Potassium-resistant high-density cementing cement slurry and preparation method thereof

Abstract

The invention provides a potash-resistant high-density cementing cement slurry used in the cementing construction of high-pressure oil and gas wells and high-pressure potassium salt wells; it is prepared from the following raw materials in mass percentages, Jiahua G-grade cement 29-58%, aggravated 12-56% of active micro-nano silicon, 10-20% of 80-mesh quartz sand, 1-2% of anti-salt dispersant, 1.8-4% of anti-salt water loss reducing agent, and 0.3-3% of anti-salt retarder 1.0%; the weighting agent is a mixture of 250 mesh and 1200 mesh hematite, the anti-salt dispersant is formaldehyde / acetone copolymer, the anti-salt fluid loss agent is N, N-dimethylacrylamide and maleic anhydride polymer , the retarder is a compound of keto acid and organic phosphate; the cementing slurry has a density of 2.0-2.6g / cm3, fluidity of 19-21cm, API water loss ≤ 50ml, rheological properties n ≥ 0.5, K ≤ 2 .

Description

technical field [0001] The invention belongs to the field of material engineering, and in particular relates to a potassium salt-resistant high-density cementing cement slurry used in high-pressure oil and gas wells and high-pressure potassium salt well cementing construction. Background technique [0002] With the increasing depletion of oil and gas resources, exploration and development are faced with the trend of looking for oil in the deep part of the earth and moving into abnormally high-pressure formations. High temperature and overpressure are common characteristics of such formations. For example, the Carboniferous Maokou Formation in the Guandu structure in the Chishui area of ​​Guizhou Province has always been a gas-bearing layer of concern, but many drilling attempts in this area have failed to reach the target layer. To overcome, the pressure stability of the formation is extremely difficult, especially the lack of high-density cement slurry during well cementing...

AI Technical Summary

Problems solved by technology

[0004] There are several difficulties in the current high-density cement slurry, mainly the poor fluidity of the cement slurry, low compressive strength, expensive individual weighting agents (such as Micromax), and the ultra-high-density cement slurry must be compounded, etc.; use recrystallization The high-density cement slurry prepared with stone as a weighting material also has difficulties such as slow strength development and unstable system.

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