RU208860U1 - HEATING DEVICE - Google Patents

Abstract

The utility model relates to variable power heating devices based on resistive wires with a 3-phase power supply system. The heating device of the 3-phase power system contains three current-carrying conductors, isolated from each other, connected at the distal end of the device in a star. Each strand has a variable cross section formed by drawing the strand. EFFECT: expansion of the arsenal of heating technical means is achieved. 11 w.p. f-ly, 3 ill.

Description

Application area

The utility model relates to variable power heating devices based on resistive wires with a 3-phase power supply system. The technical solution can be used in the field of the oil industry, as well equipment for track electric heating of a high-viscosity oil and gas mixture of wells equipped with sucker rod pumping units.

State of the art

The practice of operating oil wells has shown that the main cause of asphalt-resin-paraffin deposits (ARPD) in oil and gas wells is the line cooling of the produced fluid. Of all the types of combating these complications, the most versatile and effective tool today is to compensate for heat losses in the well by electrical heating with heating devices.

Known geophysical cable with a core of seven multi-wire conductive cores, with an insulating winding of polyethylene-tetraphthalate tape applied to each core as a pillow under a common frame - armor made of steel round wires (see Malyshev A.G. and others. "Use of heating cables to prevent paraffin-hydrate formation in oil wells". Oil Industry, 1990, No. 6, pp. 58-60).

A heating device is known, containing interconnected low-temperature and heating cable outlets, which consist of insulated conductive conductors made of a material with different resistivity, on which an armor pad and armor are laid, the conductors of the free end of the cable line are interconnected to form a closed electrical circuit and are insulated, the heating branch of the cable line is made of three consecutive cable sections, each of which includes three current-carrying conductors of different phases, one of which, heating, is made with a higher resistance than two adjacent low-temperature conductors (see RU 61935 U1, 11/16/2006) .

A heating device of a 3-phase power supply system is known, containing three conductive cores isolated from each other, each of which has a variable cross section (see RU 2587459 C2, 06/20/2016). Taken as a prototype.

A common disadvantage of the known solutions is the low efficiency of the heating device.

When fluid moves along the tubing (tubing) towards the wellhead, heat exchange with the surrounding soil occurs, as a result of which the fluid temperature decreases. As the fluid approaches the wellhead, due to changes in thermobaric and other conditions, the intensity of ARPD formation increases.

Thus, a part of the tubing at a relatively shallow depth needs the most intensive high-power heating, while less intensive heating of a lower power is required at a greater depth.

Most heating devices have a constant power along the entire length, which is selected based on the maximum required.

Essence disclosure

The objective of the claimed technical solution is to increase the efficiency of heating tubing.

The technical result achieved by using the claimed technical solution is to increase the efficiency of the heating device.

The claimed technical result is achieved through the use of the following set of essential features: a heating device of a 3-phase power system, containing three conductive wires with a variable cross section, isolated from each other, connected at the distal end of the device into a star, according to the claimed solution, additionally contains an external shaping armor . In private embodiments of the heating device, the armor can be made of galvanized steel tape. The device may have a flat or convex-concave shape in cross section. Ethylene-propylene-diene-methylene rubber or oil-resistant ethylene-propylene rubber, or ethylene propylene block copolymer can be used as core insulation. A copper single-wire or tinned single-wire conductor can be used as a conductive core. Between the armor and the conductive cores, a winding of non-woven material may be contained. The cross-sectional centers of conductive wires can be located on the same arc with a constant radius of curvature or on the same straight line.

Graphic materials explaining the essence

Graphic materials are presented explaining the essence of the claimed technical solution, where:

Fig. 1 - general view of the device in the version with armor and winding;

Fig. 2 - cross section of the device in the version with armor and winding;

Fig. 3-longitudinal section of the device in the version with armor and winding.

The designations in all drawings are identical.

Implementation of the technical solution

The heating device of the 3-phase power system contains three conductive wires 1, each of which contains insulation 2. Ethylene-propylene-diene-methylene rubber or oil-resistant ethylene-propylene rubber, or ethylene propylene block copolymer can be used as insulation 2 of the wires. Cores 1 are isolated from each other. As conductive conductors 1, a single-wire copper or tinned copper single-wire conductor can be used. The conductive wires 1 are connected at the distal end of the heating device into a star.

Each core 1 has a variable cross-section, formed by welding (in Fig. 2, pos.6 - the place of welding) individual cores of different sections or by drawing the core.

When welding individual cores of different sections or by drawing the core, it is possible to obtain a core of different sections, and, consequently, different power of the device.

Each conductive core 1 together with insulation 2 can be enclosed in a lead sheath 3 or in a sealed stainless steel sheath to provide increased mechanical strength of the heating device.

The device may contain a technical winding 4. The winding can be made, for example, from a non-woven fabric, in one layer, and serves as a substrate for the next protective layer - armor 5.

Armor 5, made, for example, of galvanized steel tape, at least in one layer, can be shaping for the heating device, due to which the device can have convex-concave surfaces, when the centers of the section of the conductive wires are located on the same arc with a constant radius of curvature , or flat surfaces, when the centers of the sections of the conductive cores are located on one straight line parallel to the flat surfaces.

Armor 5, which sets the required shape of the heating device, makes it possible to form a heating device with a single geometry of the shaping armor, which increases the strength and load-bearing capacity of the device.

The implementation of the device with a flat or convex-concave cross-sectional shape allows a closer fit of the device to the surface of the tubing, which provides the necessary heating of the produced fluid and eliminates the formation of plugs from ARPD in oil and gas wells.

During the preparatory operation on the tubing, the boundaries of paraffin formation in the well are measured, and therefore, the length of the heating device, the temperature in the area where the lower end (distal) of the heating device is located, the flow rate of the well, and the temperature parameters before introducing the heating device into the well are set. The lengths of tubing sections with the required heating power are determined. The heating power of the device is chosen in such a way that all produced oil and associated water and gases are heated to a temperature that excludes ARPD, while the device is heated to such an extent as to prevent melting of the insulating material, taking into account the downhole temperature.

Thus, when using the claimed heating device, the deposition of paraffin deposits on the tubing walls is almost completely eliminated.

The power of the heating device is selected depending on the parameters of the well, for example, in a well with a wax deposition depth of 1560 m, the length of the heating cable line is 1600 m, the power consumption is 87 kW, the supply voltage is 500 V, the current consumption is 174 A.

During operation of the heating device in the tubing, it is oriented so that the centers of the sections of the conductive wires adjoin the tubing with a flat or concave surface. The device is connected to a 3-phase power source, and the free lower (distal) ends of the device are connected to each other according to the “star” scheme, while the device is fastened with clamps to the outer surface of the tubing.

Tests of a cable line made up of three cores with a core cross section of S=6 mm ² at a phase current of 1 _f =174 A showed that the temperature of the liquid at the wellhead increased by 8-10° and the deposition of paraffin in the well stopped.

Tests have shown the high efficiency of the heating device, the duration of operation is more than 1 year.

The variable power of the heating device along the length, and in the case of use in the tubing, along the depth, allows you to get more power of the device in those areas where it is needed, and less power in areas where less intensive heating is required.

Claims (12)

1. A heating device of a 3-phase power system, containing three conductive conductors with a variable cross section, isolated from each other, connected at the distal end of the device into a star, characterized in that it additionally contains an external shaping armor. 2. Heating device according to claim 1, characterized in that the armor is made of galvanized steel tape. 3. Heating device according to claim. 1, characterized in that the device has a flat shape in cross section. 4. Heating device according to claim 1, characterized in that the device has a convex-concave shape in cross section. 5. A heating device according to claim 1, characterized in that ethylene-propylene-diene-methylene rubber is used as core insulation. 6. A heating device according to claim 1, characterized in that oil-resistant ethylene-propylene rubber is used as core insulation. 7. A heating device according to claim 1, characterized in that ethylene propylene block copolymer is used as core insulation. 8. The heating device according to claim 1, characterized in that a copper single-wire core is used as a conductive core. 9. A heating device according to claim 1, characterized in that a tinned copper single-wire core is used as a conductive core. 10. The heating device according to claim 1, characterized in that between the armor and the conductive cores there is a winding made of non-woven material. 11. The heating device according to claim 1, characterized in that the centers of the section of the conductive wires are located on the same arc with a constant radius of curvature. 12. The heating device according to claim 1, characterized in that the centers of the section of the conductive wires are located on the same straight line.

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