Frozen ground region negative-temperature well cementation cement slurry, preparation method and applications thereof

Abstract

The invention relates to the technical field of oil field well cementation, particularly to a frozen ground region negative-temperature well cementation cement slurry, a preparation method and applications thereof, wherein the frozen ground region negative-temperature well cementation cement slurry comprises, by weight, 100 parts of modified aluminate cement, 6-15 parts of a negative-temperature anti-freezing early strength agent, 0.05-3 parts of an alcohol-ammonia coagulant, 40-44 parts of water, 0-5 parts of a light metal expanding agent and 0-6 parts of a non-ionic polymer fluid loss agent.According to the invention, the frozen ground region negative-temperature well cementation cement slurry is good in rheological property, can be cured within 3 h at a temperature of -18 DEG C, has a24-h compressive strength of up to 6 MPa, can effectively solve the problems that cement is not cured and has no strength, the well cementation quality of the low-temperature frozen ground region is poor, and even well cementation operation cannot be completely conducted due to liquid-phase segregation ice condensation of the conventional cement slurry in a negative temperature environment, and meets the well cementation construction requirements of frozen ground regions.

Description

technical field [0001] The invention relates to the technical field of oil field cementing, and more particularly relates to a negative temperature cementing cement slurry in permafrost regions and a preparation method and application thereof. Background technique [0002] Polar cold sea areas have important strategic value for oil and gas exploration and development. However, these areas are mostly located in permafrost regions. The conditions for exploration and development are very harsh and they face many challenges. The biggest problem is the extremely low surface temperature. Important oil and gas reservoirs in polar regions are mostly distributed in permafrost areas, with temperatures ranging from -5 to -8°C, formation ice content as high as 80%, and depths up to 500m. The strength development of the conventional cement slurry system is extremely slow under low temperature conditions. When the ambient temperature is lower than 20°C, the cement induction period is prol...

AI Technical Summary

Problems solved by technology

The negative temperature cementing cement slurry in the permafrost region of the present invention has good rheological properties, can be solidified within 3 hours at -18°C, and has a 24-hour compressive strength higher than 2 MPa, up to 6 MPa, which effectively solves the problem of conventional cement slurry in negative temperature environments Due to the separation of condensed ice in the liquid phase, the cement does not solidify and has no strength, and the cementing quality in low-temperature permafrost areas is poor or even impossible to perform cementing operations. It meets the needs of cementing construction in permafrost areas.

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