A booster tool for a drilling tool

Abstract

The application provides a pressurizing tool for a drilling tool, comprising a power generation unit, a pressurizing unit and a power output unit connected in sequence. The power generation unit comprises a hollow cylindrical stator shell and a screw rotor installed in the stator shell. The pressurizing unit comprises a shell defining an internal passage and a pressurizing assembly installed in the shell. The pressurizing assembly is configured to periodically change the flow of fluid flowing through the internal passage, so that the screw rotor generates periodic pressure fluctuations, thereby forming a composite impact force of axial and torsional directions and transmitting to the power output unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas drilling equipment, and particularly relates to a pressurizing tool for a drilling tool for realizing drilling speed-up in oil and gas exploration and development. BACKGROUND

[0002] With the continuous development of oil and gas exploration and development, the fields of deep well and ultra-deep well drilling, deepwater offshore drilling, shale oil / gas exploitation, hot dry rock geothermal resource development, energy development and scientific drilling are continuously broadened, the drilled strata are more ancient, the rock strength is large, the abrasiveness is high, and the drillability is poor. This will cause severe bouncing of the drilling tool, and eventually lead to slow drilling speed, long drilling cycle and gradually increasing drilling cost. Therefore, the demand for drilling speed-up in the field of drilling is increasingly strong.

[0003] Rotary percussion drilling technology is one of the existing methods for fast drilling. In this technology, various percussion drilling tools are used to generate high-frequency impact dynamic load by driving a hammer with drilling fluid, which can make the rock produce volume crushing, thereby improving the rock breaking efficiency. In addition, by combining the screw composite double-drive drilling technology with the percussion rotary drilling technology, a composite percussion drilling technology is formed, and the speed-up effect is also relatively obvious. In addition, a screw rotary table double-drive composite drilling technology is also proposed, which improves the rotary speed and cutting strength by optimizing a high-power screw. In the rotary percussion drilling process, the drilling pressure keeps the cutting teeth in close contact with the rock, and the impact load instantaneously increases the rock crushing specific work. At the crack formed by the impact, the rock is further crushed and rotary shearing broken under the high rotation speed of the screw, thereby improving the rock breaking efficiency.

[0004] However, when the rock breaking capacity of the drill bit is insufficient, the drill bit that bites into the rock will instantaneously stop rotating. In this case, the drill string remains rotating until the energy accumulated at the drill bit reaches the critical value of shearing the stratum. At this time, the drill bit instantaneously rotates at high speed and releases the drill string energy, and then the entire drill string enters a "stuck-slip" cycle. The occurrence of the "stuck-slip" phenomenon directly causes irregular vibration and exerts a much higher impact load on the teeth of the drill bit than usual, resulting in premature failure of the drill bit. At the same time, this "stuck-slip" phenomenon also shortens the service life of the bottom hole assembly, and eventually also affects the wellbore quality. The above rotary percussion drilling technology, composite percussion drilling technology and screw rotary table double-drive composite drilling technology cannot well solve this "stuck-slip" phenomenon. SUMMARY

[0005] In view of the above technical problems, the applicant of the present application has found through research that by periodically applying a composite impact effect of both torsional impact and axial impact at the end of the drill bit, the rock breaking efficiency of the drill bit can be improved, and a series of problems caused by the "stuck-slip" phenomenon in the drilling process can be effectively alleviated.

[0006] According to the present application, a booster tool for a drilling tool is provided, comprising a power generation unit, a booster unit and a power output unit connected in sequence. The power generation unit comprises a stator housing in the form of a hollow cylinder, and a screw rotor installed inside the stator housing. The booster unit comprises a housing defining an internal passage, and a booster assembly installed inside the housing. The booster assembly is configured to periodically change the flow rate of fluid flowing through the internal passage, so that the screw rotor generates periodic pressure fluctuations, thereby forming a composite impact force of axial and torsional directions and being transmitted to the power output unit.

[0007] According to an embodiment of the present application, the booster assembly comprises a valve disc upstream of the screw rotor, and a valve block downstream of the screw rotor. The valve disc has axially extending through holes for fluid, and the valve block has radially extending blocks. The valve disc is rotatable by the screw rotor, so that the through holes are periodically at least partially blocked by the blocks.

[0008] According to an embodiment of the present application, the valve disc has a cylindrical portion with a smaller diameter and a disc portion with a larger diameter, and a plurality of through holes are uniformly arranged circumferentially on the disc portion.

[0009] According to an embodiment of the present application, each of the through holes is configured to have a gradually increasing diameter in a downstream direction.

[0010] According to an embodiment of the present application, the width of the blocks is greater than the width of the through holes.

[0011] According to an embodiment of the present application, the valve block comprises a first portion with a smaller diameter and a second portion with a larger diameter, and the first portion and the second portion are connected to each other by a transition slope or arc surface.

[0012] According to an embodiment of the present application, a plurality of flow converging holes are arranged circumferentially in the first portion, and each of the flow converging holes is arranged in a manner of being inclined towards the downstream in a radially inward direction.

[0013] According to an embodiment of the present application, the blocks are arranged at the upstream end of the first portion and are in contact with the downstream end surface of the valve disc.

[0014] According to an embodiment of the present application, the booster unit further comprises a universal shaft assembly installed in the housing, and the universal shaft assembly connects the screw rotor and the booster assembly.

[0015] According to one embodiment of the present application, the booster tool further comprises a drop-protection cap arranged upstream of the power generation unit, and a bypass valve arranged upstream of the drop-protection cap. The drop-protection cap is connected to the screw rotor by a connecting joint. BRIEF DESCRIPTION OF DRAWINGS

[0016] The application will be described in detail below with reference to the drawings, in which:

[0017] Figure 1 schematically shows the structure of a first part of a booster tool according to one embodiment of the present application;

[0018] Figure 2 schematically shows the structure of a second part of a booster tool according to one embodiment of the present application;

[0019] Figure 3 schematically shows Figure 1 the structure of a booster assembly in the booster tool shown;

[0020] Figure 4 shows Figure 2 the A-A cross-sectional view in

[0021] Figure 5 schematically shows Figure 3 the structure of a valve block in the booster assembly shown.

[0022] In the drawings, identical parts are marked with the same reference numerals. The drawings are not drawn to scale. DETAILED DESCRIPTION

[0023] The application will be further described below with reference to the drawings. For the sake of convenience, in the present description, the directional terms "longitudinal" or "axial" refer to the direction along the length of the booster tool, i.e. the horizontal direction in Figure 1 and 2 the directional terms "transverse" or "radial" refer to the direction perpendicular to the "longitudinal" or "axial" direction, i.e. the vertical direction in Figure 1 and 2 the directional terms "upstream" or "up" or similar refer to the direction close to the wellhead, i.e. the left end direction in Figure 1 and 2 the directional terms "downstream" or "down" or similar refer to the direction away from the wellhead, i.e. the right end direction in Figure 1 and 2 .

[0024] Figure 1 and 2 collectively schematically show a booster tool 100 according to one embodiment of the present application, wherein Figure 1A first portion of the uphole tool 100 is shown, while Figure 2 A second portion of the uphole tool 100 is shown. It is noted that the division of the uphole tool 100 into the first portion and the second portion is merely for the convenience of the illustration and does not limit the actual structure of the uphole tool 100.

[0025] As shown in Figure 1 , the uphole tool 100 includes an upper sub 10 at the most upstream end and is connected to other portions of the drilling tool through the upper sub 10. A central passage 25 is defined in the upper sub 10 for the passage of downhole fluid therethrough. The downhole fluid is, for example, drilling fluid, and for the convenience of the description, the drilling fluid will be used as an example in the following description. A bypass valve 20 is installed in the upper sub 10. Both the upper sub 10 and the bypass valve 20 are well known components in the art, and the detailed description thereof will not be given herein.

[0026] The uphole tool 100 according to the present application further includes a drop-protection cap 30 and a power generation unit 40. As shown in Figure 1 , the power generation unit 40 includes a stator housing 42 configured as a hollow cylinder. The upstream end of the stator housing 42 is fixedly connected to the downstream end of the upper sub 10, for example, by a threaded connection. A screw rotor 44 is disposed in the stator housing 42.

[0027] According to the present application, the drop-protection cap 30 is disposed in the stator housing 42 of the power generation unit 40 and is fixedly connected to the screw rotor 44. Preferably, the drop-protection cap 30 is connected to the screw rotor 44 through a connecting joint 50. For example, the connecting joint 50 can be connected to the drop-protection cap 30 and the screw rotor 44 by threaded fittings, respectively. As shown in Figure 1 , the drop-protection cap 30 can be seated on an internal step of the stator housing 42. In this way, during tripping in or tripping out, the internal components of the uphole tool 100 (for example, the power generation unit 40, the power output unit 70, etc.) and the drill bit connected to the uphole tool 100 will slide downward due to gravity, but the drop-protection cap 30 will be seated on the internal step of the stator housing 42 to prevent the entire internal string from falling to the bottom of the well.

[0028] The uphole tool 100 according to the present application further includes a pressure boosting unit 60 and a power output unit 70. As shown in Figure 2 , the pressure boosting unit 60 includes a hollow cylindrical housing 61 defining an internal passage 63 and a gimbal shaft assembly 62 and a pressure boosting assembly 90 fixedly connected to each other and installed in the housing 61. The gimbal shaft assembly 62 is connected to the screw rotor 44 of the power generation unit 40 and can be in the form of a cross-shaped gimbal shaft or a petal-shaped gimbal shaft, etc.

[0029] Figure 3The structure of the intensifier assembly 90 in the intensifier tool 100 according to the present application is schematically shown. As shown, the intensifier assembly 90 includes a valve disc member 91 at the upstream and a valve block member 95 at the downstream, wherein the valve disc member 91 is fixedly connected with the universal shaft assembly 62, and the valve block member 95 is fixedly connected with the power output spindle 72 of the power output unit 70. Figure 2 ) fixedly connected with the power output spindle 72 of the power output unit 70.

[0030] As shown, according to the present application, the valve disc member 91 is configured in the form of a stepped shaft, including a smaller-diameter cylindrical portion 94 and a larger-diameter disc portion 92. A plurality of axially extending through holes 93 are uniformly arranged on the disc portion 92 in the circumferential direction, which will be described later. Similarly, the valve block member 95 is also configured in the form of a stepped shaft, including a smaller-diameter first portion 96 and a larger-diameter second portion 97. Figure 3

[0031] Both the valve disc member 91 and the valve block member 95 have a central passage, which are aligned with each other, for a portion of the drilling fluid to flow therethrough. It is easily understood that another portion of the drilling fluid will flow downstream through the internal passage 63 of the intensifier unit 60 (i.e. between the radially outer portion of the intensifier assembly 90 and the radially inner portion of the housing 61).

[0032] As shown, according to the present application, a radially extending stopper 99 is fixedly arranged on the outer peripheral surface of the first portion 96 of the valve block member 95 at the upstream end. The end surface of the stopper 99 is flush with the end surface of the first portion 96 of the valve block member 95, such that the end surface of the stopper 99 is tightly fitted with the downstream end surface of the disc portion 92 of the valve disc member 91, as shown. Figure 5 Figure 3

[0033] Therefore, during operation, the screw rotor 44 is rotated under the impact of the drilling fluid, and drives the valve disc member 91 of the intensifier assembly 90 to rotate via the universal shaft assembly 62. After a certain angle of rotation, the through holes 93 on the valve disc member 91 will be blocked by the stopper 99 on the valve block member 95. In this case, the portion of the drilling fluid flowing through the internal passage 63 of the intensifier unit 60 will be blocked, and thus cannot flow downstream. As a result, the pressure inside the screw rotor 44 will be increased. When the valve disc member 91 continues to rotate such that the through holes 93 are away from the position of the stopper 99, the portion of the drilling fluid flowing through the internal passage 63 of the intensifier unit 60 can continue to flow downstream. In this case, the pressure inside the screw rotor 44 is restored. In this way, the stopper 99 can periodically block the through holes 93 on the valve disc member 91, thereby periodically hindering the downstream flow of a portion of the drilling fluid. Figure 4 The state where the stopper 99 does not block the through holes 93 is shown.

[0034] ​​​Therefore, on the one hand, this portion of drilling fluid will generate hydraulic pulse pressure inside the booster tool 100, which will exert pressure on the power output spindle 72 of the downstream power output unit 70 (which will be discussed in detail below). Figure 2 (To be introduced) This generates a periodic axial impact force. On the other hand, because the drilling fluid discharge rate inside the booster tool 100 varies periodically, the circumferential torque output from the screw rotor 44 to the power output spindle 72 also varies periodically, thus generating a periodic torsional impact force. In this way, the periodically varying axial impact force and the periodically varying torsional impact force, as described above, together form a periodically varying composite impact force, which can greatly reduce friction and reduce the "sticking-slipping" phenomenon, while effectively mitigating the occurrence of complex situations such as directional pressure or stuck drill bit.

[0035] It should be noted that, in Figures 3 to 5 Several through holes 93 and one stop 99 are shown for illustrative purposes only. However, it is understood that the number of through holes 93 and stop 99 can be appropriately selected according to actual needs. Multiple through holes 93 and stop 99 can be provided, and the number of through holes 93 can be equal to, more than or less than, the number of stop 99.

[0036] According to one embodiment of the invention, the stop 99 is configured as a fan-shaped or rectangular shape, while the through hole 93 is configured as a circle, strip, square, or fan-shaped shape. Preferably, the width of the stop 99 is selected to be greater than the width of the through hole 93. More preferably, the stop 99 is configured to completely cover the through hole 93.

[0037] In one embodiment (not shown), the through-hole 93 is configured to have a varying diameter. Specifically, the diameter of the through-hole 93 is set to gradually increase in the downstream direction. This configuration enhances the periodic variation in drilling fluid displacement, further amplifying the effect of the periodic combined impact force.

[0038] In addition, such as Figure 3 As shown, according to the present invention, a transitional slope or arc surface is provided between the smaller diameter first portion 96 and the larger diameter second portion 97 of the valve block 95. On the one hand, this arrangement can reduce stress concentration and increase the connection strength between the two portions. On the other hand, the smaller diameter first portion 96 reduces fluid resistance, which is beneficial to reducing the overall pressure drop of the drill bit.

[0039] In addition, according to the present application, a plurality of flow converging holes 98 are arranged in the first part 96 of the valve block 95, which has a smaller diameter, and are arranged uniformly in the circumferential direction. Each of the flow converging holes 98 is arranged in a manner that is inclined towards the downstream in a radially inward direction. In this way, a portion of the drilling fluid flowing through the through hole 93 will enter the central passage of the valve block 95 through the flow converging holes 98, so that all of the drilling fluid will continue to flow downstream from the central passage of the booster assembly 90. This significantly improves the utilization efficiency of the drilling fluid.

[0040] As shown in Figure 2 the power output unit 70 of the booster tool 100 according to the present application mainly comprises a housing 75 and a power output main shaft 72 mounted in the housing 75. The upstream end of the housing 75 is fixedly connected with the housing 61 of the booster unit 60, and the downstream end is fixedly connected with the lower joint 80. The power output main shaft 72 is fixedly connected with the booster assembly 90 and has a central passage that is in communication with the central passage of the booster assembly 90. The power output main shaft 72 is connected with a lower bit (not shown) in the drilling tool and transmits the impact force from the power generating unit 40 to the bit. The power output unit 70 and the lower joint 80 are both components well known in the art, and the relevant detailed description is omitted here.

[0041] The booster tool according to the present application can be installed on a downhole drilling tool to improve the rock breaking efficiency of the bit. Specifically, the booster tool according to the present application comprises a booster assembly that can periodically block a portion of the drilling fluid, so that the portion of the drilling fluid is periodically blocked or flows downstream. In this way, the screw rotor in the booster tool will generate periodic pressure fluctuations, forming hydraulic pulses. On one hand, due to the action of the hydraulic pressure, the lower end of the screw will generate a periodically changing axial impact force, which acts on the power output main shaft and is further transmitted to the bit. On the other hand, the pressure fluctuations of the drilling fluid will cause the torque of the screw to change, generating a changing torsional impact force. The axial impact force and the torsional impact force combine to form a periodically changing combined impact force, which can assist in rock breaking and greatly improve the rock breaking efficiency of the bit. Therefore, especially in directional wells and complex trajectory wellbores, the booster tool according to the present application can reduce friction and reduce the "stick-slip" phenomenon, and effectively reduce the occurrence of complex situations such as directional overpressure or sticking.

[0042] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited thereto. Those skilled in the art can easily make changes or modifications within the scope of the present application, and such changes or modifications shall be encompassed in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A booster tool (100) for a drilling tool, comprising a power generating unit (40), a booster unit (60) and a power output unit (70) connected in sequence, wherein, The power generation unit (40) comprises a stator housing (42) in the form of a hollow cylinder, and a screw rotor (44) mounted inside the stator housing (42), and the pressurizing unit (60) comprises a housing (61) defining an internal passage (63), and a pressurizing assembly (90) mounted inside the housing (61), The pressurizing assembly (90) is configured to periodically change the flow rate of the fluid flowing through the internal passage (63) so as to cause the screw rotor (44) to generate periodic pressure fluctuations, thereby forming a composite impact force in the axial and torsional directions and being transmitted to the power output unit (70), The pressurizing assembly comprises a valve disc member connected to the screw rotor at the upstream side and a valve block member at the downstream side, the power output spindle is fixedly connected to the pressurizing assembly, the valve disc member has axially extending through holes for fluid, and a radially extending stopper is fixedly arranged at the upstream end of the outer peripheral surface of the first part of the valve block member, the stopper can periodically block the through holes on the valve disc member, and each of the through holes (93) is configured to have a gradually increasing diameter in the direction towards the downstream side.

2. The pressurizing tool of claim 1, wherein, The valve disc member (91) has a cylindrical part (94) with a smaller diameter and a disc part (92) with a larger diameter, and a plurality of through holes (93) are uniformly arranged on the disc part (92) in the circumferential direction.

3. The pressurizing tool of claim 1, wherein, The width of the stopper (99) is greater than the width of the through hole (93).

4. The pressurizing tool according to any one of claims 1 to 3, characterized in that, The valve block member (95) comprises a first part (96) with a smaller diameter and a second part (97) with a larger diameter, and the first part (96) and the second part (97) are connected to each other by a transition slope or arc surface.

5. The pressurizing tool of claim 4, wherein, A plurality of converging holes (98) are arranged in the first part (96) in the circumferential direction, and each of the converging holes (98) is arranged in a manner inclined towards the downstream side in the direction radially inward.

6. The pressurizing tool of claim 4, wherein, The stopper (99) is arranged at the upstream end of the first part (96) and abuts against the downstream end surface of the valve disc member (91).

7. The pressurizing tool according to any one of claims 1 to 3, characterized in that, The pressurizing unit (60) further comprises a universal shaft assembly (62) mounted inside the housing (61), and the universal shaft assembly (62) connects the screw rotor (44) and the pressurizing assembly (90).

8. The pressurizing tool according to any one of claims 1 to 3, characterized in that, The pressurizing tool (100) further comprises a drop prevention cap (30) arranged upstream of the power generation unit (40), and a bypass valve (20) arranged upstream of the drop prevention cap (30), and the drop prevention cap (30) is connected to the screw rotor (44) by a connecting joint (50).

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