High collapse-resistance and hydrogen sulphide-corrosion-resistant low alloy petroleum case pipe and method of manufacturing the same

Abstract

The invention relates to a low-alloyed petroleum casing pipe with high anti-collapse and high hydrogen sulfide corrosion resistance and a production method. The weight percentages of the chemical components of the low-alloyed petroleum casing pipe are: 0.24-0.34 percent of C, 0.35-1.0 percent of Mn, 0.20-0.50 percent of Si, 0.4-1.1 percent of Cr, 0.2-0.7 percent of Mo, 0.007-0.07 percent of Al, 0.005-0.05 percent of Ti, 0.01-0.05 percent of Nb, 0.05-0.15 percent of V, 0-0.6 percent of Ni, 0-0.2 percent of Cu, less than 0.003 percent of B, less than 0.015 percent of P, less than 0.005 percent of S and less than 0.01 percent of Ca and the rest of Fe and inevitable impurities. The production method comprises: external refining and vacuum degassing, and then Ca treatment, smelting, continuous casting to form round blocker and pipe making, soaking, air cooling after rolling, sawing, and then quenching and tempering heat treatment, heating to 880-900 DEG C, water quenching after heat preservation for 30-60 min, tempering and heat preservation under 680-710 DEG C and hot sizing under 550-650 DEG C, the temperature of hot straightening is more than 450 DEG C. The low-alloyed petroleum casing pipe has better anti-collapse performance and hydrogen sulfide corrosion resistance.

Description

technical field [0001] The invention relates to a low-alloy oil casing for oil and gas wells, in particular to a low-alloy oil casing with high resistance to collapse and hydrogen sulfide corrosion and a production method thereof. Background technique [0002] High anti-collapse tubing and casing is an indispensable special pipe suitable for the completion of oil and gas wells such as deep wells and ultra-deep wells. Water layers and sealing various complex strata to ensure the role of drilling. However, corrosive media such as hydrogen sulfide are common in oilfields such as Tarim and Sichuan in my country, and the oil well pipes used are also severely eroded while being squeezed. It is conceivable that in such a stress corrosion environment, the oil casing will quickly fail and crack, which will not only cause serious economic losses to the oil field, but also affect the normal and safe production of the oil field. [0003] Generally speaking, the crush strength and corr...

AI Technical Summary

Problems solved by technology

However, due to the inevitable melting of nitrogen into the steel, Ti will react with N to form large square TiN before the molten steel is poured, and TiC will nucleate at the interface between TiC and the matrix during the subsequent cooling process The Ti(NC) particles grow further, which adversely affects the resistance to hydrogen sulfide

Images