CN220226820U - Downhole electric heating paraffin removal tool - Google Patents

Abstract

The utility model relates to an underground electric heating paraffin removal tool, which is suitable for steel wire or cable operation, wherein an upper joint, a middle cylinder and an electric heating head are sequentially connected to form an externally sealed inner space, and the inner space accommodates a power supply assembly; the periphery of the electrothermal head is a rotating surface, the lower part is provided with at least two blades with cutter points which are downwards and are arranged on the periphery of the rotating surface, the blades are distributed along the periphery of the electrothermal head and are mutually separated, and a passage for paraffin removal fragments to pass through is reserved between the blades; an electrothermal body is embedded in the blade. The electric heating body passes through a pore canal of the electric heating head through a wire to enter the inner space and is connected to the power supply assembly; the duct is sealed. When the device is used for steel wire operation, battery power supply is adopted. The utility model can be put into a pipeline including an oil pipe and a sleeve pipe underground by using steel wires or cable operation equipment, directly heats a blade for mechanical paraffin removal, thermally dissolves paraffin precipitation when mechanically cuts, solves the problems that the pure mechanical paraffin removal is difficult to remove and a paraffin scraper is easy to clamp when the paraffin precipitation thickness is large, and has no chemical pollution.

Description

Downhole electric wax removal tool

Technical field

The utility model relates to the field of oil and gas resource exploitation, and in particular to an underground electric heating wax removal tool for removing wax deposits on the inner wall of an underground pipeline.

Background technique

During oil field mining, sediments are prone to occur inside pipelines such as oil pipes and casings, the most common of which is wax deposition. Wax deposition will cause the inner diameter of the pipeline to become smaller, affect the flow of oil, and even block the pipeline, thus affecting the production and operating efficiency of the oil well. Therefore, in the oilfield mining process, mechanical wax removal, thermal wax removal and chemical wax removal technologies are commonly used to remove wax deposits on the inner walls of underground production pipelines. Each of these wax removal techniques has advantages and disadvantages.

Mechanical wax removal uses a steel wire to drive a mechanical wax scraper to clean the pipe wall. The advantage is that the wax removal effect is good and impurities can be directly physically removed. The disadvantage is that the wax removal process may cause damage to the pipe string, especially when wax builds up. When it is very thick, it is easy to get stuck or even cause a falling accident.

The electric heating wax removal of the pipe string is heated by current, so that the wax melts and is discharged with the well fluid to achieve the purpose of removing oil, wax and impurities from the pipe string. The advantage is that it has good wax removal effect and a wide range of applications; the disadvantage is that it requires a lot of energy and requires special equipment to be fixed at the wellhead.

A chemical wax remover is used to decompose the oil wax and remove the oil wax and impurities from the column by adding a wax remover. The advantage is that the wax removal speed is fast, and the wax removal effect can be improved by adding appropriate wax removal agents; the disadvantages are that the wax removal agent is toxic, pollutes the environment, and is costly.

In current production practice, there is an urgent need for a wax removal tool that can be lowered underground through steel wire or cable operation equipment, can cope with thicker wax thickness, consumes less energy, and is pollution-free.

Contents of the invention

The main idea of the utility model is to propose an underground electric heating wax removal tool that combines mechanical and electric heating wax removal methods, including an upper joint, a power supply assembly and an electric heating head, or an intermediate cylinder, and the upper joint and the electric heating The head is connected, or the upper joint, the intermediate cylinder and the electric heating head are connected in sequence to form an externally sealed internal space; the internal space accommodates the power supply component; it is characterized by:

The outer circumference of the electric heating head is a rotating surface, with an inner cavity, the upper end of which is connected to a joint or an intermediate cylinder, and the lower part has at least two blades with the tip pointing downward and the outer circumference being a rotating surface; the at least two blades are along The electric heating heads are distributed circumferentially and separated from each other, leaving a channel between the blades to allow the wax fragments to pass along with the fluid;

An electric heating body is embedded in the blade for heating the blade;

The electric heating body is connected to a wire, and the wire passes through a hole on the electric heating head and enters the internal space to be connected to the power supply component; the hole is sealed.

In a preferred embodiment of the present invention, the power supply component includes a battery pack or a delay control device; the delay control device is connected between the electric heating body and the battery pack; the battery pack It consists of at least three battery cells, which are connected in series end to end.

In a preferred embodiment of the present invention, the delay control device includes a mechanical timer and a micro switch. Two ends of a set of contacts of the micro switch are respectively connected to the electric heating body and the battery pack.

In a preferred embodiment of the present invention, the delay control device includes a delay switch composed of electronic components, and the delay switch is connected to the battery pack and the electric heating body respectively.

In a preferred embodiment of the present invention, the power supply assembly includes a temperature control circuit, a temperature sensor is embedded in the electric heating head or in the blade, and a wire with an insulating jacket passes through the hole of the electric heating head to connect the inside of the blade to the electric heating head. An embedded temperature sensor is connected to the temperature control circuit.

In a preferred embodiment of the present invention, each blade is embedded with an electric heating element and a temperature sensor; the temperature control circuit includes multiple independent temperature control loops; each loop is connected to a circuit located on a different blade. The temperature sensor and the electric heating element independently detect the temperature of the connected blades, and control the current of the electric heating element in the blade according to the temperature.

In a preferred embodiment of the present invention, the outer side of the blade tip has an inward chamfer.

In a preferred embodiment of the present invention, the upper connector is a cable connector with a central through hole, and a cable connector is installed at the upper end of the central through hole; the power supply component includes a temperature control circuit, There is a temperature sensor inside the blade, and a wire with an insulating jacket passes through the hole of the electric heating head to connect the temperature sensor to the temperature control circuit.

In a preferred embodiment of the present invention, the power supply assembly includes a splitter and does not include a temperature control circuit, and there is no temperature sensor in the blade; the splitter is connected to a cable connector and an electric heater respectively. body.

In a preferred embodiment of the present invention, the electric heating head or blade is made of copper alloy.

The downhole electric wax removal tool provided by the present invention has the following beneficial effects:

The technical solution proposed by the utility model combines the methods of mechanical wax removal and electric heating wax removal. Steel wire or cable downhole operating equipment can be lowered into underground pipelines including oil pipes and casings, and electric heating is used to directly clean the mechanical wax removal blades. Heating and mechanical cutting simultaneously dissolve the accumulated wax, which overcomes the problem that when the wax thickness is large, it is difficult to remove the pure mechanical wax and the wax scraper is easy to get stuck. At the same time, there is no chemical pollution. Use multiple blades to increase the length of contact between the cutting edge and the wax during cutting, speeding up the cutting speed; because the blades are separated from each other, leaving a gap, the blades can elastically deform and bend to adapt to the uneven inner wall of the pipe; further, the blades are The upward part away from the blade tip has a channel that allows the wax fragments to pass through with the fluid, so that the wax fragments cut by the blade can flow with the well fluid, and the wax fragments can be discharged to the wellhead with the well fluid.

Description of the drawings

Figure 1 is a schematic diagram of the overall appearance of an embodiment of the present utility model.

FIG. 2 is a cross-sectional view along line A-A of FIG. 1 .

Figure 3 is a partial enlarged view of the Y area in Figure 2.

Figure 4 is a partial enlarged view of area X in Figure 2.

Figure 5 is a partial enlarged view of the W area in Figure 2.

Figure 6 is a partial enlarged view of the V area in Figure 2.

Figure 7 is an overall perspective view of the electric heating head according to one embodiment of the present invention.

Figure 8 is a front view of an electric heating head according to one embodiment of the present invention.

FIG. 9 is a cross-sectional view along B-B in FIG. 8 .

FIG. 10 is a top view of FIG. 8 .

Figure 11 is a partial enlarged view of the Z area in Figure 9.

Figure 12 is a schematic diagram of the overall appearance of one embodiment of the present utility model.

FIG. 13 is a cross-sectional view along D-D of FIG. 12 .

In the picture: 1. Upper joint; 2. Intermediate cylinder; 3. Electric heating head; 301. Inner cavity of electric heating head; 4. Blade; 5. Battery core; 501. Battery core positive electrode; 502. Battery core negative pole; 6. Delay / Temperature control circuit; 601, circuit components; 602, circuit board; 7, battery pack insulating seat; 8, electric heating body; 9, temperature sensor; 8a, electric heating body slot; 9a, temperature sensor slot; 8b, electric heating body wire hole ; 9b. Temperature sensor wire hole; 10. Electric heating element connection wire; 11. Temperature sensor connection wire; 12. Circuit positive busbar; 13. Positive pole jack; 14. Positive pole pin; 15. Battery pack positive busbar; 16. Electricity Insulating pad between cores; 17. Connection between cells; 18. Battery pack negative busbar; 19. Battery pack shock absorber seat; 20. Battery pack negative busbar pin; 21. Negative grounding jumper; 22. Negative grounding screw; 23. Negative grounding jack; 24. Grounding jack buffer seat; 25. Grounding jack buffer spring; 26. Battery pack shock absorbing spring; 31. Cable upper connector; 32. Cable intermediate tube; 33. Cable core wire; 34 , Cable ground wire; 35. Cable connector; 36. Cable temperature control circuit; 37. Cable plug insulating seat.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation modes of the present invention are now listed.

The specific embodiments of the present invention described here are only for the purpose of explaining the present invention and cannot be understood as limiting the present invention in any way. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation manner. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing specific embodiments only and is not intended to limit the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. The word "wax deposit" used in this article can be a verb depending on the context, indicating the action of wax depositing on the inner wall of the pipe, or it can be a noun indicating the wax deposited on the inner wall of the pipe, specifically referring to the condensation and deposition on the inner wall of the pipe. instead of ordinary wax.

Embodiment 1 of the downhole electric wax removal tool proposed by the utility model includes an upper joint, an intermediate cylinder and an electric heating head that are connected in sequence from top to bottom; the upper joint, the middle cylinder and the electric heating head are connected to form an externally sealed internal space. The connections between the three are sealed with threaded connections and double O-ring rubber seals. The power supply component is accommodated in the internal space, and the power supply component includes a battery pack or a delay control device; the battery pack includes at least three battery cells, and these battery cells 5 are connected in series end to end.

Among them, the upper joint is used to upwardly connect steel wire tools such as weighted rods and rope caps. The rope caps connect the steel wires to the ground. The steel wire drives the entire wax removal tool to move up and down to clean the wax on the inner wall of the pipe; the electric heating head is used for cutting and scraping. Remove wax from the inner wall of the pipe.

The outer periphery of the electric heating head is a rotating surface, and the electric heating head has an inner cavity. The diameter of the outer circle is smaller than the inner diameter of the pipe to be removed and can just be lowered into the pipe. The upper part of the electric heating head is connected to the intermediate cylinder, and the lower part has at least two blades with the blade tips pointing downward and the outer circumference being the rotating surface. The at least two blades are distributed along the circumference of the electric heating head and separated from each other, leaving a space between the blades to allow cleaning. A channel through which the wax fragments pass with the fluid. Multiple blades increase the length of contact between the cutting edge and the wax during cutting, speeding up the cutting speed; the blades are separated from each other, leaving a gap, so the blades can elastically bend and deform to adapt to the uneven inner wall of the pipe. There is a channel between the blades that is upward away from the blade tip to allow the wax fragments to pass through with the fluid, so that the wax fragments cut by the blades can flow with the well fluid, further flow with the well fluid to the wellhead, and finally be discharged from the wellhead.

An electric heating body is embedded in the blade for heating the blade. The electric heating body is embedded in the blade and directly contacts the blade. All the heat emitted by the electric heating body is transferred to the blade, making maximum use of the limited energy stored in the battery pack. The blade is heated so that the wax melts or at least softens, making it easier to peel away from the inner wall of the pipe. The electric heating body is connected to a wire with an insulating outer layer. The wire passes through the hole of the electric heating head and is connected to the delay control device. The delay control device is further connected to the battery pack. The hole is sealed to prevent harmful substances in the underground high-pressure environment from intruding into the externally sealed space formed by the connection of the upper joint, the intermediate cylinder and the electric heating head, and causing damage to the battery pack or the delay control device.

When the power supply component housed in the internal space includes both a battery pack and a delay control device, the delay control device is connected between the battery pack and the electric heating body for delaying the power supply from the battery pack to the electric heating body. The purpose of delaying the power supply of the battery pack to the electric heating body is to reserve enough time for the underground electric wax removal tool to go down to the location where the wax is deposited underground before starting heating. The first is to save the power of the battery pack; the second is to prevent the electric heating head from damaging the steel wire due to high temperature. Wellhead sealing rubber parts used in operations. The delay control device can be implemented using an electronic circuit or a mechanical timer plus an electrical switch. The delay time of the delay control device can be flexibly adjusted as needed.

Embodiment 2 of the underground electric wax removal tool proposed by this utility model: Based on Embodiment 1 of this utility model, the delay control device adopts a mechanical timer plus an electrical switch, specifically including a mechanical timer and a micro switch; The mechanical action part of the mechanical timer is connected to the mechanical touch part of the micro switch. The mechanical action to set the timing time of the mechanical timer starts timing. This mechanical action pushes the contact of the micro switch to open; until the time expires, the mechanical action The timer mechanically releases the micro switch, and the contact of the micro switch is connected. The electric heating body is connected to a wire with an insulating layer. The wire passes through the hole of the electric heating head and is connected to a set of contacts of the micro switch. The set of contacts is further connected to the battery pack. The advantage of using a delay control device composed of a mechanical timer and a micro switch is that in an underground high-temperature environment, a mechanical timer is more stable and reliable than a conventional electronic circuit at room temperature, and is less expensive than a high-temperature electronic circuit. The disadvantage is that the timing The error is large.

Embodiment 3 of the underground electric heating wax removal tool proposed by the present utility model: Based on Embodiment 1 of the utility model, the delay control device included in the power supply assembly is a delay switch composed of electronic devices. The time switch is connected to the battery pack and the electric heating body respectively.

Embodiment 4 of the underground electric wax removal tool proposed by this utility model: Based on Embodiment 3 of this utility model, the power supply component also includes a temperature control circuit, and a temperature sensor is embedded in the electric heating head or in the blade; The temperature sensor is connected to the temperature control circuit. When the temperature sensor is embedded in the blade, the temperature sensor is connected to the temperature control circuit through the hole of the electric heating head. A temperature control circuit is added to keep the blade in the most economical wax removal temperature range. The temperature value of the temperature control circuit can be flexibly set according to the removal temperature required for each well to save and utilize the power of the battery pack to the maximum extent. .

Embodiment 5 of the downhole electric wax removal tool proposed by the present utility model: As shown in Figures 1 to 11, the downhole electric wax removal tool includes an upper joint 1, an intermediate cylinder 2 and an electric heating head 3 that are connected in sequence from top to bottom. , the electric heating head 3 has an inner cavity, that is, the electric heating head inner cavity 301; the upper joint 1, the middle cylinder 2 and the electric heating head 3 are connected to form an externally sealed internal space, and the connections between the three are threaded and double O-shaped rubber sealed. ring seal. The power supply component installed in the internal space includes a battery pack and a delay/temperature control circuit 6; the delay/temperature control circuit 6 includes a delay circuit and a temperature control circuit, and the temperature control circuit includes three independent temperature control loops. , each temperature control loop independently detects the temperature of one of the blades 4, and controls the current of the electric heating body in the blade 4 according to the detected temperature, thereby achieving the purpose of controlling the temperature of the blade 4. Both the delay circuit and the temperature control circuit can individually set the required delay time and control temperature value according to the requirements of different underground operations. The battery pack includes 16 cells 5, which are connected in series end to end.

The outer periphery of the electric heating head 3 is a rotating surface, and the outer diameter is smaller than the inner diameter of the pipe to be dewaxed, and can just be lowered into the pipe to be dewaxed. The upper end of the electric heating head 3 is connected to the intermediate cylinder 2, and the lower part has three blades 4 with the tips pointing downward and the outer circumference being the rotating surface. The three blades 4 are evenly distributed along the circumferential direction of the electric heating head 3 and separated from each other. The three blades 4 They are separated from each other, leaving a gap. The blade 4 can therefore be elastically deformed and bent to adapt to the unevenness of the inner wall of the pipe. There is a passage 402 between the blades 4 that is upward away from the blade tip and allows fluid to pass through, so that the waxy fragments cut by the blades 4 can flow with the well fluid and further flow to the wellhead with the well fluid.

The outer surface of each blade 4 is engraved with surrounding electric heating body grooves 8a and linear sensor grooves 9a throughout the blades 4. Both ends of the electric heating body groove 8a and one end of the sensor groove 9a each have a hole leading to the inner cavity 301 of the electric heating head. These holes are respectively the electric heating body wire hole 8b and the temperature sensor wire hole 9b.

For each blade 4, an electric heating body 8 is embedded in the electric heating body groove 8a. The electric heating body 8 is a stainless steel tube with an outer diameter of 2 mm. An electric heating wire is passed through the center of the tube, and magnesium oxide insulating material is filled between the electric heating wire and the inner wall of the stainless steel tube. The depth of the electric heating body groove 8a is greater than the maximum outer diameter of the electric heating body 8, and the electric heating body 8 is in close contact with the inner wall of the electric heating body groove 8a. The electric heating body 8 is only distributed on the cutting edge part of the blade, and the other parts are wires with an insulating outer layer, and the electric heating body connection wire 10 connects the electric heating body 8 and the delay/temperature control circuit 6 . The same groove 8a is carved on the outside of the blade 4 for embedding the electric heating element connection 10. The electric heating body 8 is embedded in the blade 4 and directly contacts the blade 4. All the heat emitted by the electric heating body 8 is transferred to the blade 4, and the limited energy stored in the battery pack is utilized to the maximum extent.

Each blade 4 is engraved with a sensor groove 9a, the depth of the sensor groove 9a is greater than the maximum outer diameter of the sensor 9, and the part connecting the sensor 9 and the delay/temperature control circuit 6 is the sensor body connection 11. The sensor body connection line 11 is connected to the circuit board 602 of the delay/temperature control circuit 6 through the same sensor slot 9a and temperature sensor line hole 9b.

For each blade 4, the electric heating body 8 is connected to an electric heating body connection line 10. The electric heating body connection line 10 passes through the electric heating body wire hole 8b of the electric heating head 3 and is connected to the circuit board 602 of the delay/temperature control circuit 6. connection, the circuit board 602 is further connected to the battery pack. After the electric heating body connection wire 10 passes through the electric heating body wire hole 8b, the hole is sealed to prevent harmful substances from invading the inner cavity 301 of the electric heating head in a high-pressure underground environment and causing damage to the battery pack or the delay/temperature control circuit 6. The grooves 8a and 9a inlaid with the electric heating element 8, the sensor 9, the electric heating element connection 10 and the sensor connection 11 on the blade 4 are filled with high-temperature resistant high-strength materials to cover the electric heating element 8, the sensor 9 and the electric heating element connection 10 and sensor connection 11 to prevent corrosion and impact damage. Similarly, after passing through the electric heating element connection 10 and the sensor connection 11, the electric heating element wire hole 8b and the temperature sensor wire hole 9b of the electric heating head 3 are filled and sealed with high-temperature resistant high-strength materials. The utility model uses a two-component high-temperature resistant material, which has high strength and can withstand high temperatures up to 200°C.

The delay/temperature control circuit 6 includes a delay circuit and three independent temperature control loops. Each temperature control loop is connected to the electric heating body 8 and the temperature sensor 9 of one of the three blades 4 to independently detect and control its own temperature. The temperature of blade 4 makes it reach the temperature preset by the temperature control circuit. The circuit component 601 is an electronic component with an operating temperature higher than 85°C. The circuit component 601 is welded on the circuit board 602. Both ends of the circuit board 602 have multiple welding points for external connections. The welding point at one end of the circuit board 602 is connected to the three sets of electric heating body connections 10 and the sensor connection 11 going to the three blades 4; the welding point at the other end is connected to the positive busbar 12 of the circuit leading to the battery pack and from the upper connector 1 to the middle The negative ground formed by the connection of barrel 2 and electric heating head 3.

The battery pack is composed of sixteen battery cells 5 with a voltage of 3.2V connected end to end in series. In order to ensure a reliable connection between the battery cells 5, the adjacent battery cells 5 are connected by using an inter-cell connection line 17 with both ends welded to On the positive electrode 501 of the battery cell and the negative electrode 502 of the battery cell. An inter-cell insulating pad 16 is also provided between the battery cores 5 to prevent impact between the battery cores 5 from damaging the positive and negative electrodes of the battery cores.

One end of the positive bus bar 15 of the battery pack is welded to the positive electrode 501 of the bottom cell 5, and the other end is welded to the end of the positive jack 13; the positive jack 13 is connected to the positive pin 14, and the end of the positive pin 14 Terminal welding circuit positive busbar 12. The plug-in connection method of the positive jack 13 and the positive pin 14 is used to facilitate the installation and connection between the upper connector 1, the intermediate tube 2, and the electric heating head 3. A battery pack shock-absorbing seat 19 is provided between the battery pack and the delay/temperature control circuit 6. The positive jack 13 is fixed in the battery pack shock-absorbing seat 19, and the positive pin 14 is plugged and fixed in the delay/temperature control circuit 6 The upper end of the main body.

The negative electrode of the battery pack needs to be grounded, that is, the negative electrode of the battery pack is connected to the ground formed by the connection of the upper connector 1, the intermediate tube 2, and the electric heating head 3. The negative electrode is connected to the delay/temperature control circuit 6 with the help of this ground, and forms a power supply together with the positive busbar. loop. In order to ensure that the negative electrode is reliably connected to the negative ground formed by the connection of the upper joint 1, the middle cylinder 2, and the electric heating head 3 when the upper joint 1 and the middle cylinder 2 are installed and connected, multiple components are provided for the negative ground of the battery pack, as shown in Figure 6. , including battery pack negative busbar 18, battery pack shock absorber seat 19, battery pack negative busbar pin 20, negative ground jumper 21, negative ground screw 22, negative ground jack 23, ground jack buffer seat 24, ground jack Buffer spring 25, battery pack shock absorbing spring 26. The two ends of the negative busbar 18 of the battery pack are respectively welded to the negative electrode 502 of the uppermost cell 5 and the negative busbar pin 20 of the battery pack; the two ends of the negative ground jumper 21 are welded to the negative ground screw 22 and the negative ground jack respectively. 23; The negative bus pin 20 of the battery pack is connected to the negative ground jack 23; the negative ground screw 22 is connected to the upper connector 1. The battery pack shock-absorbing seat 19 and the battery pack shock-absorbing spring 26 realize elastic support between the battery pack and the upper connector 1, ensuring close contact between each cell 5 of the battery pack and the insulating pad 16 between cells, as well as the battery pack, The battery pack shock-absorbing seat 19 and the delay/temperature control circuit 6 are in close contact to ensure reliable insertion between the positive jack 13 and the positive pin 14. The ground jack buffer seat 24 and the ground jack buffer spring 25 enable the negative ground jack 23 to float up and down with the negative bus pin 20 of the battery pack to maintain the connection between the negative bus pin 20 and the negative ground jack 23. Reliable plug-in.

There is an inward chamfer 401 on the outside of the tip of the blade 4, so that when encountering a hard protrusion on the inner wall of the pipe, the blade 4 can pass over it without getting stuck. However, the radially inward size of the chamfer 401 cannot be too large, otherwise it will affect the removal of wax close to the inner wall of the pipe. After many experiments, it has been concluded that the radial inward size of the chamfer 4 is preferably between 0.75 and 1.1 mm.

In order to improve the thermal conductivity, the blade 4 can be made of copper alloy. In this embodiment, in order to ensure high mechanical strength while ensuring thermal conductivity, the entire electric heating head is made of aluminum bronze alloy material.

The downhole electric wax removal tool in the above embodiment can use a wire working tool to be dropped downhole to perform the wax scraping operation. The wire work tools at least include a rope cap and a weighted rod, and the weighted rod is connected to an underground electric heating wax removal tool. Before placing the tool, set the delay time of the mechanical timer or delay circuit and the predetermined temperature value of the temperature control circuit before assembly. The electric heating wax removal tool is lowered to the depth of the downhole wax and the delay time of the delay circuit expires. The electric heating body 8 on the blade 4 is connected to the current and starts to heat. While heating, the blade 4 cuts downward to cut the wax; located on each blade 4 The temperature sensor 9 on the blade is always monitoring the temperature of the blade 4. When the temperature of the blade 4 reaches the predetermined temperature value set by the temperature control circuit, the temperature control loop controls to reduce or disconnect the current to the electric heating body 8 of the blade 4. To achieve the purpose of controlling the temperature of blade 4. Each of the three blades 4 has an independent temperature control circuit, which is each connected to the temperature sensor 9 and the electric heating body 8 of the respective blade 4 to achieve the purpose of independently controlling the temperature of each blade. When the wax deposits on the pipe wall are uneven around the circumference, each blade 4 is heated separately to achieve the purpose of saving electricity. The cut wax fragments flow upward to the wellhead through the channels 402 between the blades 4 along with the downhole liquid.

Embodiment 6 of the underground electric wax removal tool proposed by the present utility model: as shown in Figures 12 and 13, it is used for cable power supply and includes an upper joint, an intermediate cylinder, a power supply assembly and an electric heating head. In this embodiment, the upper The joint is a cable upper joint 31, and the intermediate tube is a cable intermediate tube 32. The cable upper joint 31, the cable intermediate tube 32 and the electric heating head 3 are connected to form an externally sealed internal space; the internal space accommodates the power supply component. The cable upper joint 31 is connected to downhole tools used for cable logging, well testing, etc., such as cable connectors (bridles), etc., and is used to realize the mechanical load-bearing connection of the cable to the downhole electric heating wax removal tool and the power supply connection to the electric heating body 3.

In this embodiment, the structure of the electric heating head is the same as that of the electric heating head 3 in Embodiment 6. The outer periphery is a rotating surface with an inner cavity 301. Its upper end is connected to the cable upper joint 31. The lower part has three knife tips pointing downward. The outer periphery is The blades 4 of the rotating surface; the three blades are distributed along the circumference of the electric heating head and separated from each other. There are channels 402 between the blades that allow the wax fragments to pass along with the fluid. As in Embodiment 6, an electric heating body 8 is embedded in the blade for heating the blade 4 . The electric heating body 8 is connected to the power supply component by passing the wire through the hole of the electric heating head 3 into the internal space; the hole is sealed.

What is different from the sixth embodiment is that the power supply assembly shown includes a cable temperature control circuit 36 and does not include a battery pack and a delay circuit. In this embodiment, the cable temperature control circuit 36 also includes three independent temperature control circuits to control the temperatures of the three blades 4 respectively.

Since the power supply depends on the cable, the upper connector in this embodiment is the cable upper connector 31 specially designed for cable power supply. Since there is no battery pack, the intermediate tube is a shorter cable intermediate tube 32. The threads at both ends of the cable intermediate tube 32 are in opposite directions, one end is left-handed and the other end is right-handed. The purpose is to prevent the internal connecting wires from getting tangled and twisted during assembly and connection.

The upper cable connector 31 has a central through hole, and a cable connector is installed at the upper end of the central through hole; the cable connector includes a cable connector 35 and a cable connector insulating seat 37 . The upper end of the cable connector 35 is plugged into the pin corresponding to the core wire of the underground test cable, and the lower terminal is connected to the cable temperature control circuit 36 through the cable core wire 33 . The cable temperature control circuit 36 is connected to the cable ground wire 34, the electric heating element connection 10 and the sensor connection 11 respectively.

On the basis of the sixth embodiment, the cable intermediate tube 32 can be omitted, the upper connector of the cable is directly connected to the electric heating head, and an O-shaped rubber sealing ring is configured at the connection. In this way, one less connection can reduce the risk of seal leakage and reduce costs, but it is more difficult to avoid kinking of the connection during installation. In such a connection method, sufficient inner cavities need to be provided on the cable connector and the electric heating head respectively to accommodate the power supply group.

For the above-mentioned cable-powered underground electric heating wax removal tool, the power supply component may not include a temperature control circuit, but may include a splitter, and the splitter is connected to the cable connector and the electric heating body respectively. Realize the power supply of the cable core wire to the electric heating body. Such a solution does not have a temperature adjustment function, but for cable power supply, it is not necessary to save power. The temperature of the blade can be summarized through experiments to determine the appropriate power supply current, and the current of the blade of the electric wax removal tool can be controlled from the ground through the cable. temperature purpose. This solution saves the cost of high-temperature temperature control circuits.

The technical solution proposed by the utility model combines the methods of mechanical wax removal and electric heating wax removal. Steel wire or cable underground operating equipment can be lowered into the underground pipeline, and electric heat is used to directly heat the blade of the mechanical wax removal, and the thermal power dissolves during mechanical cutting. Wax accumulation overcomes the problem that pure mechanical wax removal is difficult to remove when the wax thickness is large and the wax scraper is easy to get stuck. At the same time, there is no chemical pollution. Using a battery pack to heat slices maximizes the use of electric heat energy and saves electricity. Multiple blades increase the length of contact between the cutting edge and the wax during cutting, speeding up the cutting speed; because the blades are separated from each other, leaving a gap, the blades can elastically deform and bend to adapt to the uneven inner wall of the pipe. Furthermore, there is a channel between the blades that is upward and away from the blade tip, allowing the wax fragments to pass through with the fluid, so that the wax fragments cut by the blades can flow with the well fluid, and the wax fragments can be discharged to the wellhead with the well fluid.

Claims (9)

1. An underground electric heating wax removal tool, including an upper joint, a power supply assembly and an electric heating head, or an intermediate cylinder. The upper joint is connected to the electric heating head, or the upper joint, the middle cylinder and the electric heating head are connected in sequence to form an external seal. The internal space; the internal space accommodates the power supply component; characterized in that: The outer circumference of the electric heating head is a rotating surface, with an inner cavity, the upper end of which is connected to a joint or an intermediate cylinder, and the lower part has at least two blades with the tip pointing downward and the outer circumference being a rotating surface; the at least two blades are along The electric heating heads are distributed circumferentially and separated from each other, leaving a channel between the blades to allow the wax fragments to pass along with the fluid; An electric heating body is embedded in the blade for heating the blade; The electric heating body is connected to a wire, and the wire passes through a hole on the electric heating head and enters the internal space to be connected to the power supply component; the hole is sealed. 2. The underground electric heating wax removal tool according to claim 1, characterized in that: the power supply component includes a battery pack or a delay control device; the delay control device is connected between the electric heating body and the battery pack. between; the battery pack includes at least three cells, which are connected in series end to end. 3. The underground electric heating wax removal tool according to claim 2, characterized in that: the delay control device includes a mechanical timer and a micro switch, and the two ends of a set of contacts of the micro switch are respectively connected to the electric heating body and the Battery. 4. The downhole electric wax removal tool according to claim 2, characterized in that the delay control device includes a delay switch composed of electronic components, and the delay switch is respectively connected to the battery pack and the electric heating body. 5. The downhole electric wax removal tool according to any one of claims 1 to 4, characterized in that: the power supply component includes a temperature control circuit, a temperature sensor is embedded in the electric heating head or in the blade, and has an insulating jacket. The wire passes through the hole of the electric heating head to connect the temperature sensor embedded in the blade to the temperature control circuit. 6. The underground electric heating wax removal tool according to claim 5, characterized in that: each blade is embedded with an electric heating body and a temperature sensor; the temperature control circuit includes multiple independent temperature control loops; each loop is separately Each is connected to a temperature sensor and an electric heating element located on a different blade, independently detects the temperature of the respective connected blade, and controls the current of the electric heating element in the blade according to the temperature. 7. The downhole electric wax removal tool according to any one of claims 1, 2, 3, 4 and 6, characterized in that the outer side of the blade tip has an inward chamfer. 8. The underground electric heating wax removal tool according to claim 1, characterized in that: the upper connector is an upper cable connector with a central through hole, and a cable connector is installed at the upper end of the central through hole; The power supply assembly includes a temperature control circuit, and the blade is equipped with a temperature sensor. A wire with an insulating jacket passes through the hole of the electric heating head to connect the temperature sensor to the temperature control circuit. 9. The downhole electric wax removal tool according to any one of claims 1, 2, 3, 4, 6 and 8, characterized in that: the electric heating head or blade is made of copper alloy.