Cable for down hole pump

Abstract

A cable is provided for suspending a down hole pump that has a core with at least one tube for the transport of fluid and at least one conductor covered with an insulation layer made of a high temperature resistant insulating material. The core is covered by a steel tape and a first layer of steel wires are positioned radially outside the steel tape in contact with the steel tape. The wires of the first layer of steel wires are positioned side by side around the core with no filler in between the steel wires and an outer layer made of heat resistant polymer covers the steel wires.

Claims

1. A cable for suspending a down hole pump wherein said cable comprising: a core having at least one tube for the transport of fluid and at least one conductor covered with an insulation layer made of a high temperature resistant insulating material, said core further having filing elements made of perfluoroalkoxy polymer wherein the core is covered by a steel tape that is in contact with the insulation layer of the at least one conductor and at least two layers of steel wires are positioned radially outside the steel tape with a polymer film between said two layers of steel wires, wherein an inner layer of said two layers of steel wires being in direct contact with the steel tape, and wherein individual steel wires forming said inner layer have a total of 37 individual steel wires which are positioned side by side around the core and in direct contact with the steel tape with no filler in between the individual steel wires and an outer layer made of heat resistant polymer covering the individual steel wires, and wherein a total diameter of the cable is substantially 45 mm.

2. The cable in accordance with claim 1, wherein a total number of conductors within said cable is three.

3. The cable in accordance with claim 1, wherein a total number of tubes within said cable is three.

4. The cable in accordance with claim 1, wherein the conductor is made of copper.

5. The cable in accordance with claim 1, wherein the heat resistant polymer of the outer layer comprises thermoplastic polyester.

6. The cable in accordance with claim 3, wherein at least one of the tubes comprises optical fibres.

7. The cable in accordance with claim 1, wherein the high temperature resistant insulating material of the insulation layer comprises perfluoroalkoxy polymer.

8. The cable in accordance with claim 1, wherein the fluid to be transported in the at least one tube is a corrosion inhibitor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following an example of an embodiment of the invention will be described with reference to the FIGURE;

(2) FIG. 1 shows a cross section through a radial plane of the cable in accordance with the invention.

DETAILED DESCRIPTION

(3) In the embodiment of the cable 1 as shown in FIG. 1, three conductors 2 are included in the core of the cable 1. Each conductor, which may be a Cu conductor and may be stranded, is insulated with a layer 3, made of high temperature resistant insulating material such as perfluoroalkoxy polymer (PFA). In the shown embodiment the core also includes three tubes 4 for the transport of fluid and filling elements 5. In one embodiment of the invention optical fibres may be included in at least one of the three tubes 4.

(4) A steel tape 6 covers the conductors 2, the tubes 4 and the filling elements 5, for the radial protection of the core. For the provision of axial strength to the cable, plural wires 7 are arranged helically wounded in contact with the steel tape 6 surrounding the core. The wires 7 may be stranded and may be made of galvanized steel. In the FIGURE, the cable 1 is shown with one layer of wires 7, but in an alternative embodiment of the cable two or more layers of wires 7 may be included in the cable 1, in which case each layer of wire may be separated from the next by a polymer film. The wires 7 included in each layer comprise plural wires arranged side by side without the use of filling elements in between the wires 7 of a layer.

(5) An outer layer 8 of heat resistant polymer for instance of thermoplastic polyester (TPE) covers the wires 7. Perfluoroalkoxy polymer (PFA) may also be used making up the outer layer 8.