High-toughness drilling rod applicable to corrosion acid environment and processing method thereof

Abstract

The invention relates to a high-toughness drilling rod applicable to corrosion acid environment and a processing method thereof. The high-toughness drilling rod is formed by high-intensity carbon steel or alloy steel through heat processing and is used for extracting petroleum or natural gas in acid environment containing corrosive gas. The high-toughness drilling rod comprises the following ingredients in percentage by weight: 0.01 to 0.35 percent of C, 0.02 to 0.5 percent of Si, 0.1 to 1.8 percent of Mn, 0.0005 to 0.008 percent of Ca, 0.003 to 0.1 percent of Ti, 0.003 to 0.1 percent of Zr, 0 to 0.015 percent of P, 0 to 0.003 percent of S, 0.2 to 0.6 percent of Cu, 0.1 to 1.0 percent of Ni, 0.2 to 3.0 percent of Cr, 0.1 to 1.0 percent of Mo, 0.01 to 0.15 percent of Nb, 0.01 to 0.15 percent of V and the balance Fe. After hot rolled steel is made into a drilling rod body, the drilling rod body carries out quenching and normalizing treatment, the quenching temperature is between 850 DEGC and 880 DEG C, the heat insulation time is not less then 30 minutes, the quenching medium is water, the normalizing temperature is between 600 DEG C and 650 DEG C, and the heat insulation time is not less then 45 minutes. The drilling rod manufactured by the method can be applicable to the extraction of the petroleum or the natural gas in the acid environment containing sulfur, hydrogen and thelike, has good toughness and can meet the requirement of acid oil gas field extraction with lower pH values.

Description

Technical field [0001] The invention relates to a drill pipe for oil and natural gas exploitation and a processing method thereof, in particular to a high toughness drill pipe suitable for corrosive acidic environment, belonging to the technical field of petroleum drill pipes. Background technique [0002] With the increase in demand for oil and gas extraction, many oil and gas development projects are concentrated in deep wells, ultra-deep wells, and highly corrosive wells. Especially in the oil and gas wells that are more corrosive to hydrogen and sulfur, better performance is required. Drill rods to complete drilling tasks. According to ExxonMobil’s forecast, the proportion of easy-to-exploit ordinary wells will drop from 80% in 2003 to 57% in 2010, indicating that oil and natural gas has shifted to the development of difficult unconventional resources. This shows that it is necessary to continuously research and develop new types of drill pipe products that meet new drilling...

AI Technical Summary

Problems solved by technology

[0004] Chinese patent CN1715438A, invented a carbon dioxide, chloride ion corrosion resistant steel for oil drill pipes, which solves the problem of CO2 resistance of existing drill pipe steels 2 , Cl — Defects of poor corrosion performance

This patent considers the CO 2 and Cl — The use of drill pipe in the presence of hydrogen sulfide, but there is no strict control of harmful elements such as S and P, which makes the steel grade not ideal for hydrogen sulfide stress corrosion resistance, and is not suitable for oil and gas in hydrogen-containing and sulfur-containing environments. mining

Chinese patent CN1390972A 2003.1.15 provides a low-alloy ultra-high-strength steel grade, which has high strength, but is not suitable for use in acidic environments; Chinese patent CN1361306A provides a hydrogen sulfide stress corrosion resistant oil sleeve pipe and its production method, but the strength and toughness of the casing cannot be well guaranteed after being hot-rolled; U.S. Patent US4570708 also provides a casing production method that is resistant to acidic environments, and adopts cold processing for carbon steel way, its strength and toughness can not be well guaranteed