Downhole electric heating device for flowing well of oil field

Abstract

The utility model discloses an oil field flowing well downhole electric heating device which comprises an upper end assembly and a lower end assembly, the upper end assembly is connected with the lower end assembly through a cable, the upper end assembly comprises a blowout prevention head, a flow blocking pipe and a blowout prevention pipe, the flow blocking pipe is located below the blowout prevention head, and the blowout prevention pipe is located below the blowout prevention head. The blowout prevention pipe is located below the flow blocking pipe, the lower end assembly comprises a weighting rod and an electric heating rod, and the electric heating rod is located on the lower portion of the weighting rod. The cable penetrates through the blowout prevention head, the flow blocking pipe and the blowout prevention pipe. The anti-spraying head is a double-overflow anti-spraying head. The underground electric heating device for the flowing well of the oil field can realize the underground fixed-point paraffin removal of the flowing well of an empty shaft, does not need to enter an oil pipe to establish circulation, is a movable device, is suitable for a well with higher pressure, has the highest working pressure of 30MPa, is simple to install and operate, and has a good application prospect.

Description

Technical Field

[0001] The utility model relates to an oil production device, more specifically, to an underground electric heating device for a self-flowing well in an oil field. Background Art

[0002] Flowing oil production is a method of producing oil in which, when reservoir pressure exceeds the pressure of the fluid column within the wellbore, the oil in the reservoir is automatically lifted out of the wellbore through the tubing and Christmas tree. During the production process of a flowing well, as formation energy decreases, wellbore pressure, fluid velocity, and production gradually decrease, making wax deposition more likely. Furthermore, the process of lifting crude oil from the bottom of the well to the surface involves a continuous decrease in pressure and temperature. When the temperature and pressure drop to a certain level, wax will precipitate from the crude oil. Wax deposition on the inner wall of the tubing and wellbore equipment can affect well production, reduce the inner diameter of the tubing, and in severe cases, block the tubing, causing the flowing well to cease flowing.

[0003] Existing wax removal technologies are not suitable for the self-flowing production of empty wellbore shale oil wells. For example, hot-wash wax removal involves flushing hot water into the wellbore and establishing a hot water circulation system through the tubing and casing to remove wax. Chemical wax removal involves injecting a wax removal agent into the wellbore, which also requires establishing a tubing and casing circulation system. Hollow rod electric heating wax removal lacks a matching high-pressure blowout prevention device. Coiled tubing wax removal operations are expensive and time-consuming, making regular wax removal impossible. To address the wax deposition problem in the later stages of self-flowing shale oil well production, a more adaptable wax removal technology is urgently needed. Utility Model Content

[0004] Based on this, it is necessary to provide an underground electric heating device for an oilfield self-flowing well in order to solve the above technical problems.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A downhole electric heating device for an oilfield self-flowing well, characterized in that the downhole electric heating device for an oilfield self-flowing well comprises an upper assembly and a lower assembly, the upper assembly being connected to the lower assembly via a cable, the upper assembly comprising a blowout preventer, a choke tube and a lubricant preventer, the choke tube being located below the blowout preventer, the lubricant preventer being located below the choke tube, the lower assembly comprising a weighting rod and an electric heating rod, the electric heating rod being located below the weighting rod.

[0007] As a preferred embodiment of the present invention, the cable passes through the spray prevention head, the choke tube and the spray prevention tube.

[0008] As a preferred embodiment of the present invention, the anti-spray head is a double overflow anti-spray head.

[0009] As a preferred embodiment of the present invention, the head of the electric heating rod is provided with a conical electric heating head, and a spring is provided inside the electric heating head.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] The utility model provides a downhole electric heating device for oilfield flowing wells. This device can achieve fixed-point wax removal in empty wellbore flowing wells without the need to run oil pipes to establish circulation. This portable device is suitable for high-pressure wells, with a maximum operating pressure of 30 MPa. It is simple to install and operate, and has promising application prospects. This device avoids the problems of existing wax removal technologies, such as the need to establish oil-casing circulation, the inability to withstand high pressures, and the long construction period, and is therefore well-suited for shale oil flowing wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the solutions in the present invention, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0013] Figure 1 This is a schematic structural diagram of a downhole electric heating device for a flowing well in an oil field according to the present invention;

[0014] Figure 2 for Figure 1 A detailed enlarged schematic diagram of the C region;

[0015] Figure 3 for Figure 1 Schematic diagram of the use of downhole electric heating device for oilfield self-flowing wells;

[0016] The markings in the figure are explained as follows: 1. Anti-blowout head; 2. Choke tube; 3. Anti-blowout pipe; 4. Weight rod; 5. Electric heating rod; A. Upper end assembly; B. Lower end assembly; S. Cable. DETAILED DESCRIPTION

[0017] In order to help those skilled in the art better understand the present invention, the following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

[0018] like Figure 1 and Figure 2 As shown, the downhole electric heating device for the oilfield flowing well includes an upper component A and a lower component B. The upper component A is connected to the lower component B through a cable S. The upper component A includes a blowout preventer 1, a choke tube 2 and a blowout preventer 3. The choke tube 2 is located below the blowout preventer 1, and the blowout preventer 3 is located below the choke tube 2. The lower component B includes a weighting rod 4 and an electric heating rod 5. The electric heating rod 5 is located below the weighting rod 4.

[0019] It should be noted that the cable S passes through the blowout preventer 1 , the choke tube 2 and the blowout preventer 3 .

[0020] The blowout preventer 1 acts as a seal, isolating the high pressure inside the well and ensuring safety during operation. The choke tube 2 provides a step-by-step pressure reduction function. The head of the heating rod 5 is provided with a conical heating head 51, which has a spring 52 inside.

[0021] In addition, the spray head 1 is a double overflow spray head.

[0022] The following describes the working mode of the downhole electric heating device for the oilfield flowing well, including the following steps:

[0023] Step S1, ground assembly of wax cleaning device: pass the cable S through the spray head 1 of the upper assembly A, pass through the oil pipe short section D from the bottom, and then connect the weight rod 4 and the electric heating rod 5 in sequence. The connection combination of the weight rod 4 and the electric heating rod 5 is also called "electric heating tool string", such as Figure 3 As shown;

[0024] Step S2, installing the blowout preventer: Install the blowout preventer head 1 on the upper gate of the wellhead K, tighten the cable S, place the electric heating tool string in the tubing nipple D at the bottom of the blowout preventer, slowly open the gate and steadily increase the pressure to a stable level, then check all parts of the blowout preventer for leakage. After confirming that there is no leakage, fully open the gate;

[0025] Step S3: Lower the discharge heating tool string. The test vehicle or winch controls the cable to be lowered. After it slowly passes through the wellhead K, the lowering speed is controlled to be 25-30 m / min. During the lowering process, the depth and hanging weight are constantly monitored.

[0026] Step S4: Electric heating wax removal. If the hanging weight does not increase during the lowering process, it indicates that the wax has reached the resistance point. Turn on the heating power supply. After the wax is melted, if there is no resistance in the upper and lower movements, continue lowering and repeat this step.

[0027] Step S5: Lift the electric heating tool string. After the wax cleaning is completed, cut off the power supply and lift the cable at a lifting speed of 25-30 m / min. When it is 50 meters away from the wellhead K, slowly lift it and steadily lift the electric heating tool string into the oil pipe short section D at the bottom of the blowout preventer.

[0028] Step S6: Construction is completed, the upper gate of the wellhead K is closed, the nozzle 1 is depressurized, disassembled, the oil pollution is cleaned, and the site is evacuated.

[0029] The electric heating element of the electric heating rod 5 has a power of 3.0 kW, a cable diameter of 5.4 mm, and a designed lowering depth of 1000 m.

[0030] This downhole electric heating device for oilfield flowing wells can achieve fixed-point wax removal in empty wellbores, eliminating the need for running tubing to establish circulation. This portable device is suitable for high-pressure wells, with a maximum operating pressure of 30 MPa. It is simple to install and operate, and has promising application prospects. This device avoids the problems of existing wax removal technologies, such as the need for oil-casing circulation, the inability to withstand high pressures, and the long construction period. It is highly adaptable to shale oil flowing wells.

[0031] Although this application has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned specific embodiments or replace some of the technical features therein with equivalents. Any equivalent structure created using the contents of this application specification and drawings, directly or indirectly applied to other related technical fields, shall also fall within the scope of protection of this patent application.

Claims

1. An underground electric heating device for a flowing well in an oil field, characterized in that: The oilfield self-flowing well downhole electric heating device comprises an upper component (A) and a lower component (B), wherein the upper component (A) is connected to the lower component (B) via a cable (S), wherein the upper component (A) comprises a blowout preventer (1), a choke tube (2) and a blowout preventer (3), wherein the choke tube (2) is located below the blowout preventer (1), and the blowout preventer (3) is located below the choke tube (2), and wherein the lower component (B) comprises a weighting rod (4) and an electric heating rod (5), wherein the electric heating rod (5) is located below the weighting rod (4).

2. The downhole electric heating device for oilfield flowing wells according to claim 1, characterized in that: The cable (S) passes through the blowout preventer (1), the choke tube (2) and the blowout preventer (3).

3. The downhole electric heating device for oilfield flowing wells according to claim 1, characterized in that: The anti-spray head (1) is a double overflow anti-spray head.

4. The downhole electric heating device for oilfield flowing wells according to claim 1, characterized in that: The head of the electric heating rod (5) is provided with a conical electric heating head (51), and a spring (52) is provided inside the electric heating head (51).

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