High-power electric heater for heavy oil development

Abstract

The utility model discloses a high -power electric heater for thick oil development, including stainless steel outer sleeve pipe, three heating cables and thermocouple sleeve pipe are sheathed in the stainless steel outer sleeve pipe, and thermocouple assembly is sheathed in the thermocouple sleeve pipe, and the end of stainless steel outer sleeve pipe is welded with sieve tube, and the end of sieve tube is connected with the pipe through the connecting ring away from stainless steel outer sleeve pipe, and the end of pipe is connected with the plug away from the connecting ring, and thermocouple sleeve pipe and three heating cables all pass sieve tube, connecting ring and pipe in proper order. The utility model heating part adopts stainless steel mineral insulation heating cable, and the heating is even, and the heating core wire adopts nickel chromium alloy, and the heat output is big, and the service life is long, and three stainless steel mineral insulation heating cable tail stars, and the electrical connection is convenient, and the electrical control system is simplified, and contains three thermocouples, can monitor the temperature change of three positions, adjusts voltage in time, guarantees that the heating temperature satisfies the requirement, and the heater tail has sieve tube, and the steam is convenient to flow out.

Description

Technical Field

[0001] This utility model belongs to the technical field of heavy oil reservoir development equipment, specifically relating to a high-power electric heater used in heavy oil development. Background Technology

[0002] Steam flooding is an important thermal oil recovery technology, primarily used for extracting high-viscosity heavy oil resources. Heavy oil, due to its high viscosity (reaching tens of thousands of centipoises) and poor fluidity, cannot be extracted using conventional methods; global heavy oil reserves account for approximately 70% of total oil resources. Steam flooding is typically implemented after steam huff and puff (periodic steam injection in a single well) to expand the heating range and improve recovery rates. While steam huff and puff achieves only 10%-20% recovery, steam flooding can increase it to over 60%. The steam heats the oil reservoir to over 300°C, significantly reducing crude oil viscosity and creating a light fraction enrichment zone at the steam front, thus enhancing oil displacement efficiency. During steam drive, multiple temperature zones are formed: the steam zone (where residual oil saturation is lowest), the hot water zone, the hot oil zone, and the original oil zone. The displacement mechanisms of each zone are different. Steam drive combined with SAGD technology makes the extraction of extra-heavy oil possible. Currently, the commonly used steam drive method is to generate steam at the wellhead surface and inject it from the wellhead. During the flow of steam, heat loss is relatively large. When the steam reaches the downhole oil layer, the heat loss is generally 20%, which reduces the utilization rate of steam. Utility Model Content

[0003] The purpose of this invention is to provide a high-power electric heater for heavy oil development, which solves the problem of large heat loss in existing steam drive methods.

[0004] The technical solution adopted in this utility model is a high-power electric heater for heavy oil development, including a stainless steel outer tube, three heating cables and a thermocouple sheath are installed inside the stainless steel outer tube, a thermocouple assembly is installed inside the thermocouple sheath, a screen tube is welded to the end of the stainless steel outer tube, a connecting pipe is connected to the end of the screen tube away from the stainless steel outer tube through a connecting ring, and a plug is connected to the end of the connecting pipe away from the connecting ring. The thermocouple sheath and the three heating cables pass through the screen tube, the connecting ring and the connecting pipe in sequence.

[0005] The features of this utility model also include: The thermocouple assembly includes a first thermocouple, a second thermocouple, and a third thermocouple, all of which are fitted inside a thermocouple sheath.

[0006] One end of the heating core wire of the three heating cables is disposed inside the conduit, and the ends of the heating core wires of the three heating cables disposed inside the conduit are star-connected.

[0007] The heating core of the heating cable is made of nickel-chromium alloy, the outer sheath of the heating cable is made of stainless steel, and the space between the outer sheath and the heating core is filled with a magnesium oxide insulation layer.

[0008] The nozzle is filled with magnesium oxide powder.

[0009] Each heating cable is connected to the connecting ring via two first stabilizing components located at both ends of the connecting ring. The thermocouple sheath is connected to the connecting ring via two second stabilizing components located at both ends of the connecting ring.

[0010] The first stabilizing component includes a heating cable flat washer, a heating cable compression ring, and a heating cable compression nut, which are sequentially sleeved on the heating cable, with the heating cable flat washer positioned close to the connecting ring.

[0011] The second stabilizing component includes a thermocouple flat washer, a thermocouple compression ring, and a thermocouple compression nut, which are sequentially fitted onto the thermocouple sheath. The thermocouple flat washer is positioned close to the connecting ring.

[0012] The beneficial effects of this utility model are: This utility model relates to a high-power electric heater for heavy oil development. The heating element uses stainless steel mineral-insulated heating cables, which provide uniform heating. The heating core wire is made of nickel-chromium alloy, which has a large heat output and a long service life. The three stainless steel mineral-insulated heating cables are star-connected at their ends for easy electrical connection and to simplify the electrical control system. It contains three thermocouples, which can monitor temperature changes at three locations and adjust the voltage in a timely manner to ensure that the heating temperature meets the requirements. The heater is equipped with a screen tube at its tail end to facilitate steam outflow. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the high-power electric heater for heavy oil development according to this utility model; Figure 2 This is a schematic diagram of the seal in the high-power electric heater used in heavy oil development according to this utility model; Figure 3 This is a schematic diagram of the connection structure of the heating cable in the high-power electric heater for heavy oil development according to this utility model; Figure 4 This is a schematic diagram of the screen tube connection structure in the high-power electric heater for heavy oil development according to this utility model; Figure 5 This is a schematic diagram of the connection structure of the stainless steel outer sleeve in the high-power electric heater for heavy oil development according to this utility model; Figure 6 This is a schematic diagram of the connection structure of the connecting ring in the high-power electric heater for heavy oil development according to this utility model; Figure 7 This is a schematic diagram of one side of the connecting ring in the high-power electric heater used in heavy oil development according to this utility model; Figure 8This is a schematic diagram of the other side of the connecting ring in the high-power electric heater for heavy oil development according to this utility model; Figure 9 This is a schematic diagram of the end of the heating cable core wire in the high-power electric heater for heavy oil development according to this utility model; Figure 10 This is a schematic diagram of the connection structure of the connecting pipe in the high-power electric heater for heavy oil development according to this utility model; Figure 11 This is a schematic diagram of the connecting pipe in the high-power electric heater for heavy oil development according to this utility model; Figure 12 This is a schematic diagram of the connection structure of the plug in the high-power electric heater used in heavy oil development according to this utility model.

[0014] In the diagram: 1. Stainless steel outer sleeve; 2. Heating cable; 3. Screen tube; 4. Connecting ring; 5. Connecting pipe; 6. Plug; 7. Magnesium oxide powder; 8. Thermocouple sheath; 9. First thermocouple; 10. Second thermocouple; 11. Third thermocouple; 12. Thermocouple compression nut; 13. Thermocouple compression ring; 14. Thermocouple flat washer; 15. Heating cable compression nut; 16. Heating cable compression ring; 17. Heating cable flat washer. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0016] This invention provides a high-power electric heater for heavy oil development, such as... Figure 1 As shown, it includes a stainless steel outer tube 1, inside which are three heating cables 2 and a thermocouple sheath 8. Thermocouple assembly is installed inside the thermocouple sheath 8. A screen tube 3 is welded to the end of the stainless steel outer tube 1. The end of the screen tube 3 away from the stainless steel outer tube 1 is connected to a connecting pipe 5 through a connecting ring 4. The end of the connecting pipe 5 away from the connecting ring 4 is connected to a plug 6. The thermocouple sheath 8 and the three heating cables 2 all pass through the screen tube 3, the connecting ring 4 and the connecting pipe 5 in sequence. The stainless steel outer tube 1 is a continuous tube. The three heating cables 2 are manufactured using the "continuous tube + MI heating cable" method. The screen tube 3 has a steam outlet. After water is heated, it turns into steam. The steam outlet on the screen tube 3 discharges the steam. The length of the screen tube 3 is 1m-2m. The connecting ring 4 connects the heating cable 2, the thermocouple sheath 8 and the stainless steel outer tube 1 together to form a whole. The length of the connecting ring 4 is 50mm-100mm. The plug 6 seals the magnesium oxide powder 7 to form a complete heater. The length of the plug 6 is 100mm-150mm.

[0017] Example 1 A high-power electric heater for heavy oil development includes a stainless steel outer tube 1, inside which are installed three heating cables 2 and a thermocouple sheath 8. Thermocouple assembly is installed inside the thermocouple sheath 8. A screen tube 3 is welded to the end of the stainless steel outer tube 1. The end of the screen tube 3 away from the stainless steel outer tube 1 is connected to a connecting pipe 5 via a connecting ring 4. The end of the connecting pipe 5 away from the connecting ring 4 is connected to a plug 6. The thermocouple sheath 8 and the three heating cables 2 pass through the screen tube 3, the connecting ring 4 and the connecting pipe 5 in sequence.

[0018] The thermocouple assembly includes a first thermocouple 9, a second thermocouple 10, and a third thermocouple 11, all of which are fitted inside a thermocouple sheath 8. The thermocouple sheath 8 is made of stainless steel, and the three thermocouples are arranged along the length of the thermocouple sheath 8 to detect the temperature at three locations.

[0019] Example 2 A high-power electric heater for heavy oil development includes a stainless steel outer tube 1, inside which are installed three heating cables 2 and a thermocouple sheath 8. Thermocouple assembly is installed inside the thermocouple sheath 8. A screen tube 3 is welded to the end of the stainless steel outer tube 1. The end of the screen tube 3 away from the stainless steel outer tube 1 is connected to a connecting pipe 5 via a connecting ring 4. The end of the connecting pipe 5 away from the connecting ring 4 is connected to a plug 6. The thermocouple sheath 8 and the three heating cables 2 pass through the screen tube 3, the connecting ring 4 and the connecting pipe 5 in sequence.

[0020] The thermocouple assembly includes a first thermocouple 9, a second thermocouple 10, and a third thermocouple 11, all of which are fitted inside the thermocouple sheath 8.

[0021] One end of the heating core wire of the three heating cables 2 is installed inside the conduit 5, and the ends of the heating core wires of the three heating cables 2 installed inside the conduit 5 are star-connected. The star-connection of the ends of the three heating cables 2 forms a connection point, which constitutes a three-phase closed circuit, facilitates electrical connection, and simplifies the electrical control system.

[0022] Example 3 A high-power electric heater for heavy oil development includes a stainless steel outer tube 1, inside which are installed three heating cables 2 and a thermocouple sheath 8. Thermocouple assembly is installed inside the thermocouple sheath 8. A screen tube 3 is welded to the end of the stainless steel outer tube 1. The end of the screen tube 3 away from the stainless steel outer tube 1 is connected to a connecting pipe 5 via a connecting ring 4. The end of the connecting pipe 5 away from the connecting ring 4 is connected to a plug 6. The thermocouple sheath 8 and the three heating cables 2 pass through the screen tube 3, the connecting ring 4 and the connecting pipe 5 in sequence.

[0023] The thermocouple assembly includes a first thermocouple 9, a second thermocouple 10, and a third thermocouple 11, all of which are fitted inside the thermocouple sheath 8.

[0024] One end of the heating core wire of the three heating cables 2 is set inside the connector 5, and the ends of the heating core wires of the three heating cables 2 set inside the connector 5 are star-connected.

[0025] The heating core of heating cable 2 is made of nickel-chromium alloy, and the outer sheath of heating cable 2 is made of stainless steel. A magnesium oxide insulation layer is filled between the outer sheath and the heating core. The magnesium oxide serves both as a heat conductor and a structural support.

[0026] Example 4 A high-power electric heater for heavy oil development includes a stainless steel outer tube 1, inside which are installed three heating cables 2 and a thermocouple sheath 8. Thermocouple assembly is installed inside the thermocouple sheath 8. A screen tube 3 is welded to the end of the stainless steel outer tube 1. The end of the screen tube 3 away from the stainless steel outer tube 1 is connected to a connecting pipe 5 via a connecting ring 4. The end of the connecting pipe 5 away from the connecting ring 4 is connected to a plug 6. The thermocouple sheath 8 and the three heating cables 2 pass through the screen tube 3, the connecting ring 4 and the connecting pipe 5 in sequence.

[0027] The thermocouple assembly includes a first thermocouple 9, a second thermocouple 10, and a third thermocouple 11, all of which are fitted inside the thermocouple sheath 8.

[0028] One end of the heating core wire of the three heating cables 2 is set inside the connector 5, and the ends of the heating core wires of the three heating cables 2 set inside the connector 5 are star-connected.

[0029] The heating core wire of heating cable 2 is made of nickel-chromium alloy, the outer sheath of heating cable 2 is made of stainless steel, and the space between the outer sheath and the heating core wire is filled with magnesium oxide insulation layer.

[0030] The connector 5 is filled with magnesium oxide powder 7. The star junction of the heating core wires of the three heating cables 2 is located in the connector 5. The connector 5 and the magnesium oxide powder 7 seal and insulate the star junction to prevent the three heating cables 2 from getting damp. The length of the connector 5 is 150mm-200mm.

[0031] Example 5 A high-power electric heater for heavy oil development includes a stainless steel outer tube 1, inside which are installed three heating cables 2 and a thermocouple sheath 8. Thermocouple assembly is installed inside the thermocouple sheath 8. A screen tube 3 is welded to the end of the stainless steel outer tube 1. The end of the screen tube 3 away from the stainless steel outer tube 1 is connected to a connecting pipe 5 via a connecting ring 4. The end of the connecting pipe 5 away from the connecting ring 4 is connected to a plug 6. The thermocouple sheath 8 and the three heating cables 2 pass through the screen tube 3, the connecting ring 4 and the connecting pipe 5 in sequence.

[0032] The thermocouple assembly includes a first thermocouple 9, a second thermocouple 10, and a third thermocouple 11, all of which are fitted inside the thermocouple sheath 8.

[0033] One end of the heating core wire of the three heating cables 2 is set inside the connector 5, and the ends of the heating core wires of the three heating cables 2 set inside the connector 5 are star-connected.

[0034] The heating core wire of heating cable 2 is made of nickel-chromium alloy, the outer sheath of heating cable 2 is made of stainless steel, and the space between the outer sheath and the heating core wire is filled with magnesium oxide insulation layer.

[0035] The connector 5 is filled with magnesium oxide powder 7.

[0036] Each heating cable 2 is connected to the connecting ring 4 via two first stabilizing components, which are located at both ends of the connecting ring 4. Thermocouple sheaths 8 are connected to the connecting ring 4 via two second stabilizing components, which are also located at both ends of the connecting ring 4. Both ends of the connecting ring 4 are closed, and through holes are provided at both ends to facilitate the passage of the heating cables 2 and thermocouple sheaths 8. The first and second stabilizing components connect the heating cables 2, thermocouple sheaths 8, and connecting ring 4 together.

[0037] Example 6 A high-power electric heater for heavy oil development includes a stainless steel outer tube 1, inside which are installed three heating cables 2 and a thermocouple sheath 8. Thermocouple assembly is installed inside the thermocouple sheath 8. A screen tube 3 is welded to the end of the stainless steel outer tube 1. The end of the screen tube 3 away from the stainless steel outer tube 1 is connected to a connecting pipe 5 via a connecting ring 4. The end of the connecting pipe 5 away from the connecting ring 4 is connected to a plug 6. The thermocouple sheath 8 and the three heating cables 2 pass through the screen tube 3, the connecting ring 4 and the connecting pipe 5 in sequence.

[0038] The thermocouple assembly includes a first thermocouple 9, a second thermocouple 10, and a third thermocouple 11, all of which are fitted inside the thermocouple sheath 8.

[0039] One end of the heating core wire of the three heating cables 2 is set inside the connector 5, and the ends of the heating core wires of the three heating cables 2 set inside the connector 5 are star-connected.

[0040] The heating core wire of heating cable 2 is made of nickel-chromium alloy, the outer sheath of heating cable 2 is made of stainless steel, and the space between the outer sheath and the heating core wire is filled with magnesium oxide insulation layer.

[0041] The connector 5 is filled with magnesium oxide powder 7.

[0042] Each heating cable 2 is connected to the connecting ring 4 through two first stabilizing components, which are located at both ends of the connecting ring 4. The thermocouple sheath 8 is connected to the connecting ring 4 through two second stabilizing components, which are also located at both ends of the connecting ring 4.

[0043] like Figure 2 As shown, the first stabilizing component includes a heating cable washer 17, a heating cable compression ring 16, and a heating cable compression nut 15, which are sequentially fitted onto the heating cable 2. The heating cable washer 17 is positioned close to the connecting ring 4. The heating cable 2 is connected to the connecting ring 4 via the heating cable washer 17, the heating cable compression ring 16, and the heating cable compression nut 15.

[0044] The second stabilizing component includes a thermocouple flat washer 14, a thermocouple compression ring 13, and a thermocouple compression nut 12, which are sequentially sleeved on the thermocouple sheath 8. The thermocouple flat washer 14 is positioned close to the connecting ring 4. The thermocouple compression nut 12 has threads and an internal conical structure, and is threadedly connected to the connecting ring 4. The outer conical surface of the thermocouple compression ring 13 mates with the inner conical surface of the thermocouple compression nut 12. Thermocouple flat washer 14 is placed between the abutting surfaces of the thermocouple compression ring 13 and the connecting ring 4. When the thermocouple compression nut 12 is tightened, its internal conical structure directly acts on the thermocouple sheath 8, achieving initial compression and fixation. As the thermocouple compression nut 12 continues to be screwed in, its inner conical surface forces the thermocouple compression ring 13 to undergo radial plastic deformation, tightly clamping and biting into the outer wall of the thermocouple sheath 8 to form the first metal sealing ring band. At the same time, its outer conical surface presses against the inner wall of the connecting ring 4 to form the second sealing ring band, significantly enhancing sealing performance and pull-out resistance. The rear end face of the thermocouple compression ring 13, under pressure, squeezes the thermocouple flat washer 14, causing it to deform and fill the microscopic gap between the abutting surfaces of the thermocouple compression ring 13 and the connecting ring 4, forming the third end face seal, ensuring overall sealing reliability. This structure achieves main sealing and clamping through the radial deformation of the compression ring driven by the conical surface, supplemented by flat gasket end face sealing, together providing efficient and reliable sealing and mechanical fixation, realizing a durable sealing connection in harsh downhole conditions.

[0045] This utility model relates to a high-power electric heater for heavy oil development. First, the power ends of the three heating cables 2 are sealed with sealant to create power connectors. Then, the first thermocouple 9, the second thermocouple 10, and the third thermocouple 11 are inserted into the thermocouple sheath 8, as follows: Figure 3 As shown, insert the three heating cables 2 and the thermocouple sheath 8 into the stainless steel outer sheath 1, as follows. Figure 4 As shown, insert the sieve tube 3 into the tail end of the three heating cables 2 and the thermocouple sheath 8, as follows. Figure 5 As shown, the stainless steel outer sleeve 1 is welded to the screen tube 3, as follows: Figure 6 As shown, insert the connecting ring 4 into the tail end of the three heating cables 2 and the thermocouple sheath 8, as follows. Figure 7-8 As shown, on one side of the connecting ring 4, both ends of the connecting ring 4 are connected to the thermocouple sheath 8 via thermocouple compression nut 12, thermocouple compression ring 13, and thermocouple flat washer 14, respectively. Both ends of the connecting ring 4 are connected to the heating cable 2 via heating cable compression nut 15, heating cable compression ring 16, and heating cable flat washer 17. Figure 9 As shown, the core wires of the three heating cables 2 are welded together, as follows: Figure 10 As shown, weld the connector 5 to the connecting ring 4 together, as follows. Figure 11 As shown, magnesium oxide powder 7 is poured into the connector 5, as follows. Figure 12 As shown, the magnesium oxide powder 7 is sealed with plug 6, plug 6 and pipe 5 are welded together, and connecting ring 4 is welded together with screen pipe 3. All welds are ground and polished with a polishing machine to complete the heater manufacturing.

[0046] This invention relates to a high-power electric heater for heavy oil development. It does not rely on combustion reactions but directly uses electrical energy to convert into heat energy to generate steam. High pressure and high current are provided from the surface and delivered to the well through the high-power electric heater for heavy oil development. The current drives the resistive element to generate Joule heat. The heat is transferred to the forced-flowing injection water through a partition wall heat exchanger. The water is heated and vaporized into saturated steam, which is then directly injected into the oil reservoir.

Claims

1. A high-power electric heater for heavy oil development, characterized in that, The device includes a stainless steel outer tube (1), inside which are installed three heating cables (2) and a thermocouple sheath (8). Inside the thermocouple sheath (8) are installed a thermocouple assembly. A screen tube (3) is welded to the end of the stainless steel outer tube (1). The end of the screen tube (3) away from the stainless steel outer tube (1) is connected to a connecting pipe (5) via a connecting ring (4). The end of the connecting pipe (5) away from the connecting ring (4) is connected to a plug (6). The thermocouple sheath (8) and the three heating cables (2) pass through the screen tube (3), the connecting ring (4), and the connecting pipe (5) in sequence.

2. The high-power electric heater for heavy oil development according to claim 1, characterized in that, The thermocouple assembly includes a first thermocouple (9), a second thermocouple (10), and a third thermocouple (11), all of which are fitted inside a thermocouple sleeve (8).

3. The high-power electric heater for heavy oil development as described in claim 1, characterized in that, One end of the heating core wire of the three heating cables (2) is disposed in the connector (5), and the ends of the heating core wires of the three heating cables (2) disposed in the connector (5) are star-connected.

4. The high-power electric heater for heavy oil development as described in claim 3, characterized in that, The heating core of the heating cable (2) is made of nickel-chromium alloy, the outer sheath of the heating cable (2) is made of stainless steel, and the outer sheath and the heating core are filled with magnesium oxide insulation layer.

5. The high-power electric heater for heavy oil development as described in claim 1, characterized in that, The connector (5) is filled with magnesium oxide powder (7).

6. The high-power electric heater for heavy oil development as described in claim 1, characterized in that, Each heating cable (2) is connected to the connecting ring (4) through two first stabilizing components, which are located at both ends of the connecting ring (4). The thermocouple sheath (8) is connected to the connecting ring (4) through two second stabilizing components, which are located at both ends of the connecting ring (4).

7. The high-power electric heater for heavy oil development as described in claim 6, characterized in that, The first stabilizing component includes a heating cable flat washer (17), a heating cable compression ring (16) and a heating cable compression nut (15) sequentially sleeved on the heating cable (2), with the heating cable flat washer (17) positioned close to the connecting ring (4).

8. The high-power electric heater for heavy oil development as described in claim 6, characterized in that, The second stabilizing component includes a thermocouple flat washer (14), a thermocouple compression ring (13) and a thermocouple compression nut (12) sequentially fitted onto the thermocouple sheath (8), with the thermocouple flat washer (14) positioned close to the connecting ring (4).

Images