Metal pipe, in particular pipe for conveying oil and gas, comprising a metal coating in a transition region

Abstract

A metal pipe and a system of pipes, and a method of producing the same. The pipe is for conveying oil and gas. The pipe includes a metal coating in a transition region. The metal coating of the transition region obviates a subsequent coating of the inner surface of the transition region after connecting two pipes using a welding process in order to form a pipeline.

Claims

1. A metal pipe for conveying oil and gas, the metal pipe comprising: a pipe body with an inner surface and an outer surface; and a pipe joint having a transition region located at an end of the pipe body, and the inner surface of the pipe body having at least a partial base coating disposed at the transition region, wherein the transition region is coated on the inner surface of the pipe body with a weldable metal coating of a material with anti-corrosion and/or anti-abrasion properties, wherein the at least partial base coating on the inner surface of the pipe body partially covers the metal coating of the transition region, and wherein the at least partial base coating is a sprayed-on metal base coating.

2. The metal pipe according to claim 1, wherein the metal coating of the transition region consists of a nickel-based steel alloy.

3. The metal pipe according to claim 1, wherein the metal coating has a variable thickness in the transition region, such that the thickness increases toward the pipe joint.

4. The metal pipe according to claim 1, wherein the metal coating in the transition region has an average thickness of 0.1 mm to 2 mm.

5. The metal pipe according to claim 1, wherein a length of the pipe body is greater than 10 m.

6. The metal pipe according to claim 1, wherein the pipe body has an inner diameter of more than 150 mm.

7. A system comprising: at least two metal pipes, each of the at least two metal pipes including: a pipe body with an inner surface and an outer surface, and a pipe joint having a transition region located at an end of the pipe body, and the inner surface of the pipe body having at least a partial base coating disposed at the transition region, wherein: the transition region is coated on the inner surface of the pipe body with a weldable metal coating of a material with anti-corrosion and/or anti-abrasion properties, the at least partial base coating on the inner surface of the pipe body partially covers the metal coating of the transition region, the at least partial base coating is a sprayed-on metal base coating; and wherein: the at least two metal pipes are connected to one another by a weld seam at the respective pipe joints, and the at least two pipes have a continuous coating of the at least partial base coating and the metal coating on the inner surface therebetween.

8. The system according to claim 7, wherein the weld seam is made from the material of the metal coating.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1: Section through pipe with coating

(2) FIG. 2: Section through pipe with coating of the pipe joint

(3) FIG. 3: Section through pipe with coating in a recess

(4) FIG. 4: Section through two connected pipes without a weld

(5) FIG. 5: Section through two connected pipes with a weld seam

DETAILED DESCRIPTION OF THE DRAWINGS

(6) The figures in the form of embodiments are described in detail below. In all figures, the same technical elements are denoted by the same reference signs.

(7) FIG. 1 shows a section through a metal pipe according to the invention for the passage of oil or gas. The pipe body 1 consists for example of a carbon steel and forms the structure of the metal pipe. A transition region 2, which is provided with a metal coating 4, is arranged at the end of the pipe body 1. The metal coating 4 has a thickness d that increases toward the pipe joint 3. A base coating 5, in this case for example a plastics material layer, is applied to the inner surface 6 of the pipe body 1, the plastics material layer 5 partially covering the metal coating 4. The offset in the metal coating 4 allows for an almost edge-free inner surface 6 of the entire pipe.

(8) FIG. 2 shows a section through a pipe with a metal coating 4 of the transition region 2 and an additional metal coating 4 of the pipe joint 3. The metal coating 4 is designed continuously so that an L-shape results in the sectional view. In the transition region 2, the metal coating 4 is designed to rise continuously to the pipe joint 3. The pipe joint 3 is coated with a constant thickness d. The inner edge 61 of the metal coating 4 is chamfered accordingly to form a partial V groove 8 (or J groove).

(9) FIG. 3 shows a section through a pipe with a metal coating 4 of the transition region 2 in a recess 23 of the pipe body 1 and an additional metal coating 4 of the pipe joint 3. The metal coating 4 of the pipe joint and transition region 2 is designed to be continuous, so that an L-shape results in the sectional view. In the transition region 2, the base coating 5, in this case for example a sprayed-on metal coating, partially covers the metal coating.

(10) FIG. 4 shows a section through two pipes according to the invention arranged next to one another. The two pipe joints 3 are in contact with one another, so that a continuous coating is formed. The chamfered edges of the metal coating 4 form a V groove on the inner and outer edges 61, 71. Furthermore, the mutually adjacent pipe joints 3 each have a complementary groove and spring connection 11, one part being coated or formed by the metal coating 4 of the pipe joint 3.

(11) FIG. 5 shows the section from FIG. 3 with a corresponding weld seam 10 in the two V grooves 8 on the inner and outer edge 61, 71 for connecting the two pipes to form a pipeline.

(12) TABLE-US-00001 TABLE 1 Reference signs Number Description 1 Pipe body 2 Transition region (Heat-affected zone) 22 Coverage region 23 Recess 3 Pipe joint 4 Metal coating 5 Base coating 6 Inner surface 61 Inner edge 7 Outer surface 71 Outer edge 8 Part V (or J) groove 10 Weld seam 11 Groove and spring pipe body d Thickness