Drilling mud filtering equipment

Abstract

The invention discloses drilling mud filtering equipment which comprises a rotational flow pretreatment assembly used for achieving primary solid-liquid separation of mud through centrifugal force; and the filter pressing assembly comprises a hydraulically-driven upper pressing plate, a hydraulically-driven lower pressing plate, a micropore filter element which is arranged between the upper pressing plate and the lower pressing plate and has a dynamically-adjustable pore diameter, and a pressure feedback system. The device is compact in structure, high in automation degree and suitable for high-strength drilling operation, and the problems that traditional equipment is long in filtering period, prone to blockage and the like are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of geological drilling equipment, in particular to drilling mud filtering equipment. Background Art

[0002] During drilling operations, mud, as an important working medium, plays a key role in cooling the drill bit, lubricating drilling tools, and carrying cuttings. However, as drilling progresses, a large amount of solid particles such as cuttings, sand, and other impurities will be mixed into the mud. Without effective filtration, this will not only affect the mud's performance and reduce drilling efficiency, but may also lead to problems such as tool blockage and equipment damage.

[0003] Currently, existing mud filtration equipment mainly achieves solid-liquid separation through mechanical extrusion, multi-stage sedimentation or static filtration, but still has the following defects: traditional extrusion equipment relies on fixed pressure plates to apply physical pressure, the mud moisture recovery rate is low, and the gap between the extrusion plates is easily clogged by clay particles, requiring frequent shutdowns for cleaning; the multi-stage sedimentation tank uses a gradient filter mesh, which can intercept impurities of different particle sizes, but the single filtration cycle is as long as 30 minutes or more, and it occupies a large area. In high-intensity operations such as deep well drilling, the mud processing volume cannot match the drilling progress, resulting in construction delays; although the existing aperture adjustment technology (such as limit block compensation) can respond to filter hole wear, it does not solve the problem of real-time filter hole blockage. When the mud sand content suddenly increases, the filter hole blockage rate is high, resulting in increased system pressure loss and forced interruption of operations. Summary of the Invention

[0004] The purpose of the present invention is to provide a drilling mud filtration equipment, which reduces the load of the filter press unit through centrifugal pre-grading and shortens the filtration cycle. It realizes dynamic adjustment of the filter pores based on shape memory alloy to adapt to the sudden change of mud rheological properties. It prevents clogging problems by constructing a self-cleaning mechanism, reduces the frequency of shutdown maintenance, and increases the continuous operation life of the equipment.

[0005] The technical solution adopted by the present invention to solve this technical problem is: a drilling mud filtering device, comprising: Cyclone pretreatment component, used to achieve primary solid-liquid separation of mud through centrifugal force; The filter press assembly comprises a hydraulically driven upper pressure plate, a lower pressure plate, a microporous filter element with dynamically adjustable pore size arranged between the upper pressure plate and the lower pressure plate, and a pressure feedback system.

[0006] As a further solution of the present invention, the microporous filter element with dynamically adjustable pore size comprises: a temperature control unit and a microporous filter element body, the microporous filter element body being a rigid straight cylindrical structure, a memory alloy filter screen being embedded at the discharge end of the microporous filter element body, and both ends of the memory alloy filter screen being connected to the temperature control unit via wires; The pressure feedback system includes pressure sensors arranged at the feed port and the discharge port of the microporous filter element body, which are used to collect the inlet and outlet pressure values ​​of the microporous filter element body in real time.

[0007] As a further solution of the present invention, the top surface of the upper pressing plate is driven by four groups of symmetrically arranged hydraulic cylinders; A sealing structure is provided on the periphery between the upper pressing plate and the lower pressing plate; The microporous filter element body passes through the upper pressure plate and extends to the upper surface of the lower pressure plate. The bottom of the microporous filter element body protrudes from the upper pressure plate to form a frustum structure and can be embedded in the corresponding conical hole of the lower pressure plate. A guide channel is opened in the lower pressure plate, and the guide channel is connected to the filtrate outlet of the microporous filter element body.

[0008] As a further solution of the present invention, a self-cleaning component is further provided, which includes ultrasonic vibrators, and the ultrasonic vibrators are installed inside the upper pressing plate in an array distribution.

[0009] As a further solution of the present invention, the device further includes a controller connected to the pressure feedback system and the temperature control unit; the controller is configured as follows: When the pressure difference between the inlet and outlet of the microporous filter element is greater than the set threshold value N, the ultrasonic vibrator is started to run for the set time t1; When the equipment has accumulated the set running time t, the ultrasonic vibrator is started to run for the set time t2.

[0010] As a further solution of the present invention, it further includes a mud flow sensor, which is installed at the front end of the feed port of the microporous filter element body, and the controller is connected to the mud flow sensor; the controller is configured as follows: When the pressure difference growth rate exceeds the threshold and the flow rate decreases, the temperature control unit gradually increases the temperature, causing the filter aperture to gradually expand to the maximum, reducing the flow resistance to achieve a response to the sudden change in mud viscosity.

[0011] As a further solution of the present invention, the cyclone pretreatment assembly includes a conical cyclone tube and a high-frequency vibrating screen; a tangential pulp inlet is provided on the top of the cyclone tube, and a variable-diameter spiral guide vane is embedded in the inner wall of the tube; and the bottom of the cyclone tube is connected to the high-frequency vibrating screen.

[0012] As a further solution of the present invention, the guide vanes are arranged obliquely, the inclination angle between the upper surface of the guide vanes and the horizontal plane is 15° to 25°, and the distance between the upper and lower adjacent guide vanes decreases from the inlet to the outlet.

[0013] As a further solution of the present invention, the apertures of the high-frequency vibration screen are distributed in a gradient from top to bottom, becoming smaller gradually.

[0014] The present invention has at least the following beneficial effects: 1. Through the synergistic effect of the centrifugal force of the cyclone pretreatment component and the gradient screen, the particles of different particle sizes in the mud are separated step by step. After pretreatment, the solid content of the mud is reduced, which significantly reduces the load of the filter press component and shortens the filtration cycle.

[0015] 2. The memory alloy filter of the filter press assembly adjusts the pore size in real time through the temperature control unit. Heating expands the filter to the maximum pore size to reduce flow resistance; 3. When the pressure difference exceeds the threshold or the cumulative running time reaches the set value, the cleaning program will be automatically started to predict the blockage trend in advance and extend the service life of the equipment.

[0016] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a drilling mud filtration apparatus according to the present invention; Among them, 1-frame, 2-conical cyclone, 3-high-frequency vibrating screen, 4-guide plate, 5-hose, 6-ultrasonic vibrator, 7-temperature control unit, 8-upper pressure plate, 9-lower pressure plate, 10-sealing structure, 11-cone structure, 12-microporous filter element body, 13-guide channel, 14-hydraulic cylinder, 15-memory alloy filter. DETAILED DESCRIPTION

[0018] The present invention is described in detail and completely below with reference to the accompanying drawings. Those skilled in the art will be able to implement the present invention based on this description. Before describing the present invention with reference to the accompanying drawings, it should be noted that the technical solutions and technical features provided in various parts of the present invention, including those described below, may be combined with each other unless they conflict.

[0019] In addition, the embodiments of the present invention described below are generally only part of the embodiments of the present invention, rather than all of the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making any creative efforts should fall within the scope of protection of the present invention.

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific implementation process is as follows: like Figure 1 As shown, the present invention provides a drilling mud filtering device, comprising: Cyclone pretreatment component, used to achieve primary solid-liquid separation of mud through centrifugal force; The filter press assembly includes a hydraulically driven upper pressure plate 8, a lower pressure plate 9, a microporous filter element with dynamically adjustable pore size at the discharge port arranged between the upper pressure plate 8 and the lower pressure plate 9, and a pressure feedback system.

[0021] In the above technical solution, the cyclone pretreatment component and the filter press component are both fixed by the frame 1. The mud is first pretreated by the cyclone pretreatment component to remove large particles of impurities in the mud and reduce the load during the filter press. It is then further filtered by the filter press component. In addition, the hydraulic system of the filter press component is only started during the filter press stage, which can greatly reduce the power consumption of the overall equipment.

[0022] This technical solution may also include the following technical details to better achieve the technical effect: The microporous filter element with dynamically adjustable pore size includes: a temperature control unit 7 and a microporous filter element body 12. The microporous filter element body 12 is a rigid straight cylindrical structure using an alumina ceramic matrix. A memory alloy filter screen 15 is embedded at the discharge port of the microporous filter element body 12. Both ends of the memory alloy filter screen 15 are connected to the temperature control unit 7 via wires. Different currents are applied through the temperature control unit 7 to adjust the temperature of the memory alloy filter screen 15, thereby adjusting its pore size. The memory alloy filter screen 15 is arranged at the discharge port of the microporous filter element body 12 so that the memory alloy filter screen 15 is placed at the highest pressure difference point, which can improve the response speed of the pressure feedback system. The pressure feedback system includes pressure sensors provided at the feed port and the discharge port of the microporous filter element body 12 , and is used to collect the inlet and outlet pressure values ​​of the microporous filter element body 12 in real time.

[0023] In the above technical solution, slurry flows from the microporous filter element's slurry inlet, sequentially entering the filter element's straight section and the control zone of the memory alloy filter 15. It then exits the microporous filter element's filtrate outlet. As the slurry passes through the control zone of the memory alloy filter 15, the temperature of the memory alloy filter 15 is controlled based on the slurry's viscosity to accommodate sudden changes in the slurry's rheological properties. As the slurry viscosity increases, the temperature control unit 7 heats the memory alloy to expand its pore size (maximum 3mm). Under high sand content conditions, the pore size automatically contracts to 0.5mm to ensure filtration accuracy.

[0024] This technical solution may also include the following technical details to better achieve the technical effect: the top surface of the upper pressing plate 8 is driven by four groups of symmetrically arranged hydraulic cylinders 14. In this embodiment, the hydraulic cylinders 14 are connected to the upper pressing plate 8 through ball joints. A laser ranging sensor is set on the bottom surface of the upper pressing plate 8 to monitor the gap value of the four corners in real time. The controller dynamically adjusts the stroke of each hydraulic cylinder 14 to ensure the parallelism of the gap between the upper pressing plate 8 and the lower pressing plate 9; A sealing structure 10 is provided on the outer periphery between the upper pressing plate 8 and the lower pressing plate 9. The sealing structure 10 may be a stepped sealing ring to form a line seal between the upper pressing plate 8 and the lower pressing plate 9. The microporous filter element body 12 passes through the upper pressure plate 8 and extends to the upper surface of the lower pressure plate 9. The bottom of the microporous filter element body 12 protrudes from the upper pressure plate 8 to form a frustum structure 11 and can be embedded in the conical hole corresponding to the lower pressure plate 9. The self-tightening seal is achieved by driving the hydraulic cylinder 14, so that the upper pressure plate 8 and the lower pressure plate 9 form a double-layer seal. A guide channel 13 is opened in the lower pressure plate 9. The guide channel 13 is connected to the filtrate outlet of the microporous filter element body 12, and the filtered mud filtrate flows out of the guide channel 13.

[0025] The present technical solution may further include the following technical details to better achieve the technical effect: a self-cleaning component is also provided, which includes ultrasonic vibrators 6, and the ultrasonic vibrators 6 are installed inside the upper pressing plate 8 in an array distribution.

[0026] This technical solution may also include the following technical details to better achieve the technical effect: it also includes a controller, the controller is connected to the pressure feedback system and the temperature control unit 7; the controller is configured to: When the pressure difference at the inlet and outlet of the microporous filter element body 12 is greater than the set threshold, it indicates that the micropore blockage rate is high, and the ultrasonic vibrator 6 is started to run for the set time t1; When the device has accumulated the set operation time t, the ultrasonic vibrator 6 is started to operate for the set operation time t2.

[0027] In the above technical solution, ultrasonic cleaning of the filter press assembly significantly improves cleaning efficiency compared to conventional techniques. In this embodiment, the self-cleaning component specifically activates the ultrasonic vibrator 6 at a frequency of 28 kHz for 15 seconds after the device has been running for a cumulative 2 hours, substantially restoring initial filtration capacity.

[0028] This technical solution may also include the following technical details to better achieve the technical effect: it also includes a mud flow sensor, the mud flow sensor is installed at the front end of the feed port of the microporous filter body 12, and the controller is connected to the mud flow sensor; the controller is configured to: When the pressure difference growth rate exceeds the threshold and the flow rate decreases, the temperature control unit 7 gradually increases the temperature, so that the filter aperture gradually expands to the maximum, reducing the flow resistance, so as to achieve a response to the sudden change in mud viscosity.

[0029] This technical solution can also include the following technical details to better achieve the technical effect: the cyclone pretreatment component includes a conical cyclone tube 2 and a high-frequency vibrating screen 3; a tangential slurry inlet is provided on the top of the cyclone tube, and a variable-diameter spiral guide plate 4 is embedded in the inner wall of the tube; the bottom of the cyclone tube is connected to the high-frequency vibrating screen 3, and the slurry outlet of the high-frequency vibrating screen 3 is connected to the feed port of the microporous filter element body 12 through a retractable hose 5, and a sand and gravel discharge port is provided on the side of the high-frequency vibrating screen 3.

[0030] This technical solution can also include the following technical details to better achieve the technical effect: the guide plate 4 is arranged at an angle, the upper surface of the guide plate 4 is inclined at an angle of 15°~25° to the horizontal plane, and the spacing between the upper and lower adjacent guide plates 4 decreases from the inlet to the outlet. In this embodiment, the spacing between the two adjacent guide plates 4 at the inlet is 30 mm, and the spacing between the two adjacent guide plates 4 at the outlet is 10 mm.

[0031] This technical solution can also include the following technical details to better achieve the technical effect: the aperture of the high-frequency vibrating screen 3 is gradiently distributed from top to bottom, gradually becoming smaller. In this embodiment, the aperture of the top screen is 5 mm, and the aperture of the bottom screen is 1 mm.

[0032] In the above technical solution, when processing geothermal well drilling mud with a solid content of 18%-22%, the mud enters the cyclone tangentially at a flow rate of 2m / s. Under the action of centrifugal force, large particles of sand and gravel sink along the spiral guide vane 4 to the vibrating screen. After pre-separation, the solid content of the mud is reduced to 8%-10%, which can greatly reduce the solid content of the mud.

[0033] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A drilling mud filtration device, characterized in that: include: Cyclone pretreatment component, used to achieve primary solid-liquid separation of mud through centrifugal force; The filter press assembly comprises a hydraulically driven upper pressure plate, a lower pressure plate, a microporous filter element with dynamically adjustable pore size arranged between the upper pressure plate and the lower pressure plate, and a pressure feedback system.

2. The drilling mud filtering device according to claim 1, characterized in that: The microporous filter element with dynamically adjustable pore size includes: a temperature control unit and a microporous filter element body. The microporous filter element body is a rigid straight cylindrical structure. The discharge end of the microporous filter element body is embedded with a memory alloy filter screen. The two ends of the memory alloy filter screen are connected to the temperature control unit through wires. The pressure feedback system includes pressure sensors arranged at the feed port and discharge port of the microporous filter element body, which are used to collect the inlet and outlet pressure values ​​of the microporous filter element body in real time.

3. The drilling mud filtering equipment according to claim 2, characterized in that: The top surface of the upper pressing plate is driven by four groups of symmetrically arranged hydraulic cylinders; A sealing structure is provided on the periphery between the upper pressing plate and the lower pressing plate; The microporous filter element body passes through the upper pressure plate and extends to the upper surface of the lower pressure plate. The bottom of the microporous filter element body protrudes from the upper pressure plate to form a frustum structure and can be embedded in the corresponding conical hole of the lower pressure plate. A guide channel is opened in the lower pressure plate, and the guide channel is connected to the filtrate outlet of the microporous filter element body.

4. The drilling mud filtering device according to claim 3, characterized in that: A self-cleaning component is also provided, which includes ultrasonic vibrators, which are installed inside the upper pressing plate in an array distribution.

5. The drilling mud filtering equipment according to claim 4, characterized in that: The invention also includes a controller, which is connected to the pressure feedback system and the temperature control unit; the controller is configured as follows: When the pressure difference between the inlet and outlet of the microporous filter element is greater than the set threshold value N, the ultrasonic vibrator is started to run for the set time t1; When the equipment has accumulated the set running time t, the ultrasonic vibrator is started to run for the set time t2.

6. The drilling mud filtering device according to claim 5, characterized in that: It also includes a mud flow sensor, which is installed at the front end of the feed port of the microporous filter element body. The controller is connected to the mud flow sensor; the controller is configured as follows: When the pressure difference growth rate exceeds the threshold and the flow rate decreases, the temperature control unit gradually increases the temperature, causing the filter aperture to gradually expand to the maximum.

7. The drilling mud filtering device according to claim 1, wherein: The cyclone pretreatment component includes a conical cyclone tube and a high-frequency vibration screen; a tangential pulp inlet is provided on the top of the cyclone tube, and a variable-diameter spiral guide vane is embedded in the inner wall of the tube; and the bottom of the cyclone tube is connected to the high-frequency vibration screen.

8. The drilling mud filtering device according to claim 7, characterized in that: The guide plates are arranged at an angle, the inclination angle between the upper surface of the guide plates and the horizontal plane is 15° to 25°, and the spacing between the upper and lower adjacent guide plates decreases from the inlet to the outlet.

9. The drilling mud filtering device according to claim 8, characterized in that: The apertures of the high-frequency vibration screen are distributed in a gradient from top to bottom, becoming smaller gradually.

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