Anti-salt high-density cement mortar

Abstract

The invention relates to a cement slurry system used for solidifying a well in a petroleum drilling engineering: 50-300 percent of well cement aggravating agent A, 10-100 percent of well cement aggravating agent B, 0.5-4 percent of drag reducing agent, 2.5-8 percent of fluid loss additive, 0.1-5 percent of retarder and 0.15-1.2 percent of defoaming agent. The mixture of wet mixed additive occupies 50-100 percent of the cement quality. According to a salt layer, NaCl can be added during the solidifying of the well. 30-40 percent of high temperature resisting declining agent is added at high temperature. The cement slurry, the density of which reaches to 2.8g/cm3, can be prepared.

Description

technical field [0001] The invention relates to a cement slurry system used in well cementing and cementing technology in the field of petroleum drilling engineering, which is used for cementing wells in high-pressure formations, especially high-pressure salt formations. Background technique [0002] In oil exploration and development, when drilling high-pressure formations, it is necessary to increase the density of cement slurry and carry out balanced pressure cementing to prevent overflow or channeling during cementing. When drilling into a salt layer, the cement slurry is easily polluted by the salt layer, resulting in deterioration of the performance of the cement slurry. A salt-resistant slurry system is required. The current high-density cement slurry has problems such as thick slurry, low strength, and no salt resistance. Contents of the invention [0003] The technical problem to be solved in the present invention: avoid above-mentioned weak point in the prior art...

AI Technical Summary

Problems solved by technology

When drilling into a salt layer, the cement slurry is easily polluted by the salt layer, resulting in deterioration of the performance of the cement slur...

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