Preparation of polymer flooding produced fluid demulsifier

Abstract

The invention provides a preparation method of a polymer flooding produced fluid demulsifier, which mainly comprises the following steps: condensing p-tert-butyl phenol, polyethylene polyamine and formaldehyde to obtain a thermoplastic phenol amine resin of which the molecular weights are within a certain range; sequentially and proportionally carrying out ring-opening polymerization on the resin, epoxyethane and propylene oxide; mixing the synthesized products with different molecular weights in a certain mass ratio, and regulating the pH value with acetic acid; and finally, cross-linking with dicarboxylic acid to obtain the final product. The invention aims to solve the problems of severe oil / water emulsification, greater difficulty in oil-water separation, high oil content in dehydrated water and the like in the polymer flooding produced fluid, and the problem that the dehydration effect of the conventional demulsifier on the produced fluid is not ideal.

Description

technical field [0001] The invention relates to a method for synthesizing a polymer material, in particular to a method for preparing a demulsifier for polymer flooding production fluid, and belongs to the field of preparation of chemical treatment agents for oilfield production fluid. Background technique [0002] At present, polymer flooding is the most widely used EOR chemical flooding technology at home and abroad. Polymer flooding has greatly improved oil recovery; however, with the continuous injection of polymers, the polymers returned to the ground The concentration increases significantly, and the composition of the produced fluid becomes more and more complex. It is generally composed of different types of mixed emulsions such as W / O, O / W, and multiple emulsified W / O / W. The emulsification state is complex and stable. The polymer flooding produced fluid The existence of the polymer in the medium changes the interface properties of the oil-water emulsion, which direc...

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Problems solved by technology

[0002] At present, polymer flooding is the most widely used EOR chemical flooding technology at home and abroad. Polymer flooding has greatly improved oil recovery; however, with the continuous injection of polymers, the polymers returned to the ground The concentration increases significantly, and the composition of the produced fluid becomes more and more complex. It is generally composed of different types of mixed emulsions such as W / O, O / W, and multiple emulsified W / O / W. The emulsification state is complex and stable. The polymer flooding produced fluid The existence of the polymer in the medium changes the interface properties of the oil-water emulsion, which directly affects the mutual aggregation tendency between the dispersed phases, the oil-water separation speed, the oil-water separation effect, etc., making the oil-water separation of the production fluid more difficult; in the static sedimentation separation test It was found that after 10 minutes of static sedimentation and separation, a more serious intermediate mixed emulsified layer was formed between the upper oil layer and the lower water layer. The higher the polymer concentration, the lower the water content, and the thicker the intermediate emulsified layer, the more difficult it is to eliminate. This is because the polymer increases the viscosity of the water phase, increases the mutual viscous force between oil and water, and increases the emulsification strength of oil and water, which leads to a slower separation speed of the two emulsions, resulting in difficulty in demulsification, which will cause sedimentation and emulsification. The processing time is extended, the interface is not easy to control, and the water content in the oil and the oil content in the water increase after dehydration. The original production process and chemicals can no longer meet the production and technical requirements; in order to ensure the normal production of the oil field without increasing investment, On the premise of using the original process to implement oil-water separation, using chemical methods to effectively demulsify and comprehensively treat the polymer flooding production fluid is quite technically difficult.

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