Single-pipe grouting annulus slurry replacement packer and construction method

Abstract

The invention discloses a single-pipe grouting annulus slurry replacement packer. The single-pipe grouting annulus slurry replacement packer is provided with a drill rod joint; one end of the drill rod joint is coupled with an inner pipe assembly; the inner pipe assembly is sequentially sleeved with a first outer pipe, a rubber sleeve short section and a second outer pipe in the axial direction. Through cooperation of the structures, the working processes of setting, grouting, annulus grout replacement and cement waiting and unsetting are achieved. According to the packer provided by the invention, local grouting in a hole is realized, so that the grouting amount and the grouting pressure can be effectively guaranteed; and drill holes except for the packer cannot be filled with grouting liquid in a coagulation waiting manner, through hole drilling is not needed, and a large amount of repeated footage is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of mine drilling, and particularly relates to a single-pipe grouting annulus displacement packer for fixed-point grouting and plugging in mine boreholes and a construction method thereof. Background Art

[0002] Drilling technology is an indispensable means in mine production for disaster control, geological exploration, resource prospecting, etc. With the increase in the depth of mine exploitation and drilling, the situation of encountering complex tectonic fractured strata is increasing, which has an adverse impact on the stability of boreholes. Currently, the commonly used method is to grout and reinforce the fractured strata and then drill through. When the borehole depth is relatively deep, when grouting at the hole mouth, it is extremely easy to occur that the grouting volume and grouting pressure of the pre-reinforced strata at the hole bottom do not meet the design requirements, resulting in an unsatisfactory grouting effect. Moreover, the total grouting volume of the whole hole is large, and the workload of reaming after setting is large, and the economic effect is poor. Therefore, there is an urgent need to develop an in-hole local grouting packer for fixed-point reinforcement of fractured strata in boreholes, and it should be convenient to use existing drilling tools to realize grouting construction, so as to solve the defects of unsatisfactory grouting effect of the whole hole and large construction volume. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: to overcome the defects of unsatisfactory grouting effect and large reaming workload in the existing hole mouth grouting technology for reinforcement of fractured strata in boreholes, and to provide a single-pipe grouting annulus displacement packer and a construction method. When grouting, the existing drill pipe can be used to realize the functions of setting the packer, grouting, and annulus displacement in the hole, simplify the construction drill tool combination and technological steps, and realize fixed-point grouting and reinforcement of fractured strata in the hole.

[0004] The technical solutions adopted by the present invention include:

[0005] A single-pipe grouting annulus displacement packer is provided with a drill pipe joint;

[0006] An inner pipe assembly is axially connected to one end of the drill pipe joint;

[0007] The outer edge of the inner pipe assembly is axially sleeved with a first outer pipe, a rubber cylinder short section, and a second outer pipe in sequence;

[0008] Setting: Water flows from the drill pipe, the drill pipe joint and through a section of the channel of the inner pipe assembly into the inner cavity between the first outer pipe and the inner pipe assembly, and flows into the rubber cylinder short section through the gap between the inner pipe assembly and the rubber cylinder short section to realize water filling and expansion for setting;

[0009] Grouting: The grout flows through the drill pipe, the drill pipe joint and through the whole section of the inner pipe assembly, reaches the end of the second outer pipe and flows out to realize pressure grouting;

[0010] Annular slurry replacement: The inner tube assembly moves axially away from the drill pipe relative to the first outer tube, the rubber tube nipple and the second outer tube, so that the whole section of water that passes through the drill pipe, the drill pipe joint and the inner tube assembly returns to the first outer tube through the first outer tube, the rubber tube nipple and the gap between the second outer tube and the inner tube assembly to flow out, thereby achieving residual slurry flushing;

[0011] Hou Ning unsealing: the inner tube assembly moves axially close to the drill pipe relative to the first outer tube, the rubber tube pup joint and the second outer tube, and the water in the rubber tube pup joint flows out to achieve unsealing.

[0012] Optionally, the inner tube assembly is a tubular structure as a whole, and the inner cavity of the tube is an inner channel;

[0013] A plurality of fan-shaped external bosses are arranged circumferentially on the outer periphery of the inner tube assembly corresponding to the first outer tube, and a water injection port is embedded on the tube wall;

[0014] A plug is provided in the inner channel and fixed by a pin;

[0015] An isolation ring is arranged on the outer periphery of the inner tube assembly corresponding to the rubber cylinder nipple, a sealing flange is arranged on the outer periphery corresponding to the second outer tube, a water outlet is arranged at the end, and a sealing drain hole is arranged on the isolation ring.

[0016] Optionally, the plurality of fan-shaped outer bosses are arranged at intervals to ensure that the first outer tube is connected to the outside of the inner tube assembly;

[0017] A through first flow passage is arranged in the fan-shaped outer boss along the axial direction of the tube, and pin retaining grooves are arranged at both ends of two circumferentially symmetrical fan-shaped outer bosses.

[0018] Optionally, the isolation ring is arranged along the circumference to form a plurality of groups of penetrating second flow passages;

[0019] A first sealing groove and a second sealing groove are arranged at intervals on the outer surface of the isolation ring, and a plurality of sealing drain holes penetrating the inner channel are arranged circumferentially between the first sealing groove and the second sealing groove, and the sealing drain holes are not connected to the second flow channel;

[0020] A third sealing groove is arranged on the outer periphery of the end of the isolation ring away from the first sealing groove.

[0021] Optionally, a group of sealing grooves are arranged in the middle of the outer surface of the sealing flange, and sealing rings are placed in the sealing grooves.

[0022] Optionally, the inner wall of the first outer tube and the fan-shaped outer boss on the inner tube assembly are provided with a fan-shaped inner boss correspondingly;

[0023] The fan-shaped outer boss and the fan-shaped inner boss cooperate with each other to form an annular partition, which is connected to the cavity through the first flow passage.

[0024] Optionally, an outer tube drainage hole is provided on the tube wall of the first outer tube corresponding to the fan-shaped inner boss, and outer tube pin holes are provided on both sides of the outer tube drainage hole respectively. The end of the first outer tube close to the drill pipe joint is a closing end hole, which is sleeved and sealed with the inner tube assembly.

[0025] Optionally, the rubber cartridge short section includes a rubber cartridge body, a capsule coated on the rubber cartridge body, a rubber cartridge one-way valve arranged on the rubber cartridge body close to the end of the first outer tube, and a capsule drain hole arranged at the other end.

[0026] Optionally, one end of the second outer tube is connected to the short section of the rubber tube, and an inner wall of the second outer tube is provided with an inner cavity flange to fit and dock with the inner tube assembly;

[0027] The other end of the second outer tube is a closed sealed end, an outer tube one-way valve is arranged at the end, and a grouting port is arranged on the tube wall behind the outer tube one-way valve.

[0028] A construction method of a single-tube grouting annulus replacement slurry packer, used for constructing the single-tube grouting annulus replacement slurry packer of the present invention, comprising:

[0029] The right end of the inner tube assembly passes through the end hole of the first outer tube and is connected to the drill pipe joint. The fan-shaped outer boss and the fan-shaped inner boss are staggered and matched. The pins are assembled into the pin holes of the outer tube and embedded in the pin retaining grooves at both ends of the boss to limit its displacement.

[0030] The left end of the inner tube assembly is connected to the rubber tube short section and the second outer tube in sequence, the isolation ring cooperates with the inner cavity of the rubber tube short section, and the first sealing groove, the second sealing groove and the third sealing groove are all provided with sealing rings for sealing the setting drain hole and the capsule drain hole, the sealing flange cooperates with the inner cavity flange and the sealing ring is placed in the sealing groove to realize the separation of the left and right cavities, and at the same time, a pin is placed in the pin hole of the inner tube to fix the plug at the corresponding position in the inner channel;

[0031] Sealing: clean water is injected into the drill pipe connected by the drill pipe joint. When it flows through the inner channel, it is blocked by the plug and enters the right end of the chamber between the inner cavity and the inner tube through the water injection port. It enters the left end of the chamber through the first flow channel of the fan-shaped outer boss and enters the cavity surrounded by the rubber tube body and the inner tube assembly. The water flow is blocked by the sealing flange and the inner cavity flange and can only flow into the capsule from the rubber tube check valve. At the same time, the capsule drain hole is blocked, and the capsule is filled with water to expand and seal. The sealing pressure is stabilized at 5MPa. After the capsule expands, the packer is sealed in the borehole.

[0032] Grouting: After the packing is completed, slurry is injected through the drill pipe. Since the cavity surrounded by the rubber tube body and the inner tube is still full of water, the grouting pressure is further increased to more than 5MPa to 10MPa. The inner tube pin of the plug is sheared off at a pressure of 8MPa, and the plug is flushed to the left end of the inner channel. The slurry flows through the water inlet, the outer tube one-way valve and the grouting port to the left end of the packer setting capsule and is sealed in the borehole to achieve pressure grouting;

[0033] Annulus slurry replacement: After the grouting is completed, the drill pipe is pushed into the hole to drive the inner tube assembly to move, and the fan-shaped outer boss cuts off the pin placed on the left side of the outer tube pin hole. At this time, the sealing flange and the inner cavity flange are staggered, the blocking channel is connected, the capsule drainage hole is still blocked, and the capsule sealing state remains unchanged. The fan-shaped outer boss is staggered from the outer tube drainage hole. After the clean water is injected, the water flow flushes the residual slurry in the packer through the inner channel, the water inlet, the inner cavity of the second outer tube, and enters the cavity on the right side of the inner cavity flange. It is discharged from the outer tube drainage hole through the second flow channel and the first flow channel, and finally discharged from the orifice through the gap between the drill pipe and the borehole annulus. In this process, all the slurry in the packer is discharged;

[0034] Unsealing after setting: When unsealing is required after the grouting has set, pull the drill rod toward the hole mouth to drive the inner tube assembly to move, and the fan-shaped outer boss cuts off the pin placed on the right side of the outer tube pin hole. At this time, the capsule drain hole is connected with the seat seal drain hole, and the pressurized water in the capsule flows out through this channel, and the capsule shrinks to achieve unsealing.

[0035] Beneficial effects of the present invention:

[0036] (1) Local grouting in the hole is achieved, so that the grouting volume and grouting pressure can be effectively guaranteed;

[0037] (2) The boreholes outside the packer will not be filled with grouting liquid, and there is no need to drill through the holes, which reduces a lot of repeated drilling. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0039] Figure 1 It is a schematic cross-sectional structure diagram of the single-tube grouting annulus replacement packer of the present invention in the AA direction;

[0040] Figure 2 for Figure 1 A schematic diagram of the three-dimensional structure of the inner tube assembly;

[0041] Figure 3 for Figure 1 A schematic diagram of the cross-sectional structure of the first outer tube in the BB direction;

[0042] The symbols in the figure represent:

[0043] 1- Drill pipe joint;

[0044] 2-inner tube assembly; 2-1 inner channel, 2-2 water injection port, 2-3 fan-shaped outer boss, 2-4 plug, 2-5 inner tube pin hole, 2-6 isolation ring, 2-7 sealing drain hole, 2-8 sealing flange, 2-9 water outlet; 2-31 first flow passage, 2-32 pin retaining groove, 2-61 second flow passage, 2-62 first sealing groove, 2-63 second sealing groove, 2-64 third sealing groove;

[0045] 3- first outer tube; 3-1 fan-shaped inner boss, 3-2 outer tube drain hole, 3-3 outer tube pin hole, 3-4 end hole, 3-5 inner cavity;

[0046] 4-rubber cartridge nipple; 4-1 rubber cartridge body, 4-2 capsule, 4-3 rubber cartridge one-way valve, 4-4 capsule drain hole;

[0047] 5-second outer pipe, 5-1 outer pipe one-way valve, 5-2 grouting port, 5-3 inner cavity flange. DETAILED DESCRIPTION

[0048] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0049] The present invention mainly includes a single-tube grouting annulus replacement slurry packer and its working principle. In order to achieve the above-mentioned purpose and the above-mentioned technical effect, the present invention is realized by the following technical solutions:

[0050] The single-tube grouting annulus replacement slurry packer of the present invention,

[0051] Combination Figures 1-3The single-tube grouting annulus replacement slurry packer of the present invention is provided with a drill pipe joint 1; an inner tube assembly 2 is axially connected to one end of the drill pipe joint 1, and a drill pipe is inserted and arranged at the other end of the drill pipe joint 1. For example, the drill pipe joint 1 is a tubular structure, which can be connected to the inner tube assembly 2 by threading, and the other end is an open mouth with a gradually larger inner diameter, which can directly insert the drill pipe, and the drill pipe is tightly held by the change of the inner diameter, so that the drill pipe, the drill pipe joint 1 and the inner tube assembly 2 are installed as a connected whole; the first outer tube 3, the rubber tube short section 4 and the second outer tube 5 are sequentially sleeved on the outer side of the inner tube assembly 2 along the axial direction; the cooperation of the above structure realizes the working process of setting, grouting, annular replacement slurry, and post-condensation unsealing, and the specific process includes: setting: water flows from the drill pipe, the drill pipe joint 1 and a section of the inner tube assembly 2 into the inner cavity of the first outer tube 3 and the inner tube assembly 2, and flows into the rubber tube short section 2 through the gap between the inner tube assembly 2 and the rubber tube short section 4 to realize water-filled expansion setting; grouting: slurry The liquid passes through the drill pipe, the drill pipe joint 1 and the entire section of the inner tube assembly 2, reaches the end of the second outer tube 5 and flows out to realize pressure grouting; annular slurry replacement: the inner tube assembly 2 moves away from the drill pipe axially relative to the first outer tube 3, the rubber tube short section 4 and the second outer tube 5, so that the entire section of water passing through the drill pipe, the drill pipe joint 1 and the inner tube assembly 2 returns to the first outer tube 3 through the gap between the first outer tube 3, the rubber tube short section 4, the second outer tube 5 and the inner tube assembly 2 and flows out, specifically flows out from the outer tube drainage hole 3-2, to realize residual slurry flushing; post-setting unsealing: the inner tube assembly 2 moves close to the drill pipe axially relative to the first outer tube 3, the rubber tube short section 4 and the second outer tube 5, and the water filled in the rubber tube short section 4 flows out to realize unsealing; through the arrangement of the above structure, local grouting in the hole is realized, so that the grouting amount and grouting pressure can be effectively guaranteed; the borehole outside the packer will not be filled with grouting liquid post-setting, and there is no need to drill through the hole, which reduces a large amount of repeated footage.

[0052] In the embodiment of the present disclosure, the inner tube assembly 2 is a tubular structure as a whole, and the inner cavity of the tube is an inner channel 2-1; a plurality of fan-shaped outer bosses 2-3 are circumferentially arranged on the outer periphery of the inner tube assembly 2 corresponding to the first outer tube 3, and a water injection port 2-2 is embedded on the tube wall; a plug 2-4 is provided in the inner channel 2-1 and fixed by a pin; an isolation ring 2-6 is provided on the outer periphery of the inner tube assembly 2 corresponding to the rubber sleeve short section 4, a sealing flange 2-8 is provided on the outer periphery corresponding to the second outer tube 5, a water inlet 2-9 is provided at the end, and a sealing drain hole 2-7 is provided on the isolation ring 2-6. The fan-shaped outer bosses 2-3 are arranged in multiple groups along the circumference, and multiple sealing drain holes 2-7 penetrating the inner channel 2-1 are arranged in the annular groove on the isolation ring 2-6. The sealing drain holes 2-7 avoid the first flow passage 2-61. The first sealing groove 2-62 and the second sealing groove 2-63 are respectively arranged at both ends of the annular groove, and a third sealing groove 2-64 is arranged at the other end of the isolation ring; a group of sealing grooves is arranged in the middle of the sealing flange 2-8, and a sealing ring is placed in the sealing groove for sealing the pipe body;

[0053] In an embodiment of the present disclosure, a plurality of sector-shaped outer bosses 2-3 are arranged at intervals to ensure external communication between the first outer tube 3 and the inner tube assembly 2; a first through-flow channel 2-31 is arranged axially along the tube inside the sector-shaped outer boss 2-3, and pin retaining grooves 2-32 are arranged at both ends of two circumferentially symmetric sector-shaped outer bosses 2-3 for installing pins on the first outer tube 3, corresponding to the positions of the outer tube pin holes 3-3 on the first outer tube, jointly defining the positions of the pins, thereby restricting the axial position movement of the inner tube assembly 2 relative to the first outer tube 3, and it can only move under the force of shearing the pins.

[0054] In an embodiment of the present disclosure, a plurality of groups of second through-flow channels 2-61 are arranged through the isolation ring 2-6 along the circumference; a first sealing groove 2-62 and a second sealing groove 2-63 are arranged at intervals on the outer surface of the isolation ring 2-6, and a plurality of setting and bleeding holes 2-7 that penetrate the inner channel are arranged circumferentially between the first sealing groove 2-62 and the second sealing groove 2-63, and the setting and bleeding holes 2-7 are not communicated with the second through-flow channel 2-61; a third sealing groove 2-64 is arranged on the outer periphery of the end of the isolation ring 2-6 away from the first sealing groove 2-62. The settings of the above channels and sealing structures are mainly used to block the capsule bleeding hole 4-4 on the setting nipple 4. Only under specific position conditions can the expansion water in the capsule 4-2 flow out through the capsule bleeding hole 4-4 and the setting and bleeding hole 2-7 to achieve unsealing.

[0055] In an embodiment of the present disclosure, a set of sealing grooves are arranged in the middle of the outer surface of the sealing flange 2-8, and sealing rings are placed in the sealing grooves for space sealing between the pipe cavities, so that the liquid flows out through a specific channel, such as the second through-flow channel 2-61.

[0056] In an embodiment of the present disclosure, sector-shaped inner bosses 3-1 are correspondingly arranged on the inner wall of the first outer tube 3 corresponding to the sector-shaped outer bosses 2-3 on the inner tube assembly 2; the sector-shaped outer bosses 2-3 and the sector-shaped inner bosses 3-1 cooperate with each other to form an annular partition, and the cavities are communicated through the first through-flow channel 2-31, so that the liquid in the inner cavity 3-5 of the first outer tube 3 only flows out through a specific channel, such as the first through-flow channel 2-31, to achieve control of the liquid flow path.

[0057] In an embodiment of the present disclosure, outer tube bleeding holes 3-2 are arranged on the tube wall of the first outer tube 3 corresponding to the sector-shaped inner bosses 3-1, and outer tube pin holes 3-3 are respectively arranged on both sides of the outer tube bleeding holes 3-2. The end of the first outer tube 3 close to the drill pipe joint is a closed-end hole, which is sleeved and sealed with the inner tube assembly 2. The sector-shaped inner bosses 3-1 and the sector-shaped outer bosses 2-3 cooperate with each other to form an annular partition, and only the first through-flow channel 2-31 is left in the inner cavity 3-5 to communicate the left and right cavities.

[0058] In the embodiment of the present disclosure, the 4-rubber cartridge short section 4 includes a rubber cartridge body 4-1, a capsule 4-2 wrapped on the rubber cartridge body 4-1, a rubber cartridge one-way valve 4-3 arranged at the end of the rubber cartridge body 4-1 close to the first outer tube 3, and a capsule drain hole 4-4 arranged at the other end.

[0059] In the embodiment of the present disclosure, one end of the second outer tube 5 is axially connected to the rubber tube nipple 4, and an inner cavity flange 5-3 is arranged on the inner wall of the second outer tube 5 to fit and dock with the inner tube assembly 2; the other end of the second outer tube 5 is a closed sealing end, an outer tube check valve 5-1 is arranged at the end, and a grouting port 5-2 is arranged on the tube wall behind the outer tube check valve 5-1. The second outer tube 5 is provided with an outer tube check valve 5-1 and a grouting port 5-2, wherein the outer tube check valve 5-1 prevents the slurry in the injection hole from flowing back into the packer, and an inner cavity flange 5-3 is arranged in the inner cavity of the second outer tube 5, which cooperates with the sealing flange 2-8 on the inner tube assembly 2 for sealing.

[0060] The connection method of the packer is as follows: the right end of the inner tube assembly 2 passes through the end hole of the first outer tube 3 and is connected to the drill pipe joint, the fan-shaped outer boss 2-3 is staggered with the fan-shaped inner boss 3-1, and is assembled to the outer tube pin hole 3-3 with a pin and embedded in the pin retaining groove 2-32 at both ends of the boss to limit its displacement; the left end of the inner tube assembly 2 is sequentially connected to the rubber sleeve short section 4 and the second outer tube 5, the isolation ring 2-6 is matched with the inner cavity of the rubber sleeve short section 4, and its first sealing groove 2-62, the second sealing groove 2-63 and the third sealing groove 2-64 are all provided with sealing rings for sealing the seat drain hole 2-7 and the capsule drain hole 4-4, the sealing flange 2-8 is matched with the inner cavity flange 5-3 and a sealing ring is placed in the sealing groove to realize the partition of the left and right cavities, and at the same time, a pin is placed in the inner tube pin hole 2-5 to fix the plug 2-4 to the corresponding position in the inner channel 2-1.

[0061] The single-tube grouting annulus replacement slurry packer of the present invention has a working process of four steps: setting, grouting, annulus replacement slurry, and waiting for solidification and unsealing. The principle is:

[0062] Sealing: clean water is injected into the drill pipe connected by the drill pipe joint 1. When it flows through the inner channel 2-1, it is blocked by the plug 2-4, enters the right end of the chamber between the inner cavity 3-5 and the inner tube through the water injection port 2-2, enters the left end of the chamber through the first flow channel 2-31 of the fan-shaped outer boss 2-3, and enters the cavity surrounded by the rubber tube body 4-1 and the inner tube assembly 2. The water flow is blocked by the sealing flange 2-8 and the inner cavity flange 5-3, and can only flow into the capsule 4-2 from the rubber tube check valve 4-3. At the same time, the capsule drain hole 4-4 is blocked, and the capsule is filled with water to expand and seal. Generally, the sealing pressure is stabilized at 5MPa. After the capsule 4-2 expands, the packer is sealed in the borehole. The rubber tube check valve 4-3 prevents the pressure water in the capsule 4-2 from flowing back and affecting the sealing effect.

[0063] Grouting: After the sealing is completed, slurry is injected through the drill pipe. Since the cavity surrounded by the rubber tube body 4-1 and the inner tube is still full of water and the liquid is basically incompressible, the slurry basically does not enter through the water injection port 2-2 or only enters a small amount into the right end of the chamber between the inner cavity 3-5 and the inner tube, further increasing the grouting pressure to exceed 5MPa to 10MPa. Generally, the inner tube pin 2-5 of the plug 2-4 is sheared off at a pressure of about 8MPa, and the plug 2-4 is flushed to the left end of the inner channel 2-1. The slurry flows through the water port 2-9, the outer tube one-way valve 5-1 and the grouting port 5-2 to the left end of the sealing capsule of the packer, and the pressure grouting is realized in the closed borehole. At this time, the grouting pressure is adjusted according to the formation conditions until the grouting is completed. The outer tube one-way valve 5-1 can prevent the drilling slurry from flowing back after the grouting is completed and maintain the grouting pressure in the borehole.

[0064] Annular space slurry replacement: After grouting is completed, the drill pipe is pushed into the hole to drive the inner tube assembly 2 to move, and the fan-shaped outer boss 2-3 cuts off the pin placed on the left side of the outer tube pin hole 3-3. At this time, the sealing flange 2-8 is offset from the inner cavity flange 5-3, and the blocking channel is connected, but the capsule drainage hole 4-4 is still blocked, and the capsule 4-2 is in the sealed state. The fan-shaped outer boss 2-3 is offset from the outer tube drainage hole 3-2. After injecting clean water, the water flow flushes the residual slurry in the packer through the inner channel 2-1, the water inlet 2-9, and the inner cavity of the second outer tube 5 into the cavity on the right side of the inner cavity flange 5-3, and is discharged from the outer tube drainage hole 3-2 through the second flow channel 2-61 and the first flow channel 2-31, and finally discharged from the orifice through the gap between the drill pipe and the borehole annulus. In this process, all the slurry in the packer is discharged to avoid the slurry solidifying in the packer during the waiting period and causing the packer to be scrapped and damaged.

[0065] Unsealing after setting: When unsealing is required after the grouting is set, the drill rod is pulled toward the hole mouth to drive the inner tube assembly 2 to move, and the fan-shaped outer boss 2-3 cuts off the pin arranged on the right side of the outer tube pin hole 3-3. At this time, the capsule drain hole 4-4 is connected with the set seal drain hole 2-7, and the pressurized water in the capsule 4-2 is discharged through this channel. The capsule 4-2 shrinks to achieve unsealing, and the drill rod and the packer in the hole are lifted out. After replacing all the pins, the packer can be reused.

[0066] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A single-tube grouting annulus replacement packer, characterized in that: Arranging a drill pipe joint (1); An inner tube assembly (2) is axially connected to one end of the drill pipe joint (1); The inner tube assembly (2) is sleeved with a first outer tube (3), a rubber tube nipple (4) and a second outer tube (5) in sequence along the axial direction. Setting seal: water flows from the drill pipe and the drill pipe joint (1) through a section of the channel of the inner pipe assembly (2) into the inner cavity of the first outer pipe (3) and the inner pipe assembly (2), and flows into the rubber sleeve short section (2) through the gap between the inner pipe assembly (2) and the rubber sleeve short section (4) to achieve water-filled expansion and setting seal; Grouting: The slurry flows through the drill pipe, the drill pipe joint (1) and the entire section of the inner pipe assembly (2) to the end of the second outer pipe (5) and flows out to realize pressure grouting; Annular slurry replacement: the inner tube assembly (2) moves away from the axial direction of the drill pipe relative to the first outer tube (3), the rubber tube nipple (4) and the second outer tube (5), so that the entire section of water that passes through the drill pipe, the drill pipe joint (1) and the inner tube assembly (2) returns to the first outer tube (3) through the gap between the first outer tube (3), the rubber tube nipple (4) and the second outer tube (5) and the inner tube assembly (2) and flows out, thereby achieving residual slurry flushing; Post-condensation unsealing: the inner tube assembly (2) moves axially toward the drill pipe relative to the first outer tube (3), the rubber tube nipple (4) and the second outer tube (5), and the water in the rubber tube nipple (4) flows out, thus achieving unsealing.

2. The single-tube grouting annulus replacement packer according to claim 1 is characterized in that: The inner tube assembly (2) is a tubular structure as a whole, and the inner cavity of the tube is an inner channel (2-1); A plurality of fan-shaped external bosses (2-3) are arranged in a circumferential direction on the outer periphery of the inner tube assembly (2) corresponding to the first outer tube (3), and a water injection port (2-2) is embedded on the tube wall; A plug (2-4) is arranged in the inner channel (2-1) and fixed by a pin; An isolation ring (2-6) is arranged on the outer periphery of the inner tube assembly (2) corresponding to the rubber cylinder nipple (4), a sealing flange (2-8) is arranged on the outer periphery corresponding to the second outer tube (5), a water inlet (2-9) is arranged at the end, and a sealing drain hole (2-7) is arranged on the isolation ring (2-6).

3. The single-tube grouting annulus replacement packer according to claim 2 is characterized in that: The plurality of fan-shaped outer bosses (2-3) are arranged at intervals to ensure that the first outer tube (3) is externally connected to the inner tube assembly (2); A first through-flow channel (2-31) is arranged in the fan-shaped outer boss (2-3) along the axial direction of the tube, and pin retaining grooves (2-32) are arranged at both ends of two circumferentially symmetrical fan-shaped outer bosses (2-3).

4. The single-tube grouting annulus replacement packer according to claim 2 or 3, characterized in that: The isolation ring (2-6) is arranged along the circumference of a plurality of groups of penetrating second flow passages (2-61); A first sealing groove (2-62) and a second sealing groove (2-63) are arranged at intervals on the outer surface of the isolation ring (2-6); a plurality of setting drain holes (2-7) penetrating the inner channel are arranged circumferentially between the first sealing groove (2-62) and the second sealing groove (2-63); and the setting drain holes (2-7) are not connected to the second flow passage (2-61); A third sealing groove (2-64) is arranged on the outer periphery of the end of the isolation ring (2-6) away from the first sealing groove (2-62).

5. The single-tube grouting annulus replacement packer according to claim 2 or 3, characterized in that: A group of sealing grooves are arranged in the middle of the outer surface of the sealing flange (2-8), and sealing rings are placed in the sealing grooves.

6. The single-tube grouting annulus replacement packer according to claim 3 is characterized in that: The inner wall of the first outer tube (3) and the fan-shaped outer boss (2-3) on the inner tube assembly (2) are provided with a fan-shaped inner boss (3-1) correspondingly; The fan-shaped outer boss (2-3) and the fan-shaped inner boss (3-1) cooperate with each other to form an annular partition, which is connected to the cavity through the first flow passage (2-31).

7. The single-tube grouting annulus replacement packer according to claim 6 is characterized in that: An outer tube drain hole (3-2) is arranged on the tube wall of the first outer tube (3) corresponding to the fan-shaped inner boss (3-1), and outer tube pin holes (3-3) are respectively arranged on both sides of the outer tube drain hole (3-2). The end of the first outer tube (3) close to the drill pipe joint is a closing end hole, which is sleeved and sealed with the inner tube assembly (2).

8. The single-tube grouting annulus replacement packer according to claim 1, 2 or 3, characterized in that: The 4-rubber cartridge short section (4) comprises a rubber cartridge body (4-1), a capsule (4-2) coated on the rubber cartridge body (4-1), a rubber cartridge one-way valve (4-3) arranged at the end of the rubber cartridge body (4-1) close to the first outer tube (3), and a capsule drain hole (4-4) arranged at the other end.

9. The single-tube grouting annulus replacement packer according to claim 1, 2 or 3, characterized in that: One end of the second outer tube (5) is axially connected to the rubber cylinder short section (4), and an inner cavity flange (5-3) is arranged on the inner wall of the second outer tube (5) to fit and dock with the inner tube assembly (2); The other end of the second outer tube (5) is a sealed end, an outer tube one-way valve (5-1) is arranged at the end, and a grouting port (5-2) is arranged on the tube wall behind the outer tube one-way valve (5-1).

10. A construction method for a single-tube grouting annulus replacement packer, characterized in that: The single-tube grouting annulus replacement packer used for constructing any one of claims 1 to 9 of the present invention comprises: The right end of the inner tube assembly (2) passes through the end hole of the first outer tube (3) and is connected to the drill pipe joint (1); the fan-shaped outer boss (2-3) and the fan-shaped inner boss (3-1) are staggered and matched, and a pin is assembled into the outer tube pin hole (3-3) and embedded in the pin retaining grooves (2-32) at both ends of the boss to limit its displacement; The left end of the inner tube assembly (2) is connected to the rubber tube short section (4) and the second outer tube (5) in sequence, the isolating ring (2-6) cooperates with the inner cavity of the rubber tube short section (4), the first sealing groove (2-62), the second sealing groove (2-63) and the third sealing groove (2-64) are all provided with sealing rings for sealing the setting drain hole (2-7) and the capsule drain hole (4-4), the sealing flange (2-8) cooperates with the inner cavity flange (5-3) and the sealing ring is placed in the sealing groove to realize the separation of the left and right cavities, and at the same time, a pin is placed in the inner tube pin hole (2-5) to fix the plug (2-4) to the corresponding position in the inner channel (2-1); Sealing: clean water is injected into the drill pipe connected by the drill pipe joint (1). When flowing through the inner channel (2-1), it is blocked by the plug (2-4), enters the right end of the chamber between the inner cavity (3-5) and the inner tube through the water injection port (2-2), enters the left end of the chamber through the first flow passage (2-31) of the fan-shaped outer boss (2-3), and enters the cavity surrounded by the rubber tube body (4-1) and the inner tube assembly (2). The water flow is blocked by the sealing flange (2-8) and the inner cavity flange (5-3), and can only flow into the capsule (4-2) from the rubber tube check valve (4-3). At the same time, the capsule drain hole (4-4) is blocked, and the capsule (4-2) is filled with water to expand and seal. The sealing pressure is stabilized at 5MPa. After the capsule (4-2) expands, the packer is sealed in the borehole. Grouting: After the sealing is completed, slurry is injected through the drill pipe. Since the cavity surrounded by the rubber tube body (4-1) and the inner tube is still full of water, the grouting pressure is further increased to exceed 5MPa to 10MPa. The inner tube pin (2-5) of the plug (2-4) is sheared off at a pressure of 8MPa, and the plug (2-4) is flushed to the left end of the inner channel (2-1). The slurry flows through the water inlet (2-9), the outer tube one-way valve (5-1) and the grouting port (5-2) to the left end of the sealing capsule of the packer and is sealed in the borehole to achieve pressure grouting; Annular space grout replacement: After the grouting is completed, the drill pipe is pushed into the hole to drive the inner tube assembly (2) to move, and the fan-shaped outer boss (2-3) cuts off the pin placed on the left side of the outer tube pin hole (3-3). At this time, the sealing flange (2-8) and the inner cavity flange (5-3) are offset, the blocking channel is connected, the capsule drain hole (4-4) is still blocked, the capsule (4-2) remains in the sealing state, and the fan-shaped outer boss (2-3) is offset from the outer tube drain hole ( 3-2), after the clean water is injected, the water flow flushes the residual slurry in the packer through the inner channel (2-1), the water inlet (2-9) and the inner cavity of the second outer tube (5), enters the right cavity of the inner cavity flange (5-3), and is discharged from the outer tube drain hole (3-2) through the second flow passage (2-61) and the first flow passage (2-31), and finally discharged from the orifice through the gap between the drill pipe and the borehole annulus. In this process, all the slurry in the packer is discharged; Unsealing after setting: When unsealing is required after setting, the drill rod is pulled toward the hole mouth to drive the inner tube assembly (2) to move, and the fan-shaped outer boss (2-3) cuts off the pin arranged on the right side of the outer tube pin hole (3-3). At this time, the capsule drain hole (4-4) is connected with the set seal drain hole (2-7), and the pressure water in the capsule (4-2) is discharged through this channel, and the capsule (4-2) shrinks to achieve unsealing.

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