High-temperature high-density cement slurry for oil field high-temperature high-pressure well cementation and preparation method thereof

Abstract

The invention discloses a high-temperature high-density cement slurry for oil field high-temperature high-pressure well cementation and a preparation method thereof. The high-temperature high-density cement slurry includes oil well cement, a weighting agent, an anti-high temperature strength degradation agent, a stabilizer, a fluid loss agent, a dispersing agent, a retarder, a defoaming agent and the like. A particle gradation principle is employed in the invention, and the particle sizes and the dosages of various materials are optimized, thus achieving close packing of solid phase materials. A weighted blended slurry solution is mixed with the solid phase materials, secondary weighting is carried out on the cement slurry, and by cooperating with the regulation of an excellent performance high temperature salt resistant treatment agent, a high-temperature high-density liquid mixture with good comprehensive performance can be formed, thus solving the contradiction of influence between high-temperature high-pressure well cementation cement slurry density, high temperature resistance, rheological property and sedimentation stability.

Description

technical field [0001] The invention relates to cement slurry used in oil and gas well cementing in the field of oil field drilling engineering, in particular to high temperature and high density cement slurry used in high temperature and high pressure well cementing and a preparation method thereof. Background technique [0002] With the intensification of oil and gas exploration and development, a large number of high-temperature and high-pressure wells have increased, and the use of high-quality high-temperature high-density cement slurry for balanced cementing is one of the most effective methods to eliminate construction hidden dangers, prevent oil and gas water channeling, and increase the success rate of cementing. At present, high-temperature treatment agents are commonly used at home and abroad to adjust the performance of cement slurry and rely on weighting agents to increase density. However, first, many high-temperature treatment agents have poor stability against...

AI Technical Summary

Problems solved by technology

At present, high-temperature treatment agents are commonly used at home and abroad to adjust the performance of cement slurry and rely on weighting agents to increase density. However, first, many high-temperature treatment agents have poor stability against high temperatures (above 160°C), and the performance of cement slurry degrades at high temperatures. The indicators cannot meet the high-temperature and high-pressure cementing requirements, resulting in pressure instability and high-pressure formations, and oil, gas and water channeling

Second, as the density of cement slurry increases, the proportion of weighting agent increases, and the rheology or settlement stability of cement slurry becomes worse, resulting in construction difficulties and affecting the quality of cementing and the effect of stabilizing the formation

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