Oil well pipe for heavy oil thermal recovery well and its manufacturing method

Abstract

The invention relates to an oil well pipe for a heavy oil thermal recovery well, and a manufacturing method. The oil well pipe comprises, by weight percent, 0.37 to 0.42% of C, 0.15 to 0.30% of Si, 0.60 to 0.80% of Mn, not larger than 0.02% of P, not larger than 0.01% of S, 0.8 to 1.5% of Cr, 0.04 to 0.06% of Nb, 0.04 to 0.06% of Ti and the balance Fe and inevitable impurities. The oil well pipe has the beneficial effects that the cost is low, the industrial batched production is easily achieved, through the heat treatment technology of subcritical quenching, superhigh temperature tempering and surface aluminizing, the structure of the steel pipe is fine and uniform, corrosion resistance is greatly improved, and the use needs of the current and future market for the oil well pipe with thehigh temperature resistance and corrosion resistance properties are met.

Description

technical field [0001] The invention belongs to the technical field of low alloy steel production, in particular to a 2 +O 2 An oil well pipe for heavy oil thermal recovery wells with excellent corrosion resistance and high temperature resistance used in a coexisting high temperature environment of 50°C to 350°C and a manufacturing method thereof. Background technique [0002] The world's proven reserves of heavy oil resources are more than 300 billion tons, and the resources available for exploitation are about 170 billion tons. In the past, the exploitation of heavy oil was mainly concentrated in the American continent, and the exploitation of heavy oil in Asia has also been developed in the past 20 years. Thermal recovery of heavy oil puts forward special requirements on the performance of oil well pipes, and it is necessary to develop high-performance oil well pipes suitable for different blocks to achieve safe production and increase production and efficiency. [000...

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Problems solved by technology

[0003] The amount of oil casings used in heavy oil thermal recovery wells continues to increase, and as the development of heavy oil thermal recovery becomes more difficult in the later stage, in order to maintain the purpose of increasing or not reducing oil recovery, oilfields have gradually developed thermal flooding and fire flooding through technological innovation. Correspondingly, new and higher performance requirements for oil well pipes for thermal recovery wells have been put forward for new heavy oil recovery technologies. One of the major problems encountered is the CO 2 with O 2 Under coexistence conditions, the change of operating temperature will cause severe corrosion to the pipe. Therefore, it is necessary to design and manufacture special oil well pipes and pipes for the new technical requirements of thermal recovery oil wells to meet the needs of oil fields.

[0004] Among the existing published technologies, the Chinese patent application number CN00100635.5 discloses a high-strength oil casing for super heavy oil thermal recovery wells and its production method, which is mainly made of medium-carbon Cr-Mo steel through quenching and tempering heat treatment. , its shortcoming is that the invented product is limited to use under the temperature condition of 300°C, and cannot satisfy CO 2 with O 2 The latest requirements for the use of corrosion resistance under the condition of coexistence and variable temperature

The Chinese patent with the application number 200810204727.6 discloses a steel for heat-resistant casing and its manufacturing method. It is mainly designed with a medium-carbon Cr-W alloy and manufactured through quenching and tempering heat treatment. The product invented by it is an improvement over the previous invention. , which can meet the requirements of thermal recovery at 350°C, but still cannot meet the requirements of CO 2 with O 2 The latest requirements for the use of corrosion resistance under the condition of coexistence and variable temperature

The application number is CN01118707.7, which discloses carbon dioxide corrosion-resistant petroleum casing and its production method. It mainly adopts high-Cr alloy design and is used after quenching and tempering heat treatment. The disadvantage is that the invented product only has anti-CO2 2 Corrosive properties, no CO 2 with O 2 Corrosion resistance under the condition of coexistence and variable temperature, and the high temperature resistance cannot meet the use requirements of the strength level above 552MPa under the temperature of 350°C

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