CO2 and Cl<-> corrosion resistant high-strength 15Cr oil pipe for high-temperature high-pressure wells

Abstract

A CO2 and Cl<-> corrosion resistant high-strength 15Cr oil pipe for high-temperature high-pressure wells comprises the following compositions in percent by weight: carbon, <=0.03 wt%; silicon, 0.2-0.5 wt%; manganese, 0.2-0.6 wt%; phosphorus, <= 0.02 wt%; sulfur, <= 0.005 wt%; chromium, 14.5-15.3 wt%; molybdenum, 1.7-2.4 wt%; copper, 0.6-1.0 wt%; nickel, 6.5-7.5 wt%; tungsten, 0.4-0.7 wt%; titanium, 0.002-0.007 wt%; boron, 0.001-0.005 wt%; niobium, 0.04-0.09 wt%; vanadium, 0.03-0.07 wt%; nitrogen, 0.01-0.1%; oxygen, <= 0.001 wt%; hydrogen, <= 0.000005 wt%; controlled compositions: arsenic, <=0.03 wt%; antimony, <=0.03 wt%; and antimony, <=0.03 wt%; and the balance iron. According to the 15Cr oil pipe, the minimum yield strength is 925 MPa (125ksi steel grade), the critical usage temperature is 210 DEG C, the CO2 partial pressure can be 10 MPa or more, the Cl<-> concentration can be 120000 mg/L, the 15Cr oil pipe has certain H2S stress corrosion cracking resistant performance, and compared with a super II type 13Cr martensite stainless steel oil pipe material, the increased cost is not large.

Description

technical field [0001] The invention belongs to the technical field of petroleum pipes, in particular to a CO2-resistant pipe used in high temperature and high pressure wells. 2 +Cl - Corroded high-strength 15Cr tubing. Background technique [0002] With the world's increasing demand for oil and gas resources, the development of oil and gas fields has gradually developed in depth. Some oil and gas wells with a depth of 7600m or even deeper have become very common, resulting in the emergence of ultra-deep and ultra-high pressure wells. The continuous emergence of high-pressure, high-temperature, and ultra-high-pressure, high-temperature wells has gradually increased the difficulty of exploration and development, and the drilling and completion problems have increased significantly. The well completion problems they face include oil well design, technology, tools, equipment, well control, reservoir stimulation, A series of issues such as safety and material selection, the c...

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Problems solved by technology

[0003] In order to overcome the deficiencies in the prior art, the object of the present invention is to provide a CO2-resistant 2 +Cl - Corroded high-strength 15Cr tubing for high temperature and high pressure, high CO content 2 +Cl - Used in oil and gas wells to overcome the high CO content existing in the completion and production of existing high temperature and high pressure oil and gas wells 2 +Cl - Corrosion, to solve the problem of high well construction costs caused by the use of duplex stainless steel or nickel-based alloy tubing materials to avoid tubing corrosion

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