RU2192679C2 - Cable line - Google Patents

Abstract

FIELD: feeding electrical equipment; on-route electric heating of viscous oil-gas mixture in boreholes, water intake, oil and gas conveying systems. SUBSTANCE: cable line has low-temperature and high-temperature taps of different conductivity and is built of insulated current-conducting cores inside common cable-forming insulating sheath with bedding and armor placed overall. Core is assembled of n current- conducting strands having different length. At least one strand but not over (n-1) ones is made continuous throughout entire length of core. Remaining strands are shortened and may be equal or different in length. Connected to shortened current-conducting strands are additional strands of material whose conductivity is lower (down to zero) than that of low- temperature tap; they may be made of current-conducting, and/or semiconducting, and/or insulating material. Additional strands may be connected to each shortened current-conducting strand or at least to one of them. EFFECT: enhanced operating reliability, simplified design, enlarged range of available types. 7 cl, 5 dwg

Description

 The invention relates to cable technology and can be used in wells equipped with sucker rod pumps, submersible electric pumps, for powering equipment, as well as for track heating of highly viscous oil and gas mixtures in a well, eliminating paraffin-hydrate plugs in wells with a high gas factor, preventing freezing of water conduits in hazardous areas of oilfield equipment, as well as in water injection systems, oil and gas transport.

 A well-known geophysical cable is designed to deliver instruments to the well and transmit an information signal during geophysical studies, shooting and blasting in the well, etc., consisting of insulated conductive wires with a common insulating winding, on which armor is made of round steel wires ( see Malyshev AG and others. The use of heating cables to prevent paraffin hydrate formation in oil wells. Oil industry, 1990, 6, p. 58-60). In this case, each core in the cable is composed of n conductive threads (wires), all of which are made of the same length, cross section and conductivity along the entire length of the conductive core.

 However, the low level of generated electric power during the operation of such a cable in the well is not sufficient to prevent the formation of paraffin in the wells, especially in cases of a high content of paraffin fractions in oil, while using such a cable as a heating function.

 For the same reason, it cannot be used as a heating flat power cable for powering submersible electric pumps (see TU 16-505.129-82. Cable with polyethylene insulation for submersible electric pumps). Since the active losses in such a cable along the entire length are constant (since the conductive cores are made of material with one specific conductivity along the entire length of the cable), part of the heat in places where heating is not required is lost.

 In addition, the heating temperature of the conductive core of such a cable is not enough for the path heating of the well with high paraffin formation.

 The specified drawback is eliminated in the cable line, known by the certificate of the Russian Federation for utility model 10000, cl. H 01 B 7/18 of 1998. A well-known cable line is designed to power the submersible pump and at the same time for track electrical heating of the well. For the purpose of selective heating of the well in the required section of the well, the cable line is made up of interconnected low-temperature (power) and high-temperature (heating) taps with different conductivities. Each branch consists of insulated conductive cores in a common forming shell, on which a pillow for armor and armor is laid. The veins of each of the branches are connected in pairs (by welding, twisting, by means of a metal sleeve, etc.), the place of their connection is made integral. In this case, the conductive wires consist of n conductive threads (wires).

 The known cable line is the closest to the claimed technical essence, so we take it as a prototype.

 However, this cable line also has insufficient operational reliability, since a poor-quality connection of the branch wires is not excluded. As a result, local overheating and burnout of the conductive conductor section at the place of permanent connection of the cores occurs. As a result - a partial or complete failure of the cable line.

 In addition, the presence of a concentrated transition resistance at the junction of the low-temperature and high-temperature taps, the material of the conductive wires of which has different conductivity, creates a temperature field in this zone, significantly exceeding the temperature field of the high-temperature tapping. As a result - overheating and violation of the integrity of the cable line.

 The invention solves the problem of increasing the operational reliability of the cable line, simplifying its design and expanding the range.

 This goal is achieved by the fact that in a cable line consisting of low-temperature and high-temperature taps made of material with different conductivity, containing insulated conductive conductors in a common shape-forming insulating sheath, on which a pillow and armor are laid, each core made of n conductive threads, it is new that the conductive threads in the core are made of different lengths and at least one, but no more than (n-1), the conductive thread is made continuous along the entire length of the core the abel line and is made of material with the specific conductivity of the low-temperature branch of the cable line, and the remaining conductive threads in the core, also made of material with the specific conductivity of the low-temperature branch of the cable line, are made of shortened length, while to the shortened conductive threads in the high-temperature branch are connected with the possibility of filling the forming core of the core along the entire length and cross section of the additional strands of material whose conductivity is less than the specific second conduction conductive filaments.

 Shortened conductive threads in the core can be made of the same length.

 Shortened conductive threads in the core can be made unequal in length.

 An additional thread is attached to each shortened conductive thread.

 At least one shortened conductive thread is connected to one additional thread, and the remaining shortened conductive threads are connected to a common additional thread.

 Additional threads are made of conductive and / or semiconductor and / or dielectric material.

 Additional strands of semiconductor material are included in either the forward or reverse direction.

 The armor is laid on the pillow in at least one layer.

 Due to the fact that the conductive threads in the core are made of different lengths, it became possible to change the conductivity of the sections of the core along its length depending on the task of heating and thereby form a cable line with sections of the required length with different conductivities, and therefore with different capacities heat dissipation, performing the function of low-temperature (power) removal and high-temperature (heating) removal.

 Due to the fact that at least one, but no more than (n-1), the conductive thread is made continuous along the entire length of the core of the cable line, has a constant cross section along the entire length and is made of material with specific conductivity of the low-temperature branch of the cable line, and the rest are conductive the strands in the core, also made of material with the conductivity of the low-temperature branch of the cable line, are made of shortened length, it became possible to create a cable line consisting of low-temperature and high-temperature th taps, excluding place permanent connection both taps in each core, which core consists of a material with different conductivity, and thereby eliminate local overheating and high temperature field in this zone, which increases the reliability of the cable line, simplifies its construction.

 The implementation of at least one, but no more than (n-1), conductive filament of a continuous cable line along the entire length of the core made it possible, without soldering, welding, to perform high-temperature taps with different dissipation powers, which expands the range of cable lines.

 The implementation of shortened conductive threads of the same length allows you to create a cable line with a pronounced boundary between the low-temperature section and the high-temperature section, and thereby expand the scope of the cable line.

 The implementation of the shortened conductive threads of unequal length allows for a temperature increment from the low-temperature to high-temperature sections according to any law, based on the operating conditions of the cable line, which expands the scope of the cable line.

 Due to the fact that additional strands of material are connected to the shortened conductive threads in the high-temperature tap, the conductivity of which is less than (up to zero) conductivity of the conductive threads, and additional threads can be attached to either each conductive thread, or at least one while the rest of the space in the forming shell is filled with additional threads of increased cross section, while ensuring the constancy of the forming shell on the core throughout its length and cross-section, the reliability of the cable line is increased and it became possible to expand the range of cable lines while maintaining the geometric dimensions of the low-temperature (power) outlet.

 The implementation of additional filaments from a conductive and / or semiconductor and / or dielectric material also allows you to expand the range of cable lines by changing the dissipation power of the high-temperature tap.

 The implementation of the armor on the veins of the cable line in the form of coils allows you to use the cable line also as a load-carrying, for example, for delivery to the well of devices.

 The invention is illustrated by drawings, where figure 1 and 2 schematically depict embodiments of the threads in the core of the cable line; figure 3 shows a cross section of a cable line; figure 4 is a General view of the cable line; figure 5 is a General view of the conductive core.

 The cable line consists of low temperature 1 and high temperature 2 taps made of a material with different conductivity, and contains conductive wires 3 with dielectric insulation 4 from a thermoplastic elastomer.

 Insulated conductive cores 3 are covered externally by a common insulating forming shell 5, for example, of heat-oil-resistant rubber, while the gaps between the cores 3 in the casing 5 are filled, for example, with stapled glass yarn 6. A cushion 7, for example, made of polyethylene terephthalate tape, is laid over the casing 5 with a positive overlap, which serves as a substrate for the protective layer of the cable line - armor 8, made, for example, of two-drink steel galvanized wire; each layer is laid in the opposite direction.

 Each core 3 in a cable line is made of n conductive filaments 9, for example, of copper wire with a diameter of 0.2 mm. Conductive threads 9 in the core 3 are made of different lengths, but at least one, but not more than (n-1), the conductive thread 10 is made continuous along the entire length of the core 3 of the cable line. The remaining conductive threads 9 are made of shortened length depending on the required length of the low-temperature branch 1 of the cable line. Moreover, the shortened conductive threads 9 can be made equal (Fig. 1), and unequal (Fig. 2) with each other length.

 To the shortened conductive cores 9 in the high-temperature branch 2 additional threads 11 are connected from a material with a specific conductivity of less than (up to zero) conductivity of the conductive threads 9 of the low-temperature branch 1, for example, from a conductive material (e.g. steel) and / or a semiconductor material and / or dielectric material (e.g. glass yarn, asbestos filament). The implementation of the additional filament 11 from a semiconductor material allows you to change the dissipation power of the high-temperature branch 2 from the phase of the supply voltage.

 Additional threads 11 can be attached to each shortened conductive thread 9, while their cross sections coincide; or at least one shortened conductive thread 9 is connected with an additional thread 11 of the same cross-section, and the remaining shortened conductive threads 9 are connected with an additional thread of increased cross-section, and in all cases the common form-forming sheath 5 must have a constant along the entire length of the core 3 of the cable line section.

 Attachment to the shortened conductive thread 9 of the additional thread 11 is carried out by welding, soldering, twisting or gluing.

 The cable line made in the described way allows you to significantly expand the range of cable lines: with a constant design of the low-temperature branch, provide any required dissipation power with the design features of the high-temperature branch while simplifying the design and increasing the operational reliability of the cable line.

 The implementation of the armor on the veins of the cable line in the form of coils allows you to use the cable line also as a load-carrying, for example, for delivery to the well of devices.

Claims (7)

 1. A cable line consisting of low-temperature and high-temperature taps made of a material with different conductivity, containing insulated conductive conductors in a common forming insulating sheath, on which a pillow and armor are laid, each core made of n conductive threads, characterized in that the conductive threads in the core are made of different lengths, and at least one, but not more than (n-1), the conductive thread is made continuous along the entire length of the core of the cable line and is made of material and with the specific conductivity of the low-temperature branch of the cable line, and the remaining conductive threads in the core, also made of material with the specific conductivity of the low-temperature branch of the cable line, are made of shortened length, while shortened conductive threads in the high-temperature branch are connected to fill the forming core of the core throughout the length and cross section of additional threads of material whose conductivity is less than the conductivity of conductive threads.  2. The cable line according to claim 1, characterized in that the shortened conductive threads in the core are made of the same length.  3. The cable line according to claim 1, characterized in that the shortened conductive threads in the core are made unequal in length.  4. The cable line according to claim 1, characterized in that an additional thread is attached to each shortened conductive thread, and their cross sections coincide.  5. The cable line according to claim 1, characterized in that at least one shortened conductive thread is connected to one additional thread, and the remaining shortened conductive threads are connected to a common additional thread of increased cross section.  6. The cable line according to claim 1, characterized in that the additional strands are made of conductive and / or semiconductor and / or dielectric material.  7. The cable line according to claim 1, characterized in that the armor is laid in at least one layer.

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