Low-temperature hardening scurry-proof cement slurry for well cementing

Abstract

The invention relates to a low temperature early strength channeling control cement slurry, comprising portland cement, water, light strengthening agent, low-temperature early strength agent, channeling control agent, rheological performance adjusting agent and defoaming agent; wherein, the light strengthening agent consists of glass beads, fine cement, fine silicon powder and superfine, high-activity slag; the low-temperature early strengthening agent consists of sodium silicate, calcium sulphate and triethanolamine; the channeling control agent consists of polyvinyl alcohol, gypsum, poly naphthalene sulphonic sodium and borax; the rheological performance adjusting agent consists of sodium polystyrene sulfonate and calcium lignosulfonate; the defoaming agent consists of poly glycol dipropionate ether. The invention has the advantages of fast expanding speed of intensity in low temperature, strong channeling control and leakage resistance performance, low water lost and good rheological performance, and can be used as cementing material in low-temperature air layer, activity water layer and leakiness ground layer.

Description

technical field [0001] The invention relates to a low-temperature early-strength anti-channeling cement slurry for well cementing, in particular to a well cementing material for low-temperature gas layers, active water layers and easy-to-leakage formations. Background technique [0002] In the existing cementing operation, there are shallow gas and surface aquifers, low pressure bearing capacity of the formation, and low operating temperature in winter, so that the gel strength of the cement slurry develops slowly, and the weight loss of the cement slurry causes the liquid column pressure to increase. If it is lowered, it will easily lead to the occurrence of water-gas channeling, which seriously affects the cementing quality. In view of the above problems, the existing method of increasing the density of cement slurry has the disadvantage that it is very easy to cause the cement slurry to leak into the formation; the existing method of adding a coagulant such as calcium chl...

AI Technical Summary

Problems solved by technology

[0002] In the existing cementing operation, there are shallow gas and surface aquifers, low pressure bearing capacity of the formation, and low operating temperature in winter, so that the gel strength of the cement slurry develops slowly, and the weight loss of the cement slurry causes the liquid column pressure to increase. If it is reduced, it will easily lead to the occurrence of water-gas channeling, which seriously affects the cementing quality

In view of the above problems, the existing method of increasing the density of cement slurry has the disadvantage that it is very easy to cause the cement slurry to leak into the formation; the existing method of adding a coagulant such as calcium chloride can shorten the thickening time of the cement slurry , but it cannot significantly improve the development of cement slurry gel strength, cannot effectively prevent channeling, and when the amount is too large, it will have a reverse effect and bring adverse effects to the cementing operation