Polymer wide-temperature-zone retarder for oil-gas well cement and preparation method thereof

Abstract

The invention discloses a polymer wide-temperature-zone retarder for oil-gas well cement and a preparation method thereof. The preparation method of the retarder comprises the following processes: (1) dissolving itaconic acid, acrylamide and sodium p-styrenesulfonate with deionized water and mixing the solutions, and adjusting the pH value of the solution to be 6-7, wherein the mass ratio of itaconic acid to acrylamide to sodium p-styrenesulfonate is (1-2):(2-4):(2-4), and the total mass concentration of monomers in the solution is 10-20%; (2) heating the mixed solution to 40-60 DEG C, and adding an initiator to carry out polymerization reaction in a nitrogen environment for 4-6 hours to obtain a polymer solution; (3) extracting the polymer solution with absolute ethyl alcohol, drying the extract, and grinding the extract into powder. The retarder can effectively avoid super-retarding or under-retarding of oil-gas well cement paste in a low temperature zone, can effectively lengthen the thickening time of the oil-gas well cement paste in a high temperature zone, can be matched with various admixture systems, does not affect the overall performance of the cement paste, and has extensive market prospects.

Description

technical field [0001] The invention relates to a polymer wide temperature zone retarder for oil and gas well cement and a preparation method thereof in the field of macromolecules. Background technique [0002] The cementing operation of oil and gas wells is to use ground pumping equipment to inject cement slurry containing various admixtures into the predetermined formation through the casing, and make it return to the predetermined height along the annular space between the casing and the well wall for cementation. Solidification, so as to achieve the purpose of sealing the formation and casing, stabilizing the well wall, and sealing off the oil, gas and water layers. [0003] One of the most important design parameters for cementing operations is the thickening time of the oil and gas well cement slurry, that is, the time that the oil and gas well cement slurry remains in a pumpable fluid state. The slurry obtained by stirring and mixing G-grade oil and gas well cement ...

AI Technical Summary

Problems solved by technology

Although these retarders have good performance, it is found that polymer retarders have some new defects, such as: polycarboxylate retarders have poor high temperature resistance and are prone to cause abnormalities in cement paste. The generation of gelling phenomenon; it is easy to cause the thickening curve of cement slurry to appear "bulging", "stepping" and other phenomena; when the high temperature resistant retarder is applied in the low temperature well section, it is easy to cause super-retarding or under-retarding phenomenon of cement slurry , affecting the progress and quality of the project

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