A high-temperature-resistant oil casing for hot steam injection heavy oil thermal recovery well and its manufacturing method

Abstract

The invention discloses a high-temperature-resistant petroleum casing for hot steam injection heavy oil thermal recovery wells and a manufacturing method thereof. The weight percent distribution ratio of the chemical components of the petroleum casing is C: 0.15-0.25%; Si: 0.10-0.30% ;Mn: ≤0.5%; P: ≤0.008%; S: ≤0.005%; Cr: ≤0.8%; Mo: 0.1‑0.5%; 0.01%; Ca: 0.001-0.003%; B: 0.001-0.002%; RE: 0.0005-0.001%; ​​the balance is Fe and unavoidable impurities. High-precision FFX roll forming is used to make the coiled plate into a tube blank, which is welded by high-frequency welding technology, and then the welded tube blank is quickly heated to the austenitizing temperature online, then thermomechanically rolled, and passed through thermal tension. The diameter reduction process is adjusted to the specified pipe diameter and wall thickness, and then the oil casing is made after special heat treatment of the whole pipe body, pipe end thread processing, hydrostatic pressure test, coupling processing, spray marking and painting. The petroleum casing has a yield strength of ≥770MPa, a breakage rate of ≤10%, a tensile strength of ≥880MPa, and a breakage rate of ≤9% at a temperature ranging from normal temperature to 350°C.

Description

Technical field: [0001] The invention relates to a steel for low-alloy petroleum casing and a production method thereof, in particular to a high-temperature-resistant petroleum casing for steam-injected heavy oil thermal recovery wells and a manufacturing method thereof. Background technique: [0002] As an unconventional oil resource, heavy oil is mainly distributed in the Jungar Basin, Songliao Basin, and Bohai Bay Basin in my country. Due to its high viscosity and poor fluidity, it is difficult to exploit by conventional methods. At present, thermal recovery technologies such as steam injection huff and puff method, steam flooding method and oil layer combustion method are mainly used in domestic heavy oil. Among them, Xinjiang Oilfield and Liaohe Oilfield widely use steam injection to develop heavy oil reservoirs. [0003] A large number of research conclusions about casing damage in thermal recovery wells show that the main cause of casing damage is the high temperature...

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Problems solved by technology

[0004] The application number 201110148660.0 published on October 12, 2011 involves a high-strength oil casing steel for heavy oil thermal recovery wells and its manufacturing method. The composition design does not consider corrosion performance, and the Mn content is relatively high. The strength meets the requirements of P110 steel grade, but its toughness is low, and the yield ratio is greater than 0.95. In the example, the impact toughness has no sampling direction, which cannot truly reflect the toughness of the final product

The patent No. 201310125942.8 published on July 10, 2013 involves an anti-H 2 Special casing for S corrosion and its production method, the patent is produced by seamless pipe technology, and the rare earth content in the composition design does not take into account the HFW welding problem

The patent No. 201410441145.5 published on September 1, 2014 involves a heat-resistant high-strength casing and its preparation process. The chemical composition design contains W, Hf and other alloying elements. In the preparation process, the high-temperature and medium-temperature holding time Too long, the shortest time is 150 minutes, which is very unfavorable for industrialized mass production of bushings

The Chinese invention patent with the publication number CN 105925883A published on September 07, 2016 discloses a high-strength and high-toughness N80Q oil casing and its manufacturing method. Although the oil casing prepared by this manufacturing method has high strength and toughness, it cannot Satisfied with high temperature hot injection steam thermal recovery well

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