Water-in-oil association type concentrated thickener for oil displacement and preparation method of water-in-oil association type concentrated thickener

Abstract

The invention provides a water-in-oil association type concentrated thickener for oil displacement. The water-in-oil association type concentration thickener is prepared from the following components in percentage by mass: 25 weight percent to 50 weight percent of a dispersion medium, 18 weight percent to 45 weight percent of a dispersion phase, 20 weight percent to 40 weight percent of a hydrophobic association polymer thickener for the oil displacement and 2.5 weight percent to 6 weight percent of a compound emulsifier, wherein the dispersion medium is an organic solvent which is not compatible with water; the dispersion phase is water; the compound emulsifier is a compound emulsifier formed by compounding an emulsifier with the HLB (Hydrophile-Lipophile Balance) value of 3 to 7 and an emulsifier with the HLB value of 8 to 10. According to the concentrated thickener provided by the invention, the stabilization time is more than 120d and the dissolution time is less than 5min; performances of a polymer solution prepared from the concentrated thickener provided by the invention are better than performances of a polymer solution which is directly prepared from corresponding thickener powder for the oil displacement.

Description

technical field [0001] The invention belongs to the technical field of oil flooding, and in particular relates to a concentrated thickener for water-in-oil association type oil flooding and a preparation method thereof. Background technique [0002] With the continuous deepening of oilfield exploration and development, it has become impractical to continue to seek new oil resources; at the same time, with the continuous development of existing oilfields, the initial primary and secondary oil recovery methods can no longer achieve good crude oil recovery effects, and seeking new Methods Further improving the oil recovery (tertiary oil recovery) of developed oilfields has become an inevitable trend for stable and increased crude oil production. At present, chemical flooding (that is, injecting chemical agents into the oil layer to change the properties of the displacement phase and the interface properties of the displacement phase and crude oil to improve the recovery of crud...

AI Technical Summary

Problems solved by technology

However, there are still some shortcomings and needs to be improved in the application

On the one hand, the introduction of hydrophobic groups will inevitably have a certain adverse effect on the dissolution of the polymer. In addition, during the preparation process, the polymer dry powder is directly added to water and mixed to obtain a polymer solution, which is easy to form powder particles during the dissolution process. Fish eyes, local agglomeration, insufficient dissolution or longer time to completely dissolve, which not only affects the performance of the solution but also reduces the construction efficiency

On the other hand, when it is necessary to add additives such as surfactants to the polymer solution to form a composite system with a synergistic effect, the on-site process is to prepare the polymer solution and the surfactant solution separately and then mix them, which undoubtedly greatly increases It reduces the construction platform space, construction cost and construction difficulty, especially for platforms with limited space and high frequency of use of dispensing technology.

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