Slow-setting cement grout

Abstract

Disclosed is slow-setting cement grout. The ratio of basic cement grout includes that the water-cement ratio is 1-1.25:1, 1.5-2wt% of a suspending agent and a retarder are adulterated in the basic cement grout, the retarder is a mixture mixed by one, two or more of six retarders including sodium pyrophosphate, sodium tripolyphosphate, tartaric acid, potassium sodium tartrate, citric acid or zinc chloride according to arbitrary mixing ratio, wherein the mixing amount of the sodium pyrophosphate is 0.1%-0.5%, the mixing amount of the sodium tripolyphosphate is 0.1%-0.6%, the mixing amount of the tartaric acid is 0.2-0.4%, the mixing amount of the potassium sodium tartrate is 0.4%-0.5%, the mixing amount of the citric acid is 0.05%-0.35%, and the mixing amount of the zinc chloride is 0.2%-0.3%, and the suspending agent is sodium bentonite. The slow-setting cement grout has the advantages that stability of the cement grout is enhanced, settling time of cement particles is prolonged, and the concretion ratio of the grout is increased.

Description

technical field [0001] The invention relates to a grouting material, in particular to a retarded cement grout. Background technique [0002] In the wellbore construction project, with the increase of depth and ground pressure, the difficulty of surface pre-grouting and pre-grouting of working face is usually more and more difficult to control water, and the effect is also more and more difficult to guarantee; especially for high-angle parallel It is even more difficult to guarantee the grouting effect in rock formations with well-developed fissures, or sandstone formations rich in pore water. [0003] The existing cement slurry has the disadvantages of poor fluidity, low stability, short settling time of cement particles, low calculus rate and the like. Due to the complex nature of the formation, more chemical admixtures need to be added to the frozen drilling mud, which will affect the performance indicators such as the setting time of the cement slurry during the cement s...

AI Technical Summary

Problems solved by technology

[0002] In the wellbore construction project, with the increase of depth and ground pressure, the difficulty of surface pre-grouting and pre-grouting of working face is usually more and more difficult to control water, and the effect is also more and more difficult to guarantee; especially for high-angle parallel For rock formations with developed fractures, or sandstone formations rich in pore water, the grouting effect is even more difficult to guarantee

[0003] Existing cement slurries have disadvantages such as poor fluidity, low stability, short settling time of cement particles, and low calculus rate.