WO2019144507A1

WO2019144507A1 - Mechanical downhole tool for vertical well drilling using screw cam

Info

Publication number: WO2019144507A1
Application number: PCT/CN2018/082585
Authority: WO
Inventors: 田家林; 黎根银; 杨琳
Original assignee: 西南石油大学
Priority date: 2018-01-24
Filing date: 2018-04-10
Publication date: 2019-08-01
Also published as: CN108060896A; CN108060896B

Abstract

Disclosed is a mechanical downhole tool for vertical well drilling using a screw cam, consisting of a motor assembly, a universal shaft assembly and a straightening assembly. The front end of the motor assembly is connected to the universal shaft assembly, and the front end of the universal shaft assembly is connected to the straightening assembly; in the drilling process, when well deviation occurs, the heavy side of an eccentric-weight sleeve (25) is automatically rotated to the low side of a well under the effect of gravity, and drives a connection rod seat (34) to rotate, such that a connection rod a (36) and a connection rod b (40) can be located at the high side of the well at all times; liquid energy is converted into mechanical energy for rotation by means of the motor assembly to drive a central pipe (19) to rotate; a roller seat (22) rotates synchronously along with the central pipe (19) to enable a cam (26) to make vertical reciprocating movement, such that the connection rod a (36) and the connection rod b (40) are driven to be continuously pushed to the well wall, so as to generate a periodic counter-acting force to straighten the well, achieving normal drilling. Said mechanical downhole tool can effectively straighten the well, ensuring the precision of vertical drilling, improving the drilling efficiency and the well track quality, saving production costs.

Description

Mechanical downhole tool for vertical drilling using screw cam

Technical field

The present invention relates to a downhole tool for oil drilling, and more particularly to a mechanical downhole tool for vertical drilling using a screw cam.

Background technique

Straight drilling technology has an important role in improving the drilling speed of deep wells, ultra-deep wells and various complex structural wells to ensure downhole safety, and the vertical drilling technology is obtained with the increase of deep wells and ultra-deep wells. Rapid development and application. In recent years, with the rapid development and application of directional drilling technology, vertical drilling technology has made great progress on the basis of the traditional anti-slanting fast theory and technology.

The directional guiding tool is anti-slanting fast technology, which can open the rotary drill straight shaft (steady slope) and directional correction. The steerable drilling tool is a combination of downhole power drills with single or double curved housings and stabilizers. When the rotation speed of the turntable is small, the actual rotation speed of the drill bit is the sum of the output speed of the screw drill and the rotation speed of the turntable. At this time, the stable inclined well section can be drilled; when the well inclination needs to be corrected, the operation can be performed in a directional manner. Anti-clock pendulum drill combination anti-slanting fast technology, off-axis drilling tool is limited by its mechanism, mainly a kind of stable-slanting tool, the down-slope characteristic is second, and it has enough deformation space to achieve the expected deformation requirements. Therefore, its anti-slanting characteristics are greatly reduced in the small wellbore. Under such a technical demand, the anti-clock pendulum assembly anti-slanting technology came into being, which on the one hand showed sufficient strong ability to reduce the inclination; on the other hand, it still had a good effect of lowering the slope in the application of the small wellbore. Pre-bending dynamic anti-slanting fast technology, the dynamic behavior in the wellbore produces a large declination force, and at the same time eliminates the oblique force caused by the uneven pointing of the drill bit, thereby achieving the purpose of anti-slanting fast, preliminary test proves With the effectiveness of this technology, this technology is urgently needed on site. However, these anti-slanting fast technologies have their limitations. They are used in a single condition and cannot be universally applied. In some harsh terrains, the effects are not satisfactory.

Summary of the invention

The present invention provides a solution to the problem of well inclination caused by formation factors and technical reasons during vertical well drilling operations in the prior art, resulting in low drilling efficiency, high drilling cost, and long drilling cycle. A mechanical downhole tool that uses a screw cam to achieve vertical drilling.

The technical solution of the invention is that the mechanical downhole tool for vertical drilling by using the screw cam is composed of a motor assembly, a cardan shaft assembly and a twisting assembly, and the front end of the motor assembly is connected with the universal joint assembly, and the universal joint shaft is always The front end is connected to the twisting assembly; the motor assembly includes an upper joint, an anti-locking nut, an anti-drop link, a stator housing, a rubber bushing and a screw rotor, and the upper joint is connected with the stator housing through a thread to prevent it from falling off The rear end of the connecting rod is connected with the anti-locking nut, the front end is connected with the screw rotor, the rubber bushing is installed inside the stator housing to form a screw stator, and the screw rotor and the screw stator are meshed with each other; the universal joint shaft assembly comprises a live strand and a ball Seat, transmission ball, pressure ball, sealing ring a, locking sleeve, sealing sleeve, universal joint shaft connecting rod, universal shaft housing, water cap and drive shaft, the ball seat is installed inside the live strand, and the pressure ball is placed On the ball seat, the transmission ball is placed in the groove of the end of the universal joint shaft, and the universal joint rod and the live twist are matched by the locking sleeve, and the inside of the live twist is sealed by the sealing ring a and the sealing sleeve, the universal joint shaft The mounting structure at both ends of the connecting rod is the same, and the rear end of the universal joint housing is connected. a stator housing, a rear end of the water cap is connected to the live twist, and the front end is connected to the transmission shaft; the correction assembly includes a seal ring, a center tube, a sealing ring b, a bearing a, a roller seat, a roller, a screw a, a biasing sleeve, and a cam , cam cover outer ring, screw b, cam cover inner ring, spring, spring seat, pin a, pin b, connecting rod seat, ball joint, connecting rod a, roller, cylindrical pin, hinge pin, connecting rod b, bearing b , the sleeve, the bearing c and the lower joint, the roller is mounted on the roller seat by the screw a, the ball hinge is mounted on the bottom of the cam through the outer ring of the cam cover, the screw b and the inner ring of the cam cover, and the connecting rod seat is fixed on the bearing b From top to bottom, the bearing a, the roller seat, the cam, the spring, the spring seat, the bearing b, the sleeve and the bearing c are mounted on the center tube, the roller seat is fixed on the center tube by the thread, and the spring seat is fixed by the pin b On the center tube, the roller is mounted on the right end of the connecting rod b through the cylindrical pin, the connecting rod a is connected with the connecting rod b by the hinge pin, and the connecting rod a is connected with the lower end of the ball joint, and the connecting rod b is connected with the connecting rod base. Install the seal ring and seal b on the heavy-duty sleeve beforehand, and then bias The heavy bushing is set on the bearing a and the bearing c, and the pin base is fixed on the heavy-weight bushing by the pin a, the rear end of the center pipe is screwed with the drive shaft, and the front end is screwed with the lower joint.

The mechanical downhole tool for realizing vertical drilling by using a screw cam according to the above aspect is characterized in that: a sleeve pin hole is opened at a circumferential center of the middle and lower portions of the heavier side of the heavier sleeve, and the sleeve pin is away from the sleeve pin. A connecting rod expansion port is opened at a circumferential direction of the hole 180°, and the connecting rod a and the connecting rod b can be expanded and contracted through the connecting rod expansion port, and the upper and lower ends of the heavy-weight sleeve are provided with a sealing groove for placing the sealing ring; The pin hole of the connecting rod seat on the rod seat is 180° apart from the circumferential direction of the mounting point of the connecting rod b, and the pin a connects the sleeve pin hole and the connecting rod pin hole to ensure that the connecting rod a and the connecting rod b are always on the biasing sleeve The connecting rod expansion port is opposite.

The mechanical downhole tool for realizing vertical drilling by using a screw cam according to the above aspect is characterized in that: the bottom of the cam is provided with an annular sliding groove, and the outer ring of the cam and the cam cover and the inner ring of the cam cover form an annular slide, the ball The hinge can be rotated around the cam in the annular slide. Before installation, the annular chute should be coated with grease; the right end of the connecting rod b is equipped with a roller, and the sliding friction between the drill and the well wall is rolling friction. Small work resistance.

The beneficial effects of the invention are as follows: (1) real-time sensing of well inclination by using the principle of partial weight, sensitive induction, rapid response, dynamic skew correction; (2) using cam and four-bar mechanism to realize the correcting principle of the tool, the structure is novel, It has theoretical research value and the possibility of further development and perfection; (3) the motor assembly of the tool does not generate axial pressure, high energy conversion efficiency, and short axial dimension; (4) the invention is a pure mechanical structure, does not contain Electromagnetic measuring components and high-pressure oil systems have stable performance and low cost.

DRAWINGS

1 is a structural schematic view of a mechanical downhole tool connecting rod a and a connecting rod b in a state in which vertical drilling is performed by using a screw cam according to the present invention.

2 is a schematic structural view of the mechanical downhole tool connecting rod a and the connecting rod b in a retracted state by using a screw cam to realize vertical drilling according to the present invention.

Figure 3 is a cross-sectional view taken along line A-A of Figure 1 of the present invention.

Figure 4 is a partial enlarged view of Part I of Figure 1 of the present invention.

Figure 5 is a three-dimensional schematic view of the roller seat, the roller and the cam structure.

Figure 6 is a three-dimensional view of the cam, cam cover inner ring and cam cover outer ring structure.

Figure 7 is a three-dimensional schematic view of the linkage mechanism.

Figure 8 is a three-dimensional view of the structure of the biased sleeve.

In the figure, 1-upper joint, 2-anti-lock lock, 3-anti-link, 4-stator shell, 5-rubber bushing, 6-screw rotor, 7-live strand, 8-ball seat, 9- Transmission ball, 10-pressure ball, 11-seal ring a, 12-locking sleeve, 13-seal sleeve, 14-universal shaft connecting rod, 15-uniaxial shaft housing, 16-water cap, 17-drive Shaft, 18-seal ring, 19-center tube, 20-seal ring b, 21-bearing a, 22-roller seat, 23-roller, 24-screw a, 25-heavy casing, 26-cam, 27-cam Cover outer ring, 28-screw b, 29-cam cover inner ring, 30-spring, 31-spring seat, 32-pin a, 33 pin-b, 34-link seat, 35-ball joint, 36-link a, 37-roller, 38-cylinder pin, 39-hinge pin, 40-link b, 41-bearing b, 42-sleeve, 43-bearing c, 44-lower joint.

Detailed ways

The invention will now be further described with reference to the accompanying drawings.

Referring to Figure 1, the mechanical downhole tool for vertical drilling using a screw cam is composed of a motor assembly, a universal joint assembly, and a twisting assembly. The front end of the motor assembly is connected to the universal joint assembly, and the front end of the universal joint assembly. Connecting the twisting assembly; the motor assembly comprises an upper joint 1, an anti-locking nut 2, an anti-drop link 3, a stator housing 4, a rubber bushing 5 and a screw rotor 6, and the upper joint 1 passes through the thread and the stator shell The body 4 is connected, and the rear end of the anti-linking rod 3 is connected to the anti-locking nut 2, and the front end is connected to the screw rotor 6. The rubber bushing 5 is mounted inside the stator housing 4 to form a screw stator, and the screw rotor 6 and the screw stator are meshed with each other.

The universal joint shaft assembly comprises a live strand 7, a ball seat 8, a transmission ball 9, a pressure ball 10, a sealing ring a11, a locking sleeve 12, a sealing sleeve 13, a cardan shaft connecting rod 14, a universal shaft shell The body 15, the water cap 16 and the transmission shaft 17, the ball seat 8 is installed inside the movable strand 7, the pressure ball 10 is placed on the ball seat 8, and the transmission ball 9 is placed at the end groove of the cardan shaft link 14, using the lock The tight sleeve 12 cooperates with the universal joint shaft 14 and the movable strand 7, and seals the inside of the movable strand 7 by the sealing ring a11 and the sealing sleeve 13. The mounting structure of the universal joint shaft 14 is the same, and the universal joint housing 15 is behind. The stator housing 4 is connected to the end, the rear end of the water cap 16 is connected to the movable strand 7, and the front end is connected to the transmission shaft 17.

The slanting assembly comprises a sealing ring 18, a central tube 19, a sealing ring b20, a bearing a21, a roller seat 22, a roller 23, a screw a24, a biasing sleeve 25, a cam 26, a cam cover outer ring 27, a screw b28, a cam Cover inner ring 29, spring 30, spring seat 31, pin a32, pin b33, link seat 34, ball joint 35, link a36, drum 37, cylindrical pin 38, hinge pin 39, connecting rod b40, bearing b41, sleeve The cylinder 42, the bearing c43 and the lower joint 44, the roller 23 is mounted on the roller seat 22 by a screw a24, and the ball joint 35 is attached to the bottom of the cam 26 through the cam cover outer ring 27, the screw b28 and the cam cover inner ring 29, and the connecting rod The seat 34 is fixed to the bearing b41, and the bearing a21, the roller seat 22, the cam 26, the spring 30, the spring seat 31, the bearing b41, the sleeve 42 and the bearing c43 are mounted on the center tube 19 in order from top to bottom, and the roller seat 22 The spring seat 31 is fixed to the center tube 19 by means of a screw, and the spring seat 31 is fixed to the center tube 19 by means of a pin b33. The drum 37 is mounted on the right end of the link b40 through the cylindrical pin 38, and the link a36 is connected to the link b40 by the hinge pin 39. Then, the connecting rod a36 is connected to the lower end of the ball joint 35, and the connecting rod b40 is connected with the connecting rod base 34, and is densely connected in advance. The sealing ring 18 and the sealing ring b20 are mounted on the biasing sleeve 25, and the biasing sleeve 25 is fitted on the bearing a21 and the bearing c43, and the connecting rod seat 34 is fixed on the biasing sleeve 25 by the pin a32, after the center tube 19 The end is screwed to the drive shaft 17, and the front end is screwed to the lower joint 44; during the drilling process, when the well inclination occurs, the heavier side of the bias sleeve 25 is automatically rotated to the wellbore by the bearing a21 and the bearing c43 under the action of gravity. The low side drives the connecting rod seat 34 to rotate, so that the connecting rod a36 and the connecting rod b40 are always located at the high side of the wellbore, and the liquid energy is converted into the rotating mechanical energy by the motor assembly, and the central tube 19 is rotated, and the roller seat 22 follows the central tube. 19 Synchronous rotation causes the cam 26 to reciprocate up and down, thereby driving the connecting rod a36 and the connecting rod b40 to continuously push the well wall, generating a periodic reaction force to correct the well inclination, achieving normal drilling, improving drilling efficiency; when the well inclination does not occur At the time, the bias of the biasing sleeve 25 is random, so the automatic vertical drilling tool does not produce a constant side correction force and does not affect normal drilling.

a sleeve pin hole is opened at a circumferential center of the middle and lower portions of the heavier side of the heavy-weight sleeve 25, and a connecting rod expansion port is opened at a circumferential angle of 180° from the sleeve pin hole, and the connecting rod a36 and the connecting rod b40 can be Through the expansion and contraction port of the connecting rod, the upper and lower ends of the partial weight sleeve 25 are provided with a sealing groove for accommodating the sealing ring 18; the pin hole of the connecting rod seat on the connecting rod seat 34 is circumferentially spaced from the mounting point of the connecting rod b40 At 180°, the pin a32 connects the sleeve pin hole and the link pin hole to ensure that the link a36 and the link b40 are always opposite to the link expansion port on the weight sleeve 25.

The bottom of the cam 26 is provided with an annular sliding groove, and the cam 26 forms a slide with the cam cover outer ring 27 and the cam cover inner ring 29, and the ball hinge 35 can rotate circumferentially around the cam 26 in the slide, and should be ring-shaped before installation. The tank is coated with grease; the right end of the connecting rod b40 is mounted with a drum 37, and the sliding friction between the variable drilling tool and the well wall is rolling friction, which reduces the working resistance.

Claims

A mechanical downhole tool for vertical drilling using a screw cam is characterized in that: the mechanical downhole tool for vertical drilling using a screw cam is composed of a motor assembly, a cardan shaft assembly, a twisting assembly, and a motor assembly. The front end is connected to the universal joint shaft assembly, and the front end of the universal joint shaft assembly is connected with the twisting assembly; the motor assembly includes an upper joint (1), an anti-lock lock (2), an anti-drop link (3), and a stator shell. The body (4), the rubber bushing (5) and the screw rotor (6), the upper joint (1) is connected with the stator housing (4) through a thread, and the rear end of the connecting rod (3) is prevented from being connected against the locking nut (2) The front end is connected to the screw rotor (6), the rubber bushing (5) is mounted inside the stator housing (4) to form a screw stator, and the screw rotor (6) and the screw stator are coupled to each other; the universal joint shaft assembly includes Live strand (7), ball seat (8), transmission ball (9), pressure ball (10), sealing ring a (11), locking sleeve (12), sealing sleeve (13), universal joint shaft connecting rod (14), the cardan shaft housing (15), the water cap (16) and the transmission shaft (17), the ball seat (8) is installed inside the live strand (7), and the pressure ball (10) is placed on the ball seat ( 8) On, the transmission ball (9) is placed in the end groove of the cardan shaft connecting rod (14), and utilized The tight sleeve (12) cooperates with the cardan shaft link (14) and the live strand (7), and seals the inside of the live strand (7) with the seal ring a (11) and the seal sleeve (13), and the cardan shaft link ( 14) The mounting structure at both ends is the same, the rear end of the universal joint housing (15) is connected to the stator housing (4), the rear end of the water cap (16) is connected to the live strand (7), and the front end is connected to the transmission shaft (17); The slanting assembly comprises a sealing ring (18), a central tube (19), a sealing ring b (20), a bearing a (21), a roller seat (22), a roller (23), a screw a (24), a biasing sleeve (25), cam (26), cam cover outer ring (27), screw b (28), cam cover inner ring (29), spring (30), spring seat (31), pin a (32), pin b (33), connecting rod base (34), ball joint (35), connecting rod a (36), drum (37), cylindrical pin (38), hinge pin (39), connecting rod b (40), bearing b (41), sleeve (42), bearing c (43) and lower joint (44), roller (23) is mounted on roller seat (22) by screw a (24), and ball hinge (35) is passed through cam cover The outer ring (27), the screw b (28) and the cam cover inner ring (29) are mounted on the bottom of the cam (26), and the link base (34) is fixed on the bearing b (41), and the bearing is sequentially arranged from top to bottom. a (21), roller seat (22), cam (26), spring (30), spring seat (3 1) The bearing b (41), the sleeve (42) and the bearing c (43) are mounted on the center tube (19), and the roller seat (22) is fixed to the center tube (19) by means of a screw, and the spring seat (31) The pin (b) is fixed to the center tube (19), the roller (37) is mounted on the right end of the connecting rod b (40) through the cylindrical pin (38), and the connecting rod a (36) is used by the hinge pin (39) The connecting rod b (40) is connected, the connecting rod a (36) is connected with the lower end of the ball joint (35), the connecting rod b (40) is connected with the connecting rod base (34), and the sealing ring (18) and the sealing ring are preliminarily connected. b (20) is mounted on the partial bushing (25), and then the biasing bushing (25) is fitted on the bearing a (21) and the bearing c (43), and the connecting rod seat (34) is used by the pin a (32) Fixed on the heavy-weight casing (25), the rear end of the central pipe (19) is screwed to the transmission shaft (17), and the front end is screwed to the lower joint (44); during the drilling process, when the well inclination occurs, the casing is biased (25) The heavier side is automatically rotated to the lower side of the wellbore by the bearing a (21) and the bearing c (43) under the action of gravity, and the link seat (34) is rotated to make the connecting rod a (36) and the connecting rod b (40) is always located at the high side of the wellbore, and the liquid energy is converted into rotating mechanical energy by the motor assembly, which drives the central tube (19) to rotate, and the roller seat (22) The central tube (19) rotates synchronously to reciprocate the cam (26) up and down, thereby driving the connecting rod a (36) and the connecting rod b (40) to continuously push the well wall, generating a periodic reaction force to correct the well inclination and achieving normality. Drilling to improve drilling efficiency.
The mechanical downhole tool for vertical drilling using a screw cam according to claim 1, wherein a sleeve pin hole is opened at a circumferential center of the middle and lower portions of the heavier side of the heavier sleeve (25). A connecting rod expansion port is opened at a 180° circumferential direction of the sleeve pin hole, and the connecting rod a (36) and the connecting rod b (40) can be expanded and contracted through the connecting rod expansion port, and the upper and lower ends of the partial sleeve (25) are opened. Sealing groove for the sealing ring (18).
The mechanical downhole tool for vertical drilling using a screw cam according to claim 1, wherein the connecting rod pin hole and the connecting rod b (40) on the connecting rod seat (34) are circumferentially installed 180° apart, the pin a (32) connects the sleeve pin hole and the connecting rod pin hole, ensuring that the connecting rod a (36) and the connecting rod b (40) are always opposite to the connecting rod expansion port on the biasing sleeve (25). .
The mechanical downhole tool for vertical drilling using a screw cam according to claim 1, wherein the bottom of the cam (26) is provided with an annular chute, a cam (26) and a cam cover outer ring (27) and The cam cover inner ring (29) forms an annular slide, and the ball joint (35) can rotate circumferentially around the cam (26) in the annular slide, and the annular chute should be coated with grease before installation.
The mechanical downhole tool for vertical drilling using a screw cam according to claim 1, wherein the right end of the connecting rod b (40) is mounted with a drum (37), and the sliding friction between the variable drilling tool and the well wall is Rolling friction reduces work resistance.