Steel for quenched and tempered coiled tubing, hot rolled steel strip, steel tube and manufacturing methods of hot rolled steel strip and steel tube

A manufacturing method and oil pipe technology, which are applied in the fields of steel strips, steel grades, steel pipes and their manufacturing, can solve the problems of difficulty in developing ultra-high strength coiled tubing, large residual stress in welded parts, and decreased fatigue life of welded seams, etc. Permeability and tempering stability, good fatigue life and corrosion resistance, the effect of improving surface quality

CN113637925AActive Publication Date: 2021-11-12BAOSHAN IRON & STEEL CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2021-11-12

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Abstract

The invention discloses steel for a quenched and tempered coiled tubing. The steel comprises the following chemical elements including, by mass percent, 0.15%-0.35% of C, 0.08%-0.30% of Si, 0.50%-1.80% of Mn, not larger than 0.015% of P, not larger than 0.005% of S, 0.40%-0.80% of Cr, 0.01%-0.05% of Nb, 0.01%-0.03% of Ti, 0.05%-0.38% of Mo, 0.0003%-0.0015% of B, 0.001%-0.004% of Ca, 0.01%-0.05% of Al and larger than 0 and not larger than 0.006% of N. In addition, the invention further discloses a hot rolled steel strip prepared from the steel for the quenched and tempered coiled tubing and a manufacturing method of an oil casing. In addition, the invention further discloses a steel tube prepared from the hot rolled steel strip. By means of the steel for the quenched and tempered coiled tubing, the alloy cost is effectively controlled, and the prepared hot rolled steel strip is low in strength and has good plasticity, toughness and machining performance. The steel tube prepared from the low-strength hot rolled steel strip has ultrahigh strength, the structure property is uniform, and good fatigue life and corrosion resistance are achieved.
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Description

technical field

[0001] The invention relates to a metal material and a manufacturing method thereof, in particular to a steel grade, a steel strip, a steel pipe and a manufacturing method thereof. Background technique

[0002] Quenched and tempered coiled tubing (Coiled tubing, referred to as CT) is relative to conventional threaded tubing. It is called coiled tubing, coiled tubing, serpentine tubing or coiled tubing. The advantages of coiled tubing in oilfield operations are very prominent, and it has been developed rapidly in the past ten years. It is widely used in oil and gas field workover, drilling, completion, logging and other operations, and is known as the "universal operating machine".

[0003] With the development of oil and gas operations and the advancement of drilling and completion technologies, deep wells, high-pressure wells, and horizontal wells have gradually increased. At present, there are vertical wells with a depth of more than 7000m and horizontal w...

Examples

Embodiment 1-6 and comparative example 1-2

[0080] Table 1 lists the mass percentage of each chemical element in the quenched and tempered coiled tubing steel of Examples 1-6 and the steel of Comparative Examples 1-2.

[0081] Table 1. (wt%, the balance is Fe and other unavoidable impurities except P and S)

[0082]

[0083]

[0084] The steel for quenched and tempered coiled tubing in Example 1-6 of the present invention and the steel in Comparative Example 1-2 can be correspondingly made corresponding hot-rolled steel strips, and the following examples 1-1 to 6- 1 represents the hot-rolled steel strips prepared by using the steels for quenched and tempered coiled tubing in Examples 1-6 and the steels in Comparative Examples 1-2, respectively.

[0085] The hot-rolled steel strip of embodiment 1-1 to embodiment 6-1 and the hot-rolled steel strip of comparative example 1-1 and comparative example 2-1 all adopt the following steps to make:

[0086] (1) Smelting and continuous casting: In the smelting step, electric...