Throwing and fishing cable

Abstract

The invention belongs to the technical field of oilfield development, and discloses a throwing and fishing cable. The throwing-fishing cable comprises a cable core, a bearing layer and a protective sleeve. The cable core is formed by twisting a plurality of conductors, and each conductor is coated with an insulating layer; the bearing layer comprises a plurality of bearing steel wire bundles, each bearing steel wire bundle is formed by twisting a plurality of steel wires, the bearing steel wire bundles are arranged between every two adjacent conductors, and the bearing steel wire bundles are tightly attached to the adjacent conductors; the protection sleeve wraps the cable core and the bearing layer, is tangent to the bearing layer and the cable core, and is used for protecting the cable core and the bearing layer. The casting and fishing cable can guarantee the sealing effect when the casting and fishing cable penetrates out of a well mouth, oil-water mixture is prevented from leaking from the well mouth, and the working reliability of electric submersible lifting equipment is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield development, in particular to a casting and fishing cable. Background Art

[0002] With the widespread application of electric submersible lift equipment in oilfield development, in order to improve the lifting and lowering efficiency of the electric submersible lift equipment and ensure stable power supply for the electric submersible lift equipment, after the electric submersible lift equipment is lowered to a designated location underground through the oil pipeline, a fishing cable is usually lowered into the oil pipeline. One end of the fishing cable is connected to the power supply equipment on the surface, and the other end passes through the wellhead and is connected to the motor of the electric submersible lift equipment underground, thereby providing power to the electric submersible lift equipment. In order to ensure the sealing at the wellhead and prevent the oil-water mixture from leaking from the wellhead, a wellhead sealing device needs to be installed at the wellhead after the fishing cable is connected to the motor of the electric submersible lift equipment, so that the fishing cable can pass through the wellhead sealing device.

[0003] See Figure 1 The conventional fishing cable generally includes a conductor core 10, a reinforcing steel wire 20, a protective sheath 30, and a filler 40. When installing a wellhead sealing device, the wellhead sealing device and the fishing cable are squeezed. Since the reinforcing steel wire 20 of a conventional fishing cable is spirally wrapped around the conductor core 10 in the circumferential direction and has a relatively large diameter, the compression creates gaps between the reinforcing steel wire 20 and the outer protective sheath 30, as well as between the reinforcing steel wire 20 and the inner conductor core 10. This causes the cable to deform, creating a gap between the fishing cable and the wellhead sealing device, resulting in failure of the wellhead seal and leakage of oil-water mixture from the wellhead, affecting the reliability of the electric submersible oil lifting equipment. Summary of the Invention

[0004] The purpose of the present invention is to provide a casting and fishing cable, which can ensure the sealing effect of the casting and fishing cable when passing through the wellhead, avoid the leakage of oil-water mixture from the wellhead, and ensure the reliability of the operation of the electric submersible oil lifting equipment.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] Provided is a casting and fishing cable, comprising:

[0007] The cable core is composed of a plurality of conductors twisted together, each of which is covered with an insulating layer;

[0008] The load-bearing layer includes a plurality of load-bearing steel wire bundles, each of which is composed of a plurality of twisted steel wires. The load-bearing steel wire bundle is arranged between each two adjacent conductors, and the load-bearing steel wire bundles are closely attached to the adjacent conductors.

[0009] The protective sleeve is coated on the outside of the cable core and the bearing layer and is tangent to the bearing layer and the cable core, and is used to protect the cable core and the bearing layer.

[0010] Preferably, the load-bearing steel wire bundle is formed by twisting a plurality of steel wires with a diameter of 0.8 mm to 1 mm, and the diameter of the load-bearing steel wire bundle is 4 mm to 5 mm.

[0011] Preferably, the salvage cable also includes a heating layer, and the protective cover includes a first protective layer and a second protective layer, the first protective layer is coated on the cable core and the bearing layer, the heating layer is coated on the first protective layer, and the second protective layer is coated on the heating layer, and the heating layer can be connected to a heating power supply.

[0012] Preferably, the heating layer is woven from copper wires.

[0013] Preferably, a filling layer is further included, and the filling layer is used to fill the gap between the first protective layer and the cable core and between the first protective layer and the bearing layer.

[0014] Preferably, the first protective layer and the second protective layer are both made of fluoroplastic.

[0015] Preferably, the insulating layer includes an inner insulating layer and an outer insulating layer, the inner insulating layer is sintered on the outer surface of the conductor, and the outer insulating layer is coated on the outside of the inner insulating layer.

[0016] Preferably, the inner insulating layer is a polyimide film, and the outer insulating layer is made of FEP material.

[0017] Preferably, the casting and salvaging cable is cylindrical, and the outer diameter of the casting and salvaging cable is 22 mm to 25 mm.

[0018] Preferably, the conductor is a cylindrical conductor drawn from an oxygen-free copper rod.

[0019] The beneficial effects of the present invention are as follows: the cable core can transmit electrical energy to the motor of the electric submersible oil lifting equipment; the load-bearing steel wire bundle formed by twisting multiple steel wires can effectively improve the load-bearing strength of the load-bearing layer, and the load-bearing steel wire bundle is arranged between adjacent conductors, so that the load-bearing steel wire bundle and the conductor are closely fitted, making the structure of the casting cable more compact. Compared with the traditional spirally braided steel wire layer method, when the wellhead sealing device is installed at the wellhead, under the support of the load-bearing layer, no gaps will be generated between the internal structures of the casting cable, and the casting cable is not easy to deform, thereby improving the overall external strength and tensile strength of the casting cable, thereby ensuring the sealing between the casting cable and the wellhead, avoiding leakage of oil-water mixture from the wellhead, and ensuring the reliability of the electric submersible oil lifting equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional view of a cast-and-fish cable in the prior art;

[0021] Figure 2 It is a cross-sectional view of the casting and fishing cable provided by the present invention.

[0022] Figure 1 middle:

[0023] 10. Conductor core; 20. Reinforced steel wire; 30. Protective cover; 40. Filler;

[0024] Figure 2 middle:

[0025] 1. Conductor; 11. Insulation layer; 111. Inner insulation layer; 112. Outer insulation layer;

[0026] 2. Load-bearing wire bundle;

[0027] 3. Protective cover; 31. First protective layer; 32. Second protective layer;

[0028] 4. Heating layer;

[0029] 5. Filling layer. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0031] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0032] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0033] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0034] See Figure 2 This embodiment provides a salvaging cable that can ensure the sealing effect of the salvaging cable when it passes through the wellhead, prevent the oil-water mixture from leaking from the wellhead, and ensure the reliability of the electric submersible oil lifting equipment. The salvaging cable includes a cable core, a bearing layer and a protective cover 3. The cable core is composed of a plurality of conductors 1 twisted together, and each conductor 1 is coated with an insulating layer 11. The bearing layer includes a plurality of bearing steel wire bundles 2, each bearing steel wire bundle 2 is composed of a plurality of steel wires twisted together, and a bearing steel wire bundle 2 is arranged between each two adjacent conductors 1, and the bearing steel wire bundle 2 is tightly fitted with the adjacent conductors 1. The protective cover 3 is coated on the outside of the cable core and the bearing layer, and is tangent to the bearing layer and the cable core, and is used to protect the cable core and the bearing layer.

[0035] The fishing cable provided in this embodiment has a cable core that can transmit electrical energy to the motor of the electric submersible oil lifting equipment; the load-bearing steel wire bundle 2 formed by twisting multiple steel wires can effectively improve the load-bearing strength of the load-bearing layer, and the load-bearing steel wire bundle 2 is arranged between adjacent conductors 1, so that the load-bearing steel wire bundle 2 is tightly fitted with the conductor 1, making the structure of the fishing cable more compact. Compared with the traditional spirally braided steel wire layer method, when the wellhead sealing device is installed at the wellhead, under the support of the load-bearing layer, no gaps will be generated between the internal structures of the fishing cable, and the fishing cable is not easy to deform, thereby improving the overall external strength and tensile strength of the fishing cable, thereby ensuring the sealing between the fishing cable and the wellhead, avoiding leakage of oil-water mixture from the wellhead, and ensuring the reliability of the electric submersible oil lifting equipment.

[0036] In this embodiment, the cable core is formed by twisting three conductors 1 together. Accordingly, three load-bearing steel wire bundles 2 are provided. Optionally, the conductors 1 are cylindrical conductors drawn from oxygen-free copper rods. Oxygen-free copper rods have good electrical conductivity and are easy to process.

[0037] Furthermore, the fishing cable is cylindrical, and the outer diameter of the fishing cable is 22 mm to 25 mm. The cylindrical fishing cable is easy to put into the oil pipe and is easy to adapt to the wellhead sealing device.

[0038] In this embodiment, the load-bearing steel wire bundle 2 is composed of multiple steel wires with diameters ranging from 0.8 mm to 1 mm, and the diameter of the load-bearing steel wire bundle 2 ranges from 4 mm to 5 mm. This arrangement effectively reduces the diameter and weight of the fishing cable while ensuring the load-bearing capacity of the fishing cable. This results in a lighter weight and smaller diameter of the cabled fishing cable, making it less likely to deform during installation of the wellhead sealing device, thereby ensuring the seal between the fishing cable and the wellhead. For example, 19 steel wires with a diameter of 0.9 mm are twisted together to form a load-bearing steel wire bundle 2 with a diameter of 4.5 mm.

[0039] Optionally, the fishing cable further includes a heating layer 4, and the protective sheath 3 includes a first protective layer 31 and a second protective layer 32. The first protective layer 31 is coated on the cable core and the bearing layer, the heating layer 4 is coated on the first protective layer 31, and the second protective layer 32 is coated on the heating layer 4. The heating layer 4 can be connected to a heating power source. The oil-water mixture lifted by the electric submersible oil lifting equipment has characteristics such as high viscosity and wax content. As the oil-water mixture rises in the oil pipe, its temperature gradually decreases, and the oil-water mixture may increase in viscosity or precipitate wax crystals, which can easily cause blockage in the oil pipe, leading to pump jamming of the electric submersible oil lifting equipment, and even system failure, resulting in losses in subsequent well repair operations and oil well production. Therefore, a heating layer 4 is provided between the first protective layer 31 and the second protective layer 32. Heating layer 4 generates heat when energized, and this heat is transferred to the oil-water mixture in the oil pipe through the second protective layer 32. This reduces the viscosity of the oil-water mixture and prevents the precipitation of wax crystals, thus avoiding oil pipe blockage and pump jams and system failures caused by oil pipe blockage in the electric submersible lift equipment, thereby ensuring the reliability of the electric submersible lift equipment. The second protective layer 32 effectively protects the internal structure of the fishing cable, while the first protective layer 31 effectively isolates the heating layer 4 from the cable core and the load-bearing layer.

[0040] Preferably, the heating layer 4 is woven from copper wire. Copper wire has good electrical conductivity, is readily available, and is easy to process. Furthermore, both the first protective layer 31 and the second protective layer 32 are made from fluoroplastic. Fluoroplastic has excellent resistance to oil, solvents, wear, moisture, and low temperatures. It also stably transfers the heat generated by the heating layer 4 to the oil-water mixture in the oil pipe via the second protective layer 32.

[0041] Optionally, a filling layer 5 is also included, which is used to fill the gaps between the first protective layer 31 and the cable core, and between the first protective layer 31 and the bearing layer. In order to ensure that the outer diameter of the salvage cable is relatively round after being cabled and to ensure the stability of the internal structure of the salvage cable, a filling layer 5 is provided between the first protective layer 31 and the cable core, and between the first protective layer 31 and the bearing layer. The filling layer 5 can also provide thermal insulation and insulation to prevent the heat generated by the heating layer 4 from being transferred to the cable core, while further improving the insulation performance of the cable core. Optionally, the filling layer 5 is a glass fiber rope. Glass fiber rope is lightweight and has good corrosion resistance, high temperature resistance, and insulation properties.

[0042] Optionally, the insulating layer 11 includes an inner insulating layer 111 and an outer insulating layer 112. The inner insulating layer 111 is sintered to the outer surface of the conductor 1, and the outer insulating layer 112 is coated on the outer surface of the inner insulating layer 111. This configuration effectively reduces the size of the conductor 1. The inner and outer insulating layers 111 and 112 work together to effectively ensure the insulation performance of the conductor 1 when transmitting high-voltage electricity. Preferably, the inner insulating layer 111 is a polyimide film, and the outer insulating layer 112 is made of FEP material. Both polyimide and FEP materials have high insulation properties, effectively ensuring the insulation performance of the insulating layer 11.

[0043] It is understood that the temperature of the heating layer 4 is controlled by controlling the current passed through the heating layer 4 by the heating power supply. In this embodiment, the heating temperature of the heating layer is not higher than 80°C to prevent the strength of the cable from being affected by excessive temperature.

[0044] Optionally, the cable core, the load-bearing layer, the first protective layer 31, the heating layer 4 and the second protective layer 32 are bonded to each other by a high-temperature adhesive. The type of the high-temperature adhesive is not specifically limited in this embodiment, as long as it meets the bonding requirements.

[0045] The following is a brief description of the use of the fishing cable provided in this embodiment: After the electric submersible lifting equipment is lowered to the designated position underground through the oil pipe, the lower connector is connected to one end of the fishing cable, and the lower connector is dropped into the oil pipe and docked with the motor of the electric submersible lifting equipment (the connection method between the fishing cable and the lower connector is the existing technology and is not described in detail in this embodiment); then, a wellhead sealing device is installed at the wellhead, so that the fishing cable passes through the wellhead sealing device. After that, the power supply equipment on the ground is started to transfer electrical energy to the electric submersible lifting equipment through the fishing cable, thereby driving the electric submersible lifting equipment to lift the oil-water mixture underground to the ground. During the lifting process, the heating layer 4 can be powered so that the heat generated by the heating layer 4 is transferred to the oil-water mixture in the oil pipe, thereby preventing the oil-water mixture from increasing in viscosity or precipitating wax crystals, and thus preventing the oil pipe from being blocked. It should be noted that the wellhead sealing device is not within the scope of protection of this application and is not described in detail in this embodiment.

[0046] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Casting and fishing cable, characterized in that, include: The cable core is composed of a plurality of conductors (1) twisted together, and each of the conductors (1) is coated with an insulating layer (11); A bearing layer comprising a plurality of bearing steel wire bundles (2), each of the bearing steel wire bundles (2) being composed of a plurality of twisted steel wires, a bearing steel wire bundle (2) being provided between each two adjacent conductors (1), and the bearing steel wire bundles (2) being in close contact with the adjacent conductors (1); A protective sleeve (3) is coated on the outside of the cable core and the bearing layer and is tangent to the bearing layer and the cable core, and is used to protect the cable core and the bearing layer.

2. The fishing cable according to claim 1, characterized in that: The load-bearing steel wire bundle (2) is formed by twisting together a plurality of steel wires with a diameter of 0.8 mm to 1 mm, and the diameter of the load-bearing steel wire bundle (2) is 4 mm to 5 mm.

3. The fishing cable according to claim 1, characterized in that: The fishing cable further comprises a heating layer (4); the protective cover (3) comprises a first protective layer (31) and a second protective layer (32); the first protective layer (31) is coated on the cable core and the bearing layer; the heating layer (4) is coated on the first protective layer (31); the second protective layer (32) is coated on the heating layer (4); and the heating layer (4) can be connected to a heating power source.

4. The fishing cable according to claim 3, characterized in that: The heating layer (4) is woven from copper wires.

5. The fishing cable according to claim 3, characterized in that: It also includes a filling layer (5), which is used to fill the gaps between the first protective layer (31) and the cable core and between the first protective layer (31) and the bearing layer.

6. The fishing cable according to claim 3, characterized in that: The first protective layer (31) and the second protective layer (32) are both made of fluoroplastic.

7. The fishing cable according to any one of claims 1 to 6, characterized in that: The insulating layer (11) comprises an inner insulating layer (111) and an outer insulating layer (112); the inner insulating layer (111) is sintered on the outer surface of the conductor (1); and the outer insulating layer (112) is coated on the outside of the inner insulating layer (111).

8. The fishing cable according to claim 7, characterized in that: The inner insulating layer (111) is a polyimide film, and the outer insulating layer (112) is made of FEP material.

9. The fishing cable according to any one of claims 1 to 6, characterized in that: The casting and bailing cable is cylindrical, and the outer diameter of the casting and bailing cable is 22 mm to 25 mm.

10. The fishing cable according to any one of claims 1 to 6, characterized in that: The conductor (1) is a cylindrical conductor drawn from an oxygen-free copper rod.

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