Preparation method for 110ksi high grade steel and high CO2-corrosion resistant tubing and casing and the tubing and casing

Abstract

The invention provides 110ksi high steel grade and high CO2 corrosion resistance 13Cr steel for an oil casing, the oil casing made of the same and a method for making the oil casing. The component proportion of the steel for the oil casing has the addition of a few nickel, molybdenum and nitrogen alloy elements based on API L80-13Cr oil casing alloy design. The steel for oil casing comprises the following chemical component by weight: 0.15-0.25 percent of C, 0.2-1.0 percent of Si, 0.20-1.0 percent of Mn, 12.0-14.0 percent of Cr, 0.5-1.5 percent of Ni, 0.2-1.0 percent of Mo, 0.03-0.10 percent of N, and the balance being Fe and inevitable impurities. The oil casing with the CO2-chloridion corrosion resistant strength up 110 steel grade at the temperature over 150 DEG C can be obtained after the steel is smelted, rolled and performed with proper heat treatment. Due to low alloy and production cost and good CO2 corrosion resistance, the 110ksi high steel grade and high CO2 corrosion resistance oil casing can be widely used for oil well pipes and other occasions requiring corrosion resistance.

Description

technical field [0001] The invention relates to a steel for oil casing, in particular to a 110ksi high steel grade, high resistance to CO 2 13Cr steel for corroded oil casing, the oil casing made of the steel and the manufacturing method of the oil casing. Background technique [0002] With the intensification of my country's oil and gas development, oil well casings and tubing for collecting oil and gas are facing high temperature, high pressure, and high CO content. 2 , chlorine ions, etc. coexisted in a strong corrosive environment, resulting in multiple downhole tubing breaks and gas gathering trunk leakage accidents in oil and gas fields. [0003] First, CO 2 Corrosion of tubing is a problem often encountered in the production process of oil and gas wells. CO2 has been extensively studied at home and abroad 2 On the basis of the corrosion mechanism, characteristics and influencing factors of oil pipes, a prediction CO 2 Various numerical simulation calculation met...

AI Technical Summary

Problems solved by technology

[0028]In addition, in addition to the high cost caused by the high content of Mo, Ni, Cu and other precious metals in the existing 110ksi steel grade ultra-low carbon 13Cr oil casing steel grade, other The carbon content is only ultra-low carbon, the converter cannot be smelted, and the electric furnace-forging-peeling-rolling production line must be adopted, which also leads to a low success rate of the production line and high manufacturing costs

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