Deep-water low-temperature low-density early-strength cementing slurry for well cementation

Abstract

The invention relates to deep-water low-temperature low-density early-strength cementing slurry for well cementation in petroleum drilling engineering, which contains 100 parts of low-temperature early-strength cement, 10 to 30 parts of low-temperature reinforcing material, 10 to 80 parts of low-density light-weight material, 0.5 to 4 parts of drag reducer, 2.5 to 8 parts of fluid loss additive, 0.1 to 5 parts of retarder, 0.15 to 1.2 parts of defoamer, 2.5 to 8 parts of early strength agent and 57 to 95 parts of water, and slurry with the density of 1.2g / cm3 to 1.7g / cm3 can be prepared. The slurry system at least has the following advantages that: the maximum early strength (24 hours) can reach 14.7MPa, the long-term strength stability is good, the static gelling transition time is short, and the system is stable. The invention provides technical support for the quality of deep-water well cementation.

Description

technical field [0001] The invention relates to the field of petroleum drilling engineering, in particular to a deep-water low-density early-strength cementing cement slurry used in the cementing cementing technology, which is used for deep-water low-temperature cementing. Background technique [0002] The world's offshore oil reserves are about 100 billion tons, and the proven reserves are more than 38 billion tons; the offshore natural gas reserves are about 140 trillion cubic meters, and the proven reserves are about 40 trillion cubic meters. The average depth of the ocean is 3,730 meters, and the sea area with a water depth of 3,000 to 6,000 meters accounts for 73.83% of the total ocean area. However, 80% of the proven offshore oil reserves are still concentrated in the near-continental shelf area within a water depth of 500 meters, which shows that there are still untapped reserves in the deep water (500 meters-1500 meters) or even ultra-deep water (above 1500 meters). ...

AI Technical Summary

Problems solved by technology

[0006] The main problems: the high alumina cement system has advantages in the development of compressive strength, but it is highly sensitive to temperature, sensitive to pollutants, and the heat release of hydration is too fast; the technology of aerated cement slurry is complicated and the cost is high; the use of G-grade oil wells The strength of cement develops slowly at low temperature, and the development of static gelation is slow, which affects the anti-channeling ability of cement slurry and the quality of deep water cementing. The quality of deep water cementing affects the life of deep water oil and gas wells, and even endangers the safety of oil and gas production and platforms.