A hydraulic multi-stage expansion drill for small wells

Abstract

The present invention discloses a small borehole hydraulic multi-stage reaming drill, comprising an upper joint, a body, a push rod, a bypass piston rod, an upper spring, a rotating pin, a reaming blade, a middle spring, a connector and a lower joint, wherein the upper joint and the connector are respectively threadedly connected at the upper and lower ends of the body, and the lower joint is threadedly connected at the lower end of the connector, a push rod is slidably connected in the inner hole of the body, and the lower end of the push rod extends into the inner hole of the connector and slidably cooperates with the inner hole of the connector, a bypass piston rod is slidably connected in the inner hole of the push rod, an upper spring is installed between the push rod and the bypass piston rod, a middle spring is installed between the push rod and the connector, and a bypass hole is opened at the upper part of the inner hole of the bypass piston rod. The present invention can realize multi-stage reaming in one well, and can continue drilling, saving the time of drilling and drilling, thereby saving the drilling cost and cycle, and improving the drilling efficiency.

Description

Technical Field

[0001] The invention relates to a small-hole hydraulic multi-stage reaming drill, belonging to the technical field of downhole tools in oil fields. Background Art

[0002] During the drilling process, we often need to expand the hole at a certain section of the wellbore to facilitate other operations. This requires a tool that can first pass through the small wellbore section above, start expanding the hole when it reaches the predetermined position, and continue drilling after expanding the hole.

[0003] Most of the existing hydraulic reamer drills cannot achieve the function of continuing to drill after reaming. Some can achieve this but need to be dropped, but the dropping of the ball will block the entire water hole, and it will not be possible to start again. Therefore, the existing tools cannot achieve the functions of reaming, drilling, reaming, and drilling. Summary of the invention

[0004] The purpose of the present invention is to provide a small-bore hydraulic multi-stage reaming drill, which can realize the function of continuing drilling after reaming, saving the time of drilling and drilling, and improving the drilling efficiency.

[0005] The technical solution of the present invention is as follows: a small wellbore hydraulic multi-stage reaming drill comprises an upper joint, a body, a push rod, a bypass piston rod, an upper spring, a rotating pin, a reaming blade, a middle spring, a connecting body and a lower joint, wherein the upper joint and the connecting body are respectively threadedly connected at the upper and lower ends of the body, and the lower end of the connecting body is threadedly connected with the lower joint, a push rod is slidably connected in the inner hole of the body, and the lower end of the push rod extends into the inner hole of the connecting body and slidably cooperates with the inner hole of the connecting body, a bypass piston rod is slidably connected in the inner hole of the push rod, and an upper push rod is installed between the push rod and the bypass piston rod. A spring is provided, a middle spring is installed between the push knife rod and the connecting body, a bypass hole is opened on the upper part of the inner hole of the bypass piston rod, a transition gap is reserved between the lower outer wall of the bypass piston rod and the inner wall of the inner hole of the push knife rod, a radial flow hole connected with the transition gap is opened on the push knife rod, mounting grooves connected with the inner hole of the body are evenly distributed on the main body, and the mounting grooves are connected with the radial flow holes, a reaming knife wing is rotatably connected with a rotating pin in each mounting groove, an incomplete tooth is arranged on the end of the reaming knife wing close to the rotating pin, and a tooth groove matching with the incomplete tooth is opened on the outer wall of the push knife rod.

[0006] Furthermore, a limited fluid is slidably connected in the inner hole of the connector, a lower spring is installed between the limited fluid and the lower joint, the limited fluid is a stepped shaft, the end surface of the large diameter shaft is evenly distributed with outer ring holes, a blind hole with an expanded cone hole is provided in the central interior of the limited fluid, and a conical head is provided at the lower end of the small diameter shaft of the limited fluid, and the conical head cooperates with the inner conical surface of the water eye opening of the lower joint. In the normal assembly state, that is, the low pressure state, the conical head of the limited fluid and the inner conical surface of the lower joint are separated, leaving sufficient clearance.

[0007] Furthermore, except for the limiting fluid, the upper joint, the main body, the push rod, the bypass piston rod, the connecting body and the lower joint are all hollow shaft structures.

[0008] Furthermore, the upper joint and the main body, the main body and the connector, and the connector and the lower joint are all connected by tapered pipe threads, and double O-rings are provided at the roots of the tapered pipe threads. The connector and the front end of the main body thread connection are matched through the optical axis clearance, and an O-ring is provided at the matching point.

[0009] Furthermore, a double sealing groove is provided on the push knife rod and at the sliding connection with the inner hole of the main body, and BA-type lip sealing rings in opposite directions are installed in the double sealing grooves; a double sealing groove is also provided on the inner wall of the inner hole of the connecting body and at the sliding connection with the lower end of the push knife rod, and an O-ring is installed in the double sealing groove; double sealing grooves are provided at three locations where the inner hole of the push knife rod and the bypass piston rod are slidably connected, and the three double sealing grooves are respectively arranged on the outer diameter of the large end and the outer diameter of the small end of the bypass piston rod, and the other is arranged on the stepped inner hole of the push knife rod, and O-rings are installed in the three double sealing grooves.

[0010] Furthermore, a double sealing groove is provided on the flow limiting body and at a position where the flow limiting body is slidably connected to the inner hole of the connecting body, and an O-ring is installed in the double sealing groove.

[0011] Furthermore, the push rod is a three-step shaft, the outer circle of the large diameter shaft is slidably matched with the inner hole of the body, the outer circle of the intermediate shaft is provided with incomplete teeth and multiple rows of radial flow holes, and the lower end face of the small diameter shaft is provided with more than two evenly distributed flow grooves; and the inner hole of the push rod is a double shoulder hole composed of a first step hole and a second step hole, the first step hole is an upper spring limit, and the second step hole is a stroke limit of the bypass piston rod, and a recessed annular groove is provided in the second step hole, and a transition gap is formed between the recessed annular groove and the bypass piston rod.

[0012] Due to the adoption of the above technical solution, the advantages of the present invention are: the present invention can realize multiple-stage hole expansion in one trip down the well, and can continue drilling, saving the time of drilling and drilling, thereby saving drilling costs and cycles, and improving drilling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0014] Figure 2 It is a schematic diagram of the structure of the pusher rod and the bypass piston rod;

[0015] Figure 3 It is a structural schematic diagram of the limiting fluid and the lower joint.

[0016] Explanation of the reference numerals: 1-upper joint, 2-main body, 3-knife push rod, 4-bypass piston rod, 5-upper spring, 6-rotating pin, 7-expanding knife wing, 8-middle spring, 9-connector, 10-limiting fluid, 11-lower spring, 12-lower joint, 13-mounting groove, 14-bypass hole, 15-incomplete teeth, 16-radial flow hole, 17-transition gap, 18-tooth groove, 19-outer ring hole, 20-flow groove, 21-BA type lip seal ring, 22-first step hole, 23-second step hole, 24-blind hole, 25-conical head, 26-inner conical surface. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0018] Embodiment of the present invention: The structural schematic diagram of the small wellbore hydraulic multi-stage reaming drill of the present invention is as follows Figure 1 and Figure 2 As shown, it includes an upper joint 1, a body 2, a pusher rod 3, a bypass piston rod 4, an upper spring 5, a rotating pin 6, a reaming blade 7, a middle spring 8, a connector 9 and a lower joint 12. The upper joint 1 and the connector 9 are threadedly connected at the upper and lower ends of the body 2 respectively, and the lower joint 12 is threadedly connected at the lower end of the connector 9. The pusher rod 3 is slidably connected in the inner hole of the body 2, and the lower end of the pusher rod 3 extends into the inner hole of the connector 9 and slidably cooperates with the inner hole of the connector 9. The bypass piston rod 4 is slidably connected in the inner hole of the pusher rod 3, and the upper spring 5 is installed between the pusher rod 3 and the bypass piston rod 4. A middle spring 8 is installed in between, a bypass hole 14 is opened in the upper part of the inner hole of the bypass piston rod 4, a transition gap 17 is reserved between the lower outer wall of the bypass piston rod 4 and the inner wall of the inner hole of the push knife rod 3, a radial flow hole 16 connected with the transition gap 17 is opened on the push knife rod 3, and mounting grooves 13 connected with the inner hole of the main body 2 are evenly distributed on the main body 2, and the mounting grooves 13 are connected with the radial flow holes 16, and a reaming blade wing 7 is rotatably connected through a rotating pin 6 in each mounting groove 13, and an incomplete tooth 15 is arranged on the end of the reaming blade wing 7 close to the rotating pin 6, and a tooth groove 18 matching the incomplete tooth 15 is opened on the outer wall of the push knife rod 3.

[0019] See also Figure 3The inner hole of the connector 9 is slidably connected with the limiting fluid 10, and a lower spring 11 is installed between the limiting fluid 10 and the lower joint 12. The limiting fluid 10 is a stepped shaft, and the end surface of the large-diameter shaft is evenly distributed with outer annular holes 19. A blind hole 24 with an expanded cone hole is provided in the central interior of the limiting fluid 10, and a conical head 25 is provided at the lower end of the small-diameter shaft of the limiting fluid 10. The conical head 25 cooperates with the inner conical surface 26 of the water eye opening of the lower joint 12. In the normal assembly state, that is, the low-pressure state, the conical head 25 of the limiting fluid 10 and the inner conical surface 26 of the lower joint 12 are separated, leaving enough clearance.

[0020] Furthermore, except for the limiting fluid 10, the upper joint 1, the main body 2, the pusher rod 3, the bypass piston rod 4, the connector 9 and the lower joint 12 are all hollow shaft structures.

[0021] Furthermore, the upper joint 1 and the body 2, the body 2 and the connector 9, and the connector 9 and the lower joint 12 are all connected by tapered pipe threads, and the roots of the tapered pipe threads are provided with double O-rings. The front end of the threaded connection of the connector 9 and the body 2 is matched through the optical axis 20, and an O-ring is provided at the matching position. A double sealing groove is provided on the push rod 3 and at the sliding connection with the inner hole of the body 2, and a BA-type lip seal 21 in opposite directions is installed in the double sealing groove; a double sealing groove is also provided on the inner wall of the inner hole of the connector 9 and at the sliding match with the lower end of the push rod 3, and an O-ring is installed in the double sealing groove; the three places where the inner hole of the push rod 3 is slidably connected with the bypass piston rod 4 are provided with double sealing grooves, and the three double sealing grooves are respectively arranged on the outer diameter of the large end and the outer diameter of the small end of the bypass piston rod 4, and the other is arranged on the stepped inner hole of the push rod 3, and O-rings are installed in the three double sealing grooves. A double sealing groove is provided on the limiting body 10 and at the sliding connection with the inner hole of the connecting body 9, and an O-shaped sealing ring is installed in the double sealing groove.

[0022] Furthermore, the pusher rod 3 is a three-step shaft, the outer circle of the large diameter shaft is slidably matched with the inner hole of the body 2, the outer circle of the intermediate shaft is provided with incomplete teeth 15 and multiple rows of radial flow holes 16, and the lower end surface of the small diameter shaft is provided with more than two evenly distributed flow grooves 20; and the inner hole of the pusher rod 3 is a double shoulder hole composed of a first step hole 22 and a second step hole 23, the first step hole 22 is a limit for the upper spring 5, and the second step hole 23 is a stroke limit for the bypass piston rod 4, and a section of a concave annular groove is provided in the second step hole 23, and a transition gap 17 is formed between the concave annular groove and the bypass piston rod 4. The flow groove 20 can ensure that the fluid can normally flow to the lower joint 12 through the outer ring hole 19 on the limiting fluid 10 in a low pressure state.

[0023] Working principle of the present invention:

[0024] The hydraulic reamer adopts the dual pressure principle: the reamer blade 7 is expanded for reaming under high pressure, and the reamer blade 7 is retracted for drilling under low pressure. That is, under high pressure, the push rod 3, the bypass piston rod 4, and the limiting fluid 10 all move downward under the thrust of the fluid to compress the springs in various parts. At this time, the push rod 3 moves downward to open the reamer blade 7 to achieve reaming. The bypass piston rod 4 moves downward to open the bypass hole 14, so that the mud passes through the bypass hole 14 and the transition gap 17 in turn, and finally sprays out from the radial flow hole 16 to flush and cool the reamer blade 7 and carry rock chips. The limiting fluid 10 moves downward to block the water eye at the lower end, so that all the mud pressure is applied to reaming, achieving better rock breaking and carrying rock chips. This is reaming drilling. Under low pressure, the push rod 3, the bypass piston rod 4, and the limiting fluid 10 cannot be opened due to the pre-installed load of the spring, the reaming blade 7 is in a retracted state, and the mud can only flow from the outer ring hole 19 of the limiting fluid 10 to the lower joint 12, providing mud to the drill bit at the lower end to enable the drill bit to drill.

Claims

1. A small-hole hydraulic multi-stage reaming drill, comprising an upper joint (1), a body (2), a push rod (3), a bypass piston rod (4), an upper spring (5), a rotating pin (6), a reaming blade (7), a middle spring (8), a connector (9) and a lower joint (12), characterized in that: An upper joint (1) and a connecting body (9) are respectively threadedly connected at the upper and lower ends of the body (2), a lower joint (12) is threadedly connected at the lower end of the connecting body (9), a push rod (3) is slidably connected in the inner hole of the body (2), and the lower end of the push rod (3) extends into the inner hole of the connecting body (9) and slidably cooperates with the inner hole of the connecting body (9), a bypass piston rod (4) is slidably connected in the inner hole of the push rod (3), an upper spring (5) is installed between the push rod (3) and the bypass piston rod (4), a middle spring (8) is installed between the push rod (3) and the connecting body (9), and a bypass hole (14) is opened at the upper part of the inner hole of the bypass piston rod (4). ), a transition gap (17) is reserved between the lower outer wall of the bypass piston rod (4) and the inner wall of the inner hole of the push rod (3), a radial flow hole (16) connected to the transition gap (17) is opened on the push rod (3), mounting grooves (13) connected to the inner hole of the body (2) are evenly distributed on the body (2), and the mounting grooves (13) are connected to the radial flow holes (16), a reaming blade (7) is rotatably connected in each mounting groove (13) through a rotating pin (6), an incomplete tooth (15) is arranged on the end of the reaming blade (7) close to the rotating pin (6), and a tooth groove (18) matching the incomplete tooth (15) is opened on the outer wall of the push rod (3); A limiting fluid (10) is slidably connected in the inner hole of the connecting body (9), a lower spring (11) is installed between the limiting fluid (10) and the lower joint (12), the limiting fluid (10) is a stepped shaft, and outer annular holes (19) are evenly distributed on the end surface of the large-diameter shaft, a blind hole (24) with an expanded cone hole at the center of the limiting fluid (10) is provided, and a conical head (25) is provided at the lower end of the small-diameter shaft of the limiting fluid (10), and the conical head (25) cooperates with the inner conical surface (26) of the water eye opening of the lower joint (12); A double sealing groove is provided on the pusher rod (3) and at a sliding connection with the inner hole of the body (2), and BA-type lip sealing rings (21) in opposite directions are installed in the double sealing grooves; A double sealing groove is also provided on the inner wall of the inner hole of the connecting body (9) and is slidably matched with the lower end of the pusher rod (3), and an O-shaped sealing ring is installed in the double sealing groove; Double sealing grooves are provided at three locations where the inner hole of the pusher rod (3) and the bypass piston rod (4) are slidably connected. The three double sealing grooves are respectively arranged on the outer diameter of the large end and the outer diameter of the small end of the bypass piston rod (4), and another double sealing groove is arranged on the stepped inner hole of the pusher rod (3). O-rings are installed in the three double sealing grooves. A double sealing groove is provided on the limiting body (10) and at a location where the limiting body (10) is slidably connected to the inner hole of the connecting body (9), and an O-ring is installed in the double sealing groove; The pusher rod (3) is a three-step shaft, the outer circle of the large-diameter shaft is slidably matched with the inner hole of the body (2), the outer circle of the intermediate shaft is provided with incomplete teeth (15) and multiple rows of radial flow holes (16), and the lower end surface of the small-diameter shaft is provided with more than two evenly distributed flow grooves (20); and the inner hole of the pusher rod (3) is a double shoulder hole composed of a first step hole (22) and a second step hole (23), the first step hole (22) is a limit for the upper spring (5), and the second step hole (23) is a stroke limit for the bypass piston rod (4), and a section of a recessed annular groove is provided in the second step hole (23), and a transition gap (17) is formed between the recessed annular groove and the bypass piston rod (4).

2. The small hole hydraulic multi-stage reaming drill according to claim 1, characterized in that: Except for the limiting fluid (10), the upper joint (1), the main body (2), the pusher rod (3), the bypass piston rod (4), the connecting body (9) and the lower joint (12) are all hollow shaft structures.

3. The small hole hydraulic multi-stage reaming drill according to claim 1, characterized in that: The upper joint (1) and the body (2), the body (2) and the connector (9), and the connector (9) and the lower joint (12) are all connected by tapered pipe threads, and the roots of the tapered pipe threads are provided with double O-rings. The front ends of the threaded connections between the connector (9) and the body (2) are fitted through a clearance of the optical axis (20), and an O-ring is provided at the fitting locations.

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