A variable angle drilling screw drilling tool

Abstract

The present invention relates to a variable angle drilling screw drill. The main purpose is to solve the problem that the existing screw drill cannot adapt to ultra-short radius horizontal wells with high inclination rate and small curvature radius. The lower part of the articulated joint assembly (1) is connected in sequence to a motor assembly (2), a variable angle universal shaft assembly (3), and a transmission shaft assembly (5), and the transmission shaft assembly (5) is provided with a straightener (4) on the outside; the variable angle universal shaft assembly (3) includes an upper shell (33), the lower end of the upper shell (33) is connected to an intermediate shell (34), and the upper shell (33) is provided with a shaft (32) inside, the upper end of the shaft (32) is connected to the universal shaft upper joint (31), and the lower end is connected to the universal shaft lower joint (35), and the lower end of the universal shaft lower joint (35) is connected to a flexible shaft (46). The screw drill can be adjusted automatically along the wellbore trajectory to achieve a high inclination rate, thereby meeting the on-site construction requirements of ultra-short radius horizontal wells.

Description

Technical Field

[0001] The invention relates to the field of drilling equipment, in particular to a variable-angle drilling screw tool. Background Art

[0002] With the deepening of the development of old oil fields, the water content of oil fields has gradually increased, the crude oil production has gradually decreased, and the development situation has become more severe. Through the ultra-short radius horizontal well technology, the upper well section of the target layer of the old wellbore is used for directional window side drilling, and the MWD while drilling monitoring, multi-angle guide screw and other instruments and tools are used to achieve large curvature deflection and directional horizontal drilling, which can realize the directional potential tapping and transformation of the target layer, expand the oil leakage area, improve the production conditions of the oil well, and further improve the crude oil recovery rate. However, the ultra-short radius horizontal well has a small wellbore size (114mm), a high deflection rate (60° / 30m or more), and a small curvature radius (within 30m), which causes great difficulties for on-site construction, especially the screw drilling tools for directional section deflection have higher requirements, requiring smaller size, larger deflection rate, and higher power screw drilling tools.

[0003] The commonly used screw drill tools are mainly composed of a bypass valve assembly, a motor assembly, a universal joint assembly and a drive shaft assembly. During drilling, the motor assembly is driven by the drilling fluid to output power, and the power output is transmitted to the drill bit connected to the bottom of the screw drill tool through the universal joint assembly and the drive shaft assembly, so as to perform drilling work. When used in ultra-short radius horizontal wells, the loading drilling pressure is not very stable due to the bending of the well body or the sticking of the drill string to the well wall. If the loaded drilling pressure is too large, the motor output torque will exceed the maximum pressure drop that the rubber structure can withstand, which will cause damage to the motor components, shorten the service life of the screw drill tool, and reduce the working efficiency of the screw drill tool. Summary of the invention

[0004] In order to overcome the shortcomings of existing screw drill bits that cannot adapt to ultra-short radius horizontal wells with high inclination rate and small curvature radius, the present invention provides a variable bend angle drilling screw drill bit, which can adjust itself along the wellbore trajectory to achieve a high inclination rate, thereby meeting the on-site construction requirements of ultra-short radius horizontal wells.

[0005] The technical solution of the present invention is: a variable angle drilling screw drill, including an articulated head assembly, characterized in that: the lower part of the articulated head assembly is sequentially connected with a motor assembly, a variable angle universal shaft assembly, and a transmission shaft assembly, and a centralizer is provided outside the transmission shaft assembly;

[0006] The articulated joint assembly comprises an upper joint and a lower joint, wherein a ball head A is connected to the interior of the upper joint, and a ball seat A is provided inside the lower joint, wherein the ball head A and the ball seat A are matched with each other through a spherical surface;

[0007] The variable-angle universal joint assembly includes an upper shell, the lower end of which is connected to an intermediate shell, a shaft rod is provided inside the upper shell, the upper end of the shaft rod is connected to an upper joint of the universal shaft, and the lower end is connected to a lower joint of the universal shaft, and the lower end of the lower joint of the universal shaft is connected to a flexible shaft; a ball seat B is provided at the lower end of the intermediate shell, a ball head B is connected inside the ball seat B, and the lower part of the ball head B is connected to the lower shell.

[0008] The bottom of the upper joint is connected to the upper joint lock nut, and the interior of the upper joint lock nut cooperates with the open sleeve through a conical surface; the upper end of the lower joint is connected to the lower joint lock nut A, and a sealing ring A is provided at the lower part of the lower joint lock nut A.

[0009] The lower end of the intermediate shell is connected to the intermediate shell lock nut, and a sealing ring B is provided between the intermediate shell lock nut and the ball head B; the lower end of the ball head B is externally connected to the lower shell, and the upper end of the lower shell is connected to the lower joint lock nut B. The interior of the lower joint lock nut B cooperates with the cone sleeve through a cone surface, and an adjustment sleeve is provided at the lower end of the cone sleeve.

[0010] The joint on the universal shaft includes a movable joint, a ball seat C is provided inside the movable joint, and the lower end of the ball seat C is connected to the shaft rod through a steel ball B; the lower end of the movable joint is internally threadedly connected to a locking sleeve, the interior of the locking sleeve cooperates with the sealing sleeve through a step, and a pressure ring is provided between the interior of the sealing sleeve and the shaft rod.

[0011] The motor assembly includes a stator housing, a stator is arranged inside the stator housing, and a rotor is arranged inside the stator, wherein the inner wall of the stator is provided with a spiral groove, and the outer wall of the rotor is provided with a spiral protrusion matching the groove; the inside of the rotor is connected to the core shaft through a key, and the lower end of the core shaft is connected to the joint on the universal shaft.

[0012] The transmission shaft assembly comprises a transmission shaft housing and a transmission shaft, a bearing group is arranged between the two, the transmission shaft housing is connected with the lower housing, and the transmission shaft is connected with the flexible shaft.

[0013] The present invention has the following beneficial effects: Due to the adoption of the above scheme, the screw drill adopts a double hinge structure, the screw is divided into two parts, the lower part is the deflection mechanism, the upper part is the power mechanism, and the middle is connected by a hinge. On the one hand, the power part can be made longer, increasing the output power of the screw, and on the other hand, it can ensure the normal lowering of the screw, with a better pass rate, ensuring the normal construction requirements of ultra-short radius wells. The screw drill is provided with a floating block. When the drill is lowered to the bottom of the well, it is affected by the hydraulic force of the drilling fluid, and the floating block extends to support the well wall to form a deflection force, so that the deflection force can reach 110° / 30m, thereby meeting the on-site construction requirements of ultra-short radius horizontal wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the structure of the present invention, wherein a is the upper half and b is the lower half;

[0015] Figure 2 1 is a schematic diagram of the structure of the hinge joint assembly;

[0016] Figure 3 It is a structural schematic diagram of the motor assembly;

[0017] Figure 4 It is a structural schematic diagram of a variable bending angle universal shaft assembly;

[0018] Figure 5 It is a structural schematic diagram of the transmission shaft assembly;

[0019] Figure 6 It is a schematic diagram of the structure of the joint on the universal shaft.

[0020] In the figure, 1- hinged joint assembly, 2- motor assembly, 3- variable angle universal joint assembly, 4- centralizer, 5- transmission shaft assembly, 10- spring, 11- upper joint, 12- open sleeve, 13- upper joint lock nut, 14- ball head A, 15- lower joint lock nut A, 16- sealing ring A, 17- ball seat A, 18- lower joint, 19- steel ball A, 21- stator housing, 22- core shaft, 23- stator, 24- rotor, 31- universal shaft upper joint, 32- shaft rod, 33- upper housing, 34- intermediate housing, 35- universal shaft lower joint, 36- floating block, 37- ball seat B, 38-intermediate housing lock nut, 39-sealing ring B, 40-angle adjustment sheet, 41-ball head B, 42-lower joint lock nut B, 43-taper sleeve, 44-adjustment sleeve, 45-lower housing, 46-flexible shaft, 51-upper TC bearing static ring, 52-upper TC bearing dynamic ring, 53-series bearing, 54-transmission shaft housing, 55-spacer, 56-middle lock nut, 57-lower TC bearing static ring, 58-lower TC bearing dynamic ring, 59-transmission shaft, 311-movable joint, 312-ball seat C, 313-pressure ring, 314-locking sleeve, 315-sealing sleeve, 316-steel ball B. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings:

[0022] Depend on Figures 1 to 6 As shown, a variable-angle drilling screw drill bit includes an articulated head assembly 1, the lower part of which is sequentially connected to a motor assembly 2, a variable-angle universal shaft assembly 3, and a transmission shaft assembly 5, and a centralizer 4 is provided on the outside of the transmission shaft assembly 5.

[0023] The hinge joint assembly 1 includes an upper joint 11, a lower joint 18, a ball head A14, and a ball seat A17. The upper end of the ball head A14 is a cylinder, and the lower end is a spherical surface, and the center of the spherical surface is coaxial with the center of the cylinder. The cylinder is threadedly connected to the inner wall of the upper joint 11, and the ball seat 17 is located inside the lower joint 18. The spherical surface of the ball head A14 matches with the ball seat A17, and a steel ball A19 is provided at the matching position. The bottom of the upper joint 11 is connected to the upper joint lock nut 13, and the interior of the upper joint lock nut 13 matches with the open sleeve 12 through a conical surface. When the upper joint lock nut 13 is twisted up and down, the gap between the upper joint lock nut and the open sleeve 12 can be adjusted, thereby adjusting the circumferential swing range of the ball head A14. The upper end of the lower joint 18 is connected to the lower joint lock nut A15, and a sealing ring A16 is provided at the lower part of the lower joint lock nut A15. The sealing ring A16 is pressed on the upper part of the ball head A14, and a spring 10 is provided between the lower joint lock nut A15 and the sealing ring A16. By twisting the lower joint lock nut A15 up and down, the gap between the sealing ring A16 and the ball head A14 can be adjusted, thereby adjusting the circumferential swing range of the ball head A14.

[0024] The motor assembly 2 includes a stator housing 21, a stator 23 is arranged inside the stator housing 21, and a circumferential groove is arranged on the inner wall of the stator housing 21 corresponding to the stator 23, so as to limit the axial movement of the stator 23. A rotor 24 is arranged inside the stator 23, wherein the inner wall of the stator 23 is provided with a spiral groove, and the outer wall of the rotor 24 is provided with a spiral protrusion matched with the groove. A core shaft 2 is arranged inside the rotor 24, a keyway is opened on the inner wall of the rotor 24, and a protrusion is arranged on the outer wall of the core shaft 22, and the rotor 24 can drive the core shaft 22 to rotate by matching the protrusion with the keyway. When liquid flows into the motor assembly 2, it acts on the threaded protrusion on the outer wall of the rotor 24, so that the rotor 24 rotates along the spiral line of the inner wall of the stator 23, and at the same time, the rotor 24 rotates through the keying core shaft 22.

[0025] The variable angle universal joint assembly 3 includes an upper shell 33, the lower end of which is threadedly connected to an intermediate shell 34, and a shaft 32 is provided inside the upper shell 33, the upper end of which is connected to the universal joint 31, and the lower end is connected to the universal joint 35. The upper end of the universal joint 31 is connected to the core shaft 22 in the motor assembly 2, and the lower end of the universal joint 35 is connected to the flexible shaft 46. The universal joint 31 and the universal joint 35 are connected by a ball head and a ball seat, respectively, and can achieve 360° rotation. A floating block 36 is provided on the side wall of the intermediate shell 34, and the floating block 36 corresponds to the universal joint 35. A ball seat B37 is provided at the lower end of the intermediate shell 34, and a ball head B41 is provided inside the ball seat B37, and the two are matched through a spherical surface. The lower end of the intermediate housing 34 is connected to the intermediate housing lock nut 38, and a sealing ring B39 is provided between the intermediate housing lock nut 38 and the ball head B41. By twisting the intermediate housing lock nut 38 up and down, the gap between the sealing ring B39 and the ball head B41 can be adjusted, thereby adjusting the circumferential swing range of the ball head B41. The lower part of the ball head B41 is a cylinder, and the lower part of the cylinder is threadedly connected to the lower housing 45. The upper end of the lower housing 45 is connected to the lower joint lock nut B42. The interior of the lower joint lock nut B42 cooperates with the cone sleeve 43 through a cone surface. An adjustment sleeve 44 is provided at the lower end of the cone sleeve 43. By twisting the lower joint lock nut B42 up and down, the gap between the lower joint lock nut B42 and the cone sleeve 43 can be adjusted, thereby adjusting the circumferential swing range of the ball head B41.

[0026] The upper joint 31 of the universal joint includes a movable joint 311, a ball seat C312 is provided inside the movable joint 311, the lower end of the ball seat C312 is connected to the shaft 32 through a steel ball B316, and the ball rod 32 and the ball seat C312 can rotate relative to each other within a range of 360 degrees. The lower end of the movable joint 311 is internally threadedly connected to a locking sleeve 314, the locking sleeve 314 is matched with a sealing sleeve 315 through a step, and a pressure ring 313 is provided between the sealing sleeve 315 and the shaft 32. The lower joint 35 of the universal joint is opposite to the upper joint 31 of the universal joint, and the structure is similar, so it will not be described here.

[0027] When the drill tool is lowered into the well and enters the directional well section, the drill tool forms a certain flexible bend along the wellbore trajectory of the directional well section. When the lower shell 45 and the intermediate shell 34 in the variable bend angle universal shaft assembly 3 are bent at an angle, the ball head B41 and the ball seat B37 are bent at a certain angle, so that the flexible shaft 46 that passes through B41 and the ball seat B37 is bent flexibly. The bent flexible shaft 46 drives the universal shaft lower joint 35 connected thereto to float, and the universal shaft lower joint 35 makes the floating block 36 float to fit the well wall, forming an effect that the drilling tool bending point position fits the well wall, which plays a role in stabilizing the tool face and improving the deflection ability of the variable bend angle drilling screw drill tool.

[0028] The transmission shaft assembly 5 includes a transmission shaft housing 54 and a transmission shaft 59, with a bearing group arranged between the two. The transmission shaft housing 54 is connected to the lower housing 45, and the transmission shaft 59 is connected to the flexible shaft 46. The bearing group includes an upper TC bearing, a lower TC bearing and a series bearing in the middle. An upper TC bearing static ring 51 is arranged inside the transmission shaft housing 54, and an upper TC bearing dynamic ring 52 is located outside the transmission shaft 59. The lower part of the transmission shaft housing 54 is threadedly connected to the lower TC bearing static ring 57, and the lower TC bearing dynamic ring 58 is located outside the transmission shaft 59. A series bearing 53 is arranged between the upper TC bearing and the lower TC bearing. The series bearing 53 requires a central lock nut 56 to be threadedly connected to the transmission shaft 59 of the working part, and a spacer 55 is arranged between the series bearing 53 and the lower TC bearing.

[0029] When the variable angle drilling screw drill tool is lowered into the well and enters the directional well section, the drill tool forms a certain flexible bend along the wellbore trajectory of the directional well section. When the lower shell 45 in the variable angle universal shaft assembly 3 and the intermediate shell 34 are bent at an angle, the lower shell 45 drives the ball head B41 placed therein and the ball seat B37 placed in the intermediate shell 34 to bend at a certain angle, so that the flexible shaft 46 passing through the ball head B41 and the ball seat B37 is bent flexibly. The bent flexible shaft 46 drives one end of the transmission shaft assembly 5 connected thereto to float, so that the floating block 36 floats to fit the well wall, forming an effect in which the bending point of the screw drill tool fits the well wall, plays a role in stabilizing the tool face, and improves the deflection capability of the variable angle drilling screw drill tool.

Claims

1. A variable angle drilling screw tool, comprising an articulated joint assembly (1), characterized in that: The lower part of the articulated joint assembly (1) is connected in sequence to a motor assembly (2), a variable-angle universal joint assembly (3), and a transmission shaft assembly (5); a centralizer (4) is provided on the outside of the transmission shaft assembly (5); The hinge joint assembly (1) comprises an upper joint (11) and a lower joint (18); the upper joint (11) is internally connected to a ball head A (14); the lower joint (18) is internally provided with a ball seat A (17); the ball head A (14) and the ball seat A (17) are spherically matched; The variable-angle universal joint assembly (3) comprises an upper shell (33), the lower end of the upper shell (33) being connected to an intermediate shell (34), a shaft (32) being provided inside the upper shell (33), the upper end of the shaft (32) being connected to an upper universal joint (31), and the lower end being connected to a lower universal joint (35), the upper end of the upper universal joint (31) being connected to a core shaft (22) in the motor assembly (2), and the lower end of the lower universal joint (35) being connected to a flexible shaft (46); a ball seat B (37) being provided at the lower end of the intermediate shell (34), a ball head B (41) being connected inside the ball seat B (37), and the lower part of the ball head B (41) being connected to the lower shell (45); The lower end of the intermediate housing (34) is connected to the intermediate housing lock nut (38), and a sealing ring B (39) is provided between the intermediate housing lock nut (38) and the ball head B (41); the lower end of the ball head B (41) is externally connected to the lower housing (45), the upper end of the lower housing (45) is connected to the lower joint lock nut B (42), the interior of the lower joint lock nut B (42) is matched with the cone sleeve (43) through a cone surface, and an adjustment sleeve (44) is provided at the lower end of the cone sleeve (43); The transmission shaft assembly (5) comprises a transmission shaft (59), and the transmission shaft (59) is connected to the flexible shaft (46).

2. The variable angle drilling screw tool according to claim 1, characterized in that: The bottom of the upper joint (11) is connected to the upper joint lock nut (13), and the interior of the upper joint lock nut (13) cooperates with the open sleeve (12) through a conical surface; the upper end of the lower joint (18) is connected to the lower joint lock nut A (15), and a sealing ring A (16) is provided at the lower part of the lower joint lock nut A (15).

3. The variable angle drilling screw tool according to claim 2, characterized in that: The universal shaft upper joint (31) comprises a movable joint (311), a ball seat C (312) is provided inside the movable joint (311), and the lower end of the ball seat C (312) is connected to the shaft (32) via a steel ball B (316); the lower end of the movable joint (311) is internally threadedly connected to a locking sleeve (314), the interior of the locking sleeve (314) is matched with a sealing sleeve (315) via a step, and a pressing ring (313) is provided between the interior of the sealing sleeve (315) and the shaft (32).

4. The variable angle drilling screw tool according to claim 3 is characterized in that: The motor assembly (2) comprises a stator housing (21), a stator (23) is arranged inside the stator housing (21), a rotor (24) is arranged inside the stator (23), wherein the inner wall of the stator (23) is provided with a spiral groove, and the outer wall of the rotor (24) is provided with a spiral protrusion matching the groove; the inner part of the rotor (24) is connected to the core shaft (22) via a key, and the lower end of the core shaft (22) is connected to the joint (31) on the universal shaft.

5. The variable angle drilling screw tool according to claim 4, characterized in that: The transmission shaft assembly (5) comprises a transmission shaft housing (54) and a transmission shaft (59), with a bearing group arranged between the two. The transmission shaft housing (54) is connected to the lower housing (45), and the transmission shaft (59) is connected to the flexible shaft (46).

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