CN112228006A

CN112228006A - Cable conversion device

Info

Publication number: CN112228006A
Application number: CN201910633589.1A
Authority: CN
Inventors: 徐月红
Original assignee: Tec Electric Co ltd
Current assignee: Tec Electric Co ltd
Priority date: 2019-07-15
Filing date: 2019-07-15
Publication date: 2021-01-15

Abstract

The invention provides a cable conversion device, which comprises a closed container; a plurality of monocable cables passing through one end of the container into the inner cavity of the container; the heating cables of the integrated heating cable group are respectively connected with corresponding single-core cables in the inner cavity of the container; inorganic mineral insulator of packing in the inner chamber of container, cable conversion equipment make heating integration heating cable group can extend to before the pump to liquid before the heating pump reduces the viscosity of viscous crude, and then improves the pump string height of sucker-rod pump, reduces the lifting power of pump, reduces the sucker-rod pump and overhauls the number of times, prolongs the life of sucker-rod pump.

Description

Cable conversion device

Technical Field

The invention relates to the technical field of downhole tools of oil and gas wells, in particular to a cable conversion device.

Background

Petroleum plays a very important role in the operation of a country as a strategic resource for the operation of the country. Regardless of the daily life, industry and military equipment operation of people, a large amount of petroleum resources are needed as a foundation. The thick oil reserves are abundant, but the exploitation difficulty is large.

In the prior art, a thin oil blending viscosity reduction process or a mineral insulated heating cable heating process is often adopted to reduce the viscosity of thick oil. For the thin oil blending viscosity reduction process, the development is limited along with the reduction of thin oil resources. For the cable heating technology, the heating efficiency in the shaft is very high, the temperature loss of the mixed liquid in the shaft can be reduced, and the lifting and viscosity reduction effect of the shaft is good. However, for a large number of pumping wells, the heating cable does not extend to the front of the pump due to space limitations, which results in low temperature at the pumping inlet and a series of heavy oil lift problems.

Thus, it is desirable to provide a cable switching device that allows thick oil to be heated before pumping.

Disclosure of Invention

The present invention is directed to a cable conversion device that solves some or all of the above-mentioned problems of the prior art. The cable conversion device enables the single-core cable to firstly pass through the pump and then be converted into the integrated heating cable group to extend in the oil pipe so as to electrically heat the liquid medium in front of the pump. Thereby can heat for the viscous crude before the pump through this cable conversion equipment's integration heating cable group, guarantee the temperature of liquid medium before the pump, reduce the viscosity of viscous crude, and then improve the pump string height of sucker-rod pump, reduce the lifting power of pump, reduce the sucker-rod pump and overhaul the number of times, prolong the life of sucker-rod pump. Meanwhile, the single-core cable can be used for additionally heating the liquid medium behind the pump of the sucker-rod pump, so that the liquid outlet temperature of a wellhead is guaranteed, and the reduction of back pressure and the oil conveying of a gathering and transportation pipeline are facilitated.

According to the present invention, there is provided a cable conversion apparatus comprising:

a closed container is arranged in the container body,

a plurality of monocable cables passing through one end of the container into the inner cavity of the container,

an integrated heating cable group which passes through the other end of the container and enters the inner cavity of the container, each heating cable of the integrated heating cable group is respectively connected with a corresponding single-core cable in the inner cavity of the container,

an inorganic mineral insulation filled in the interior cavity of the container.

In one embodiment, an axially extending blind connecting hole is provided in the connecting section of one of the monocable and the heating cable, and the connecting section of the other is inserted into the blind hole and radially penetrates the monocable and the heating cable by means of a fixing member to perform a fixed connection therebetween.

In one embodiment, a fixing sleeve is sleeved on the outer wall of the single core cable or the heating cable provided with the blind hole, and a fixing hole is formed in the fixing sleeve for a fixing piece constructed as a rivet to pass through.

In one embodiment, grooves are engraved on the outer wall of the connecting section of the heating cable or the single core cable, which is not provided with a blind hole.

In one embodiment, the inorganic mineral insulation is magnesium oxide powder.

In one embodiment, the magnesia powder includes three kinds of magnesia powder of 200 mesh, 120 mesh and 100 mesh which are uniformly mixed, and in the case that the mass of the 200 mesh magnesia powder is 1, the 120 mesh magnesia powder is 0.5-2, and the 100 mesh magnesia powder is 0.5-2.

In one embodiment, the container has:

a main body in the shape of a cylinder,

an upper end cover which is arranged at the opening of the upper end of the main body in a sealing way,

a lower end cover which is arranged at the lower end opening of the main body in a sealing way,

wherein the single core cable extends downwards through the upper end cover, and the integrated heating cable group extends upwards through the lower end cover.

In one embodiment, the lower cap has an upper end configured in a cylindrical shape and inserted at least partially into the inner cavity of the body, and a lower end configured in a tapered shape having a sectional area gradually decreasing from the top to the bottom,

or/and the upper end cover is in a column shape and is partially inserted into the inner cavity of the main body, and an anti-bending triangular cone barrel for the single-core cable to pass through is arranged on the upper end face of the upper end cover.

In one embodiment, ceramic plates are arranged in the inner cavity of the container, and axial through holes are arranged on the ceramic plates at intervals.

In one embodiment, the heating cable assembly further comprises a bearing seat fixedly arranged on the integrated heating cable assembly in a sleeved mode, and the outer wall of the bearing seat is provided with a communication hole extending axially.

Compared with the prior art, the cable conversion device has the advantages that the integrated heating cable group is connected with the single-core cable, so that the integrated heating cable group can extend to the front of the pump, a liquid medium in front of the pump is heated, the viscosity of thick oil is reduced, the pump hanging height of the sucker-rod pump is increased, the lifting power of the pump is reduced, the maintenance frequency of the sucker-rod pump is reduced, and the service life of the sucker-rod pump is prolonged. In addition, the cable conversion device passes through the pump through the single-core cable, so that the problem that the integrated heating cable set is difficult to pass through the pump is solved. In addition, the single-core cable can be used for supplementing and heating the post-pump liquid medium of the sucker-rod pump, so that the liquid outlet temperature of a wellhead is ensured, and reduction of back pressure and oil conveying of a gathering and transportation pipeline are facilitated.

Drawings

Preferred embodiments of the present invention will be described in detail below with reference to the attached drawing figures, wherein:

FIG. 1 illustrates a cross-sectional view of a cable transition device according to one embodiment of the present invention;

figure 2 shows a cross-sectional view of the junction of a monocable and a heating cable according to one embodiment of the invention.

In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

Detailed Description

The invention will be further explained with reference to the drawings.

Fig. 1 shows a cable conversion device 100 according to the present invention. As shown in fig. 1, the cable converter 100 includes a sealed container 1, a plurality of single-core cables 2, an integrated heating cable group 3, and an inorganic mineral insulator (not shown). Wherein, a plurality of single-core cables 2 all pass through one end of the container 1 and enter the inner cavity of the container 1. The single-core cable 2 is used for transmitting electric energy to the integrated heating cable group 3, and meanwhile, the single-core cable can generate heat to supplement and heat a pumped liquid medium of the sucker rod pump, so that the liquid outlet temperature of a wellhead is guaranteed. The integrated heating cable group 3 passes through the other end of the container 1 and enters the inner cavity of the container 1. Meanwhile, the integrated heating cable group 3 is composed of a plurality of heating cables 31, and the heating cables 31 are respectively connected with the single-core cables 2 in a one-to-one matching manner, so that electric energy is received and heat is generated to heat a liquid medium in front of the pump. An inorganic mineral insulation is filled in the inner cavity of the container 1 for insulation and to reduce the temperature of the connection point of the monocable 2 and the heating cable 31.

In the use process, the single-core cable 2 is small in diameter and can be easily distributed and arranged on the pump and the outer side of the oil pipe behind the pump. The single-core cable 2 is connected with the integrated heating cable group 3 after penetrating into the inner cavity of the oil pipe after passing through the pump. From this, cable conversion equipment 100 makes heating integration heating cable group 3 can extend to before the pump to liquid medium before the heating pump reduces the viscosity of viscous crude, and then improves the pump string height of sucker rod pump, reduces the lifting power of pump, reduces the sucker rod pump and overhauls the number of times, prolongs the life of sucker rod pump. In addition, the cable conversion device 100 avoids the problem that the integrated heating cable group 3 is difficult to pass through the pump by passing through the single-core cable 2. In addition, the single-core cable 2 can be used for supplementing and heating the liquid medium behind the pump of the sucker-rod pump, so that the liquid outlet temperature of a wellhead is guaranteed, and the reduction of back pressure and the oil conveying of a gathering and transportation pipeline are facilitated.

In one embodiment, as shown in fig. 2, a blind connecting hole 21 extending axially is provided at the connecting section of the single core cable 2. The connecting section of the corresponding heating cable 31 is inserted into the blind hole 21. The outer wall of the single-core cable 2 is sleeved with a fixed sleeve 4. The fixing member 5 radially penetrates the single core cable 2, the heating cable 31 and the fixing sheath 4 to connect the single core cable 2 and the heating cable 31 together. The connecting method realizes the locking connection of the single-core cable 2 and the heating cable 31 in the axial direction and the radial direction, effectively avoids the separation of conductors made of different materials due to different expansion coefficients in a high-temperature state, and ensures the firmness of the connection.

Preferably, a plurality of grooves 32 are engraved on the outer wall of the connection section of the heating cable 31. For example, the grooves 32 may be triangular in cross-section and the grooves 32 may be 0.5-1 mm deep. The provision of the groove 32 can improve the electrical conductivity between the monocable 2 and the heating cable 31, thereby ensuring the heating efficiency.

During production, for example, a blind hole 21 with a diameter of 4 mm is provided at the connecting section of the single core cable 2, and the axial dimension of the blind hole 21 is about 20 mm. Correspondingly, 5 slots 32 are provided over about 20mm of the connecting section of the heating cable 31. Two grooves 32 are provided on one side of the circumferential direction of the heating cable 31, and three grooves 32 are provided on the other side substantially opposite to the one side. The grooves 32 arranged on different sides are spaced apart from one another in the axial direction. Thereafter, the connecting section of the heating cable 31 is inserted into the blind hole 21. Then, a fixing sleeve 4 is sleeved on the outer side of the single core cable 2. The internal diameter of the sleeve 4 is 6mm, on which two sets of radially penetrating fixing holes 41 are predisposed. The center position of the fixing hole 41 is 5mm and 15mm from the end face of the fixing sleeve 4. Then, a force is applied to the two sets of fixing holes 41 by using hydraulic pliers to press the fixing sleeve 4 and the single-core cable 2. Next, a drill having a diameter of, for example, 2.6mm is used to perforate the single core cable 2 and the heating cable 31 at the corresponding position of the fixing hole 41. Then, a stainless steel rivet of M2.4 is passed through the fixing sleeve 4, the mono cable 2 and the heating cable 31 to perform connection. And finally, grinding and leveling the lug boss of the rivet.

The above description is given by taking an example in which the blind hole 21 is provided in the single core cable 2 and the heating cable 3 is inserted into the blind hole 21. However, blind holes may also be provided in the heating cable 3 and this connection is similar to that described above and will not be described further here. It should be noted that, in the actual operation, the outer diameters of two pieces to be connected are considered, and the blind hole is arranged on the piece with the larger outer diameter.

For example, the monocable 2 may be a copper wire and the heating cable 3 may be a nichrome heating wire. Of course, the application is not limited to the above-mentioned limitations, for example, the heating cable 3 may also be constructed as a copper alloy or other electric heating wire.

In one embodiment, the inorganic mineral insulation is magnesium oxide powder. Preferably, the magnesia powder comprises three kinds of magnesia powder with uniformly mixed particle sizes of 200 meshes, 120 meshes and 100 meshes, and in the case that the mass of the magnesia powder with 200 meshes is 1, the magnesia powder with 120 meshes is 0.5-2, and the magnesia powder with 100 meshes is 0.5-2. And the magnesia powder is baked at high temperature and is arranged in the inner cavity of the container 1 by strong extrusion. Through the setting, the insulation between the joint of the heating cable 3 and the single-core cable 2 and the outside is realized, the heat conduction performance of inorganic mineral insulators can be improved, the temperature of the connecting point is effectively distributed, and the realization of high electric heat conversion performance is facilitated.

In one embodiment, the container 1 has a cylindrical body 11, an upper end cap 12 sealingly disposed at an upper end opening of the body 11, and a lower end cap 13 sealingly disposed at a lower end opening of the body 11. Wherein the monocable 2 extends downwards through the upper end cover 12, and the integrated heating cable group 3 extends upwards through the lower end cover 13. The container 1 with the arrangement has a simple structure, and is convenient for the connection operation of the heating cable 3 and the single-core cable 2.

Preferably, the lower cap 13 has an upper end configured in a cylindrical shape and is at least partially inserted into the inner cavity of the body 11, and a lower end configured in a tapered shape having a sectional area gradually decreasing from the top to the bottom. The main body 11 and the lower end cap 13 are fixedly connected by welding, for example, welding spots are concentrated at the intersection of the main body 11 and the lower end cap 13 and are full-welded. Meanwhile, the lower end of the lower end cap 13 is welded to the integrated heating cable group 3. In addition, the upper cap 12 is configured in a cylindrical shape and is partially inserted into the inner cavity of the body 11. An anti-bending triangular cone 14 for the single-core cable 2 to pass through is arranged on the upper end face of the upper end cover 12. The triangular cone 14 has a cross-sectional area that increases stepwise in the top-to-bottom direction. The main body 11 and the upper end cap 12 are fixedly connected by welding, for example, welding spots are concentrated at the intersection of the main body 11 and the upper end cap 12 and are full-welded. The number of the triangular cones 14 matches the number of the monocable 2 and the positions are spaced on the upper end cap 12 to define the corresponding monocable 2. The upper end and the lower end of the triangular cone 14 are respectively welded with the single-core cable 2 and the upper end cover 12. The conical lower end cover 13 and the bending-resistant triangular conical barrel 14 can well protect the corresponding integrated heating cable group 3 and the single-core cable 2. In addition, the main body 11, the lower end cap 13, and the upper end cap 12 are made of stainless steel. Of course, the body 11, the lower end cap 13 and the upper end cap 12 may also be made of 35 CrMoA. The above arrangement helps to ensure high mechanical strength and high pressure-bearing sealing capacity of the container 1.

In one embodiment, a ceramic disc 6 in the shape of a disc is arranged in the cavity of the container 1. Meanwhile, axial through holes 61 are arranged on the ceramic plate 6 at intervals. Preferably, the number of the through holes 61 is matched with the single core cable 2, and the plurality of the through holes 61 are uniformly distributed. The connecting section of the heating cable 3 and the monocable 2 passes through the through hole 61. The ceramic sheet 6 not only serves to insulate the cables (the heating cable 3 and the single core cable 2) from the outside, but also to position the cables and to insulate the cables from each other.

In one embodiment, the cable conversion device 100 further includes a force bearing seat 7 fixedly disposed on the integrated heating cable group 3 in a sleeved manner. In use, the force bearing seat 7 will sit on the step surface of the oil pipe for hanging the integrated heating cable group 3 extending downwards in the oil pipe. Structurally, the bearing seat 7 has a cylindrical upper end and a cylindrical lower end with increased diameter. The lower end surface of the cylindrical column with a large diameter is provided with a communicating groove 72. At the same time, the outer wall surface of the cylindrical body with a large diameter is provided with a communication hole 71 which penetrates in the axial direction. For example, a plurality of communication holes 71 may be provided at intervals in the circumferential direction. The communication hole 71 communicates with the communication groove 72. During use, the lower end surface of the large-diameter cylindrical body is clamped with the step surface of the oil pipe, so that the integrated heating cable group 3 extending downwards in the oil pipe is hung, and the communicating groove 72 and the communicating hole 71 which are communicated with each other are used for liquid communication in the oil pipe. The upper end of the bearing seat 7 is welded with the integrated heating cable group 3 to realize fixation. It should be noted that all welded portions of the cable converter 100 need to be subjected to flaw detection, and annealing is performed after the integral welding is completed to eliminate welding stress, so as to ensure the mechanical strength and high pressure-bearing sealing capability of the cable converter 100.

The cable conversion device 100 of the present application has a pressure-bearing sealing capability up to 35MPa, and can operate at high temperatures, e.g., 250 °, and also can ensure high electrothermal conversion performance.

In the present application, the terms "upper" and "lower" are used with reference to the actual operating orientation of the cable conversion device 100.

The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily make changes or variations within the technical scope of the present invention disclosed, and such changes or variations should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A cable conversion device, comprising:

a closed container is arranged in the container body,

the heating cables of the integrated heating cable group are respectively connected with the corresponding single-core cables in the inner cavity of the container,

an inorganic mineral insulation filled in the interior cavity of the container.

2. The cable transition device defined in claim 1, wherein an axially extending blind connecting hole is provided in the connecting section of one of the single core cable and the heating cable, and the connecting section of the other is inserted into the blind hole and radially passed through the single core cable and the heating cable by a fixing member to perform a fixed connection therebetween.

3. The cable transition device according to claim 2, wherein a fixing sleeve is sleeved on an outer wall of the single core cable or the heating cable provided with the blind hole, and a fixing hole is provided on the fixing sleeve for the fixing member configured as a rivet to pass through.

4. Cable transition device according to claim 2 or 3, wherein a plurality of grooves are engraved on the outer wall of the connecting section of the heating cable or the single core cable which is not provided with a blind hole.

5. The cable conversion arrangement according to any one of claims 1 to 5, wherein the inorganic mineral insulation is magnesium oxide powder.

6. The cable conversion apparatus according to claim 5, wherein the magnesium oxide powder comprises three magnesium oxide powders of 200 mesh, 120 mesh and 100 mesh which are uniformly mixed, and in the case where the mass of the magnesium oxide powder of 200 mesh is 1, the magnesium oxide powder of 120 mesh is 0.5 to 2 and the magnesium oxide powder of 100 mesh is 0.5 to 2.

7. The cable conversion apparatus of any one of claims 1 to 6, wherein the container has:

a main body in the shape of a cylinder,

wherein the monocable extends downwards through the upper end cover, and the integrated heating cable group extends upwards through the lower end cover.

8. The cable conversion apparatus of claim 7, wherein the lower end cap has an upper end configured in a cylindrical shape and inserted at least partially into the inner cavity of the main body, and a lower end configured in a tapered shape having a sectional area gradually decreasing from top to bottom,

and the upper end cover is in a columnar structure and is partially inserted into the inner cavity of the main body, and an anti-bending triangular cone barrel for the single-core cable to pass through is arranged on the upper end face of the upper end cover.

9. The cable transition device defined in any one of claims 1 to 8, wherein a ceramic plate is provided in the interior of the vessel, axial through-holes being provided at intervals on the ceramic plate.

10. The cable conversion device according to any one of claims 1 to 9, further comprising a pedestal fixedly arranged on the integrated heating cable assembly in a socket-type manner, wherein an axially extending communication hole is arranged on an outer wall of the pedestal.