In-hole expander and using method thereof

Abstract

The invention relates to an in-hole expander and a use method thereof, the in-hole expander is used for in-hole wall protection pipe expansion construction in drilling construction in the fields of geological exploration, tunnel exploration and the like, and the in-hole expander comprises a drill rod, high-pressure liquid, an outer pipe, a piston, an expansion cone, a copper plate, an expansion block, a baffle block, a belleville spring, a screw, an expansion pipe and a rubber plug. The piston pushes the expansion cone to move downwards, the expansion cone is matched with the expansion block through an inclined face, the expansion block slightly moves outwards, the axial force of the expansion cone is changed into the radial force of the expansion block, a large force increasing effect is generated, and the expansion block enables the diameter of the expansion pipe to be enlarged. The belleville spring generates large upward thrust on the expansion cone, and after the pressure of the high-pressure liquid is relieved, the expansion cone can move upwards, and the expansion block moves inwards and shrinks. The expander is simple in structure and low in manufacturing cost, and the cost of the expander is about 20% of that of an existing expander; the construction process is simple, the construction efficiency can be effectively improved, and the construction cost is saved.

Description

Technical Field

[0001] The present invention relates to the fields of geological exploration, tunnel investigation, drilling engineering, etc. Specifically, it is an in-hole expander and its usage method, which is used for the in-hole retaining pipe expansion construction in drilling operations in fields such as geological exploration and tunnel investigation. Background Art

[0002] The expansion pipe technology is to lower the expansion pipe string into the hole and use an expander to cause its radial plastic deformation and increase in diameter, so that the expansion pipe fits tightly against the hole wall to achieve engineering goals such as sand control and hole wall support. This technology replaces the traditional multi-layer casing design with a single-size casing, simplifies the drilling structure, improves the drilling efficiency, reduces the drilling cost, is applicable to the drilling operations of deep holes and complex formations, and effectively solves the contradiction between the limited casing program and the complex geological conditions.

[0003] Currently, there are mainly three types of expanders: mechanical, hydraulic, and composite. All three types of expanders need to be used in conjunction with an in-hole hanger. The existing complete set of expander equipment has a complex structure, high cost, cumbersome process, long installation time for the expansion pipe, high installation cost, large expansion force required during operation, and high pump pressure for the supporting equipment. It has high requirements for the regularity of the hole, and the on-site application of the existing expander is restricted. Summary of the Invention

[0004] The first object of the present invention is to provide an in-hole expander that can simplify the structure of the expander and reduce the manufacturing cost on the premise of ensuring sand control and hole wall stability.

[0005] The second object of the present invention is to provide a usage method for the in-hole expander, which has a simple construction process and low construction cost.

[0006] An in-hole expander includes a drill pipe, high-pressure liquid, an outer pipe, a piston, an expansion cone, a copper plate, expansion blocks, stoppers, disc springs, screws, an expansion pipe, and a rubber plug; the expansion pipe is sleeved outside the outer pipe, the piston, expansion cone, expansion blocks, stoppers, and disc springs are arranged inside the outer pipe, the drill pipe is connected to and communicates with the outer pipe, a piston is arranged in the inner cavity of the outer pipe, at least three expansion cones are located below the piston and fixedly connected to the piston, each expansion block is arranged outside the expansion cone, the copper plate is located between the expansion cone and the expansion block, the copper plate is fixed to the inner wall of the expansion block by screws, a dovetail groove extending along the inclined plane is provided on the outer surface of the expansion cone, and the copper plate can slide in the dovetail groove; the rubber plug is installed between the expansion pipe and the outer pipe, and the rubber plug is used to increase the contact friction force between the two, so that the expander can be lowered into the hole together with the expansion pipe; after the expansion pipe expands, the expander can be separately withdrawn from the drill hole; the disc spring is arranged at the bottom of the outer pipe, the upper end of the disc spring abuts against the lower end of the expansion cone, a stopper is fixed on the side wall of the outer pipe at the bottom surface of each expansion block, the stopper can block the expansion block, the inner cavity of the drill pipe communicates with the inner cavity of the outer pipe, and the high-pressure liquid is filled in the inner cavities of the drill pipe and the outer pipe.

[0007] The rubber plug is of an annular structure and is made of elastic rubber with a high coefficient of friction.

[0008] The disc spring is formed by stacking multiple disc spring plates and is used to provide the restoring force for the upward movement of the expansion cone.

[0009] The expansion tube is a screen pipe or a casing made of metal.

[0010] The outer tube is connected to the drill pipe through threads, and high-pressure liquid acts on the piston through the drill pipe.

[0011] The working process and principle of the present invention: The piston moves synchronously with the expansion cone. The piston can be axially moved downward under the drive of high-pressure liquid in the outer tube and compress the disc spring, and its stroke is limited by the stop block; under the thrust of the disc spring, the piston can be axially moved upward; When the piston and the expansion cone are driven downward by high-pressure liquid, the expansion cone forces the expansion block to move radially outward through the action of the inclined surface structure with the expansion block, and then pushes the expansion tube to expand; When the pressure of the high-pressure liquid is removed, the disc spring, the piston and the expansion cone move upward. The expansion cone drives the expansion block to retract into the outer tube through the sliding fit of the dovetail groove and the copper plate.

[0012] A method for using an in-hole expander of the present invention includes the following steps: Step 1: The drill pipe drives the expander to be lowered to a predetermined depth in the hole. High-pressure liquid enters the expander through the drill pipe. Under the action of the high-pressure liquid, the piston compresses the disc spring and pushes the expansion cone downward. Under the action of the inclined surface structure of the expansion cone and the expansion block, at least three expansion blocks generate a large radial force, pushing the expansion tube to expand outward. The diameter of the expansion tube becomes larger, undergoes plastic deformation, and fits against the hole wall; Step 2: The high-pressure liquid is depressurized. Under the thrust of the disc spring, the expansion cone and the piston move upward. Under the action of the dovetail groove on the expansion cone and the copper plate, the expansion block retracts into the outer tube of the expander, and the outer tube of the expander is separated from the expansion tube; Step 3: The drill pipe drives the expander to rotate by °, and repeat the steps to expand the diameter of the bottommost section of the expansion tube and make the entire expansion tube fit against the hole wall; Step 4: The high-pressure liquid is depressurized. The expansion block retracts into the outer tube of the expander, and the outer tube of the expander is separated from the expansion tube. The expander is lifted by a certain height through the drill pipe, and repeat Steps 1, 2 and 3 to expand the diameter of all the expansion tubes in segments. Then the high-pressure liquid is depressurized, and the expander is withdrawn from the borehole through the drill pipe to complete the in-hole installation of the expansion tube.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. The structure of this expander is simple and the manufacturing cost is low, about 20% of the cost of the existing expander, with significant economic advantages.

[0014] 2. The construction process of this expander is simple, with low technical requirements for operators, extremely easy to master and implement, which can effectively improve the construction efficiency, shorten the construction period and save the construction cost.

[0015] 3. This expander effectively reduces the pressure of the high-pressure liquid during the working process, greatly reduces the input cost of the supporting high-pressure pump, and further improves the overall economic efficiency and safety.

[0016] 4. This expander has a longer service life, and its reuse times are increased by about 5 times compared with the traditional surface expander, which not only improves the utilization rate of the equipment, but also effectively reduces the equipment replacement and maintenance frequency, and significantly reduces the comprehensive operation and maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a longitudinal sectional schematic view of the present invention; Figure 2 is Figure 1 the enlarged A-A sectional view after removing the expansion tube in

[0018] In the figure: 1 - drill pipe; 2 - high-pressure liquid; 3 - outer tube; 4 - piston; 5 - expansion cone; 6 - copper plate; 7 - expansion block; 8 - stop block; 9 - disc spring; 10 - screw; 11 - expansion tube; 12 - rubber plug. DETAILED DESCRIPTION OF THE INVENTION

[0019] As Figure 1 and Figure 2As shown in the figure, an in-hole expander includes a drill pipe 1, high-pressure liquid 2, an outer pipe 3, a piston 4, an expansion cone 5, a copper plate 6, expansion blocks 7, a stop block 8, a disc spring 9, a screw 10, an expansion pipe 11, and a rubber plug 12. The expansion pipe 11 is sleeved outside the outer pipe 3. The piston 4, the expansion cone 5, the expansion blocks 7, the stop block 8, and the disc spring 9 are arranged inside the outer pipe 3. The drill pipe 1 is connected to and communicates with the outer pipe 3. A piston 4 is arranged in the inner cavity of the outer pipe 3. At least three expansion cones 5 are located below the piston 4 and fixedly connected to the piston 4. Each expansion block 7 is arranged outside the expansion cone 5. The copper plate 6 is located between the expansion cone 5 and the expansion block 7. The copper plate 6 is fixed to the inner wall of the expansion block 7 by a screw 10. The outer surface of the expansion cone 5 is provided with a dovetail groove extending along the inclined surface. The copper plate 6 can slide in the dovetail groove. The rubber plug 12 is installed between the expansion pipe 11 and the outer pipe 3. The rubber plug 12 is used to increase the contact friction force between the two, so that the expander can be lowered into the hole together with the expansion pipe 11. After the expansion pipe 11 expands, the expander can be separately withdrawn from the drill hole. The disc spring 9 is arranged at the bottom of the outer pipe 3. The upper end of the disc spring 9 abuts against the lower end of the expansion cone 5. A stop block 8 is fixed on the side wall of the outer pipe 3 at the bottom surface of each expansion block 7. The stop block 8 can block the expansion block 7. The inner cavity of the drill pipe 1 communicates with the inner cavity of the outer pipe 3. The high-pressure liquid 2 is filled in the inner cavity of the drill pipe 1 and the inner cavity of the outer pipe 3.

[0020] The rubber plug 12 is of an annular structure and is made of elastic rubber with a high friction coefficient.

[0021] The disc spring 9 is formed by stacking a plurality of disc spring sheets and is used to provide a reset force for the upward movement of the expansion cone 5.

[0022] The expansion pipe 11 is a screen pipe or a casing made of metal material.

[0023] The outer pipe 3 is connected to the drill pipe 1 by threads. The high-pressure liquid 2 acts on the piston 4 through the drill pipe.

[0024] The working process and principle of the present invention: As Figure 1 and Figure 2 shown in the figure, the piston 4 and the expansion cone 5 move synchronously. The piston 4 can be axially moved downward in the outer pipe 3 under the drive of the high-pressure liquid 2 and compress the disc spring 9. Its stroke is limited by the stop block 8. Under the thrust of the disc spring, the piston can move axially upward; When the piston 4 and the expansion cone 5 are driven by the high-pressure liquid 2 to move downward, the expansion cone 5 forces the expansion block 7 to move radially outward through the action of the inclined surface structure with the expansion block 7, thereby pushing the expansion pipe 11 to expand; When the pressure of the high-pressure liquid 2 is removed, the disc spring 9 pushes the piston 4 and the expansion cone 5 to move upward. The expansion cone 5 drives the expansion block 7 to retract into the outer pipe 3 through the sliding fit of the dovetail groove and the copper plate 6.

[0025] As Figure 1 and Figure 2 shown, a method for using an in-hole expander of the present invention includes the following steps: Step 1: The drill rod 1 drives the expander to lower into the hole to a predetermined depth. The high-pressure liquid 2 enters the expander through the drill rod 1. Under the action of the high-pressure liquid 2, the piston 4 compresses the disc spring 9 and pushes the expansion cone 5 downward. Under the action of the inclined surface structures of the expansion cone 5 and the expansion blocks 7, at least three expansion blocks 7 generate a large radial force, pushing the expansion tube 11 to expand outward. The diameter of the expansion tube 11 becomes larger, undergoes plastic deformation, and fits against the hole wall; Step 2: The high-pressure liquid 2 is depressurized. Under the thrust of the disc spring 9, the expansion cone 5 and the piston 4 move upward. Under the action of the dovetail groove on the expansion cone 5 and the copper plate 6, the expansion blocks 7 retract into the outer tube 3 of the expander, and the outer tube 3 of the expander separates from the expansion tube 11; Step 3: The drill rod 1 drives the expander to rotate 45°. Repeat Step 1 to expand the diameter of the bottommost section of the expansion tube 11 and make the entire expansion tube 11 fit against the hole wall; Step 4: The high-pressure liquid 2 is depressurized. The expansion blocks 7 retract into the outer tube 3 of the expander, and the outer tube 3 of the expander separates from the expansion tube 11. The expander is lifted by a certain height through the drill rod 1. Repeat Steps 1, 2, and 3 to expand the diameter of the entire expansion tube 11 in segments. Then the high-pressure liquid 2 is depressurized, and the expander is lifted out of the borehole through the drill rod 1 to complete the in-hole installation of the expansion tube 11.

Claims

1. An in-hole expander, characterized in that: It includes a drill pipe (1), high-pressure liquid (2), an outer pipe (3), a piston (4), an expansion cone (5), a copper plate (6), expansion blocks (7), stoppers (8), disc springs (9), screws (10), an expansion pipe (11) and a rubber plug (12); the expansion pipe (11) is sleeved outside the outer pipe (3), and the piston (4), expansion cone (5), expansion blocks (7), stoppers (8) and disc springs (9) are arranged inside the outer pipe (3). The drill pipe (1) is connected and communicated with the outer pipe (3). The inner cavity of the outer pipe (3) is provided with the piston (4). At least three expansion cones (5) are located below the piston (4) and fixedly connected to the piston (4). Each expansion block (7) is arranged outside the expansion cone (5). The copper plate (6) is located between the expansion cone (5) and the expansion block (7). The copper plate (6) is fixed on the inner wall of the expansion block (7). The outer surface of the expansion cone (5) is provided with a dovetail groove extending along the inclined surface. The copper plate (6) can slide in the dovetail groove; the rubber plug (12) is installed between the expansion pipe (11) and the outer pipe (3); the disc spring (9) is arranged at the bottom of the outer pipe (3). The upper end of the disc spring (9) abuts against the lower end of the expansion cone (5). Stoppers (8) are fixed on the side wall of the outer pipe (3) at the bottom surface of each expansion block (7). The stoppers (8) can block the expansion blocks (7). The inner cavity of the drill pipe (1) is communicated with the inner cavity of the outer pipe (3). The high-pressure liquid (2) is filled in the inner cavities of the drill pipe (1) and the outer pipe (3).

2. The internal hole expander according to claim 1, characterized in that: The rubber plug (12) is of an annular structure.

3. The hole expander according to claim 1, characterized in that: The disc spring (9) is formed by stacking a plurality of disc spring sheets.

4. The hole expander according to claim 1, wherein: The expansion pipe (11) is a screen pipe or a casing made of metal material.

5. The hole expander according to claim 1, characterized in that: The outer pipe (3) is connected to the drill pipe (1) by threads. The high-pressure liquid (2) acts on the piston (4) through the drill pipe.

6. The hole expander according to claim 1, wherein: The copper plate (6) is fixed on the inner wall of the expansion block (7) by screws (10).

7. The method for using an in-hole expander as claimed in claim 1, characterized in that: It includes the following steps: Step 1: The drill pipe (1) drives the expander to lower into the hole to a predetermined depth. The high-pressure liquid (2) enters the expander through the drill pipe (1). Under the action of the high-pressure liquid (2), the piston (4) compresses the disc spring (9) and pushes the expansion cone (5) downward. Under the action of the inclined surface structures of the expansion cone (5) and the expansion blocks (7), at least three expansion blocks (7) generate a large radial force and push the expansion pipe (11) to expand outward. The diameter of the expansion pipe (11) becomes larger, undergoes plastic deformation, and fits against the hole wall; Step 2: The high-pressure liquid (2) is depressurized. Under the thrust of the disc spring (9), the expansion cone (5) and the piston (4) move upward. Under the action of the dovetail groove on the expansion cone (5) and the copper plate (6), the expansion blocks (7) retract into the outer pipe (3) of the expander, and the outer pipe (3) of the expander is separated from the expansion pipe (11); Step 3: Drive the expander to rotate 45° through the drill pipe (1), repeat step (1), expand the diameter of the bottommost section of the expansion pipe (11) and make the entire expansion pipe (11) fit against the hole wall; Step 4: The high-pressure liquid (2) is depressurized, the expansion block (7) retracts into the outer tube 3 of the expander, the outer tube (3) of the expander separates from the expansion tube (11), the expander is lifted a certain height through the drill pipe (1), and Steps 1, 2, and 3 are repeated to expand the diameter of all the expansion tubes (11) in segments. Then the high-pressure liquid (2) is depressurized, and the expander is lifted out of the borehole through the drill pipe (1) to complete the installation of the expansion tube (11) in the borehole.

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