High temperature resistant oil well cement retarder and preparation method thereof

Abstract

The invention discloses a high temperature resistant oil well cement retarder, belonging to the oil well cementing technology, which mainly solves the problem of poor oil well cementing effect in the prior art. The retarder comprises AMPS, IA, AM and DMAPAA the mass ratio of which is 82-91:10-26:8-30:31-38. Meanwhile, the invention further provides a preparation method of the retarder, comprising the following steps: (1) weighing the AMPS, the IA, the AM and the DMAPAA respectively based on the mass ratio of 82-91:10-26:8-30:31-38, and dissolving the weighed materials in water; (2) adjusting the pH value of the solution obtained in step (1) to 4-7; (3) putting the solution in a flask for thermostatic water bath; and (4) adding an initiator dropwise to the solution and continuously reacting for 2-4h to obtain the final product. In the invention, hydration of cement paste can be delayed and influence on other performances of the cement paste is reduced.

Description

technical field [0001] The invention relates to an oil well cement retarder, in particular to a high temperature resistant oil well cement retarder used in oil well cementing construction and a preparation method thereof. Background technique [0002] Cementing is the main link in the process of oil well construction. The quality of cementing is directly related to the continuous drilling of oil wells, as well as the quality of subsequent operations such as well completion, oil production, and workover. There are two steps in the cementing operation, namely, casing running and cement injection. Through cement injection, oil well cement is used to fill the annular space between the casing and the wellbore. The main function of the cement slurry is to isolate the fluid from flowing between layers and support Casing, preventing pipe wall corrosion, sealing leakage layer or low pressure layer, etc. The cement injection process refers to the process of preparing cement slurry, p...

AI Technical Summary

Problems solved by technology

For example, carboxymethyl hydroxyethyl cellulose is suitable for 135°C, but this type of retarder has the characteristics of thickening and poor salt resistance; hydroxycarboxylic acids and their salts, including tartaric acid and its salts, sugar retarders coagulant, organic phosphoric acid

Tartaric acid and its salts are high-temperature retarders, which are used in wells at 150-200°C. They have a strong retarding ability and a certain degree of dispersion to change the fluidity of cement slurry. However, the retarder is extremely sensitive, and the dosage varies by ten thousandths. It will prolong the setting time by one time, which will bring difficulties to the construction.

Glucose retarder has a strong retarding effect due to its multiple hydroxyl active groups, and its service temperature can reach 160°C, but the sensitivity to dosage is still the biggest disadvantage; other retarders include inorganic compounds, such as boric acid, phosphoric acid, Hydrofluoric acid and their salts, oxides of zinc and lead, etc.

[0005] To sum up, existing retarders for oil wells all have large or small defects and deficiencies, especially when delaying the hydration reaction of cement slurry, they generally have obvious adverse effects on other properties of cement slurry. If the strength development of cement stone is affected, the cementing quality of existing oil wells cannot be effectively guaranteed.

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