Drilling tool filter screen connector for well drilling

Abstract

The invention relates to the field of petroleum drilling operation, in particular to a drilling tool filter screen connector for drilling. According to the technical scheme, the filter comprises a barrel with two ends provided with connectors respectively, a filter screen assembly is mounted in the barrel and comprises an upper sitting and hanging section and a lower filter screen section, a hanging part is arranged on the periphery of the sitting and hanging section, a bearing part corresponding to the hanging part is arranged on the inner wall of the barrel, a plurality of filter holes are formed in the filter screen section, and the filter screen section is connected with the hanging part. And a gap is formed between the outer wall of the filter screen section and the inner wall of the barrel. The filter screen is simple in structure, easy to disassemble and maintain, capable of effectively solving the problems of vibration and pressure building of the filter screen, long in service life and good in safety and reliability.

Description

[0001] The present application relates to the field of oil drilling operation, in particular to a drilling tool filter screen joint. BACKGROUND

[0002] In the process of drilling operation, drilling fluid will be mixed with rubber, rock debris, wood chips, plugging material and other impurities due to various reasons. Although a filter screen is arranged on the water end of the drilling pump, the above impurities will still enter the drilling tool water eye along with the drilling fluid due to the large circulating discharge of the drilling fluid, resulting in blockage of directional instruments, drill bit water eyes and other parts, and affecting normal drilling operation.

[0003] To solve the above problems, a conical filter screen is usually placed in the uppermost drilling tool water eye. However, the filter screen is not fixed in the water eye, and the impact of the drilling fluid will cause vibration, which will affect the signal of the directional instrument. In addition, due to insufficient passability, the pump pressure will increase, and the filter screen body is easy to be damaged by washing. Moreover, if the filter screen is placed at the wellhead and is forgotten to be taken out, the entire drilling tool needs to be disassembled and inspected, which increases the workload.

[0004] Patent No. CN202222234714.1 discloses an embedded detachable filter screen joint. A second female thread and a filter screen male thread are arranged, and when the device is used, a second female thread is processed inside the joint body, and a filter screen male thread of corresponding size and type is processed on the upper part of the filter screen. The filter screen and the joint are connected through the threads to realize detachable connection, and have the advantage of high connection strength. However, for downhole equipment, the problem of pump pressure increase cannot be solved, which can easily cause pipeline damage or injury events.

[0005] For example, Patent No. CN201420446455.1 discloses a top drive system square protector joint inner step filter screen device. The filter screen is placed in the square protector joint, which is independent of the drill pipe and can realize drilling fluid filtration without inner step drill pipe. However, the problems of filter screen vibration, jumping and pressure increase are not solved. SUMMARY

[0006] The present application aims to solve the above technical problems, and provides a drilling tool filter screen joint with simple structure, easy disassembly and maintenance, effective solution to filter screen vibration and pressure increase, long service life and good safety and reliability.

[0007] The drilling tool filter screen joint of the present application comprises a cylinder body provided with a connecting head at each end, a filter screen assembly is arranged in the cylinder body, the filter screen assembly comprises a hanging section in the upper section and a filter screen section in the lower section, a hanging part is arranged on the outer periphery of the hanging section, a receiving part corresponding to the hanging part is arranged on the inner wall of the cylinder body, a plurality of filter holes are arranged on the filter screen section, and the outer wall of the filter screen section has a gap with the inner wall of the cylinder body.

[0008] Preferably, the outer wall of the filter screen section is provided with at least three support ribs symmetrically along the central axis of the filter screen section, and the cross-sectional outer diameter surrounded by the at least three support ribs is consistent with the inner diameter of the cylinder.

[0009] Preferably, the filter hole diameter is 5-6mm.

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

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

[0012] Preferably, the seat hanging section and the filter screen section are connected in an insertion manner and sealed by a sealing rubber ring.

[0013] Preferably, a limiting stop ring is arranged on the inner wall of the cylinder below the filter screen section, and the lower end of the support rib is longer than the lower end surface of the filter screen section or parallel to the lower end surface of the filter screen section.

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

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

[0016] Preferably, the hanging part is an annular protrusion, and the receiving part is a corresponding annular step.

[0017] Beneficial effects: Instead of the traditional filter screen structure arranged in the drilling tool, the whole filter screen joint structure is used to connect the drilling tool, which can be easily disassembled, maintained and repaired, and reduce the impact of vibration on the instrument.

[0018] 2) The filter screen assembly in the cylinder includes a seat hanging section of the upper section and a filter screen section of the lower section, which realizes hanging with the cylinder by the seat hanging section, is convenient for disassembly and cleaning, and reduces the vibration and jumping problems caused by impact; the filter screen section realizes effective filtration of the drilling fluid, and at the same time, due to the filtering gap between the filter screen section and the cylinder wall, there is a filter screen vibration problem under the impact of high-pressure drilling fluid, therefore, by arranging the support ribs symmetrically along the center on the outer wall of the filter screen section, the support between the filter screen section and the inner wall of the cylinder is realized, which can well solve the filter screen vibration problem and improve the impact resistance of the filter screen section.

[0019] 3) The seat-hanging section and the filter screen section can be connected in a detachable manner, such as threaded connection, for easy disassembly. In view of the fact that when the filter screen is blocked, the pump pressure will rise sharply, causing the pump to be blocked, and a series of serious consequences will occur, the seat-hanging section and the filter screen section can be connected in an insertion manner, such as clamping, and a sealing ring is arranged to keep the sealing property. A limiting stop ring is arranged below the filter screen assembly. When the pressure of the filter screen section is too large and is impacted, the seat-hanging section and the filter screen section will be disconnected, and the pressure is quickly released. When the supporting rib of the filter screen section falls, it will be limited by the limiting stop ring below, so that the filter screen section will not fall into the drilling tool. In addition, due to the existence of the supporting rib, the filter screen section will fall along the axial direction of the cylinder, and will not be inclined, thereby affecting the passing property of the drilling fluid. When the lower end of the supporting rib is longer than the lower end surface of the filter screen section, the local gap between the filter screen section and the limiting stop ring is large enough to facilitate the passing property of the drilling fluid, and the purpose of quickly releasing the pressure is achieved. Further, in view of the fact that the downhole drilling fluid pressure is large (up to 35 MPa) and even blocked, the seat-hanging section and the filter screen section can be connected in an insertion manner, which may be difficult to withstand pressure under certain conditions. A pressure spring is arranged between the supporting rib and the limiting stop ring, and the pressure spring is used to ensure the sealing property of the filter screen assembly in the normal working state. By selecting a suitable pressure spring, the pressure release threshold can be easily adjusted. When the pressure is released, the filter screen section can be inserted back into the seat-hanging section under the action of the pressure spring and the guidance of the supporting rib. The supporting rib, the pressure spring and the limiting stop ring are cooperated, and the passing property of the drilling fluid in the pressure release state is also ensured.

[0020] The present application has the advantages of simple structure, easy disassembly and maintenance, effective solution to the problems of filter screen vibration and pressure blocking, long service life and good safety and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The figure is a structural schematic diagram of the present application.

[0022] Figure 2 The figure is a structural schematic diagram of the filter screen assembly.

[0023] Figure 3 The figure is a schematic diagram of the filter screen section in the pressure release state.

[0024] Figure 4 The figure is a partial schematic diagram of the filter screen section of another embodiment of the present application.

[0025] In the figure, 1 is the seat-hanging section, 1.1 is an annular protrusion, 2 is the filter screen section, 3 is the supporting rib, 4 is the filter hole, 5 is the cylinder, 5.1 is an annular step, 6 is the pressure spring, 7 is the limiting stop ring, 8 is the male buckle, 9 is the female buckle, and 10 is the gap. DETAILED DESCRIPTION

[0026] The principles and features of the present invention 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 the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description and claims. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[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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