Casinghead gas corrosion resistant pumping rod steel and manufacturing method thereof

Abstract

The invention provides steel for a pumping rod resisting casinghead gas corrosion and a manufacture method thereof. The steel comprises the following chemical compositions by mass percentage: 0.05 to 0.25 percent of carbon, 0.50 to 2.00 percent of silicon, 1.10 to 2.50 percent of manganese, 0.02 to 0.50 percent of molybdenum, 0.02 to 0.50 percent of nickel, 0.50 to 1.50 percent of chromium, 0.01 to 0.10 percent of vanadium, 0.005 to 0.050 percent of aluminum, 0.02 to 0.10 percent of niobium, 0.05 to 0.50 percent of copper, 0.01 to 0.10 percent of titanium, less than or equal to 0.015 percent of sulphur, less than or equal to 0.020 percent of phosphorus, and the balance being ferrum. The method is to manufacture a pumping rod wire through a design of adding the niobium and other trace alloy elements and corresponding compositions into steel, and controlled rolling and controlled cooling organization control technology. The pumping rod manufactured by the wire has excellent oilwell medium corrosion resistance, proper strength, excellent plastic tenacity and excellent welding performance, thereby improving the service life and reliability of the pumping rod, and improving the whole stability of pumping equipment, and further solving the problem that the prior pumping rod has repeated stress failure caused by endurance of complex casinghead gas corrosion.

Description

technical field [0001] The invention relates to compositional design and manufacturing method of structural steel in the metallurgical industry, in particular to an oil well gas corrosion-resistant sucker rod steel and its manufacturing technology. Background technique [0002] Mechanical oil recovery is the main means of oilfield development, and the rod pumping system plays an important role in mechanical oil recovery. The sucker rod is an important part of rod pumping equipment. Its function is to transmit the power of the pumping unit to the downhole pump and extract oil through the oil well pipe. [0003] Sucker rods are generally made of steel wire rods, which can be divided into D-grade rods and H-grade rods according to their strength levels, of which the latter has higher strength. The steel types used to manufacture D-grade rods include 35Mn2, 35CrMo, 42CrMo steel, etc. The D-grade sucker rods recommended by the American Petroleum Institute are: 1536 and 4142 (equ...

AI Technical Summary

Problems solved by technology

The sucker rod made of this wire has good oil well medium corrosion resistance, appropriate strength, excellent plasticity and toughness, and good welding performance, thereby improving the service life and reliability of the sucker rod and improving the overall stability of the pumping equipment , to further solve the problem of fatigue fracture of existing sucker rods due to complex oil well gas corrosion

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