Efficient composite defoaming agent for oil well cement and preparation method thereof

Abstract

The invention discloses an efficient composite defoaming agent for oil well cement and a preparation method thereof. The defoaming agent is applied to the defoaming and foam inhibition of various admixtures containing cement paste for well cementation in the processes of high-speed shearing and mixing. The defoaming agent comprises the following components in percentage by mass: 15-59.5% of mineral oil, 40-84.5% of polyol fatty acid ester, 0-15% of polyacid fatty alcohol ester and 0.5-15% of a defoaming auxiliary component, wherein the defoaming auxiliary component contains one or two of polyether and tri-isobutyl phosphate. The preparation method of the defoaming agent comprises the following steps: under the condition of stirring at room temperature, sequentially adding the mineral oil, the polyol fatty acid ester, the polyacid fatty alcohol ester and the defoaming auxiliary component into a batching kettle; mixing for 0.5-2.0 hours; filtering the obtained mixture, and discharging the obtained object; and carrying out measurement packing on the obtained product. Compared with common defoaming agents for oil well cement, the defoaming agent disclosed by the invention is low in cost and simple in manufacturing process, products are uniform and stable, and the defoaming agent concurrently has the functions of defoaming and foam inhibition, and does not affect the rheological property and thickening property of cement paste and the compressive strength and the like of cement.

Description

Technical field [0001] The invention belongs to the field of cement defoamer composite materials, and specifically relates 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 additives in the cement slurry, foam is generated during the slurry preparation 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 rapid defoaming is not possible, the measured density of the cement slurry will be significantly lower than the true value, resulting in a decrease in cement strength and cementation strength, and a higher 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 ...

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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