Heating power transmission cable for oil reservoir

Abstract

The utility model provides a heating power transmission cable for an oil reservoir. The heating power transmission cable comprises a power section cable, a transition section cable and a heating section cable, the power section cable is provided with a wire core layer and a wrapping layer arranged outside the wire core layer; the wire core layer wraps three power wire cores used for power transmission and an optical fiber wire core used for transmitting temperature control information. The transition section cable is provided with a transition section protection layer and three transition copper conductors arranged in the transition section protection layer; the heating section cable is provided with a heating section protection layer and three heating section copper conductors arranged in the heating section protection layer; the power wire core is connected with the heating section copper conductor through the transition copper conductor. According to the utility model, the steel protection layer is adopted, so that the cable is tensile, anti-corrosion and anti-collision, and the requirement of outward heat dissipation of the cable is met.

Description

Technical Field

[0001] The utility model belongs to the field of cables for heavy oil exploitation operations, and in particular relates to a heating power transmission cable for oil reservoirs. Background Art

[0002] In the oil extraction industry, oil extraction has gradually turned to heavy oil extraction. Heavy oil is crude oil with high asphaltene and colloid content and high viscosity. Usually, crude oil with a relative density greater than 0.92 (20°C) and an underground viscosity greater than 50 centipoise is called heavy oil.

[0003] In the oil production of oil fields, heavy oil has special high viscosity and high freezing point characteristics. In terms of heavy oil production technology, colloids, asphaltene and long-chain paraffins cause the fluidity of crude oil in reservoirs and wells to deteriorate, requiring the implementation of high-investment tertiary oil recovery processes. The transportation of high-viscosity and high-freezing heavy oil must use higher-power pumping equipment, and in order to achieve a reasonable pumping displacement, the transportation system is required to be heated.

[0004] At present, the main methods for heavy oil recovery are steam throughput, steam drive, oil layer burning, electromagnetic heating and other operation methods. The use of high-temperature steam throughput and steam drive is slow and requires a lot of manpower and material costs. Although the oil layer burning method can improve the recovery rate, it has the disadvantages of uncontrollable operation and large fluctuations, and the use of steam and fire causes environmental pollution. Electric heating is also used in the heavy oil recovery process, but because heavy oil extraction is done underground, there are higher requirements for power supply cables. The cables need to be corrosion-resistant, tensile-resistant and anti-collision in order to provide electricity to the underground and achieve the heating effect. How to configure a heating power transmission cable that is corrosion-resistant, tensile-resistant and anti-collision, and meets the requirements of heavy oil extraction is a technical problem that needs to be solved urgently. Utility Model Content

[0005] The utility model provides a heating power transmission cable for oil reservoirs. The cable can meet the needs of heavy oil exploitation and improve the recovery rate.

[0006] The heating power transmission cable for oil reservoir includes: power section cable, transition section cable and heating section cable;

[0007] The power section cable is provided with a wire core layer and a sheath layer provided outside the wire core layer;

[0008] The wire core layer is wrapped with three power wire cores for power transmission and an optical fiber wire core for transmitting temperature control information;

[0009] The transition section cable is provided with a transition section protective layer and three transition copper conductors arranged inside the transition section protective layer;

[0010] The heating section cable is provided with a heating section protective layer and three heating section copper conductors arranged inside the heating section protective layer;

[0011] The power line core is connected to the heating section copper conductor via a transition copper conductor.

[0012] It should be further explained that the wire core layer is a 316 stainless steel armor layer.

[0013] It should be further explained that the outside of the power line core is wrapped with a polyimide composite film, the outside of the polyimide composite film is wrapped with a fluoroplastic insulation layer, the outside of the fluoroplastic insulation layer is provided with a fluoroplastic sheath, and the outside of the fluoroplastic sheath is provided with an armor cushion layer.

[0014] It should be further explained that the transition copper conductor is wound with a transition synthetic fluorphlogopite tape on the outside; and a transition steel protective layer is arranged on the outside of the transition synthetic fluorphlogopite tape.

[0015] It should be further explained that the transition section protective layer is a transition section 825 stainless steel armor layer;

[0016] The transition section 825 stainless steel armor layer is internally wound with a transition section wrapped insulation layer.

[0017] It should be further explained that the outside of the heating section copper conductor is wrapped with a heating section synthetic fluorphlogopite tape; and the outside of the heating section synthetic fluorphlogopite tape is provided with a heating section steel protective layer.

[0018] It should be further explained that the heating section protective layer is a heating section 825 stainless steel armor layer;

[0019] The heating section 825 stainless steel armor layer is internally wound with a heating section wrapping insulation layer.

[0020] It should be further explained that the transition copper conductor and the heating section copper conductor are connected by silver welding rod welding.

[0021] It can be seen from the above technical solutions that the utility model has the following advantages:

[0022] The utility model provides a heating power transmission cable for oil reservoirs, which includes a power section cable, a transition section cable and a heating section cable. When in use, the heating section cable can continuously heat the wellbore, thereby facilitating the heavy oil recovery operation when the oil-pumping layer needs to be diluted. Compared with the operation mode of steam operation and fire-driven operation vehicle, it has the advantage of continuous heating to improve the dilution efficiency.

[0023] The heating power transmission cable for oil reservoirs uses 825 stainless steel armor, which can resist tension, corrosion and collision for the entire cable.

[0024] The heating section protective layer of the heating section cable is covered with a steel protective layer. The steel protective layer can play a role in resisting tension, corrosion and bumping for the entire cable, and also helps to improve the uniformity of heat dissipation to the outside. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solution of the utility model, the drawings required for use in the description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 This is a schematic diagram of the power section cable in the heating power transmission cable for oil reservoirs;

[0027] Figure 2 This is a schematic diagram of the transition section cable of the utility model;

[0028] Figure 3 This is a schematic diagram of the heating section cable of the utility model;

[0029] Figure 4 This is a schematic diagram of welding the transition copper conductor and the heating section copper conductor;

[0030] Description of reference numerals:

[0031] 1-power line core, 2-optical fiber core, 3-core layer, 4-polyimide composite film, 5-fluoroplastic insulation layer, 6-fluoroplastic sheath, 7-armor cushion layer, 8-transition copper conductor, 9-heating section copper conductor, 10-transition synthetic fluorphlogopite tape, 11-transition steel protective layer, 12-transition section protective layer, 13-heating section synthetic fluorphlogopite tape, 14-heating section steel protective layer, 15-heating section protective layer, 16-weld. DETAILED DESCRIPTION

[0032] In order to make the purpose, features and advantages of the utility model more obvious and easy to understand, the technical scheme of the utility model will be clearly and completely described below in combination with the drawings in the specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the utility model, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0033] like Figures 1 to 4As shown, the heating power transmission cable for oil reservoir provided by the utility model is used in the process of oil extraction to provide electric heating power to the oil reservoir. The electric heating process of the oil reservoir can be powered by a three-phase power supply (AC380V), and can include a power distribution cabinet, a wellhead junction box, a heating power transmission cable and a temperature measurement system.

[0034] The heating power transmission cable for oil reservoirs includes: a power section cable, a transition section cable and a heating section cable.

[0035] Among them, the power section cable is provided with a core layer 3 and a sheath arranged outside the core layer; the core layer is wrapped with three power cores 1 for power transmission and an optical fiber core 2 for transmitting temperature control information.

[0036] The power line core 1 is used to realize the electrical connection between the external power supply system (such as the power distribution cabinet) and the transition section cable in the well. The optical fiber core 2 is used to connect the temperature measurement system and the downhole temperature detector, and transmit the temperature information sensed by the downhole temperature detector to the power distribution cabinet, and then transmit it to the monitoring center through the power distribution cabinet. The monitoring personnel can obtain the downhole temperature information and control the heating state of the heating section cable.

[0037] In the utility model, the transition section cable is provided with a transition section protective layer 12 and three transition copper conductors 8 arranged inside the transition section protective layer 12; the heating section cable is provided with a heating section protective layer 15 and three heating section copper conductors 9 arranged inside the heating section protective layer 15.

[0038] When the utility model is in use, the power line core 1 is connected to the heating section copper conductor 9 through the transition copper conductor 8. Figure 4 As shown, the transition copper conductor 8 and the heating section copper conductor 9 are connected by silver welding. Before welding, the transition copper conductor 8 and the heating section copper conductor 9 are polished to a 45° angle to form a weld 16, which is then filled with silver welding rods. The surface of the welding point is then polished to be smooth. The resistance at the welding point can be made smaller than the resistance of the heating cable conductor.

[0039] The downhole temperature information is uploaded to the monitoring center through the optical fiber core 2. The monitoring personnel control the power distribution cabinet to supply power to the heating section copper conductor 9 according to the downhole temperature information, thereby realizing the heating control of the oil-pumping layer.

[0040] As an exemplary embodiment of the present utility model, three power line cores 1 and optical fiber cores 2 wrapped by a core layer 3 are placed side by side, and the core layer 3 is a 316 stainless steel armor layer for protecting the three power line cores 1 and optical fiber cores 2.

[0041] The power line core 1 is wrapped with a polyimide composite film 4 , the polyimide composite film 4 is wrapped with a fluoroplastic insulation layer 5 , the fluoroplastic insulation layer 5 is provided with a fluoroplastic sheath 6 , and the fluoroplastic sheath 6 is provided with an armor cushion layer 7 .

[0042] For example, the conductor cross section of the power line core 1 is: 33mm 2 ; The diameter is 6.54mm, and the conductor resistance is 0.54Ω / Km. The thickness of the polyimide composite film is 1.1mm to 1.3mm, and the diameter is 8.74mm. The armor cushion layer can be made of armor steel strip, and the thickness of the armor cushion layer is 0.5mm.

[0043] The transition copper conductor 8 of the utility model is externally wound with a transition synthetic fluorphlogopite tape 10; the transition synthetic fluorphlogopite tape 10 is externally provided with a transition steel protective layer 11. The transition section protective layer 12 is a transition section 825 stainless steel armor layer; the transition section 825 stainless steel armor layer is internally wound with a transition section wrapped insulation layer.

[0044] The 825 stainless steel used in this utility model is an austenitic nickel-iron-chromium-molybdenum-copper alloy containing high levels of chromium, nickel, molybdenum and copper, which can provide a high level of corrosion resistance for moderately oxidizing and moderately reducing environments. Compared with standard stainless steel, this alloy has a high level of nickel, which combines with the molybdenum and copper content to produce significantly improved corrosion resistance in reducing environments. The nickel content is high enough to provide very good resistance to chloride stress corrosion cracking. The chromium and molybdenum content in the alloy provides a level of resistance to chloride ion pitting.

[0045] Exemplarily, the three transition copper conductors 8 are round heating cables in the form of three-core cabling filled with wrapping, and are protected by continuously welded stainless steel pipes on the outside.

[0046] Specifically, the transition section 825 stainless steel armor layer can play a role in tensile resistance, corrosion resistance and collision resistance for the entire cable, and also help to improve the uniformity of heat dissipation. The transition section 825 stainless steel armor layer uses a steel pipe made of 825 stainless steel strip with a thickness of not less than 1.5mm (millimeter) through a pipe coiling machine, welding and polishing.

[0047] The transition copper conductor 8 is twisted in a regular manner using the power line core 1. When twisted, the twist pitch ratio is in the range of 25 to 28 times.

[0048] The transition section cable also includes an insulating filling layer filled between the three transition copper conductors 8. The insulating filling layer uses glass fibers. The insulating filling layer and the transition section wrapped insulating layer serve as cushions, which can effectively buffer the effects of external pressure and isolate ambient temperature on the power line core 1 and the optical fiber core 2.

[0049] In specific implementation, the twisted transition copper conductor 8 can be wrapped together by a glass ribbon to make its shape round and structure stable.

[0050] As another exemplary embodiment of the utility model, the heating section copper conductor 9 is wound with a heating section synthetic fluorphlogopite tape 13; the heating section synthetic fluorphlogopite tape 13 is provided with a heating section steel protective layer 14. The heating section protective layer 15 is a heating section 825 stainless steel armor layer; the heating section 825 stainless steel armor layer is wound with a heating section wrapped insulation layer.

[0051] Specifically, the temperature resistance level of the heating section synthetic fluorphlogopite tape 13 is greater than 700°C, and the actual working temperature is about 350°C. The heating section synthetic fluorphlogopite tape 13 is wrapped with a heating section steel protective layer, that is, a high temperature resistant sheath layer. The heating section protective layer 15 is covered with a steel protective layer. The steel protective layer can play a role in tensile resistance, corrosion resistance and collision resistance for the entire cable, and also helps to improve the uniformity of heat dissipation to the outside. The steel protective layer adopts a steel pipe made of a 316 stainless steel strip with a thickness of not less than 1.5 mm (millimeter) through a pipe coiling machine, welding and polishing.

[0052] As another embodiment of the utility model, the power line core, transition copper conductor and heating section copper conductor are all made of the first type of conductor in "GB / T 3956-2008 Cable Conductors" made by continuous extrusion annealing of a solid copper rod extruder, and the specifications of the first type of conductor are shown in Table 1 below.

[0053] Table 1

[0054]

[0055] The inner insulation layer of the power line core uses 7.25KV grade polyimide F46 composite film and F46 combined insulation. Specifically, the polyimide F46 film is wrapped around the power line core by a film wrapping machine, with an overlap rate of 50%, making its thickness reach 6 times that of a single layer of film, and sintered at a high temperature of ≥320℃ to make the film firmly bonded to the power conductor. Afterwards, the F46 high temperature resistant plastic is extruded and firmly bonded to the film.

[0056] The outer insulation layer of the transition copper conductor and the heating section copper conductor can be insulated by synthetic fluorphlogopite wrapping. Specifically, three layers are tightly wrapped by a high-speed wrapping machine, with a lap rate of 50% and a thickness of 6 times the thickness of a single layer. Two layers of fluorphlogopite tape are tightly wrapped outside the insulation layer, with a lap rate of 50% and a thickness of 6 times the thickness of a single layer. At the same time, the heating core can be heated in a short time, at a higher heating temperature, with a wide heating range and higher thermal efficiency through a closed process. The transition section cable and the heating section cable involved in the utility model can withstand a temperature of 700 degrees Celsius and an operating temperature of 350-400 degrees Celsius.

[0057] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0058] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A heating power transmission cable for oil reservoir, characterized in that: include: Power section cables, transition section cables and heating section cables; The power section cable is provided with a wire core layer and a sheath layer provided outside the wire core layer; The wire core layer is wrapped with three power wire cores for power transmission and an optical fiber wire core for transmitting temperature control information; The transition section cable is provided with a transition section protective layer and three transition copper conductors arranged inside the transition section protective layer; The heating section cable is provided with a heating section protective layer and three heating section copper conductors arranged inside the heating section protective layer; The power line core is connected to the heating section copper conductor via a transition copper conductor.

2. The heating power transmission cable for oil reservoir according to claim 1, characterized in that: The wire core layer is a 316 stainless steel armor layer.

3. The heating power transmission cable for oil reservoir according to claim 1 or 2, characterized in that: The power line core is wrapped with a polyimide composite film, the polyimide composite film is wrapped with a fluoroplastic insulation layer, the fluoroplastic insulation layer is provided with a fluoroplastic sheath, and the fluoroplastic sheath is provided with an armor cushion layer.

4. The heating power transmission cable for oil reservoir according to claim 1 or 2, characterized in that: The transition copper conductor is wound with a transition synthetic fluorphlogopite tape outside; and a transition steel protective layer is arranged outside the transition synthetic fluorphlogopite tape.

5. The heating power transmission cable for oil reservoir according to claim 4, characterized in that: The transition section protective layer is a transition section 825 stainless steel armor layer; The transition section 825 stainless steel armor layer is internally wound with a transition section wrapped insulation layer.

6. The heating power transmission cable for oil reservoir according to claim 1 or 2, characterized in that: The outside of the heating section copper conductor is wound with a heating section synthetic fluorphlogopite tape; the outside of the heating section synthetic fluorphlogopite tape is provided with a heating section steel protective layer.

7. The heating power transmission cable for oil reservoir according to claim 6, characterized in that: The heating section protective layer is a heating section 825 stainless steel armor layer; The heating section 825 stainless steel armor layer is internally wound with a heating section wrapping insulation layer.

8. The heating power transmission cable for oil reservoir according to claim 1 or 2, characterized in that: The transition copper conductor and the heating section copper conductor are connected by silver welding rod welding.

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