obtain block polyether; (2) under the existence of esterification catalysts and polymerization inhibitors, the block polyether and unsaturated carboxylate take ester exchange reaction, so that the tail end of the block polyether has unsaturated carboxylic ester; then, reduced pressure distillation is performed for removing alcohol; an esterification product is obtained; (3) under the existence of radical initiators and polymerization auxiliary agents, the esterification product and positive ion unsaturated monomers are subjected to polymerization reaction. The demulsifying agent provided by the invention can achieve an excellent demulsification effect on the binary compound flooding produced liquid at low dosage.

Description

technical field [0001] The invention relates to the field of demulsification of produced fluid from binary composite flooding, in particular to a demulsifier and a preparation method thereof and its application in the demulsification of produced fluid from binary composite flooding. Background technique [0002] Binary composite flooding refers to the technology of using polymers and surfactants to enhance oil recovery. Due to the use of more efficient surfactants, polymers and improved reservoir models, the role of binary composite flooding has received more and more attention . But it follows that demulsification is very difficult due to the high concentration of surfactants and polymers in the produced fluid of binary composite flooding. [0003] People try traditional nonionic demulsifiers to break demulsification, but the effect is not ideal, and the dosage of conventional crude oil demulsifiers is tens to hundreds of times larger. , but it is still not ideal for the ...

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Problems solved by technology

But what follows is that due to the high concentration of surfactants and polymers in the produced fluid of binary compound flooding, it is very difficult to break the emulsion

[0003] People try traditional non-ionic demulsifiers for demulsification, but the effect is not ideal, and the amount of demulsifiers is tens to hundreds of times larger than that of conventional crude oil demulsifiers. Although the use of special non-ionic demulsifiers, such as CN101029253A and CN1570034A, can improve the demulsification effect , but it is still not ideal for the demulsification of binary compound flooding heavy oil produced fluid

There are also aluminum salts and traditional cationic polymer flocculants, but sticky precipitates will be produced at the bottom of the oil phase, contaminating the oil phase

[0004] CN1621123A has reported that block polyether is reacted with aluminum salt or ethyl silicate nucleating nanomaterials to prepare nuclear membrane structure demulsifier, which is used for chemical flooding production fluid demulsification, but silicon-containing demulsifier remains in the oil phase It may have an impact on subsequent processing; CN102233249A and CN104479731A use dendritic polyamide-amine cationic compounds, which can be used as reverse phase demulsifiers for oilfield sewage to demulsify binary flooding heavy oil production fluids with high surfactant content, adding volume is still large

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