CN112523712B - Device and method for repairing damaged well wall - Google Patents

Abstract

A device and a method for repairing damaged well walls belong to the field of underground well formation engineering, and comprise a drill rod, a hot melt centrifugal cylinder and a reverse well drill bit which are sequentially connected from top to bottom and are coaxially arranged; the hot melting centrifugal cylinder consists of an inner cylinder and a hot melting cylinder, a cavity for containing a well wall repairing material is formed between the inner cylinder and the hot melting cylinder, and liquid discharge holes are uniformly formed in the side wall of the hot melting cylinder; an electric heating wire connected with a cable is welded on the inner wall surface of the hot melting cylinder; the cutting edge of the inverted well drill is disposed face up. The resistance wire is electrified and heated, at the moment, the orifice drilling machine drives the whole device to rotate, the well wall repairing material is heated and melted and is converted into liquid state from solid state, and the liquid state is thrown to the damaged well wall through the liquid discharge hole until the damaged well wall is completely filled with the well wall repairing material; and after the well wall repairing material is completely hardened, the orifice drilling machine drives the whole device to rotate, the drill rod is lifted up, and the repaired well wall is trimmed through the reverse well drill bit, so that the well wall repairing is completed. The invention can repair damaged well walls efficiently and reliably.

Description

A device and method for repairing damaged shaft walls

Technical field

The present invention relates to the field of underground well construction engineering, and in particular, to a device and method for repairing damaged well walls.

Background technique

During the process of underground well formation, due to the influence of rock properties, geological conditions, fluid erosion, pipe string collision, etc., well wall collapse and instability occur frequently. In addition, the well wall of an existing well may be damaged due to formation stress release, rock creep and other reasons. After the well wall is damaged, an irregular wellbore is formed, which seriously affects the later engineering operations and production.

For the problem of well wall damage, currently the more commonly used repair methods include sealing method, cutting method, etc. For example: Patent Document No. CN106677787B discloses a shaft repair and reinforcement structure and a repair and reinforcement construction method. The shaft is repaired by anchor grouting. During anchor rod construction, secondary collapse of the shaft wall may occur; Patent Document No. CN110593810A discloses A method for repairing damaged screen pipes in offshore oil fields, which only repairs the screen pipes but cannot solve the problem of repairing damaged well walls; the well wall repair tool disclosed in patent document number CN210483536U and the well wall repair device disclosed in patent document number CN206957619U use a repair device Cutting the reduced borehole wall is not suitable for repairing the expanded borehole wall and damaged borehole wall; the patent document number CN202645485U discloses a new borehole wall repair pipe string, which expands and seals the borehole wall by pressing the corrugated pipe section, but The expansion size of the bellows is limited and is greatly restricted by the well diameter, so it is not suitable for large-diameter wellbore; Patent Document No. CN111577290A discloses a method of using a frozen soil curtain to repair the shaft wall. The frozen ground forms a frozen soil curtain to seal the water. , this method is only suitable for blocking water-producing strata, and its scope of application is limited. "Research on the Hot Melt Method for Well Wall Reinforcement Technology, "Geology and Exploration", 2012, Issue 5, Pages 1034-1038", the hot melt material is squeezed into the damaged well wall through the heating element, and the size of the heating element and the well wall is required Equally, the requirements for the size of the well wall are relatively high and the applicability is relatively poor.

In summary, the existing well wall repair methods have limited scope of application, their long-term effectiveness cannot be guaranteed, and they face the risk of secondary damage. Therefore, how to repair damaged well walls efficiently and reliably is the key to current high-quality well construction, well completion and subsequent well wall maintenance.

Contents of the invention

The purpose of the present invention is to provide a device and method for repairing damaged well walls, so as to solve the problems of difficulty in repairing damaged well walls and long repair time during drilling.

In order to achieve the above objects, the present invention adopts the following technical solutions:

The invention proposes a device for repairing damaged well walls, which is characterized in that it includes: a drill pipe, a hot melt centrifuge barrel and a raise drill bit. The drill pipe, the hot melt centrifuge barrel and the raise drill bit are coaxial and run from top to bottom. The upper part of the drill pipe is coaxially connected to the hole drilling rig; the hot-melt centrifugal cylinder is composed of an inner cylinder and a hot-melt cylinder, and the inner cylinder and the hot-melt cylinder are an integrated structure, and the inner cylinder is in the form of It is in the shape of a hollow cylinder with both ends open, and both ends of the inner cylinder have threads. The upper end of the inner cylinder is threadedly connected to the drill pipe, and the lower end of the inner cylinder is threadedly connected to the raise drill bit; the hot melt barrel is in the shape of a hollow cylinder, The hot melt barrel is coaxially sleeved on the outside of the inner barrel. The top of the hot melt barrel is open. The bottom of the hot melt barrel has a through hole for the inner barrel to pass through. A hole is formed between the hot melt barrel and the inner barrel to accommodate the well wall repair material. The cavity of the hot melt barrel is evenly provided with liquid discharge holes on the side wall; the inner wall of the hot melt barrel is welded with an electric heating wire connected to the cable; the raise drill bit is an integrated structure, and the cutting of the raise drill bit Place the blade side up.

Further, the diameter of the liquid discharge hole is 5 mm to 10 mm.

Furthermore, the electric heating wire is made of iron-chromium-aluminum alloy heating wire.

Further, the raise bit is composed of a drill bit body and a drill bit cutting disc that is sleeved on the outside of the drill bit body. The drill bit body is a hollow cylindrical structure. The top of the drill bit body has threads. The raise bit communicates with the hot-melt centrifugal barrel through the threads. Threaded connection, a chip discharge port is reserved on the drill bit cutting disc, and the cutting edge surface of the drill bit cutting disc is arranged upward.

The present invention also proposes a method for repairing a damaged well wall, which is characterized in that: the method uses the above-mentioned device for repairing a damaged well wall to repair the damaged well wall, specifically including the following steps:

Step 1. Determine the exact location and damage volume of the well wall through conventional well logging methods;

Step 2: Assemble the device for repairing the damaged well wall on the ground, and place the well wall repair material in the cavity formed between the hot melt barrel and the inner barrel of the hot melt centrifuge barrel. Wall repair materials are in a solid state;

Step 3. Use the orifice drilling rig to lower the device for repairing the damaged well wall to the location of the damaged well wall, where the position of the hot-melt centrifuge tube is at the same level as the damaged well wall;

Step 4: The resistance wire is energized and heated. At this time, the hole drilling rig drives the entire device for repairing the damaged well wall to rotate. The well wall repair material is melted by heat and converted from solid to liquid. The liquid well wall repair material passes through the hot melt centrifuge. The liquid discharge hole is thrown to the damaged well wall until the damaged well wall is completely filled with the well wall repair material, and the entire device for repairing the damaged well wall stops rotating;

Step 5. After the well wall repair material is completely hardened, the hole drilling rig drives the entire device for repairing the damaged well wall to rotate, lifts the drill pipe while rotating, and uses the raise drill bit to trim the repaired well wall to complete the well. Wall repair.

Furthermore, EVA hot melt adhesive is selected as the well wall repair material.

Through the above design scheme, the present invention can bring the following beneficial effects:

1. The device and method proposed by the present invention for repairing damaged well walls have a simple structure, few parts, and are easy to operate;

2. The device and method for repairing damaged well walls proposed by the present invention can adjust the speed of the hole drilling rig according to the diameter of the well, so as to repair damaged well walls of different well diameters;

3. The device and method for repairing damaged well walls proposed by the present invention uses EVA hot melt adhesive as the well wall repair material to repair the well walls. The hardening time is short and rapid repair can be performed.

Description of the drawings

The description of the drawings here is used to provide a further understanding of the present invention and constitutes a part of the application of the present invention. The illustrative embodiments of the present invention and their descriptions are used to understand the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings :

Figure 1 is a schematic diagram of the working state of the device used to repair damaged shaft walls;

Figure 2 is a schematic diagram of the lifting process state of the device used to repair damaged shaft walls;

Figure 3 is the front view of the hot melt centrifuge cylinder;

Figure 4 is a cross-sectional view along line A-A of Figure 3;

Figure 5 is a cross-sectional view along line B-B of Figure 3;

Figure 6 is a top view of the hot melt centrifuge cylinder;

Figure 7 is the front view of the raise drill bit;

Figure 8 is a top view of the raise drill bit.

The marks in the figure are as follows: 1-hole drilling rig; 2-drill pipe; 3-cable; 4-damaged well wall; 5-hot melt centrifugal cylinder; 6-raise drill bit; 501-inner cylinder; 502-hot melt cylinder ; 503-liquid discharge hole; 504-heating wire; 601-drill body; 602-drill cutting disc; 603-chip discharge port.

Detailed ways

In order to have a clearer understanding of the technical solutions, purposes and effects of the present invention, the technical solutions in the embodiments of the present invention are now clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention. Not all examples. In order to avoid obscuring the essence of the present invention, well-known methods, processes, flows, components and circuits have not been described in detail.

As shown in Figures 1, 2, 3, 4, 5, 6, 7 and 8, the present invention proposes a device for repairing damaged well walls, including: drill pipe 2, hot melt The centrifugal tube 5 and the raise bit 6, the drill pipe 2, the hot melt centrifugal tube 5 and the raise bit 6 are coaxial and connected in sequence from top to bottom.

The upper part of the drill pipe 2 is coaxially connected to the hole drilling rig 1. The hole drilling rig 1 adopts a rotary motor. The hole drilling rig 1 can drive the drill pipe 2 to rise, fall and rotate. Since this belongs to the existing technology, no details will be given. redundant;

The hot-melt centrifugal cylinder 5 is composed of an inner cylinder 501 and a hot-melt cylinder 502, and the inner cylinder 501 and the hot-melt cylinder 502 are an integrated structure. The inner cylinder 501 is in the shape of a hollow cylinder with both ends open, and the inner cylinder 501 is in the shape of a hollow cylinder with both ends open. 501 has threads at both ends, the upper end of the inner barrel 501 is threaded with the drill pipe 2, and the lower end of the inner barrel 501 is threaded with the raise drill bit 6; the hot melt barrel 502 is in the shape of a hollow cylinder, and the hot melt barrel 502 is coaxial The hot melt barrel 502 is sleeved on the outside of the inner cylinder 501. The top of the hot melt barrel 502 is open. The bottom of the hot melt barrel 502 has a through hole for the inner barrel 501 to pass through. A hole is formed between the hot melt barrel 502 and the inner barrel 501 to accommodate well wall repair. In the cavity of the material, liquid discharge holes 503 are evenly provided on the side wall of the hot melt barrel 502. The diameter of the liquid discharge holes 503 is 5 mm to 10 mm, ensuring that the melted well wall repair material can be smoothly thrown out of the hot melt barrel 502 at high speed. . If the diameter of the liquid discharge hole 503 is smaller than this range, the melted well wall repair material may not be thrown out due to high viscosity; if the diameter of the liquid discharge hole 503 is larger than this range, the melted well wall repair material may be thrown out at a low speed and cannot be thrown out. There are 4 damaged well walls; an electric heating wire 504 connected to the cable 3 is welded to the inner wall of the heat melt barrel 502. The external power supply supplies power to the electric heating wire 504 through the cable 3, thereby heating the resistance wire 504.

The raise drill bit 6 is an integrated structure. The raise drill bit 6 is composed of a drill bit body 601 and a drill bit cutting disk 602 sleeved on the outside of the drill bit body 601. The drill bit body 601 is a hollow cylindrical structure. The top of the drill bit body 601 It has threads through which the raise drill bit 6 is threadedly connected to the hot-melt centrifugal barrel 5. A chip discharge port 603 is reserved on the drill bit cutting disc 602, and the cutting edge surface of the drill bit cutting disc 602 is arranged upward.

Furthermore, the heating wire 504 is made of iron-chromium-aluminum alloy heating wire. The iron-chromium-aluminum alloy heating wire has long service life, high resistivity, high surface recombination, and good oxidation resistance. The maximum operating temperature can reach 1400°C.

The well wall repair material in the present invention uses EVA hot melt adhesive. The currently known EVA hot melt adhesive is a polymer that does not require solvents, does not contain moisture, and has 100% solid meltability. It is a solid and can be heated and melted to a certain extent to become a liquid adhesive that can flow and have a certain viscosity. The main component of EVA hot melt adhesive, that is, the basic resin is copolymerized by ethylene and vinyl acetate under high pressure, and is combined with tackifiers. Agents, viscosity regulators, antioxidants, etc. are used to make hot melt adhesives. The surface tension is small when melted, and it has thermal adhesion to rocks and metal materials, and the solidification speed is fast.

A method for repairing a damaged shaft wall using the above device for repairing a damaged shaft wall, the method includes the following steps:

Step 1. Determine the exact location and damage volume of the well wall through conventional well logging methods;

Step 2. Assemble the device for repairing the damaged well wall on the ground, and place the well wall repair material in the cavity formed between the hot melt cylinder 502 and the inner cylinder 501 of the hot melt centrifuge cylinder 5 , at this time the well wall repair material is in a solid state;

Step 3. Lower the device for repairing the damaged well wall to the location of the damaged well wall through the orifice drilling rig 1. The position of the hot melt centrifuge 5 is at the same level as the damaged well wall 4, ensuring that the complete well wall can be repaired. repair;

Step 4. The cable 3 is connected to the electric heating wire 504, and the resistance wire 504 is energized and heated. At this time, the hole drill rig 1 drives the drill pipe 2 to rotate through the chuck, and the drill pipe 2 drives the entire device for repairing the damaged well wall to rotate. The solid well wall repair material melts when heated and becomes liquid. It generates centrifugal force under high-speed rotation and is thrown to the damaged well wall 4 through the liquid discharge hole 503 on the hot-melt centrifuge 5. According to the volume of the well wall damage and the liquid rejection ratio, Speed to determine the working time. When the working time is reached, perform a second well log on the damaged area. If the damaged well wall 4 is not completely filled, continue to rotate until the damaged well wall 4 is completely filled with the well wall repair material. The well wall repair material attached to the undamaged area will be ground away by the subsequent raise drill bit 6;

Step 5. After the well wall repair material is completely hardened, the borehole drilling rig 1 drives the entire device for repairing the damaged well wall to rotate, lifts the drill pipe 2 during the rotation, and trims the repaired well wall through the raise drill bit 6 , to ensure the penetration of the well.

The invention can repair damaged well walls efficiently and reliably.

Claims (2)

1. A method for repairing damaged well walls, characterized in that: the method uses a device for repairing damaged well walls to repair damaged well walls, and the device for repairing damaged well walls includes: a drill pipe ( 2), the hot-melt centrifugal tube (5) and the raise bit (6), the drill pipe (2), the hot-melt centrifugal tube (5) and the raise bit (6) are coaxial and connected in sequence from top to bottom; The upper part of the drill pipe (2) is coaxially connected to the hole drilling rig (1); the hot-melt centrifugal cylinder (5) is composed of an inner cylinder (501) and a hot-melt cylinder (502), and the inner cylinder (501) and the hot-melt centrifugal cylinder (502) are The melting barrel (502) has an integrated structure. The inner barrel (501) is in the shape of a hollow cylinder with openings at both ends. The inner barrel (501) has threads at both ends. The upper end of the inner barrel (501) is connected to the drill pipe (501). 2) Threaded connection, the lower end of the inner barrel (501) is threadedly connected to the raise drill bit (6); the hot melt barrel (502) is in the shape of a hollow cylinder, and the hot melt barrel (502) is coaxially sleeved in the inner barrel (502). 501) Outside, the top of the hot melt cylinder (502) is open, and the bottom of the hot melt cylinder (502) has a through hole for the inner cylinder (501) to pass through. A hole is formed between the hot melt cylinder (502) and the inner cylinder (501). A cavity used to accommodate well wall repair materials. The side walls of the hot melt barrel (502) are evenly provided with liquid discharge holes (503); the inner wall of the hot melt barrel (502) is welded with cables (3). Heating wire (504); the raise bit (6) is an integral structure, and the cutting edge of the raise bit (6) is arranged upward; The specific method includes the following steps: Step 1. Determine the exact location and damage volume of the well wall through conventional well logging methods; Step 2. Assemble the device for repairing the damaged well wall on the ground, and place the well wall repair material between the hot melt cylinder (502) and the inner cylinder (501) of the hot melt centrifuge cylinder (5) In the formed cavity, the well wall repair material is in a solid state at this time; Step 3. Use the orifice drilling rig (1) to lower the device for repairing the damaged well wall to the location of the damaged well wall, where the position of the hot-melt centrifuge (5) is at the same level as the damaged well wall (4); Step 4: The electric heating wire (504) is energized and heated. At this time, the hole drilling rig (1) drives the entire device for repairing the damaged well wall to rotate. The well wall repair material is heated and melted, and is converted from solid to liquid. The liquid well wall repair material passes through The liquid discharge hole (503) on the hot melt centrifuge (5) is thrown to the damaged well wall (4) until the damaged well wall (4) is completely filled with the well wall repair material, and the entire device is used to repair the damaged well wall. Stop spinning; Step 5. After the well wall repair material is completely hardened, the hole drilling rig (1) drives the entire device for repairing the damaged well wall to rotate, and lifts the drill pipe (2) during the rotation, and uses the raise drill bit (6) to repair the damaged well wall. The completed well wall is trimmed and the repair of the well wall is completed. 2. The method according to claim 1, characterized in that: EVA hot melt adhesive is selected as the well wall repair material.