A downhole screen with self-cleaning function

Abstract

The present invention discloses a downhole screen with a self-cleaning function, comprising a screen body, a transmitting transducer, a flow sensor, a controller, and a power supply device disposed within the screen body. The transmitting transducer is disposed in the middle section of the screen body, its axis parallel to the axis of the screen. The flow sensor is disposed at one end of the screen body near the water outlet, and the controller is electrically connected to the transmitting transducer, flow sensor, and power supply device. This downhole screen can effectively clean impurities clogged between the screen wire wraps or slits, ensuring normal pump fluid supply, extending the pump inspection cycle, improving the pumping efficiency of oil and gas wells, and reducing coalbed methane extraction costs.

Description

Technical Field

[0001] The present invention relates to the technical field of downhole tools, and in particular to a downhole screen pipe with a self-cleaning function. Background Art

[0002] Screens are a commonly used downhole tool, available in several forms, including wire-wound, laser-slotted, and laser-perforated. Their primary function is to serve as the suction port for downhole pumps, electric submersible pumps, and hydraulic jet pumps. They also filter out impurities, such as fracturing proppants and rock dust, from the fluid before it enters the various pumps. The wire wrap or slits on the screen typically range from 0.1 to 4 mm, and the appropriate size should be selected based on the sand production of the well and the pump's operating conditions.

[0003] When the pumping unit or submersible electric pump is working, the downhole fluid enters the pump through the screen pipe and is pumped to the surface. As time goes by, various impurities also flow with the downhole fluid; impurities with a diameter smaller than the screen pipe wire gap or slit width pass through the screen pipe with the downhole fluid into the pump and are discharged to the surface through the oil pipe; impurities larger than the gap are blocked outside the screen pipe; some impurities will get stuck between the wires or slits. Over time, especially powdery impurities, they will gradually accumulate, eventually leading to the complete blockage of some wire gaps or slits, reducing the flow area of ​​the screen pipe, resulting in a decrease in fluid supply, affecting pump efficiency, increasing the workload of the pumping equipment, and seriously causing production accidents such as broken rods, shortening the pump inspection cycle. Summary of the Invention

[0004] To this end, the present invention provides a downhole screen pipe with a self-cleaning function to solve the technical problems of blocked wire winding gaps or cut slits in the screen pipe, which affects pump efficiency and shortens the pump inspection cycle.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A downhole screen pipe with a self-cleaning function comprises a screen pipe body and a transmitting transducer, a flow sensor, a controller and a power supply device arranged in the screen pipe body. The transmitting transducer is arranged in the middle section of the screen pipe body, and the axial direction of the transmitting transducer is parallel to the axial direction of the screen pipe. The flow sensor is arranged at one end of the screen pipe body close to the water outlet. The controller is electrically connected to the transmitting transducer, the flow sensor and the power supply device.

[0007] Furthermore, the downhole screen pipe further comprises a waterproof shell, which is arranged in the screen pipe body, and the controller and the power supply device are both arranged in the waterproof shell.

[0008] Furthermore, the downhole screen pipe also includes a control device bracket, which is horizontally arranged in the screen pipe body, and the waterproof shell is fixed on the upper side of the control device bracket. The control device bracket is provided with a plurality of bracket guide holes.

[0009] Furthermore, the downhole screen pipe also includes an embedded transducer bracket, which includes a center tube and a cross plate; the center tube is vertically arranged in the center of the screen tube body, the upper end of the center tube is connected to the control device bracket, and one or more side holes are provided on the circumference below the upper end; one end of the cross plate is connected to the center tube, and the other end is connected to the inner wall of the screen tube body. There are two groups of cross plates, and the two groups of cross plates are spaced apart in the length direction of the center tube. The transmitting transducer is sleeved on the circumference of the center tube and located between the two groups of cross plates. Each group of cross plates is provided with multiple cross plates, and the multiple cross plates in the same group are evenly distributed on the circumference of the center tube.

[0010] Furthermore, the downhole screen tube also includes a sensor installation box, which is horizontally arranged on the inner side of the water outlet of the screen tube body. A water hole is provided in the middle of the sensor installation box. The connection terminal of the flow sensor is located in the sensor installation box, and the sensing end of the flow sensor is located in the water hole.

[0011] Furthermore, the downhole screen pipe also includes a data line pipe and a lead pipe; one end of the data line pipe is sealed and inserted into the sensor installation box, and the other end is sealed and inserted into the waterproof shell, and the data transmission line connecting the flow sensor and the controller is inserted into the data line pipe; the lead pipe is inserted into the control device bracket, and the wire connecting the controller and the transducer is inserted into the lead pipe.

[0012] Furthermore, the controller is a PLC control board, and the power supply device is a rechargeable power supply.

[0013] Furthermore, the upper and lower ends of the screen tube body are both provided with connecting threads, and the circumference of the screen tube body is wound with screen tube wire or is provided with slits.

[0014] The present invention has the following advantages:

[0015] The present invention provides a downhole screen with a self-cleaning function. A flow sensor can measure real-time flow and transmit it to a controller. When the real-time flow falls below a lower flow threshold, the controller controls the transmitter transducer to operate. The transmitter transducer generates high-frequency vibrations, using the fluid in the screen body as a propagation medium to transmit the vibrations to the screen wires or slits of the screen body, thereby removing impurities between the wires or slits. When the real-time flow exceeds an upper flow threshold, the controller controls the transmitter transducer to stop operating. This downhole screen can effectively clean impurities clogged between the wires or slits, ensuring normal pump supply, extending the pump inspection cycle, improving the pumping efficiency of oil and gas wells, and reducing coalbed methane extraction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0017] The structures, proportions, sizes, etc. illustrated in this specification are intended solely to complement the contents disclosed herein and to facilitate understanding and reading by persons skilled in the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in sizes, without affecting the efficacy and objectives of the present invention, shall remain within the scope of the technical contents disclosed herein.

[0018] Figure 1 A schematic structural diagram of a downhole screen with a self-cleaning function provided by an embodiment of the present invention;

[0019] Figure 2 A top view of the installation of an embedded transducer support and a transducer for a downhole screen with a self-cleaning function provided by an embodiment of the present invention;

[0020] Figure 3 A diagram illustrating the use status of a downhole screen with a self-cleaning function provided by an embodiment of the present invention.

[0021] In the figure: 1-upper connecting thread, 2-screen pipe winding wire, 3-screen pipe body, 4-waterproof shell, 5-power supply device, 6-control device bracket, 7-flow sensor, 8-data transmission line, 9-transducer bracket, 10-transmitting transducer, 11-tube through hole, 12-lower connecting thread, 13-electrical wire, 14-data line pipe, 15-lead pipe, 16-controller, 17-plug, 18-oil pump, 19-oil pipe, 20-bracket diversion hole. DETAILED DESCRIPTION

[0022] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0023] The terms "upper", "lower", "left", "right", "middle", etc. used in this specification are only for the convenience of description and are not intended to limit the scope of the present invention. Changes or adjustments to their relative relationships should be regarded as within the scope of the present invention without substantially changing the technical content.

[0024] like Figure 1-3 As shown, this embodiment provides a downhole screen with a self-cleaning function, including a screen body 3 and a transmitting transducer 10, a flow sensor 7, a controller 16, and a power supply 5 disposed within the screen body 3. The screen body 3 is conventional, with an upper connecting thread 1 at the upper end for connecting to an oil pipe 19 under a pump 18, and a lower connecting thread 12 at the lower end for connecting to an oil pipe 19 with a plug 17 at the lower end. The circumference is wrapped with a screen wire 2 or slits. The transmitting transducer 10 is disposed in the middle section of the screen body 3 and is controlled by the controller 16 to generate high-frequency vibrations during operation. The axial direction of the transmitting transducer 10 is parallel to the axial direction of the screen, and generally, the axes of the two coincide. The flow sensor 7 is disposed at the end of the screen body 3 near the water outlet to more accurately measure the real-time flow rate. The controller 16, a Tianlang TL-2G PLC control board, is connected to the terminals of the transmitting transducer 10 via wires 13 to control its start and stop. It is also connected to the flow sensor 7 via data transmission line 8 to obtain real-time flow data. It is also connected to the power supply 5 via wires 13 to obtain electrical power. The controller 16 presets upper and lower flow thresholds before lowering the tool into the well. The power supply 5 is rechargeable and is charged before lowering the tool into the well or after it is pulled out of the well.

[0025] The downhole screen flow sensor 7 with a self-cleaning function provided in this embodiment can measure real-time flow and transmit it to a controller 16. When the real-time flow falls below a lower flow threshold, the controller 16 controls the transmitting transducer 10 to operate. The transmitting transducer 10 generates high-frequency vibrations, using the fluid in the screen body 3 as a propagation medium to transmit the vibrations to the screen wires 2 or slits of the screen body 3, thereby removing impurities between the screen wires 2 or slits. When the real-time flow exceeds an upper flow threshold, the controller 16 controls the transmitting transducer 10 to stop operating. This downhole screen can automatically identify the screen's operating status and effectively clean impurities clogged between the screen wires 2 or slits, ensuring normal pumping, extending the pump inspection cycle, improving the pumping efficiency of oil and gas wells, and reducing coalbed methane extraction costs.

[0026] In this embodiment, the downhole screen further comprises a waterproof shell 4, which is disposed in the screen body 3. The controller 16 and the power supply device 5 are both disposed in the waterproof shell 4. In this way, the controller 16 and the power supply device 5 are prevented from being damaged by water.

[0027] In this embodiment, the downhole screen pipe also includes a control device bracket 6, which is horizontally arranged in the screen pipe body 3, and the waterproof shell 4 is fixed on the upper side of the control device bracket 6, thereby effectively fixing the waterproof shell 4; the control device bracket 6 is provided with a plurality of bracket guide holes 20 to avoid affecting the upward flow of the fluid below the bracket.

[0028] In this embodiment, the downhole screen also includes an embedded transducer bracket 9, which includes a central tube and a transverse plate. The central tube is vertically arranged in the center of the screen body 3, with its upper end connected to the control device bracket 6. One or more side holes are provided on the circumference below the upper end, which are connected to the tube through hole 11. One end of the transverse plate is connected to the central tube, and the other end is connected to the inner wall of the screen body 3. Two sets of transverse plates are provided, and the two sets of transverse plates are spaced apart along the length of the central tube. The transmitting transducer 10 is sleeved around the circumference of the central tube and located between the two sets of transverse plates. Each set of transverse plates has multiple transverse plates, and the multiple transverse plates in the same set are evenly distributed around the circumference of the central tube. In this way, the transmitting transducer 10 can be effectively fixed or embedded in the screen body 3.

[0029] Optionally, the downhole screen tube also includes a sensor mounting box, which is horizontally arranged on the inner side of the water outlet of the screen tube body 3. A water hole is provided in the middle of the sensor mounting box. The connection terminal of the flow sensor 7 is located in the sensor mounting box, and the sensing end of the flow sensor 7 is located in the water hole. In this way, the real-time flow measured by the flow sensor 7 is more accurate. Preferably, the downhole screen tube also includes a data line pipe 14, one end of which is sealed and penetrated into the sensor mounting box, and the other end is sealed and penetrated into the waterproof shell 4. The data transmission line 8 connecting the flow sensor 7 and the controller 16 is passed through the data line pipe 14, which effectively prevents the connection terminal of the flow sensor 7, the controller 16, and the power supply device 5 from being immersed in water. The downhole screen tube also includes a lead pipe 15, which is passed through the control device bracket 6, and the wire 13 connecting the controller 16 and the transducer 10 is passed through the lead pipe 15.

[0030] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A downhole screen with self-cleaning function, characterized in that: The device comprises a screen tube body and a transmitting transducer, a flow sensor, a controller, and a power supply device disposed in the screen tube body. The transmitting transducer is disposed in the middle section of the screen tube body, and the axial direction of the transmitting transducer is parallel to the axial direction of the screen tube. The flow sensor is disposed at one end of the screen tube body close to the water outlet. The controller is electrically connected to the transmitting transducer, the flow sensor, and the power supply device. The downhole screen pipe further comprises a waterproof shell, which is arranged in the screen pipe body, and the controller and the power supply device are both arranged in the waterproof shell; The downhole screen pipe further includes a control device bracket, the control device bracket is horizontally arranged in the screen pipe body, the waterproof shell is fixed on the upper side of the control device bracket, and the control device bracket is provided with a plurality of bracket guide holes; The downhole screen pipe also includes an embedded transducer bracket, and the embedded transducer bracket includes a central tube and a transverse plate; the central tube is vertically arranged in the center of the screen pipe body, the upper end of the central tube is connected to the control device bracket, and one or more side holes are provided on the circumference below the upper end; one end of the transverse plate is connected to the central tube, and the other end is connected to the inner side wall of the screen pipe body, and the transverse plates are provided in two groups, and the two groups of transverse plates are spaced apart in the longitudinal direction of the central tube, and the transmitting transducer is sleeved on the circumference of the central tube and located between the two groups of transverse plates, and each group of transverse plates is provided with a plurality of transverse plates, and the plurality of transverse plates in the same group are evenly distributed on the circumference of the central tube; Wherein, the controller is a PLC control board, and the power supply device is a rechargeable power supply.

2. The downhole screen pipe with self-cleaning function according to claim 1, characterized in that: The downhole screen pipe also includes a sensor installation box, which is horizontally arranged on the inner side of the water outlet of the screen pipe body. A water hole is provided in the middle of the sensor installation box. The connection terminal of the flow sensor is located in the sensor installation box, and the sensing end of the flow sensor is located in the water hole.

3. The downhole screen pipe with self-cleaning function according to claim 2, characterized in that: The downhole screen pipe also includes a data line pipe and a lead pipe; one end of the data line pipe is sealed and inserted into the sensor installation box, and the other end is sealed and inserted into the waterproof shell, and the data transmission line connecting the flow sensor and the controller is inserted into the data line pipe; the lead pipe is inserted into the control device bracket, and the wire connecting the controller and the transducer is inserted into the lead pipe.

4. The downhole screen pipe with self-cleaning function according to claim 1, characterized in that: The upper and lower ends of the screen tube body are both provided with connecting threads, and the circumference of the screen tube body is wound with screen tube wire or is provided with slits.

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