A kind of high-efficiency composite defoamer for oil well cement and preparation method thereof

Abstract

The invention discloses a high-efficiency composite defoamer for oil well cement and a preparation method thereof, which are used for defoaming and foam suppression in the process of high-speed shear mixing of cement slurry containing various admixtures. In terms of mass percentage, it consists of 15-59.5% mineral oil, 40-84.5% polyol fatty acid ester, 0-15% polybasic acid fatty alcohol ester and 0.5-15% defoaming auxiliary component, said defoaming auxiliary component Contains one or both of polyether and triisobutyl phosphate. The preparation method of the defoamer is as follows: under stirring at room temperature, successively add mineral oil, polyhydric alcohol fatty acid ester, polybasic acid fatty alcohol ester and defoaming auxiliary components to the batching kettle, stir and mix for 0.5-2.0 hours, filter out Material, measurement and packaging. Compared with ordinary oil well cement defoamers, the defoamer of the present invention has low cost, simple production process, uniform and stable product, and has both defoaming and foam suppression functions, and does not affect the rheology, thickening performance and compressive resistance of cement slurry. performance such as strength.

Description

technical field [0001] The invention belongs to the field of cement defoamer composite materials, in particular to a high-efficiency composite defoamer for oil well cement and a preparation method thereof. Background technique [0002] During the cementing operation of oil and gas wells, due to the application of various admixtures in the cement slurry, foam is generated during the mixing process, which reduces the density and other properties of the cement slurry, making it difficult to monitor and control the density and performance. [0003] Under continuous construction conditions, if the foam cannot be quickly defoamed, the measured density of the cement slurry will be significantly smaller than the real value, resulting in a decrease in cement stone strength and bonding strength, and a high acoustic amplitude logging curve, which will affect the cementing quality; at the same time, due to This kind of error information is fed back to the slurry mixing system in real t...

AI Technical Summary

Problems solved by technology

The product produced by the above method is an emulsion defoamer, the cost of packaging and transportation is high, the dosage is larger than that of the base type product, and the cost performance is not high

[0011] To sum up, the current defoamers used in cementing have many deficiencies, such as: some have a strong smell, are flammable, are dangerous goods, and are unsafe; some have a complicated preparation process and high cost; poor storage stability, easy to Delamination and deposition; some have adverse effects on the performance of the cementing slurry system, poor compatibility; etc.

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