an anti-co 2 、h 2 s corrosion cementing cement slurry

Abstract

An anti-CO 2 、H 2 S-corrosion cementing cement slurry is composed of water and cement with a mass ratio of 0.40 to 0.50:1, and the cement is composed of G grade high sulfate-resistant oil well cement, fine cement, dispersant, fluid loss reducer, micro silicon, powder Composed of coal ash, expansion agent, latex, water-soluble resin, early strength agent, retarder, defoamer. The grout formula is CO resistant 2 、H 2 S has excellent corrosion performance and can effectively block CO 2 、H 2 S erosion, maximum protection of casing and other downhole tools, especially suitable for high CO 2 、H 2 S used in sour oil and gas field cementing.

Description

Technical field [0001] The invention belongs to the preparation of petrochemical products, involving a suitable for CO 2 H 2 Cement slurry formulation in the wells of acid oil and gas fields. Background technique [0002] With the continuous deepening of oil and gas resources exploration and development, many high COs 2 H 2 S oil and gas resources have been incorporated into the development of the focus, and more and more acid oils. The cement ring is directly in contact with the formation environment, and it is used as a sealing formation in the oil and gas well first protection barrier. In Co 2 H 2 Under the common influence of S et al. And groundwater, the cementation group in cement cement is continuously reduced, and the penetration rate is increased, resulting in a decrease in compressive strength or even completely. The performance of the cement ring is deteriorated, and will gradually lose the protection of the casing, water, gas, the casing is like completely in the corr...

AI Technical Summary

Problems solved by technology

in CO 2 , H 2 Under the joint influence of corrosive media such as S and groundwater, the cement components in the cement stone will continue to decrease, and the permeability will increase, resulting in a decrease in its compressive strength or even no strength at all.

The performance of the cement sheath deteriorates, which will gradually lose the protective effect on the casing, water and gas channeling will occur, and the casing will be completely in the corrosive medium, which will greatly shorten the life of the oil and gas well and affect the normal production

At present, cement extrusion is usually used at home and abroad to block the cement stone corrosion channel, but cement extrusion requires professional equipment, which is expensive and risky

Adding corrosion inhibitors to the wellbore can also alleviate the corrosion problem to a certain extent, but it needs to be added continuously for a long time, which is time-consuming and labor-intensive. In the long run, the cost is not low, and the channeling problem cannot be solved fundamentally, and the symptoms are not cured.

In recent years, scholars at home and abroad have conducted a lot of research on the anti-corrosion cement slurry system, most of which focus on the density of cement slurry and latex cement system. Although these two methods can alleviate the corrosion of cement stone to a certain extent, But the effect is not obvious, and in the environment of complex strata, the cement slurry technology that can effectively seal the strata for a long time is still rare so far.

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