A plugging string for open hole well

Abstract

The present invention discloses a plugging string for an open-hole well, comprising a delivery string, a separation device, a suspension support device, a plugger, a check valve and an open-hole wellbore; the delivery string, the separation device, the suspension support device, the plugger and the check valve are connected in sequence and then lowered into the open-hole wellbore. At the same time, the present invention provides a plugging method for a plugging string for an open-hole well, firstly, a positive well wash is performed, and drilling fluid is injected from the delivery string; then, a ball is cast to pressurize the delivery string, 7-9 MPa is pressed into the delivery string to anchor the suspension support device; 12-14 MPa is pressed into the delivery string to make the plugger seal the open-hole wellbore; 18-19 MPa is pressed into the delivery string to separate the separation device into two bodies. The present invention has a simple process, is convenient and fast, and fundamentally avoids the construction risks, wellbore complexity and oil layer damage caused by the use of suspended cement plugs, and can safely and efficiently perform operations such as sealing and isolation in an open-hole wellbore that needs to seal the lower invalid well section or leaking layer.

Description

Technical Field

[0001] The invention relates to the field of petroleum production and completion equipment, and in particular to a plugging string for an open hole well. Background Art

[0002] When the oil well is drilled, it is necessary to seal the invalid well section or leaking layer at the bottom. In order to reduce cementing and sealing the well section or prevent leakage, the bottom of the well needs to be permanently sealed. This operation is called sealing and isolation in the oil field. Since there is no casing in this section of the well wall, it is called sealing and isolation in the open hole wellbore. At present, when sealing and isolating in the open hole wellbore, the method of drilling suspended cement plugs is mostly used to seal and isolate the bottom of the well. For example, a patent entitled "Method for plugging a perforating section of a small-bore side-drilling well" (application number 201611075931.3, publication number CN106639969A) proposes a method for plugging a perforating section of a small-bore side-drilling well, wherein the method comprises the following steps: Step S100, opening the wellhead plugger, injecting workover fluid into the casing, using a first well gauge to plow the well to the top of the hanger, and then using a second well gauge to plow the well to the artificial bottom of the side-drilling well section; Step S200, lowering the working pipe string, and plugging each perforating section in turn from top to bottom until the perforating section close to the artificial bottom of the well is plugged; Step S300, cleaning the casing with a scraper drill bit until the artificial bottom of the well is reached; Wherein, the plugging operation in step S200 includes the following steps: step S210, drilling a suspended cement plug into the perforating section through the working pipe string below the perforating section, and waiting for the suspended cement plug to solidify into shape; step S220, performing cement squeezing plugging operation on the perforating section, and forming a temporary cement plug of the perforating section in the casing and above the suspended cement plug; closing the wellhead plugger, and waiting for the temporary cement plug to solidify into shape under pressure; step S230, opening the wellhead plugger, lowering a scraper drill bit, the scraper drill bit contacts the temporary cement plug, and the scraper drill bit drills through the temporary cement plug and the suspended cement plug from top to bottom in sequence, thereby completing the plugging operation of the perforating section.

[0003] However, the use of suspended cement plugs has the following defects: (1) The cement plugging process is complex and takes a long time; (2) Some wells have leakage and well gusher phenomena, and the risk of cement plugging is high; (3) Cement plugging can easily cause wellbore complexity; (4) The cement plugging process causes damage to the upper oil layer. Summary of the invention

[0004] In view of the defects of the prior art, the present invention provides a plugging string for open hole wells, which has a simple process, is convenient and quick, and fundamentally avoids the construction risks, wellbore complexity and oil layer damage caused by driving suspended cement plugs.

[0005] The technical solution of the present invention is: comprising a delivery pipe string, a separation device, a suspension support device, a plugging device, a check valve and an open hole wellbore; the delivery pipe string, the separation device, the suspension support device, the plugging device and the check valve are connected in sequence and then lowered into the open hole wellbore.

[0006] The plugger comprises a sealing inner tube, a constant pressure shear nail, a one-way opening locking ring, an upper sealing ring, a lower sealing ring, a sealing outer tube, an upper cone, a rubber tube, an inner tube, a lower cone and a connecting sleeve; the outer side of the sealing inner tube is provided with an outer diameter reducing shoulder surface, the sealing inner tube is provided with a pressure transmission hole, an upper sealing ring is installed on the outer wall of the sealing inner tube, and an outer one-way locking buckle is provided on the outer wall of the sealing inner tube; the sealing outer tube is sleeved outside the sealing inner tube, the inner side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the inner side of the sealing outer tube is provided with a lower sealing ring; the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed ... upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed; the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed; the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed; the upper side of the sealing outer tube is provided A conical shoulder is provided on the inner side of the part and a one-way open locking ring is placed. An inner one-way locking buckle is provided on the inner wall of the one-way open locking ring, and the inner one-way locking buckle cooperates with the outer one-way locking buckle; the lower part of the connecting sleeve is connected to the upper part of the sealed inner tube, and the connecting sleeve is connected to the sealed inner tube by a constant pressure shear nail; the lower part of the sealed outer tube is connected to the upper cone, and the lower part of the upper cone is a cone; the upper part of the lower cone is a cone; the outer part of the inner tube is covered with a rubber sleeve, and the upper and lower parts of the rubber sleeve are provided with conical holes; the lower part of the inner tube is connected to the upper part of the lower cone.

[0007] The separation device comprises a separation upper joint, a separation shear pin, a sealing ring, a hanging joint, an upper sealing ring, a thrust piston, a lower sealing ring, a locking sleeve, a separation locking block, a separation lower joint and an inverted joint; the lower part of the separation upper joint is sleeved on the upper outer side of the separation lower joint, and the separation locking block is installed at the window of the separation upper joint; the locking sleeve is sleeved on the lower outer side of the separation upper joint, and a release chamber is provided at the lower part of the locking sleeve; a lower sealing ring is installed between the locking sleeve and the separation upper joint, an outer shoulder is provided on the outer side of the separation upper joint, a connecting hole is provided on the separation upper joint, a thrust piston is installed in the annular space between the separation upper joint and the locking sleeve, the thrust piston is connected to the separation upper joint by the separation shear pin, and a sealing ring is installed between the separation upper joint and the thrust piston; an upper sealing ring is installed between the thrust piston and the locking sleeve, and a hanging joint is installed on the upper part of the locking sleeve; the lower part of the separation lower joint is threadedly connected with the upper part of the inverted joint.

[0008] The suspension support device includes a main body, an upper hinge shaft, a suspension support plate, a hinge shaft, a lever, a lower hinge shaft, a support piston, a sealing sleeve, an inner upper sealing ring, an outer upper sealing ring, an outer lower sealing ring, a locking block, a starting shear pin, a lower piston, an inner lower sealing ring and a bottom joint; a pressure charging hole is provided on the main body, the support piston is sleeved on the main body, and an inner upper sealing ring is installed between the support piston and the main body; the locking block is installed in a window at the lower part of the support piston, and the upper part of the lower piston is sleeved on the lower part of the support piston; a pressure charging hole is provided on the main body, and ... an inner upper sealing ring is installed between the support piston and the main body An inner lower sealing ring is installed; the upper end of the suspension support plate is connected to the side of the main body by an upper hinge shaft, and the lower end of the lever is connected to the side of the upper part of the support piston by a lower hinge shaft, and the hinge shaft hinges the suspension support plate and the lever; the sealing sleeve is sleeved on the periphery of the support piston and the lower piston, an outer upper sealing ring is installed between the sealing sleeve and the support piston, an outer lower sealing ring is installed between the sealing sleeve and the lower piston, the sealing sleeve is connected to the lower piston by a starting shear nail, and a drain hole is provided at the lower part of the sealing sleeve; the upper part of the bottom joint is connected to the lower part of the main body.

[0009] The rubber cylinder is a self-expanding rubber cylinder.

[0010] The present invention also provides a plugging method for an open hole plugging pipe string, which comprises the following steps:

[0011] Step 1: Positive well washing: drilling fluid is pumped into the wellbore from the delivery pipe string, and then returns to the annulus of the open hole wellbore through the separation device, the suspension support device, the plugging device and the check valve;

[0012] Step 2: Throwing ball to pressurize: throw the valve ball on the check valve into the delivery string, wait for the valve ball to be seated, pressurize the delivery string to 7-9MPa to anchor the suspension support device on the wall of the open hole wellbore; pressurize the delivery string to 12-14MPa to make the plug work and seal the open hole wellbore; pressurize the delivery string to 18-19MPa to make the separation device separate into two bodies, the suspension support device, plug and check valve under the lower body remain in the open hole wellbore, and the upper body is lifted out with the delivery string.

[0013] Compared with the prior art, the present invention mainly has the following beneficial technical effects:

[0014] 1. The process is simple, convenient and fast, which fundamentally avoids the construction risks, wellbore complexity and oil layer damage caused by driving suspended cement plugs. It can safely and efficiently perform sealing and isolation operations in open hole wellbores that need to seal the lower invalid well section or leaking layer.

[0015] 2. The method of gradually pressurizing the delivery pipe string is adopted to continuously realize the anchoring, plugging and sealing of the suspension support and the separation and release, so that the rubber tube of the plugging device can permanently seal the open hole wellbore. In particular, the rubber tube adopts a self-expanding rubber tube that can expand and compress. It can expand in oil and water and can seal the wellbore with a large diameter, which is particularly suitable for the isolation of open hole sections.

[0016] 3. The separation device adopts a locking connection and step-by-step separation start structure. During separation, the thrust piston starts upward alone, which is not affected by factors such as well inclination, string stiffness, and string upsetting, and can ensure reliable and safe separation under the designed pressure.

[0017] 4. The suspension support device adopts a lever ratio structure. The lever is inserted deep into the well wall. The suspension support plate has a large diameter range and can adapt to open hole wells of different diameters. The anchoring suspension is reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of a wellbore string structure according to an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 Schematic diagram of the structure of the occluder;

[0020] Figure 3 yes Figure 1 Schematic diagram of the upper structure of the middle occluder;

[0021] Figure 4 yes Figure 1 A schematic diagram of the structure of the separation device;

[0022] Figure 5 yes Figure 1 A schematic diagram of the structure of the middle suspension support device;

[0023] In the figure: 1. conveying pipe string, 2. separation device, 3. suspension support device, 4. plugging device, 5. check valve, 6. open hole wellbore, 2-1. separation upper joint, 2-1-1. connecting hole, 2-1-2. outer shoulder, 2-2. separation shear nail, 2-3. sealing ring, 2-4. hanging joint, 2-5. upper sealing ring, 2-6. thrust piston, 2-7. lower sealing ring, 2-8. locking sleeve, 2-8-1. release chamber, 2-9. separation locking block, 2-10. separation lower joint, 2-11. undercut joint, 3-1. main body, 3-1-1. charging hole, 3-2. upper hinge shaft, 3-3. suspension support plate, 3-4. hinge shaft, 3-5. lever, 3-6. lower hinge shaft, 3-7. support piston, 3-8. seal Sleeve, 3-8-1. Drain hole, 3-9. Inner upper sealing ring, 3-10. Outer upper sealing ring, 3-11. Outer lower sealing ring, 3-12. Locking block, 3-13. Starting shear pin, 3-14. Lower piston, 3-15. Inner lower sealing ring, 3-16. Bottom joint, 4-1. Sealed inner tube, 4-1-1. External one-way lock buckle, 4-1-2. External reducer shoulder surface, 4-1-3. Pressure transmission hole, 4-2. Constant pressure shear pin, 4-3. One-way open locking ring, 4-4. Upper sealing ring, 4-5. Lower sealing ring, 4-6. Sealed outer tube, 4-6-1. Conical shoulder, 4-6-2. Inner reducer shoulder surface, 4-7. Upper cone, 4-8. Rubber cylinder, 4-9. Inner tube, 4-10. Lower cone, 4-11. Connecting sleeve. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with the embodiments and drawings. Example 1

[0025] See also Figure 1 , Figure 2 and Figure 3 A plugging string for an open hole well comprises a delivery string 1, a separation device 2, a suspension support device 3, a plugging device 4, a check valve 5 and an open hole wellbore 6. The delivery string 1, the separation device 2, the suspension support device 3, the plugging device 4 and the check valve 5 are connected in sequence and lowered into the open hole wellbore 6.

[0026] The plugging device comprises a sealing inner tube 4-1, a constant pressure shear nail 4-2, a one-way open lock ring 4-3, an upper sealing ring 4-4, a lower sealing ring 4-5, a sealing outer tube 4-6, an upper cone 4-7, a rubber tube 4-8, an inner tube 4-9, a lower cone 4-10 and a connecting sleeve 4-11. An outer reducing shoulder surface 4-1-2 is provided on the outside of the sealing inner tube 4-1, the outer diameter above the reducing shoulder surface 4-1-2 is larger than the outer diameter below, a pressure transmission hole 4-1-3 is provided on the sealing inner tube 4-1, the pressure transmission hole 4-1-3 is located below the reducing shoulder surface 4-1-2, an upper sealing ring 4-4 ​​is installed on the outer wall of the sealing inner tube 4-1, the upper sealing ring 4-4 ​​is located above the reducing shoulder surface 4-1-2, an outer one-way lock buckle 4-1-1 is provided on the outer wall of the sealing inner tube 4-1, and the outer one-way lock buckle 4-1-1 is located above the upper sealing ring 4-4. The sealed outer tube 4-6 is sleeved outside the sealed inner tube 4-1, and an inner reducer shoulder surface 4-6-2 is provided inside the sealed outer tube 4-6. The inner diameter of the sealed outer tube 4-6 above the inner reducer shoulder surface 4-6-2 is larger than the inner diameter below it. The lower sealing ring 4-5 is installed inside the sealed outer tube 4-6. The lower sealing ring 4-5 is below the inner reducer shoulder surface 4-6-2. The inner reducer shoulder surface 4-6-2 is below the outer reducer shoulder surface 4-1-2. The lower sealing ring 4-5 is below the pressure transmission hole 4-1-3. The gap between the upper sealing ring 4-4, the lower sealing ring 4-5, the sealed inner tube 4-1 and the sealed outer tube 4-6 prevents the fluid from leaking from the pressure transmission hole 4-1-3 into the gap between the inner reducer shoulder surface 4-6-2 and the outer reducer shoulder surface 4-1-2. The inner side of the upper part of the sealed outer tube 4-6 is provided with a conical shoulder 4-6-1 and a one-way open lock ring 4-3. The cone at the lower end of the one-way open lock ring 4-3 matches the conical shoulder 4-6-1. The one-way open lock ring 4-3 is located above the outer one-way lock buckle 4-1-1. The inner wall of the one-way open lock ring 4-3 is provided with an inner one-way lock buckle. The inner one-way lock buckle matches the outer one-way lock buckle 4-1-1. When the two are buckled, the one-way open lock ring 4-3 cannot move upward. The lower part of the connecting sleeve 4-11 is connected to the upper part of the sealed inner tube 4-1, so that the one-way open lock ring 4-3 cannot move axially in the sealed outer tube 4-6. The connecting sleeve 4-11 is connected to the sealed inner tube 4-1 by the constant pressure shear nail 4-2. The lower part of the sealed outer tube 4-6 is connected to the upper cone 4-7. The lower part of the upper cone 4-7 is a cone, and the lower end diameter of the cone is smaller than the upper end diameter. The upper part of the inner tube 4-9 passes through the upper cone 4-7 and is connected to the lower part of the sealed inner tube 4-1, and the connection is kept sealed. The upper part of the lower cone 4-10 is a cone, and the upper end diameter of the cone is smaller than the lower end diameter. The outer part of the inner tube 4-9 is covered with a rubber sleeve 4-8, and the upper part of the rubber sleeve 4-8 is provided with a conical hole that is covered outside the lower cone of the upper cone 4-7, and the lower part of the rubber sleeve 4-8 is provided with a conical hole that is covered on the upper cone of the lower cone 4-10. The lower part of the inner tube 4-9 is connected to the upper part of the lower cone 4-10, and the connection is kept sealed. Example 2

[0027] See also Figure 1 , Figure 2 , Figure 3 and Figure 4 A plugging string for an open hole well comprises a delivery string 1, a separation device 2, a suspension support device 3, a plugging device 4, a check valve 5 and an open hole wellbore 6. The delivery string 1, the separation device 2, the suspension support device 3, the plugging device 4 and the check valve 5 are connected in sequence and lowered into the open hole wellbore 6.

[0028] The plugging device comprises a sealing inner tube 4-1, a constant pressure shear nail 4-2, a one-way open lock ring 4-3, an upper sealing ring 4-4, a lower sealing ring 4-5, a sealing outer tube 4-6, an upper cone 4-7, a rubber tube 4-8, an inner tube 4-9, a lower cone 4-10 and a connecting sleeve 4-11. An outer reducing shoulder surface 4-1-2 is provided on the outside of the sealing inner tube 4-1, the outer diameter above the reducing shoulder surface 4-1-2 is larger than the outer diameter below, a pressure transmission hole 4-1-3 is provided on the sealing inner tube 4-1, the pressure transmission hole 4-1-3 is located below the reducing shoulder surface 4-1-2, an upper sealing ring 4-4 ​​is installed on the outer wall of the sealing inner tube 4-1, the upper sealing ring 4-4 ​​is located above the reducing shoulder surface 4-1-2, an outer one-way lock buckle 4-1-1 is provided on the outer wall of the sealing inner tube 4-1, and the outer one-way lock buckle 4-1-1 is located above the upper sealing ring 4-4. The sealed outer tube 4-6 is sleeved outside the sealed inner tube 4-1, and an inner reducer shoulder surface 4-6-2 is provided inside the sealed outer tube 4-6. The inner diameter of the sealed outer tube 4-6 above the inner reducer shoulder surface 4-6-2 is larger than the inner diameter below it. The lower sealing ring 4-5 is installed inside the sealed outer tube 4-6. The lower sealing ring 4-5 is below the inner reducer shoulder surface 4-6-2. The inner reducer shoulder surface 4-6-2 is below the outer reducer shoulder surface 4-1-2. The lower sealing ring 4-5 is below the pressure transmission hole 4-1-3. The gap between the upper sealing ring 4-4, the lower sealing ring 4-5, the sealed inner tube 4-1 and the sealed outer tube 4-6 prevents the fluid from leaking from the pressure transmission hole 4-1-3 into the gap between the inner reducer shoulder surface 4-6-2 and the outer reducer shoulder surface 4-1-2. The inner side of the upper part of the sealed outer tube 4-6 is provided with a conical shoulder 4-6-1 and a one-way open lock ring 4-3. The cone at the lower end of the one-way open lock ring 4-3 matches the conical shoulder 4-6-1. The one-way open lock ring 4-3 is located above the outer one-way lock buckle 4-1-1. The inner wall of the one-way open lock ring 4-3 is provided with an inner one-way lock buckle. The inner one-way lock buckle matches the outer one-way lock buckle 4-1-1. When the two are buckled, the one-way open lock ring 4-3 cannot move upward. The lower part of the connecting sleeve 4-11 is connected to the upper part of the sealed inner tube 4-1, so that the one-way open lock ring 4-3 cannot move axially in the sealed outer tube 4-6. The connecting sleeve 4-11 is connected to the sealed inner tube 4-1 by the constant pressure shear nail 4-2. The lower part of the sealed outer tube 4-6 is connected to the upper cone 4-7. The lower part of the upper cone 4-7 is a cone, and the lower end diameter of the cone is smaller than the upper end diameter. The upper part of the inner tube 4-9 passes through the upper cone 4-7 and is connected to the lower part of the sealed inner tube 4-1, and the connection is kept sealed. The upper part of the lower cone 4-10 is a cone, and the upper end diameter of the cone is smaller than the lower end diameter. The outer part of the inner tube 4-9 is covered with a rubber sleeve 4-8, and the upper part of the rubber sleeve 4-8 is provided with a conical hole that is covered outside the lower cone of the upper cone 4-7, and the lower part of the rubber sleeve 4-8 is provided with a conical hole that is covered on the upper cone of the lower cone 4-10. The lower part of the inner tube 4-9 is connected to the upper part of the lower cone 4-10, and the connection is kept sealed.

[0029] The above-mentioned separation device 2 comprises a separation upper joint 2-1, a separation shear pin 2-2, a sealing ring 2-3, a hanging joint 2-4, an upper sealing ring 2-5, a thrust piston 2-6, a lower sealing ring 2-7, a locking sleeve 2-8, a separation locking block 2-9, a separation lower joint 2-10 and an undercut joint 2-11. The lower part of the separation upper joint 2-1 is sleeved on the upper outer part of the separation lower joint 2-10, the separation locking block 2-9 is installed at the window of the separation upper joint 2-1, and the inner side of the separation locking block 2-9 is in the locking groove on the side wall of the separation lower joint 2-10. The locking sleeve 2-8 is sleeved on the lower outer part of the separation upper joint 2-1, and the inner wall of the locking sleeve 2-8 covers the separation locking block 2-9, so that the separation locking block 2-9 cannot be removed from the locking groove of the separation lower joint 2-10. The lower part of the locking sleeve 2-8 is provided with a release chamber 2-8-1, and the release chamber 2-8-1 is below the separation locking block 2-9. A lower sealing ring 2-7 is installed between the locking sleeve 2-8 and the separation upper joint 2-1. An outer shoulder 2-1-2 is provided on the outside of the separation upper joint 2-1. The lower sealing ring 2-7 is located below the outer shoulder 2-1-2. A connecting hole 2-1-1 is provided on the separation upper joint 2-1. The connecting hole 2-1-1 is located above the outer shoulder 2-1-2. A thrust piston 2-6 is installed in the annular space between the separation upper joint 2-1 and the locking sleeve 2-8. The thrust piston 2-6 covers the connecting hole 2-1-1. The thrust piston 2-6 is connected to the separation upper joint 2-1 by a separation shear pin 2-2. A sealing ring 2-3 is installed between the separation upper joint 2-1 and the thrust piston 2-6. The sealing ring 2-3 is located above the connecting hole 2-1-1. The upper sealing ring 2-5 is installed between the thrust piston 2-6 and the lock sleeve 2-8, and the upper part of the lock sleeve 2-8 is installed with the hanging joint 2-4, and the inner diameter of the hanging joint 2-4 is smaller than the lower outer diameter of the thrust piston 2-6. The lower part of the separation lower joint 2-10 is threadedly connected with the upper part of the inverted joint 2-11, and the connecting thread is a left-hand thread. When pressing, the pressure is transmitted from the connecting hole 2-1-1 to the lower end surface of the thrust piston 2-6, and the upward thrust is generated to cut the separation shear pin 2-2, and the thrust piston 2-6 drives the hanging joint 2-4 and the lock sleeve 2-8 upward; after the release chamber 2-8-1 reaches the separation lock block 2-9, the separation lock block 2-9 is separated from the separation lower joint 2-10, and the separation upper joint 2-1 is separated from the separation lower joint 2-10, so as to achieve the release. During separation, the thrust piston 2-6 is independently activated upwards, and is not affected by factors such as well inclination, string stiffness, and downsetting of the lower string, so that reliable and safe separation can be ensured under the design pressure. Forward rotation and reverse buckle separation can be achieved between the separation lower joint 2-10 and the reverse buckle joint 2-11. Example 3

[0030] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5A plugging string for an open hole well comprises a delivery string 1, a separation device 2, a suspension support device 3, a plugging device 4, a check valve 5 and an open hole wellbore 6. The delivery string 1, the separation device 2, the suspension support device 3, the plugging device 4 and the check valve 5 are connected in sequence and lowered into the open hole wellbore 6.

[0031] The plugging device comprises a sealing inner tube 4-1, a constant pressure shear nail 4-2, a one-way open lock ring 4-3, an upper sealing ring 4-4, a lower sealing ring 4-5, a sealing outer tube 4-6, an upper cone 4-7, a rubber tube 4-8, an inner tube 4-9, a lower cone 4-10 and a connecting sleeve 4-11. An outer reducing shoulder surface 4-1-2 is provided on the outside of the sealing inner tube 4-1, the outer diameter above the reducing shoulder surface 4-1-2 is larger than the outer diameter below, a pressure transmission hole 4-1-3 is provided on the sealing inner tube 4-1, the pressure transmission hole 4-1-3 is located below the reducing shoulder surface 4-1-2, an upper sealing ring 4-4 ​​is installed on the outer wall of the sealing inner tube 4-1, the upper sealing ring 4-4 ​​is located above the reducing shoulder surface 4-1-2, an outer one-way lock buckle 4-1-1 is provided on the outer wall of the sealing inner tube 4-1, and the outer one-way lock buckle 4-1-1 is located above the upper sealing ring 4-4. The sealed outer tube 4-6 is sleeved outside the sealed inner tube 4-1, and an inner reducer shoulder surface 4-6-2 is provided inside the sealed outer tube 4-6. The inner diameter of the sealed outer tube 4-6 above the inner reducer shoulder surface 4-6-2 is larger than the inner diameter below it. The lower sealing ring 4-5 is installed inside the sealed outer tube 4-6. The lower sealing ring 4-5 is below the inner reducer shoulder surface 4-6-2. The inner reducer shoulder surface 4-6-2 is below the outer reducer shoulder surface 4-1-2. The lower sealing ring 4-5 is below the pressure transmission hole 4-1-3. The gap between the upper sealing ring 4-4, the lower sealing ring 4-5, the sealed inner tube 4-1 and the sealed outer tube 4-6 prevents the fluid from leaking from the pressure transmission hole 4-1-3 into the gap between the inner reducer shoulder surface 4-6-2 and the outer reducer shoulder surface 4-1-2. The inner side of the upper part of the sealed outer tube 4-6 is provided with a conical shoulder 4-6-1 and a one-way open lock ring 4-3. The cone at the lower end of the one-way open lock ring 4-3 matches the conical shoulder 4-6-1. The one-way open lock ring 4-3 is located above the outer one-way lock buckle 4-1-1. The inner wall of the one-way open lock ring 4-3 is provided with an inner one-way lock buckle. The inner one-way lock buckle matches the outer one-way lock buckle 4-1-1. When the two are buckled, the one-way open lock ring 4-3 cannot move upward. The lower part of the connecting sleeve 4-11 is connected to the upper part of the sealed inner tube 4-1, so that the one-way open lock ring 4-3 cannot move axially in the sealed outer tube 4-6. The connecting sleeve 4-11 is connected to the sealed inner tube 4-1 by the constant pressure shear nail 4-2. The lower part of the sealed outer tube 4-6 is connected to the upper cone 4-7. The lower part of the upper cone 4-7 is a cone, and the lower end diameter of the cone is smaller than the upper end diameter. The upper part of the inner tube 4-9 passes through the upper cone 4-7 and is connected to the lower part of the sealed inner tube 4-1, and the connection is kept sealed. The upper part of the lower cone 4-10 is a cone, and the upper end diameter of the cone is smaller than the lower end diameter. The outer part of the inner tube 4-9 is covered with a rubber sleeve 4-8, and the upper part of the rubber sleeve 4-8 is provided with a conical hole that is covered outside the lower cone of the upper cone 4-7, and the lower part of the rubber sleeve 4-8 is provided with a conical hole that is covered on the upper cone of the lower cone 4-10. The lower part of the inner tube 4-9 is connected to the upper part of the lower cone 4-10, and the connection is kept sealed.

[0032] The above-mentioned separation device 2 comprises a separation upper joint 2-1, a separation shear pin 2-2, a sealing ring 2-3, a hanging joint 2-4, an upper sealing ring 2-5, a thrust piston 2-6, a lower sealing ring 2-7, a locking sleeve 2-8, a separation locking block 2-9, a separation lower joint 2-10 and an undercut joint 2-11. The lower part of the separation upper joint 2-1 is sleeved on the upper outer part of the separation lower joint 2-10, the separation locking block 2-9 is installed at the window of the separation upper joint 2-1, and the inner side of the separation locking block 2-9 is in the locking groove on the side wall of the separation lower joint 2-10. The locking sleeve 2-8 is sleeved on the lower outer part of the separation upper joint 2-1, and the inner wall of the locking sleeve 2-8 covers the separation locking block 2-9, so that the separation locking block 2-9 cannot be removed from the locking groove of the separation lower joint 2-10. The lower part of the locking sleeve 2-8 is provided with a release chamber 2-8-1, and the release chamber 2-8-1 is below the separation locking block 2-9. A lower sealing ring 2-7 is installed between the locking sleeve 2-8 and the separation upper joint 2-1. An outer shoulder 2-1-2 is provided on the outside of the separation upper joint 2-1. The lower sealing ring 2-7 is located below the outer shoulder 2-1-2. A connecting hole 2-1-1 is provided on the separation upper joint 2-1. The connecting hole 2-1-1 is located above the outer shoulder 2-1-2. A thrust piston 2-6 is installed in the annular space between the separation upper joint 2-1 and the locking sleeve 2-8. The thrust piston 2-6 covers the connecting hole 2-1-1. The thrust piston 2-6 is connected to the separation upper joint 2-1 by a separation shear pin 2-2. A sealing ring 2-3 is installed between the separation upper joint 2-1 and the thrust piston 2-6. The sealing ring 2-3 is located above the connecting hole 2-1-1. The upper sealing ring 2-5 is installed between the thrust piston 2-6 and the lock sleeve 2-8, and the upper part of the lock sleeve 2-8 is installed with the hanging joint 2-4, and the inner diameter of the hanging joint 2-4 is smaller than the lower outer diameter of the thrust piston 2-6. The lower part of the separation lower joint 2-10 is threadedly connected with the upper part of the inverted joint 2-11, and the connecting thread is a left-hand thread. When pressing, the pressure is transmitted from the connecting hole 2-1-1 to the lower end surface of the thrust piston 2-6, and the upward thrust is generated to cut the separation shear pin 2-2, and the thrust piston 2-6 drives the hanging joint 2-4 and the lock sleeve 2-8 upward; after the release chamber 2-8-1 reaches the separation lock block 2-9, the separation lock block 2-9 is separated from the separation lower joint 2-10, and the separation upper joint 2-1 is separated from the separation lower joint 2-10, so as to achieve the release. During separation, the thrust piston 2-6 is independently activated upwards, and is not affected by factors such as well inclination, string stiffness, and downsetting of the lower string, so that reliable and safe separation can be ensured under the design pressure. Forward rotation and reverse buckle separation can be achieved between the separation lower joint 2-10 and the reverse buckle joint 2-11.

[0033] The suspension support device 3 comprises a main body 3-1, an upper hinge shaft 3-2, a suspension support plate 3-3, a hinge shaft 3-4, a lever 3-5, a lower hinge shaft 3-6, a support piston 3-7, a sealing sleeve 3-8, an inner upper sealing ring 3-9, an outer upper sealing ring 3-10, an outer lower sealing ring 3-11, a locking block 3-12, a start shear pin 3-13, a lower piston 3-14, an inner lower sealing ring 3-15 and a bottom joint 3-16. A pressure charging hole 3-1-1 is provided on the main body 3-1, the support piston 3-7 is sleeved on the main body 3-1, an inner upper sealing ring 3-9 is installed between the support piston 3-7 and the main body 3-1, and the inner upper sealing ring 3-9 is located above the pressure charging hole 3-1-1. The lock block 3-12 is installed in the window at the bottom of the support piston 3-7, the inner wall of the lock block 3-12 is in the lock groove on the outer wall of the main body 3-1, the upper part of the lower piston 3-14 is sleeved on the lower part of the support piston 3-7, and the upper part of the lower piston 3-14 covers the lock block 3-12, so that the lock block 3-12 will not fall out of the main body 3-1. An inner lower sealing ring 3-15 is installed between the lower piston 3-14 and the main body 3-1, and the inner lower sealing ring 3-15 is under the pressure charging hole 3-1-1. The upper end of the suspension support plate 3-3 is connected to the side of the main body 3-1 by the upper hinge shaft 3-2, and the lower end of the lever 3-5 is connected to the side of the upper part of the support piston 3-7 by the lower hinge shaft 3-6. The hinge shaft 3-4 hinges the suspension support plate 3-3 and the lever 3-5. The sealing sleeve 3-8 is mounted on the outer periphery of the supporting piston 3-7 and the lower piston 3-14, an outer upper sealing ring 3-10 is installed between the sealing sleeve 3-8 and the supporting piston 3-7, an outer lower sealing ring 3-11 is installed between the sealing sleeve 3-8 and the lower piston 3-14, the sealing sleeve 3-8 is connected to the lower piston 3-14 by the starting shear nail 3-13, and a drain hole 3-8-1 is provided at the lower part of the sealing sleeve 3-8, and the drain hole 3-8-1 is located below the outer lower sealing ring 3-11. The upper part of the bottom joint 3-16 is connected to the lower part of the main body 3-1, and the connection is kept sealed. When the pressure is pressed, the pressure is transmitted to the upper end of the lower piston 3-14 through the pressure charging hole 3-1-1, causing it to generate a downward thrust, so that the starting shear pin 3-13 is sheared, and the liquid at the lower end of the lower piston 3-14 is discharged through the drain hole 3-8-1. The lower piston 3-14 moves downward to release the lock block 3-12, and the support piston 3-7 pushes the lever 3-5 upward to expand the lower end of the suspension support plate 3-3 outward, so that the tip of the lever 3-5 is inserted into the wall of the open hole, thereby suspending and supporting the pipe string on the wall of the open hole. The suspension support device 3 adopts a lever ratio structure, the lever 3-5 is inserted into the wall of the well to a deep depth, and the suspension support plate 3-3 has a large diameter range, which can adapt to open holes of different diameters, and the anchoring suspension is reliable. Example 4

[0034] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5A plugging string for an open hole well comprises a delivery string 1, a separation device 2, a suspension support device 3, a plugging device 4, a check valve 5 and an open hole wellbore 6. The delivery string 1, the separation device 2, the suspension support device 3, the plugging device 4 and the check valve 5 are connected in sequence and lowered into the open hole wellbore 6.

[0035] The plugging device comprises a sealing inner tube 4-1, a constant pressure shear nail 4-2, a one-way open lock ring 4-3, an upper sealing ring 4-4, a lower sealing ring 4-5, a sealing outer tube 4-6, an upper cone 4-7, a rubber tube 4-8, an inner tube 4-9, a lower cone 4-10 and a connecting sleeve 4-11. An outer reducing shoulder surface 4-1-2 is provided on the outside of the sealing inner tube 4-1, the outer diameter above the reducing shoulder surface 4-1-2 is larger than the outer diameter below, a pressure transmission hole 4-1-3 is provided on the sealing inner tube 4-1, the pressure transmission hole 4-1-3 is located below the reducing shoulder surface 4-1-2, an upper sealing ring 4-4 ​​is installed on the outer wall of the sealing inner tube 4-1, the upper sealing ring 4-4 ​​is located above the reducing shoulder surface 4-1-2, an outer one-way lock buckle 4-1-1 is provided on the outer wall of the sealing inner tube 4-1, and the outer one-way lock buckle 4-1-1 is located above the upper sealing ring 4-4. The sealed outer tube 4-6 is sleeved outside the sealed inner tube 4-1, and an inner reducer shoulder surface 4-6-2 is provided inside the sealed outer tube 4-6. The inner diameter of the sealed outer tube 4-6 above the inner reducer shoulder surface 4-6-2 is larger than the inner diameter below it. The lower sealing ring 4-5 is installed inside the sealed outer tube 4-6. The lower sealing ring 4-5 is below the inner reducer shoulder surface 4-6-2. The inner reducer shoulder surface 4-6-2 is below the outer reducer shoulder surface 4-1-2. The lower sealing ring 4-5 is below the pressure transmission hole 4-1-3. The gap between the upper sealing ring 4-4, the lower sealing ring 4-5, the sealed inner tube 4-1 and the sealed outer tube 4-6 prevents the fluid from leaking from the pressure transmission hole 4-1-3 into the gap between the inner reducer shoulder surface 4-6-2 and the outer reducer shoulder surface 4-1-2. The inner side of the upper part of the sealed outer tube 4-6 is provided with a conical shoulder 4-6-1 and a one-way open lock ring 4-3. The cone at the lower end of the one-way open lock ring 4-3 matches the conical shoulder 4-6-1. The one-way open lock ring 4-3 is located above the outer one-way lock buckle 4-1-1. The inner wall of the one-way open lock ring 4-3 is provided with an inner one-way lock buckle. The inner one-way lock buckle matches the outer one-way lock buckle 4-1-1. When the two are buckled, the one-way open lock ring 4-3 cannot move upward. The lower part of the connecting sleeve 4-11 is connected to the upper part of the sealed inner tube 4-1, so that the one-way open lock ring 4-3 cannot move axially in the sealed outer tube 4-6. The connecting sleeve 4-11 is connected to the sealed inner tube 4-1 by the constant pressure shear nail 4-2. The lower part of the sealed outer tube 4-6 is connected to the upper cone 4-7. The lower part of the upper cone 4-7 is a cone, and the lower end diameter of the cone is smaller than the upper end diameter. The upper part of the inner tube 4-9 passes through the upper cone 4-7 and is connected to the lower part of the sealed inner tube 4-1, and the connection is kept sealed. The upper part of the lower cone 4-10 is a cone, and the upper end diameter of the cone is smaller than the lower end diameter. The outer part of the inner tube 4-9 is covered with a rubber sleeve 4-8, and the upper part of the rubber sleeve 4-8 is provided with a conical hole that is covered outside the lower cone of the upper cone 4-7, and the lower part of the rubber sleeve 4-8 is provided with a conical hole that is covered on the upper cone of the lower cone 4-10. The lower part of the inner tube 4-9 is connected to the upper part of the lower cone 4-10, and the connection is kept sealed.

[0036] The above-mentioned separation device 2 comprises a separation upper joint 2-1, a separation shear pin 2-2, a sealing ring 2-3, a hanging joint 2-4, an upper sealing ring 2-5, a thrust piston 2-6, a lower sealing ring 2-7, a locking sleeve 2-8, a separation locking block 2-9, a separation lower joint 2-10 and an undercut joint 2-11. The lower part of the separation upper joint 2-1 is sleeved on the upper outer part of the separation lower joint 2-10, the separation locking block 2-9 is installed at the window of the separation upper joint 2-1, and the inner side of the separation locking block 2-9 is in the locking groove on the side wall of the separation lower joint 2-10. The locking sleeve 2-8 is sleeved on the lower outer part of the separation upper joint 2-1, and the inner wall of the locking sleeve 2-8 covers the separation locking block 2-9, so that the separation locking block 2-9 cannot be removed from the locking groove of the separation lower joint 2-10. The lower part of the locking sleeve 2-8 is provided with a release chamber 2-8-1, and the release chamber 2-8-1 is below the separation locking block 2-9. A lower sealing ring 2-7 is installed between the locking sleeve 2-8 and the separation upper joint 2-1. An outer shoulder 2-1-2 is provided on the outside of the separation upper joint 2-1. The lower sealing ring 2-7 is located below the outer shoulder 2-1-2. A connecting hole 2-1-1 is provided on the separation upper joint 2-1. The connecting hole 2-1-1 is located above the outer shoulder 2-1-2. A thrust piston 2-6 is installed in the annular space between the separation upper joint 2-1 and the locking sleeve 2-8. The thrust piston 2-6 covers the connecting hole 2-1-1. The thrust piston 2-6 is connected to the separation upper joint 2-1 by a separation shear pin 2-2. A sealing ring 2-3 is installed between the separation upper joint 2-1 and the thrust piston 2-6. The sealing ring 2-3 is located above the connecting hole 2-1-1. The upper sealing ring 2-5 is installed between the thrust piston 2-6 and the lock sleeve 2-8, and the upper part of the lock sleeve 2-8 is installed with the hanging joint 2-4, and the inner diameter of the hanging joint 2-4 is smaller than the lower outer diameter of the thrust piston 2-6. The lower part of the separation lower joint 2-10 is threadedly connected with the upper part of the inverted joint 2-11, and the connecting thread is a left-hand thread. When pressing, the pressure is transmitted from the connecting hole 2-1-1 to the lower end surface of the thrust piston 2-6, and the upward thrust is generated to cut the separation shear pin 2-2, and the thrust piston 2-6 drives the hanging joint 2-4 and the lock sleeve 2-8 upward; after the release chamber 2-8-1 reaches the separation lock block 2-9, the separation lock block 2-9 is separated from the separation lower joint 2-10, and the separation upper joint 2-1 is separated from the separation lower joint 2-10, so as to achieve the release. During separation, the thrust piston 2-6 is independently activated upwards, and is not affected by factors such as well inclination, string stiffness, and downsetting of the lower string, so that reliable and safe separation can be ensured under the design pressure. Forward rotation and reverse buckle separation can be achieved between the separation lower joint 2-10 and the reverse buckle joint 2-11.

[0037] The suspension support device 3 comprises a main body 3-1, an upper hinge shaft 3-2, a suspension support plate 3-3, a hinge shaft 3-4, a lever 3-5, a lower hinge shaft 3-6, a support piston 3-7, a sealing sleeve 3-8, an inner upper sealing ring 3-9, an outer upper sealing ring 3-10, an outer lower sealing ring 3-11, a locking block 3-12, a start shear pin 3-13, a lower piston 3-14, an inner lower sealing ring 3-15 and a bottom joint 3-16. A pressure charging hole 3-1-1 is provided on the main body 3-1, the support piston 3-7 is sleeved on the main body 3-1, an inner upper sealing ring 3-9 is installed between the support piston 3-7 and the main body 3-1, and the inner upper sealing ring 3-9 is located above the pressure charging hole 3-1-1. The lock block 3-12 is installed in the window at the bottom of the support piston 3-7, the inner wall of the lock block 3-12 is in the lock groove on the outer wall of the main body 3-1, the upper part of the lower piston 3-14 is sleeved on the lower part of the support piston 3-7, and the upper part of the lower piston 3-14 covers the lock block 3-12, so that the lock block 3-12 will not fall out of the main body 3-1. An inner lower sealing ring 3-15 is installed between the lower piston 3-14 and the main body 3-1, and the inner lower sealing ring 3-15 is under the pressure charging hole 3-1-1. The upper end of the suspension support plate 3-3 is connected to the side of the main body 3-1 by the upper hinge shaft 3-2, and the lower end of the lever 3-5 is connected to the side of the upper part of the support piston 3-7 by the lower hinge shaft 3-6. The hinge shaft 3-4 hinges the suspension support plate 3-3 and the lever 3-5. The sealing sleeve 3-8 is mounted on the outer periphery of the supporting piston 3-7 and the lower piston 3-14, an outer upper sealing ring 3-10 is installed between the sealing sleeve 3-8 and the supporting piston 3-7, an outer lower sealing ring 3-11 is installed between the sealing sleeve 3-8 and the lower piston 3-14, the sealing sleeve 3-8 is connected to the lower piston 3-14 by the starting shear nail 3-13, and a drain hole 3-8-1 is provided at the lower part of the sealing sleeve 3-8, and the drain hole 3-8-1 is located below the outer lower sealing ring 3-11. The upper part of the bottom joint 3-16 is connected to the lower part of the main body 3-1, and the connection is kept sealed. When the pressure is pressed, the pressure is transmitted to the upper end of the lower piston 3-14 through the pressure charging hole 3-1-1, causing it to generate a downward thrust, so that the starting shear pin 3-13 is sheared, and the liquid at the lower end of the lower piston 3-14 is discharged through the drain hole 3-8-1. The lower piston 3-14 moves downward to release the lock block 3-12, and the support piston 3-7 pushes the lever 3-5 upward to expand the lower end of the suspension support plate 3-3 outward, so that the tip of the lever 3-5 is inserted into the wall of the open hole, thereby suspending and supporting the pipe string on the wall of the open hole. The suspension support device 3 adopts a lever ratio structure, the lever 3-5 is inserted into the wall of the well to a deep depth, and the suspension support plate 3-3 has a large diameter range, which can adapt to open holes of different diameters, and the anchoring suspension is reliable.

[0038] The rubber cylinders 4-8 are self-expanding rubber cylinders that can expand and compress. They expand by themselves when encountering oil or water and can seal the wellbore with a large diameter change, which is particularly suitable for sealing open hole sections. Example 5

[0039] See also Figure 1 A plugging method for plugging a pipe string in an open hole well, characterized by comprising the following steps:

[0040] Step 1: Positive well washing: drilling fluid is pumped into the delivery pipe string 1, and returns through the separator 2, the suspension support device 3, the plug 4 and the check valve 5 to enter the annulus of the open hole wellbore 6;

[0041] Step 2, ball-throwing and pressure-pressurizing: throw the valve ball on the check valve 5 into the delivery pipe string 1, and after the valve ball is seated, pressurize the delivery pipe string 1 by 7-9 MPa to anchor the suspension support device 3 on the wall of the open hole wellbore 6; pressurize the delivery pipe string 1 by 12-14 MPa to make the plugger 4 work and seal the open hole wellbore 6; pressurize the delivery pipe string 1 by 18-19 MPa to make the separation device 2 work and separate into two bodies, the suspension support device 3, plugger 4 and check valve 5 under the lower body remain in the open hole wellbore 6, and the upper body is lifted out with the delivery pipe string 1. Example 6

[0042] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 A plugging method for plugging a pipe string in an open hole well, characterized by comprising the following steps:

[0043] Step 1: Positive well washing: drilling fluid is pumped into the delivery pipe string 1, and returns through the separator 2, the suspension support device 3, the plug 4 and the check valve 5 to enter the annulus of the open hole wellbore 6;

[0044] Step 2, ball-throwing and pressure-pressurizing: throw the valve ball on the check valve 5 into the delivery pipe string 1, and after the valve ball is seated, pressurize the delivery pipe string 1 by 7-9 MPa to anchor the suspension support device 3 on the wall of the open hole wellbore 6; pressurize the delivery pipe string 1 by 12-14 MPa to make the plugger 4 work and seal the open hole wellbore 6; pressurize the delivery pipe string 1 by 18-19 MPa to make the separation device 2 work and separate into two bodies, the suspension support device 3, plugger 4 and check valve 5 under the lower body remain in the open hole wellbore 6, and the upper body is lifted out with the delivery pipe string 1.

[0045] The plugging device comprises a sealing inner tube 4-1, a constant pressure shear nail 4-2, a one-way open lock ring 4-3, an upper sealing ring 4-4, a lower sealing ring 4-5, a sealing outer tube 4-6, an upper cone 4-7, a rubber tube 4-8, an inner tube 4-9, a lower cone 4-10 and a connecting sleeve 4-11. An outer reducing shoulder surface 4-1-2 is provided on the outside of the sealing inner tube 4-1, the outer diameter above the reducing shoulder surface 4-1-2 is larger than the outer diameter below, a pressure transmission hole 4-1-3 is provided on the sealing inner tube 4-1, the pressure transmission hole 4-1-3 is located below the reducing shoulder surface 4-1-2, an upper sealing ring 4-4 ​​is installed on the outer wall of the sealing inner tube 4-1, the upper sealing ring 4-4 ​​is located above the reducing shoulder surface 4-1-2, an outer one-way lock buckle 4-1-1 is provided on the outer wall of the sealing inner tube 4-1, and the outer one-way lock buckle 4-1-1 is located above the upper sealing ring 4-4. The sealed outer tube 4-6 is sleeved outside the sealed inner tube 4-1, and an inner reducer shoulder surface 4-6-2 is provided inside the sealed outer tube 4-6. The inner diameter of the sealed outer tube 4-6 above the inner reducer shoulder surface 4-6-2 is larger than the inner diameter below it. The lower sealing ring 4-5 is installed inside the sealed outer tube 4-6. The lower sealing ring 4-5 is below the inner reducer shoulder surface 4-6-2. The inner reducer shoulder surface 4-6-2 is below the outer reducer shoulder surface 4-1-2. The lower sealing ring 4-5 is below the pressure transmission hole 4-1-3. The gap between the upper sealing ring 4-4, the lower sealing ring 4-5, the sealed inner tube 4-1 and the sealed outer tube 4-6 prevents the fluid from leaking from the pressure transmission hole 4-1-3 into the gap between the inner reducer shoulder surface 4-6-2 and the outer reducer shoulder surface 4-1-2. The inner side of the upper part of the sealed outer tube 4-6 is provided with a conical shoulder 4-6-1 and a one-way open lock ring 4-3. The cone at the lower end of the one-way open lock ring 4-3 matches the conical shoulder 4-6-1. The one-way open lock ring 4-3 is located above the outer one-way lock buckle 4-1-1. The inner wall of the one-way open lock ring 4-3 is provided with an inner one-way lock buckle. The inner one-way lock buckle matches the outer one-way lock buckle 4-1-1. When the two are buckled, the one-way open lock ring 4-3 cannot move upward. The lower part of the connecting sleeve 4-11 is connected to the upper part of the sealed inner tube 4-1, so that the one-way open lock ring 4-3 cannot move axially in the sealed outer tube 4-6. The connecting sleeve 4-11 is connected to the sealed inner tube 4-1 by the constant pressure shear nail 4-2. The lower part of the sealed outer tube 4-6 is connected to the upper cone 4-7. The lower part of the upper cone 4-7 is a cone, and the lower end diameter of the cone is smaller than the upper end diameter. The upper part of the inner tube 4-9 passes through the upper cone 4-7 and is connected to the lower part of the sealed inner tube 4-1, and the connection is kept sealed. The upper part of the lower cone 4-10 is a cone, and the upper end diameter of the cone is smaller than the lower end diameter. The outer part of the inner tube 4-9 is covered with a rubber sleeve 4-8, and the upper part of the rubber sleeve 4-8 is provided with a conical hole that is covered outside the lower cone of the upper cone 4-7, and the lower part of the rubber sleeve 4-8 is provided with a conical hole that is covered on the upper cone of the lower cone 4-10. The lower part of the inner tube 4-9 is connected to the upper part of the lower cone 4-10, and the connection is kept sealed.

[0046] The above-mentioned separation device 2 comprises a separation upper joint 2-1, a separation shear pin 2-2, a sealing ring 2-3, a hanging joint 2-4, an upper sealing ring 2-5, a thrust piston 2-6, a lower sealing ring 2-7, a locking sleeve 2-8, a separation locking block 2-9, a separation lower joint 2-10 and an undercut joint 2-11. The lower part of the separation upper joint 2-1 is sleeved on the upper outer part of the separation lower joint 2-10, the separation locking block 2-9 is installed at the window of the separation upper joint 2-1, and the inner side of the separation locking block 2-9 is in the locking groove on the side wall of the separation lower joint 2-10. The locking sleeve 2-8 is sleeved on the lower outer part of the separation upper joint 2-1, and the inner wall of the locking sleeve 2-8 covers the separation locking block 2-9, so that the separation locking block 2-9 cannot be removed from the locking groove of the separation lower joint 2-10. The lower part of the locking sleeve 2-8 is provided with a release chamber 2-8-1, and the release chamber 2-8-1 is below the separation locking block 2-9. A lower sealing ring 2-7 is installed between the locking sleeve 2-8 and the separation upper joint 2-1. An outer shoulder 2-1-2 is provided on the outside of the separation upper joint 2-1. The lower sealing ring 2-7 is located below the outer shoulder 2-1-2. A connecting hole 2-1-1 is provided on the separation upper joint 2-1. The connecting hole 2-1-1 is located above the outer shoulder 2-1-2. A thrust piston 2-6 is installed in the annular space between the separation upper joint 2-1 and the locking sleeve 2-8. The thrust piston 2-6 covers the connecting hole 2-1-1. The thrust piston 2-6 is connected to the separation upper joint 2-1 by a separation shear pin 2-2. A sealing ring 2-3 is installed between the separation upper joint 2-1 and the thrust piston 2-6. The sealing ring 2-3 is located above the connecting hole 2-1-1. The upper sealing ring 2-5 is installed between the thrust piston 2-6 and the lock sleeve 2-8, and the upper part of the lock sleeve 2-8 is installed with the hanging joint 2-4, and the inner diameter of the hanging joint 2-4 is smaller than the lower outer diameter of the thrust piston 2-6. The lower part of the separation lower joint 2-10 is threadedly connected with the upper part of the inverted joint 2-11, and the connecting thread is a left-hand thread. When pressing, the pressure is transmitted from the connecting hole 2-1-1 to the lower end surface of the thrust piston 2-6, and the upward thrust is generated to cut the separation shear pin 2-2, and the thrust piston 2-6 drives the hanging joint 2-4 and the lock sleeve 2-8 upward; after the release chamber 2-8-1 reaches the separation lock block 2-9, the separation lock block 2-9 is separated from the separation lower joint 2-10, and the separation upper joint 2-1 is separated from the separation lower joint 2-10, so as to achieve the release. During separation, the thrust piston 2-6 is independently activated upwards, and is not affected by factors such as well inclination, string stiffness, and downsetting of the lower string, so that reliable and safe separation can be ensured under the design pressure. Forward rotation and reverse buckle separation can be achieved between the separation lower joint 2-10 and the reverse buckle joint 2-11.

[0047] The suspension support device 3 comprises a main body 3-1, an upper hinge shaft 3-2, a suspension support plate 3-3, a hinge shaft 3-4, a lever 3-5, a lower hinge shaft 3-6, a support piston 3-7, a sealing sleeve 3-8, an inner upper sealing ring 3-9, an outer upper sealing ring 3-10, an outer lower sealing ring 3-11, a locking block 3-12, a start shear pin 3-13, a lower piston 3-14, an inner lower sealing ring 3-15 and a bottom joint 3-16. A pressure charging hole 3-1-1 is provided on the main body 3-1, the support piston 3-7 is sleeved on the main body 3-1, an inner upper sealing ring 3-9 is installed between the support piston 3-7 and the main body 3-1, and the inner upper sealing ring 3-9 is located above the pressure charging hole 3-1-1. The lock block 3-12 is installed in the window at the bottom of the support piston 3-7, the inner wall of the lock block 3-12 is in the lock groove on the outer wall of the main body 3-1, the upper part of the lower piston 3-14 is sleeved on the lower part of the support piston 3-7, and the upper part of the lower piston 3-14 covers the lock block 3-12, so that the lock block 3-12 will not fall out of the main body 3-1. An inner lower sealing ring 3-15 is installed between the lower piston 3-14 and the main body 3-1, and the inner lower sealing ring 3-15 is under the pressure charging hole 3-1-1. The upper end of the suspension support plate 3-3 is connected to the side of the main body 3-1 by the upper hinge shaft 3-2, and the lower end of the lever 3-5 is connected to the side of the upper part of the support piston 3-7 by the lower hinge shaft 3-6. The hinge shaft 3-4 hinges the suspension support plate 3-3 and the lever 3-5. The sealing sleeve 3-8 is mounted on the outer periphery of the supporting piston 3-7 and the lower piston 3-14, an outer upper sealing ring 3-10 is installed between the sealing sleeve 3-8 and the supporting piston 3-7, an outer lower sealing ring 3-11 is installed between the sealing sleeve 3-8 and the lower piston 3-14, the sealing sleeve 3-8 is connected to the lower piston 3-14 by the starting shear nail 3-13, and a drain hole 3-8-1 is provided at the lower part of the sealing sleeve 3-8, and the drain hole 3-8-1 is located below the outer lower sealing ring 3-11. The upper part of the bottom joint 3-16 is connected to the lower part of the main body 3-1, and the connection is kept sealed. When the pressure is pressed, the pressure is transmitted to the upper end of the lower piston 3-14 through the pressure charging hole 3-1-1, causing it to generate a downward thrust, so that the starting shear pin 3-13 is sheared, and the liquid at the lower end of the lower piston 3-14 is discharged through the drain hole 3-8-1. The lower piston 3-14 moves downward to release the lock block 3-12, and the support piston 3-7 pushes the lever 3-5 upward to expand the lower end of the suspension support plate 3-3 outward, so that the tip of the lever 3-5 is inserted into the wall of the open hole, thereby suspending and supporting the pipe string on the wall of the open hole. The suspension support device 3 adopts a lever ratio structure, the lever 3-5 is inserted into the wall of the well to a deep depth, and the suspension support plate 3-3 has a large diameter range, which can adapt to open holes of different diameters, and the anchoring suspension is reliable.

[0048] The rubber cylinders 4-8 are self-expanding rubber cylinders that can expand and compress. They expand by themselves when encountering oil or water and can seal the wellbore with a large diameter change, which is particularly suitable for sealing open hole sections.

[0049] The basic operation process of the present invention is as follows:

[0050] The valve ball on the check valve 5 is not put in first, and the open hole plugging string of the present invention is lowered into the invalid well section or the upper part of the leaking layer to be plugged to perform positive well washing. The drilling fluid is pumped in from the delivery string 1, and is returned to the annulus of the open hole wellbore 6 through the separation device 2, the suspension support device 3, the plugger 4 and the inside of the check valve 5; the valve ball on the check valve 5 is put into the delivery string 1, and after the valve ball is seated, the delivery string 1 is pressurized by 7-9 MPa to anchor the suspension support device 3 on the wall of the open hole wellbore 6; the delivery string 1 is pressurized by 12-14 MPa, the pressure is transmitted from the pressure transmission hole 4-1-3 to the space enclosed by the upper sealing ring 4-4 ​​and the lower sealing ring 4-5, the pressure generates a downward force on the inner reducer shoulder surface 4-6-2, the constant pressure shear nail 4-2 is cut off, the one-way open lock ring 4-3 moves downward with the sealing outer tube 4-6, the upper cone 4-7 and the lower cone 4-10 squeeze the rubber tube 4-8, so that the rubber tube 4-8 is compressed and expanded to seal the open hole well wall, and the one-way open lock ring 4-3 reaches the outer one-way lock buckle 4-1-1 at the same time and locks together, fixing the compression and expansion state of the rubber tube 4-8, so as to achieve the purpose of permanently sealing the open hole wellbore; 18-19 MPa is pressed into the conveying pipe string 1, the separation device 2 works, the separation upper joint 2-1 is separated from the separation lower joint 2-10, the suspension support device 3, the plugging device 4, and the one-way valve 5 under its lower body are left in the open hole wellbore 6, and its upper body is raised with the conveying pipe string 1.

Claims

1. A plugging string for an open hole well, characterized by: It includes a delivery pipe string, a separation device, a suspension support device, a plugging device, a check valve and an open hole wellbore; the delivery pipe string, the separation device, the suspension support device, the plugging device and the check valve are connected in sequence and then lowered into the open hole wellbore; The plugger comprises a sealing inner tube, a constant pressure shear nail, a one-way opening locking ring, an upper sealing ring, a lower sealing ring, a sealing outer tube, an upper cone, a rubber tube, an inner tube, a lower cone and a connecting sleeve; the outer side of the sealing inner tube is provided with an outer diameter reducing shoulder surface, the sealing inner tube is provided with a pressure transmission hole, an upper sealing ring is installed on the outer wall of the sealing inner tube, and an outer one-way locking buckle is provided on the outer wall of the sealing inner tube; the sealing outer tube is sleeved outside the sealing inner tube, the inner side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the inner side of the sealing outer tube is provided with a lower sealing ring; the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed ... upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed; the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed; the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed; the upper side of the sealing outer tube is provided A conical shoulder is provided on the inner side of the part and a one-way open lock ring is placed thereon, an inner one-way lock buckle is provided on the inner wall of the one-way open lock ring, and the inner one-way lock buckle cooperates with the outer one-way lock buckle; the lower part of the connecting sleeve is connected to the upper part of the sealed inner tube, and the connecting sleeve is connected to the sealed inner tube by a constant pressure shear nail; the lower part of the sealed outer tube is connected to the upper cone, and the lower part of the upper cone is a cone; the upper part of the lower cone is a cone; a rubber sleeve is sheathed on the outside of the inner tube, and the upper and lower parts of the rubber sleeve are both provided with conical holes; the lower part of the inner tube is connected to the upper part of the lower cone; The separation device comprises a separation upper joint, a separation shearing pin, a sealing ring, a hanging joint, an upper sealing ring, a thrust piston, a lower sealing ring, a locking sleeve, a separation locking block, a separation lower joint and an undercut joint; the lower part of the separation upper joint is sleeved on the upper outer side of the separation lower joint, and a separation locking block is installed at the window of the separation upper joint; the locking sleeve is sleeved on the lower outer side of the separation upper joint, and a release chamber is provided at the lower part of the locking sleeve; a lower sealing ring is installed between the locking sleeve and the separation upper joint, an outer shoulder is provided on the outer side of the separation upper joint, a connecting hole is provided on the separation upper joint, a thrust piston is installed in the annular space between the separation upper joint and the locking sleeve, the thrust piston is connected to the separation upper joint by a separation shearing pin, and a sealing ring is installed between the separation upper joint and the thrust piston; an upper sealing ring is installed between the thrust piston and the locking sleeve, and a hanging joint is installed on the upper part of the locking sleeve; the lower part of the separation lower joint is threadedly connected with the upper part of the undercut joint; The suspension support device includes a main body, an upper hinge shaft, a suspension support plate, a hinge shaft, a lever, a lower hinge shaft, a support piston, a sealing sleeve, an inner upper sealing ring, an outer upper sealing ring, an outer lower sealing ring, a locking block, a starting shear pin, a lower piston, an inner lower sealing ring and a bottom joint; a pressure charging hole is provided on the main body, the support piston is sleeved on the main body, and an inner upper sealing ring is installed between the support piston and the main body; the locking block is installed in a window at the lower part of the support piston, and the upper part of the lower piston is sleeved on the lower part of the support piston; a pressure charging hole is provided on the main body, and ... an inner upper sealing ring is installed between the support piston and the main body The lower sealing ring is installed inside; the upper end of the suspension support plate is connected to the side of the main body by the upper hinge shaft, and the lower end of the lever is connected to the side of the upper part of the support piston by the lower hinge shaft, and the hinge shaft hinges the suspension support plate and the lever; the sealing sleeve is sleeved on the periphery of the support piston and the lower piston, an outer upper sealing ring is installed between the sealing sleeve and the support piston, and an outer lower sealing ring is installed between the sealing sleeve and the lower piston, the sealing sleeve is connected to the lower piston by the starting shear nail, and the lower part of the sealing sleeve is provided with a drain hole; the upper part of the bottom joint is connected to the lower part of the main body; The rubber cylinder is a self-expanding rubber cylinder.

2. A plugging method for an open hole plugging pipe string according to claim 1, characterized in that The steps include: Step 1: Positive well washing: drilling fluid is pumped into the wellbore from the delivery pipe string, and then returns to the annulus of the open hole wellbore through the separation device, the suspension support device, the plugging device and the check valve; Step 2: Throwing ball to pressurize: put the valve ball on the check valve into the delivery pipe string, wait for the valve ball to be seated, pressurize the delivery pipe string by 7-9MPa to anchor the suspension support device on the wall of the open hole wellbore; pressurize the delivery pipe string by 12-14MPa to make the plug work and seal the open hole wellbore; pressurize the delivery pipe string by 18-19MPa to make the separation device work and separate into two bodies, the suspension support device, plug and check valve under the lower body remain in the open hole wellbore, and the upper body is lifted out with the delivery pipe string; The plugger comprises a sealing inner tube, a constant pressure shear nail, a one-way opening locking ring, an upper sealing ring, a lower sealing ring, a sealing outer tube, an upper cone, a rubber tube, an inner tube, a lower cone and a connecting sleeve; the outer side of the sealing inner tube is provided with an outer diameter reducing shoulder surface, the sealing inner tube is provided with a pressure transmission hole, an upper sealing ring is installed on the outer wall of the sealing inner tube, and an outer one-way locking buckle is provided on the outer wall of the sealing inner tube; the sealing outer tube is sleeved outside the sealing inner tube, the inner side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the inner side of the sealing outer tube is provided with a lower sealing ring; the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed ... upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed; the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed; the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the upper side of the sealing outer tube is provided with an inner diameter reducing shoulder surface, and the lower side of the sealing outer tube is installed; the upper side of the sealing outer tube is provided A conical shoulder is provided on the inner side of the part and a one-way open lock ring is placed thereon, an inner one-way lock buckle is provided on the inner wall of the one-way open lock ring, and the inner one-way lock buckle cooperates with the outer one-way lock buckle; the lower part of the connecting sleeve is connected to the upper part of the sealed inner tube, and the connecting sleeve is connected to the sealed inner tube by a constant pressure shear nail; the lower part of the sealed outer tube is connected to the upper cone, and the lower part of the upper cone is a cone; the upper part of the lower cone is a cone; a rubber sleeve is sheathed on the outside of the inner tube, and the upper and lower parts of the rubber sleeve are both provided with conical holes; the lower part of the inner tube is connected to the upper part of the lower cone; The separation device comprises a separation upper joint, a separation shearing pin, a sealing ring, a hanging joint, an upper sealing ring, a thrust piston, a lower sealing ring, a locking sleeve, a separation locking block, a separation lower joint and an undercut joint; the lower part of the separation upper joint is sleeved on the upper outer side of the separation lower joint, and a separation locking block is installed at the window of the separation upper joint; the locking sleeve is sleeved on the lower outer side of the separation upper joint, and a release chamber is provided at the lower part of the locking sleeve; a lower sealing ring is installed between the locking sleeve and the separation upper joint, an outer shoulder is provided on the outer side of the separation upper joint, a connecting hole is provided on the separation upper joint, a thrust piston is installed in the annular space between the separation upper joint and the locking sleeve, the thrust piston is connected to the separation upper joint by a separation shearing pin, and a sealing ring is installed between the separation upper joint and the thrust piston; an upper sealing ring is installed between the thrust piston and the locking sleeve, and a hanging joint is installed on the upper part of the locking sleeve; the lower part of the separation lower joint is threadedly connected with the upper part of the undercut joint; The suspension support device includes a main body, an upper hinge shaft, a suspension support plate, a hinge shaft, a lever, a lower hinge shaft, a support piston, a sealing sleeve, an inner upper sealing ring, an outer upper sealing ring, an outer lower sealing ring, a locking block, a starting shear pin, a lower piston, an inner lower sealing ring and a bottom joint; a pressure charging hole is provided on the main body, the support piston is sleeved on the main body, and an inner upper sealing ring is installed between the support piston and the main body; the locking block is installed in a window at the lower part of the support piston, and the upper part of the lower piston is sleeved on the lower part of the support piston; a pressure charging hole is provided on the main body, and ... an inner upper sealing ring is installed between the support piston and the main body The lower sealing ring is installed inside; the upper end of the suspension support plate is connected to the side of the main body by the upper hinge shaft, and the lower end of the lever is connected to the side of the upper part of the support piston by the lower hinge shaft, and the hinge shaft hinges the suspension support plate and the lever; the sealing sleeve is sleeved on the periphery of the support piston and the lower piston, an outer upper sealing ring is installed between the sealing sleeve and the support piston, and an outer lower sealing ring is installed between the sealing sleeve and the lower piston, the sealing sleeve is connected to the lower piston by the starting shear nail, and the lower part of the sealing sleeve is provided with a drain hole; the upper part of the bottom joint is connected to the lower part of the main body; The rubber cylinder is a self-expanding rubber cylinder.

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