High-strength hydrogen-sulfide environmental corrosion-resistant seamless petroleum casing pipe and manufacturing method thereof

Abstract

The invention discloses a high-strength hydrogen-sulfide environmental corrosion-resistant seamless petroleum casing pipe which conforms to a 125ksi steel grade and comprises the following components in mass percentage: 0.25-0.35 percent of C, 0.1-0.5 percent of Si, 0.4-1.0 percent of Mn, 0.1-2.0 percent of Cr, 0.2-2.0 percent of Mo, 0.03-0.3 percent of V, 0.01-0.3 percent of Nb, less than 0.015 percent of P, less than 0.010 percent of S and the balance of Fe and inevitable impurities. The seamless petroleum casing pipe can be widely applied to sulfur-contained deep-well and ultradeep-well drilling and mining operations and has quite broad application prospect. The invention also discloses a manufacturing method of the seamless petroleum casing pipe.

Description

technical field [0001] The invention relates to a hydrogen sulfide environment corrosion-resistant seamless oil casing conforming to 125ksi steel grade and a manufacturing method thereof. Background technique [0002] About 1 / 3 of the world's existing oil and gas fields contain hydrogen sulfide gas. These acidic hydrogen sulfide gases can cause sulfide stress corrosion cracking (Sulfide Stress Cracking) in steel materials. This problem occurs in high-strength low-alloy steel (High Strength Low Alloy Steel) is particularly prominent. Since the hydrogen sulfide corrosion resistance of oil well pipes is directly related to the safety of oilfield equipment and personnel, the sulfur resistance of HSLA steel has become a major concern of oil well pipe manufacturers and oilfield users. When purchasing steel pipes, in addition to requiring the products to meet API standards, oil companies often have requirements for hydrogen sulfide corrosion resistance, that is, steel pipe materia...

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Problems solved by technology

For example, techniques such as induction heating and direct quenching in Japanese Patent Application Laid-Open 6-322478, Japanese Patent Laid-Open 8-311551 and Japanese Patent Laid-Open 2006-265657 all have larger difficulties in the implementation of large-scale production on the spot; -335731, JP 2000-178682 Bulletin, JP 2000-256783, JP 2000-297344 and JP 2000-119798 all use B element to improve hardenability, but Ti must be added after adding B to prevent brittleness BN increases the difficulty of smelting control and the fluctuation of material properties. In addition, these patent applications also use alloying elements such as W and Zr to improve the tempering resistance of the material and enhance the precipitation strengthening effect, which greatly increases the cost of the alloy.

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