Drilling tool screen sub

Abstract

The utility model relates to the field of petroleum drilling operation, and specifically relates to a drilling tool filter screen joint. The technical scheme comprises a cylinder body provided with a connecting head at both ends, the cylinder body is internally provided with a filter screen assembly, the filter screen assembly comprises a sitting and hanging section of an upper section and a filter screen section of a lower section, the sitting and hanging section is provided with a hanging part at the outer periphery, the inner wall of the cylinder body is provided with a receiving part corresponding to the hanging part, a plurality of filter holes are formed in the filter screen section, and the outer wall of the filter screen section has a gap with the inner wall of the cylinder body. The utility model has the advantages of simple structure, easy dismounting and maintenance, effective solution to the problems of filter screen vibration and pressure accumulation, long service life and good safety reliability.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling operations, specifically a drill string filter connector for drilling. Background Technology

[0002] During drilling operations, drilling fluid may contain impurities such as rubber, rock cuttings, wood chips, and plugging materials for various reasons. Although a filter screen is installed at the water inlet of the drilling pump, due to the large circulation volume of the drilling fluid, these impurities will still enter the water holes of the drill string with the drilling fluid, causing blockages in the directional instrument and drill bit water holes, thus affecting normal drilling operations.

[0003] To address these issues, a conical filter screen is often placed in the uppermost water inlet of the drill string. However, the filter screen is not fixed within the water inlet, and the impact of drilling fluid causes vibration, affecting the direction-of-care instrument signal. Furthermore, due to insufficient flow capacity, it can lead to increased pump pressure, and the filter screen itself is easily washed away and damaged. Moreover, if the filter screen is placed at the wellhead and is forgotten to be removed, the entire drill string needs to be disassembled and inspected, increasing the workload.

[0004] Patent No. CN202222234714.1 discloses an embedded detachable filter screen connector. It uses a second female thread and a filter screen male thread. When using the device, the second female thread is machined inside the connector body, and a filter screen male thread with corresponding thread type and size is machined on the upper part of the filter screen. The filter screen is connected to the connector through the thread, which achieves a detachable connection and has the advantage of high connection strength. However, for downhole equipment, it cannot solve the problem of pump blockage when the pump pressure rises, which can easily lead to pipeline damage or injury.

[0005] For example, patent number CN201420446455.1 discloses a stepped filter device inside the square joint of a top drive system. The filter is placed inside the square joint, so the placement of the filter is independent of the drill pipe, which can achieve drilling fluid filtration without internal steps in the drill pipe. However, it does not solve the problems of filter vibration, jumping and pressure buildup. Summary of the Invention

[0006] The purpose of this utility model is to solve the above-mentioned technical problems and provide a drilling tool filter screen connector that is simple in structure, easy to disassemble and repair, can effectively solve the problems of filter screen vibration and pressure buildup, has a long service life, and is safe and reliable.

[0007] This utility model relates to a drill bit filter screen connector, which includes a cylinder with connectors at both ends. A filter screen assembly is installed inside the cylinder. The filter screen assembly includes an upper mounting section and a lower filter screen section. The mounting section has a mounting part on its outer periphery. The inner wall of the cylinder has a receiving part corresponding to the mounting part. The filter screen section has multiple filter holes, and there is a gap between the outer wall of the filter screen section and the inner wall of the cylinder.

[0008] Preferably, the outer wall of the filter segment is provided with at least three supporting ribs symmetrically arranged along the central axis of the filter segment, and the outer diameter of the cross section formed by the at least three supporting ribs is consistent with the inner diameter of the cylinder.

[0009] Preferably, the pore size of the filter is 5-6 mm.

[0010] Preferably, the connectors at both ends of the cylinder are male and female, respectively.

[0011] Preferably, the hanging section and the filter section are detachably connected.

[0012] Preferably, the hanging section and the filter section are connected by an insert and sealed with a sealing ring.

[0013] Preferably, a limiting ring is provided on the inner wall of the cylinder below the filter segment, and the lower end of the supporting rib is longer than the lower end face of the filter segment or parallel to the lower end face of the filter segment.

[0014] Preferably, a pressure spring is provided between the support rib and the limiting retaining ring.

[0015] Preferably, the distance between the lower end of the support rib and the limiting ring is greater than the displacement distance between the seat section and the filter section when they are disengaged.

[0016] Preferably, the hook-on portion is an annular protrusion, and the receiving portion is a corresponding annular step.

[0017] Beneficial effects: 1) Instead of the traditional filter screen structure set in the drill bit, an integrated filter screen connector structure is used to connect the drill bit, which can be easily disassembled, making maintenance and repair easier and reducing the impact of vibration on the instrument.

[0018] 2) The filter assembly inside the cylinder includes an upper mounting section and a lower filter section. The mounting section is used to connect with the cylinder, which also facilitates disassembly and cleaning, and reduces vibration and jumping caused by impact. The filter section effectively filters the drilling fluid. However, since there is a filtration gap between the filter section and the cylinder wall, the filter may vibrate under the impact of high-pressure drilling fluid. To address this, symmetrical support ribs are installed on the outer wall of the filter section to support the filter section and the inner wall of the cylinder, which can effectively solve the filter vibration problem and improve the impact resistance of the filter section.

[0019] 2) The mounting section and the filter section can be detachably connected, such as by a threaded connection for easy disassembly. However, considering that insufficient flow and a sharp increase in pump pressure when the filter becomes clogged can lead to pump stalling and a series of serious consequences, the mounting section and the filter section can be connected by an insert type, such as a snap-fit ​​connection, with a sealing ring to maintain a tight seal. A limiting ring is provided below the filter assembly. When the filter section is under excessive pressure and impact, it will detach from the mounting section for rapid pressure relief. At the same time, the supporting ribs of the filter section will be limited by the limiting ring below when they fall, ensuring that the filter section will not fall into the drill string. Furthermore, due to the presence of the supporting ribs, the filter section will fall along the axial direction of the cylinder without tilting, which would affect the flow of drilling fluid. When the lower end of the supporting ribs is longer than the lower end face of the filter section, it can also ensure that there is a sufficient gap between the filter section and the limiting ring, which is conducive to the flow of drilling fluid and achieves the purpose of rapid pressure relief. Furthermore, considering the high downhole drilling fluid pressure (up to 35 MPa) and even the possibility of blockage, the insertion connection between the mounting section and the filter section may be insufficient to withstand pressure under certain conditions. A pressure spring is installed between the support rib and the limiting ring to ensure the sealing of the filter assembly during normal operation. By selecting a suitable pressure spring, the pressure relief threshold can be easily adjusted. After the pressure is released, the filter section can be reinserted into the mounting section under the action of the pressure spring and the guidance of the support rib. The combination of the support rib, pressure spring, and limiting ring also ensures the flow of drilling fluid under pressure relief.

[0020] 3) This utility model has a simple structure, is easy to disassemble and repair, can effectively solve the problems of filter vibration and pressure buildup, has a long service life, and is safe and reliable. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model.

[0022] Figure 2 This is a schematic diagram of the filter assembly.

[0023] Figure 3 This is a schematic diagram of the filter segment of this utility model in the state of being detached and depressurized.

[0024] Figure 4 This is a partial schematic diagram of a filter segment according to another embodiment of the present invention.

[0025] Among them, 1 is the hanging section, 1.1 is the annular protrusion, 2 is the filter section, 3 is the support rib, 4 is the filter hole, 5 is the cylinder, 5.1 is the annular step, 6 is the pressure spring, 7 is the limit ring, 8 is the male buckle, 9 is the female buckle, and 10 is the gap. Detailed Implementation

[0026] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of this utility model. The utility model is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of this utility model will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this utility model.

[0027] Example 1: See Figure 1 and Figure 2 In this embodiment, the drilling tool filter connector has a male thread 8 and a female thread 9 at both ends of the cylinder 5, which can be used to connect with the upper and lower drilling tools. The cylinder 5 contains a filter assembly, which includes an upper mounting section 1 and a lower filter section 2. The mounting section 1 has a hook-on part on its outer periphery, and the inner wall of the cylinder 5 has a receiving part corresponding to the hook-on part. In this embodiment, the hook-on part is an annular protrusion 1.1, and the receiving part is a corresponding annular step 5.1. When the annular protrusion 1.1 presses down against the annular step 5.1, the filter assembly is stably mounted on the cylinder 5. The filter section 2 has multiple filter holes 4 with a diameter of 5-6 mm, and the outer wall of the filter section 2 has a gap 10 with the inner wall of the cylinder, which is used to filter out fine rock cuttings, sand, gravel, large particles of plugging material, and other impurities. The outer wall of the filter section 2 is provided with at least three supporting ribs 3 symmetrically arranged along the central axis of the filter section 2. In this embodiment, four supporting ribs 3 are symmetrically arranged, and their outer diameter is consistent with the inner diameter of the cylinder 1, so as to support the filter section 2 and reduce the vibration of the filter section 2 caused by the impact of drilling fluid during filtration. The mounting section 1 and the filter section 2 are detachably connected. For example, a direct threaded connection can resist impact and facilitate disassembly.

[0028] In this embodiment, to further address the pump stalling problem, the mounting section and the filter section are connected by an insertion method (such as snap-fit) and sealed with a sealing ring. Furthermore, a limiting ring 7 is provided on the inner wall of the cylinder 5 below the filter section 2, and a pressure spring 6 is provided between the support rib 3 and the limiting ring 7. The distance between the lower end of the support rib 3 and the limiting ring 7 is greater than the displacement distance required for the mounting section 1 and the filter section 2 to disengage. See also... Figure 3When filter screen section 2 becomes clogged and the pressure inside the filter exceeds the set pressure, the drilling fluid pushes filter screen section 2 downwards, overcoming the force of pressure spring 6, until filter screen section 2 detaches from the mounting section 1. The drilling fluid can then flow out quickly from the detached position, and then discharge downwards through the gap 10, pressure spring 6, and limit ring 7, preventing pump blockage and avoiding pipeline damage or injury. Due to the presence of support rib 3, the detachment process also has a guiding and supporting function, preventing the possibility of filter screen section 2 vibrating or tilting and blocking the cylinder, thus preventing pump blockage again. When cleaning or maintenance is required, since all components are detachable, simply disconnect the cylinder 5 from the upper and lower drill strings, and the mounting section 1, filter screen section 2, and pressure spring 6 can all be removed for cleaning or replacement.

[0029] As another embodiment of this application, if the insertion connection between the hanging section and the filter section has a certain impact resistance to meet the filtration requirements, the pressure spring 6 may not be installed. It is only necessary to ensure that the lower end of the support rib 3 is longer than the lower end of the filter section 2 (see [reference]). Figure 4 When filter segment 2 is overpressurized and detaches, the support rib 3 moves down and abuts against the limiting ring 7. Since the support rib 3 extends, there is a certain distance between the lower end face of filter segment 2 and the limiting ring 7, so it will not block the hole of the limiting ring 7 and will not affect the rapid depressurization.

Claims

1. A drilling tool filter screen connector, comprising a cylindrical body with connectors at both ends, characterized in that, The cylinder is equipped with a filter assembly, which includes an upper hanging section and a lower filter section. The hanging section has a hanging part on its outer periphery, and the inner wall of the cylinder has a receiving part corresponding to the hanging part. The filter section has multiple filter holes, and there is a gap between the outer wall of the filter section and the inner wall of the cylinder.

2. The drilling tool filter screen connector as described in claim 1, characterized in that, The outer wall of the filter section is provided with at least three supporting ribs symmetrical along the central axis of the filter section, and the outer diameter of the cross section formed by the at least three supporting ribs is consistent with the inner diameter of the cylinder.

3. The drilling tool filter screen connector as described in claim 1, characterized in that, The filter pore diameter is 5-6 mm.

4. The drilling tool filter screen connector as described in claim 1, characterized in that, The connectors at both ends of the cylinder are male and female, respectively.

5. The drilling tool filter screen connector as described in any one of claims 1-4, characterized in that, The hanging section and the filter section are detachably connected.

6. The drilling tool filter screen connector as described in claim 5, characterized in that, The hanging section and the filter section are connected by an insert and sealed with a sealing ring.

7. The drilling tool filter screen connector as described in claim 6, characterized in that, A limiting ring is provided on the inner wall of the cylinder below the filter screen segment, and the lower end of the supporting rib is longer than the lower end face of the filter screen segment, or parallel to the lower end face of the filter screen segment.

8. The drilling tool filter screen connector as described in claim 7, characterized in that, A pressure spring is provided between the support rib and the limiting retaining ring.

9. The drilling tool filter screen connector as described in claim 7 or 8, characterized in that, The distance between the lower end of the support rib and the limiting ring is greater than the displacement distance between the seat section and the filter section when they are disengaged.

10. The drilling tool filter screen connector as described in claim 1, characterized in that, The hook-on part is an annular protrusion, and the receiving part is a corresponding annular step.

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