Axial pressure boosting and hole enlarging device for large displacement horizontal well drilling

Abstract

The application provides a large displacement horizontal well drilling axial pressure boosting and reaming device, which comprises a first connecting pipe and a second connecting pipe connected in adjacency and communication, and a flow channel is arranged in the first connecting pipe and the second connecting pipe, characterized in that the device further comprises an axial transmission part and a spiral drill sleeve, the spiral drill sleeve is rotatably arranged between the first connecting pipe and the second connecting pipe, the first connecting pipe, the second connecting pipe and the spiral drill sleeve form an installation space, the installation space is in communication with the first connecting pipe and the second connecting pipe, and the outer diameter of the spiral drill sleeve is larger than the outer diameter of a selected drill bit for drilling; the axial transmission part is arranged in the installation space and in communication with the first connecting pipe and the second connecting pipe, drilling fluid entering the installation space can drive the axial transmission part to rotate, the axial transmission part is further engaged with the inner wall of the spiral drill sleeve and used for driving the spiral drill sleeve to rotate on the first connecting pipe and the second connecting pipe.

Description

Technical Field

[0001] This invention belongs to the field of drilling engineering technology, specifically relating to a device for axial pressurization and hole enlargement during drilling in horizontal wells with large displacement. Background Technology

[0002] As the horizontal drilling length of extended-reach horizontal wells continuously increases, the contact length and area between the bottomhole drill string assembly and the wellbore wall also increase during the drilling of long horizontal sections. This significantly increases the friction between the bottomhole drill string assembly and the wellbore wall of the long horizontal section, making it difficult to transmit the drilling pressure output by the drilling rig and the weight of the drill string in the vertical section to the drill bit, resulting in severe drill bit pressure buildup. Simultaneously, due to the continuous extension of the horizontal well section length, the pressure from the overlying strata may cause the wellbore diameter to narrow in the horizontal section, similarly making it difficult to transmit the drilling pressure output by the drilling rig and the weight of the drill string in the vertical section to the drill bit, resulting in severe drill bit pressure buildup.

[0003] Currently, to address the aforementioned drill string assembly pressure drag phenomenon and ensure the transfer of drilling pressure (DP) from the drilling rig to the drill bit via the weight of the drill string in the vertical well section, two common methods are hydraulic oscillators and impact vibration drag reduction tools. Both methods rely on drilling fluid circulation to trigger the hydraulic oscillator or impact vibration drag reduction tool, outputting pulsed axial pressure to transfer DP to the drill bit. While these methods do effectively transfer DP to the drill bit and improve rock-breaking efficiency, the DP transmitted by these methods is pulsed. Whether it's a roller cone bit or a PDC bit, the DP it experiences during high-speed rotation and rock-breaking must be stable over a long period. Otherwise, it could cause the roller cone bit to break or the PDC bit to chip, potentially leading to extremely complex downhole accidents. Furthermore, the pulsed DP makes it difficult to control the well trajectory when drilling through complex formations with alternating soft and hard rock. These two methods also fail to consider the drill bit pressure drag phenomenon caused by the overlying rock pressure in the horizontal well section, which leads to a narrowing of the borehole diameter. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a device for axial pressurization and reaming while drilling in horizontal wells with large displacement, thereby solving the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A drilling axial pressurization and reaming device for extended reach horizontal wells includes a first connecting pipe and a second connecting pipe that are adjacent and interconnected, with a flow channel inside each pipe. It also includes an axial transmission unit and a auger sleeve.

[0007] The auger sleeve is rotatably fitted between the first connecting pipe and the second connecting pipe. The first connecting pipe, the second connecting pipe and the auger sleeve form an installation space. The installation space is connected to the first connecting pipe and the second connecting pipe. The outer diameter of the auger sleeve is larger than the outer diameter of the drill bit selected for drilling.

[0008] The axial drive unit is located in the installation space and communicates with the flow channel. The drilling fluid enters the installation space through the flow channel and can drive the axial drive unit to rotate. The axial drive unit also engages with the inner wall of the auger sleeve to drive the auger sleeve to rotate on the first connecting pipe and the second connecting pipe.

[0009] Preferably, the axial transmission part includes two gear sets, the inner wall of the spiral drill sleeve is an internal gear structure, the installation space has two through passages, each gear set is correspondingly located at both ends of the passage and connected to the first connecting pipe and the second connecting pipe respectively, each gear set also meshes with the inner wall of the spiral drill sleeve, and the tooth diameter of each gear set is less than half of the inner diameter of the spiral drill sleeve.

[0010] Preferably, the ratio of the tooth diameter of the gear set to the tooth diameter of the gear inside the spiral drill sleeve is 5:2.

[0011] Preferably, the auger sleeve is an auger sleeve, and the outer diameter of the auger sleeve is 2mm to 3mm larger than the size of the drill bit selected for drilling.

[0012] Preferably, the spiral drill sleeve is provided with cutting teeth at one end axially close to the first connecting pipe. The cutting teeth are rotatably sleeved on the first connecting pipe, and the tooth diameter of the cutting teeth is larger than the outer diameter of the spiral drill sleeve.

[0013] Preferably, fixed pressure blocks are provided at both ends of each passage, and the fixed pressure blocks are provided with mounting grooves. Each gear set is matched with the mounting groove and is set in the mounting groove. The fixed pressure blocks are connected to the first connecting pipe or the second connecting pipe by fixing bolts.

[0014] Preferably, each gear set has a sealed bearing fitted at both ends and connected to the first connecting pipe and the second connecting pipe, respectively.

[0015] Preferably, the two ends of the auger sleeve are connected to the first connecting pipe and the second connecting pipe respectively through sliding bearings, and the two ends of the auger sleeve are respectively fitted with limiting rings, which are set on the first connecting pipe and the second connecting pipe through limiting pins.

[0016] A drill pipe assembly includes an axial pressurization and reaming device for horizontal wells with large displacement. An axial pressurization and reaming device and a drill pipe are installed at preset intervals between drill pipes. A first connecting pipe or a second connecting pipe is connected to a threaded joint drill pipe through a casing coupling.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] (I) The axial pressurization and reaming device of the present invention, by setting an axial transmission part, the drilling fluid flows into the axial transmission part through the first connecting pipe, and the high-pressure and high-speed drilling fluid drives the axial transmission part to achieve high-speed rotation. The outer side of the axial transmission part meshes with the inner wall of the spiral drill sleeve. When the axial transmission part rotates at high speed, it will drive the spiral drill sleeve to rotate. The outer wall of the spiral drill sleeve is in close contact with the well wall of the long horizontal section during the drilling process. The tangential component force during the high-speed rotation process can effectively increase the axial drilling pressure of the drill bit and increase the rock-breaking drilling power of the drill bit. At the same time, the outer wall of the spiral drill sleeve can exert pressure on the overlying rock strata to make the horizontal section of the wellbore shrink and then re-ream the hole. It can also grind and smooth the wellbore formed by the drill bit breaking the rock to facilitate subsequent casing operation. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of the present invention;

[0020] Figure 2 This is a schematic diagram of the connection structure between the gear set and the spiral drill sleeve of the present invention;

[0021] Figure 3 This is a schematic diagram of the gear set of the present invention;

[0022] Figure 4 This is a schematic diagram of the spiral drill sleeve of the present invention;

[0023] Figure 5 This is a three-dimensional schematic diagram of the present invention;

[0024] Figure 6 This is a schematic diagram of the gear set end face mounting structure of the present invention;

[0025] The meanings of the labels in the diagram are as follows:

[0026] 1-First connecting pipe, 2-Second connecting pipe, 3-Axial transmission part, 4-Auger sleeve, 5-Gear set, 6-Cutting teeth, 7-Sealed bearing, 8-Sliding bearing, 9-Limiting ring, 10-Limiting pin, 11-Sleeve coupling, 12-Flow channel, 14-Fixing pressure block, 15-Fixing bolt, 16-Threaded joint.

[0027] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0028] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0029] The directional terms used in this document, such as “radial,” “axial,” “upper,” and “lower,” correspond to the specific directions on the paper in the accompanying drawings or the corresponding directions of the space shown in the drawings.

[0030] Example 1:

[0031] A drilling axial pressurization and reaming device for a large-displacement horizontal well includes a first connecting pipe 1 and a second connecting pipe 2 that are adjacent and interconnected. A flow channel 12 is provided inside the first connecting pipe 1 and the second connecting pipe 2. The device also includes an axial transmission unit 3 and a spiral drill sleeve 4.

[0032] The auger sleeve is rotatably fitted between the first connecting pipe 1 and the second connecting pipe 2. The first connecting pipe 1, the second connecting pipe 2 and the auger sleeve 4 form an installation space. The installation space is connected to the first connecting pipe 1 and the second connecting pipe 2. The outer diameter of the auger sleeve 4 is larger than the outer diameter of the drill bit selected for drilling.

[0033] The axial drive unit 3 is located within the installation space and communicates with the flow channel 12. Drilling fluid enters the installation space through the flow channel, driving the axial drive unit 3 to rotate. The axial drive unit 3 also engages with the inner wall of the auger sleeve 4, driving the auger sleeve 4 to rotate on the first connecting pipe and the second connecting pipe.

[0034] In this invention, the axial pressurization and reaming device incorporates an axial transmission unit. Drilling fluid flows into the axial transmission unit through a first connecting pipe, and the high-pressure, high-speed drilling fluid drives the axial transmission unit to rotate at high speed. The outer side of the axial transmission unit meshes with the inner wall of the spiral drill sleeve 4. The high-speed rotation of the axial transmission unit drives the spiral drill sleeve 4 to rotate. The outer side of the spiral drill sleeve has spiral drill teeth, which, during drilling in long horizontal well sections, maintain close contact with the well wall due to their own gravity. The tangential component of the spiral drill teeth during high-speed rotation effectively increases the axial drilling pressure of the drill bit. This invention increases the drilling power of the drill bit in breaking rocks and also disturbs the rock cuttings broken by the drill bit, making it difficult to form a cuttings bed in long horizontal well sections. This effectively improves the axial drilling pressure transmission and drilling speed. At the same time, the outer wall of the auger casing can exert pressure on the overlying rock formations, causing the horizontal section of the wellbore to narrow and then enlarge again for drilling. It can also grind and smooth the wellbore formed by the drill bit breaking rocks to facilitate subsequent casing operations. Drilling with this invention's device can effectively increase axial drilling pressure by 30% to 40% compared to drilling without this invention's device; and effectively increase drilling speed by 25% to 37%.

[0035] As a preferred embodiment, the axial transmission part 3 includes two gear sets 5, the inner wall of the spiral drill sleeve 4 is an internal gear structure, and the installation space has two through passages. Each gear set is correspondingly located at both ends of the passage and is connected to the first connecting pipe 1 and the second connecting pipe 2 respectively. Each gear set also meshes with the inner wall of the spiral drill sleeve 4, and the tooth diameter of each gear set 5 is less than half of the inner diameter of the spiral drill sleeve 4.

[0036] In this design, two gear sets are installed in the passage. The high-speed drilling fluid enters the passage after entering the first connecting pipe, thereby driving the gear set 5 to rotate. The design uses two gear sets 5 to drive the single spiral drill sleeve 6 to rotate at high speed, which helps to extend the service life of the gear structure, enhances the overall stability of the device in this embodiment, and improves work efficiency.

[0037] As a preferred embodiment, the ratio of the tooth diameter of the gear set 5 to the tooth diameter of the gear inside the inner wall of the spiral drill sleeve 4 is 5:2.

[0038] When the ratio of the tooth diameter of the gear set 5 to the tooth diameter of the gear inside the inner wall of the spiral drill sleeve 4 is 5:2, the meshing transmission efficiency between the gear set 5 and the spiral drill sleeve 4 is optimal, thus improving work efficiency.

[0039] As a preferred embodiment, the auger sleeve 4 is an auger sleeve, and the outer diameter of the auger sleeve is 2mm to 3mm larger than the size of the drill bit selected for drilling.

[0040] Among them, the size of the auger sleeve is larger than the size of the drill bit, which plays the role of expanding the borehole diameter. The drilling method of the auger sleeve is auger drilling. When the outer diameter of the auger sleeve is 2mm to 3mm larger than the size of the drill bit selected for drilling, it can ensure that the borehole is expanded while better increasing the radial axial drilling force.

[0041] As a preferred embodiment, the spiral drill sleeve 4 is further provided with cutting teeth 6 at one end axially close to the first connecting pipe. The cutting teeth 6 are rotatably sleeved on the first connecting pipe 1, and the tooth diameter of the cutting teeth 6 is larger than the outer diameter of the spiral drill sleeve 4.

[0042] In this embodiment, the cutting tooth 6 is a PDC cutting tooth, which can reduce the diameter of the horizontal section of the wellbore and re-enlarge it due to the pressure of the overlying rock strata, and can also grind and smooth the wellbore formed by the drill bit breaking the rock so that the subsequent casing operation can proceed smoothly.

[0043] As a preferred embodiment, each end of the passage is provided with a fixing block 14, the fixing block 14 is provided with an installation groove, each gear set is matched with the installation groove and is located in the installation groove, and the fixing block 14 is connected to the first connecting pipe or the second connecting pipe by fixing bolts 15.

[0044] In this embodiment, the sealed bearings are interference-fitted to both ends of the turbine power gear. Turbine gears are welded to the turbine power gears. The turbine power gears with sealed bearings are placed in the passage and fixed at both ends to the first connecting pipe 1 and the second connecting pipe 2 by fixing blocks 14 and fixing bolts 15. The purpose of setting the fixing blocks 14 is to make the two ends of each gear set more stably set on the first connecting pipe and the second connecting pipe, thereby improving the connection stability.

[0045] As a preferred embodiment, each gear set is fitted with a sealed bearing 7 at both ends and connected to the first connecting pipe and the second connecting pipe.

[0046] The sealed bearing 7 serves to reduce the frictional resistance between the high-pressure fluid and the first or second connecting pipe when the gear set rotates, while also providing a seal.

[0047] As a preferred embodiment, the two ends of the spiral drill sleeve 4 are connected to the first connecting pipe 1 and the second connecting pipe 2 respectively through sliding bearings 8. Limiting rings 9 are provided at both ends of the spiral drill sleeve 4, and the limiting rings 9 are provided on the first connecting pipe 1 and the second connecting pipe 2 through limiting pins 10.

[0048] Among them, the sliding bearing 8 is assembled on the spiral drill sleeve limiting ring, and together with the spiral drill sleeve limiting ring, it is transferred to the first connecting pipe 1 and the second connecting pipe 2, and is fixed to the first connecting pipe 1 and the second connecting pipe 2 by the limiting pin.

[0049] The usage process of this embodiment:

[0050] The drilling fluid enters the axial transmission part through the flow channel in the first connecting pipe. The high-pressure drilling fluid drives the axial transmission part (3) to rotate, and the axial transmission part drives the auger sleeve (4) to rotate on the first connecting pipe and the second connecting pipe.

[0051] Example 2:

[0052] A drill pipe assembly includes multiple axial pressurization and reaming devices for large displacement horizontal wells as described in Embodiment 1. An axial pressurization and reaming device and a drill pipe are installed at preset intervals between drill pipes. A first connecting pipe or a second connecting pipe is connected to the drill pipe through a casing coupling 11.

[0053] In extended reach horizontal wells, as the horizontal section length increases to approximately twice the vertical depth, the frictional resistance between the drill string assembly and the wellbore increases, and the borehole diameter narrows in the horizontal section. This makes it difficult for the drilling pressure applied by the rig to be transmitted to the drill bit, resulting in severe drill bit pressure drag. At this point, it is necessary to retrieve the current drill string assembly from the bottom of the well and replace it with a new one. The device of this invention re-optimizes the drill string assembly, connecting one of the invention's devices approximately every 100m of drill pipe. The device is connected to the upper drill pipe via a casing coupling 11 and to the lower drill pipe via a threaded connector 16.

Claims

1. A large displacement horizontal well drilling axial pressure boosting and hole enlarging device, comprising a first connecting pipe (1) and a second connecting pipe (2) connected in adjacent communication, a flow channel (12) is arranged in the first connecting pipe (1) and the second connecting pipe (2), characterized in that, It also includes an axial drive unit (3) and a spiral drill sleeve (4). The spiral drill sleeve is rotatably fitted between the first connecting pipe (1) and the second connecting pipe (2). The first connecting pipe (1), the second connecting pipe (2) and the spiral drill sleeve (4) form an installation space. The installation space is connected to the first connecting pipe (1) and the second connecting pipe (2). The outer diameter of the spiral drill sleeve (4) is larger than the outer diameter of the drill bit selected for drilling. The axial transmission part (3) is located in the installation space and communicates with the flow channel (12). The drilling fluid enters the installation space through the flow channel (12) and can drive the axial transmission part (3) to rotate. The axial transmission part (3) also engages with the inner wall of the spiral drill sleeve (4) to drive the spiral drill sleeve (4) to rotate on the first connecting pipe and the second connecting pipe. The axial transmission part (3) includes two gear sets (5). The inner wall of the spiral drill sleeve (4) is an internal gear structure. The installation space has two through passages. Each gear set is located at both ends of the passage and is connected to the first connecting pipe (1) and the second connecting pipe (2) respectively. Each gear set also meshes with the inner wall of the spiral drill sleeve (4). The tooth diameter of each gear set (5) is less than half of the inner diameter of the spiral drill sleeve (4). The ratio of the tooth diameter of the gear set (5) to the tooth diameter of the gear inside the inner wall of the spiral drill sleeve (4) is 5:2; The spiral drill sleeve (4) is a spiral drill sleeve, and the outer diameter of the spiral drill sleeve is 2mm~3mm larger than the size of the drill bit selected for drilling; The spiral drill sleeve (4) is also provided with cutting teeth (6) at one end axially close to the first connecting pipe. The cutting teeth (6) are rotatably sleeved on the first connecting pipe (1). The tooth diameter of the cutting teeth (6) is larger than the outer diameter of the spiral drill sleeve (4). Each passage is provided with a fixed pressure block (14) at both ends. The fixed pressure block (14) is provided with an installation groove. Each gear set is matched with the installation groove and is placed in the installation groove. The fixed pressure block (14) is connected to the first connecting pipe or the second connecting pipe by a fixing bolt (15). Each gear set is fitted with a sealed bearing (7) at both ends, which is connected to the first connecting pipe and the second connecting pipe respectively; The two ends of the spiral drill sleeve (4) are connected to the first connecting pipe (1) and the second connecting pipe (2) respectively through sliding bearings (8). The two ends of the spiral drill sleeve (4) are respectively fitted with limiting rings (9), and the limiting rings (9) are set on the first connecting pipe (1) and the second connecting pipe (2) through limiting pins (10).

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