A device for retrieving a stuck drill string in a high pressure earth formation

Abstract

The present application relates to a kind of high pressure earth layer in the device of taking up stuck drill, the casing pipe with seamless steel pipe casing of middle opening is used to take up stuck drill tool, both ends limiting packing seal is fixed on stuck drill tool, butterfly valve sealing device, variable diameter sealing device, casing sealing device with grouting port pass through stuck drill tool, in turn fixed on tunnel segment, so that stuck drill taking up device and tunnel segment every step form effective seal, prevent water and soil in external high pressure earth layer from rushing into tunnel.The present application is suitable for the taking up of various caliber stuck drill tool, especially suitable for the working condition of high pressure earth layer stuck drill tool taking up.

Description

Technical Field

[0001] This invention relates to a drill bit retrieval device in highly confined soil layers, which is particularly suitable for the retrieval of drill bits in highly confined soil layers. Background Technology

[0002] As underground spaces continue to descend, high-pressure soil layers gradually come into the scope of foundation treatment needs. High-pressure soil layers are characterized by abundant water, rapid seepage, and significant impact, making them a critical area of ​​engineering risk. Many reports of ground subsidence and building tilting are related to leakage in pressure soil layers.

[0003] Horizontal freezing and horizontal MJS construction methods are methods of reinforcing existing structures by opening holes outwards. After passing through existing pipe segments or underground walls, the outside is a high-pressure soil layer. High-pressure soil layers are often mainly sandy soil with poor self-supporting properties. They are easily stuck in the drill after being disturbed. Drilling in high-pressure soil layers has always been a difficult problem and a risk point. Summary of the Invention

[0004] To address the above problems, the present invention provides a drill-holding and retrieval device for high-pressure soil layers.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a drill bit retrieval device in a high-pressure soil layer, which uses a casing with a central opening and a seamless steel pipe casing to retrieve the drill bit being retrieved. Packing seals at both ends are fixed to the drill bit being retrieved. A butterfly valve sealing device, a variable diameter sealing device, and a casing sealing device with a grouting port pass through the drill bit being retrieved and are sequentially fixed to the tunnel segment, so that the drill bit retrieval device and the tunnel segment form an effective seal at each step, preventing water and soil from the external high-pressure soil layer from flowing into the tunnel.

[0006] Furthermore, the packing seal is fixedly welded to the drill bit at both ends with annular fixing points to prevent packing displacement, thereby sealing the gap between the casing and the drill bit, and preventing bentonite slurry from leaking outwards when the pilot hole is being drilled.

[0007] Furthermore, the grouting port is located on the casing sealing device. Bentonite grout enters the casing with a central opening through the grouting port, and then is conveyed forward to the seamless steel casing, which serves to remove sand and soil between the casing and the drill bit and to protect the borehole wall.

[0008] Furthermore, after each two strokes of the central perforated sleeve, it retracts to the outside of the packing seal, and then an additional seamless steel pipe sleeve is sequentially sleeved forward.

[0009] Furthermore, the sleeve sealing device is tightened and fixed by a flange, which serves to seal the sleeve and prevent water, soil, and bentonite slurry from leaking out.

[0010] Furthermore, the variable diameter sealer first seals the casing and then seals the gripped drill bit. After the casing is removed, the casing is removed first, and after all the casings are removed, the variable diameter sealer seals the gripped drill bit, and then the gripped drill bit is removed in sequence.

[0011] Furthermore, the butterfly valve sealing device is sealed after all the drilling tools have been removed from the valve to prevent water and soil from entering.

[0012] The beneficial effects of this invention are:

[0013] This invention employs multiple interlocking sealing layers, which at each stage prevent the intrusion of high-pressure soil layers; and delivers the pilot hole grout into the casing to facilitate the pilot hole extraction. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the drill bit extraction device in high-pressure soil layers according to the present invention. Detailed Implementation

[0015] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0016] like Figure 1 As shown, the drill bit extraction device in the high-pressure soil layer of the present invention includes a drill bit 1, a casing with a central opening 2, a seamless steel pipe casing 3, a packing seal with limiting at both ends 4, a grouting port 5, a casing sealing device 6, a variable diameter sealing device 7, a butterfly valve sealing device 8, and a tunnel segment 9.

[0017] The casing 2 with a central opening and the seamless steel pipe casing 3 are used to hold the drill bit 1. The drill bit holding device and the tunnel segment 9 are effectively sealed at each step to prevent water and soil from the high-pressure soil layer outside from flowing into the tunnel.

[0018] The packing seal 4 with limiting at both ends is fixed to the drill bit 1. The butterfly valve sealing device 8, the variable diameter sealing device 7, and the casing sealing device 6 with the grouting port 5 pass through the drill bit 1 and are fixed to the tunnel segment 9 in sequence.

[0019] The present invention employs a packing seal 4 with two ends for sealing the gripped drill bit and the casing for removal. The casing sealing device 6 seals the casing to prevent water and soil from flowing in from the outer wall of the casing. The variable diameter sealing device 7 seals the gripped drill bit after the casing is removed to prevent water and soil from flowing in. The butterfly valve sealing device 8 seals the drill bit after the drill bit is removed to prevent water and soil from flowing in.

[0020] The present invention uses a casing sealing device with an injection port 5. Bentonite slurry enters the outer wall of the casing through the injection port and enters the inside of the casing through the casing with a central opening 2. This serves to assist in the drilling and slag removal, so as to facilitate the smooth slag removal and advance of the casing.

[0021] The usage method of this invention is as follows:

[0022] a. First, fill the external gaps of tunnel segment 9 with double-liquid grouting to prevent water and sand from flowing in before the casing is removed.

[0023] b. Fix the packing seal 4, which limits the two ends, onto the drill bit 1.

[0024] c. Pass the butterfly valve sealing device 8, the variable diameter sealing device 7, and the casing sealing device 6 with the grouting port 5 through the gripped drill bit 1 and fix them sequentially onto the tunnel segment 9.

[0025] d.2 The casing 2 with the middle opening is drilled forward with the help of the power head. Bentonite slurry is delivered into the casing through the grouting port 5, and the slag discharge assists the pilot hole.

[0026] After the casing 2 with the middle opening in section e.2 completes two strokes, seamless steel pipe casing 3 is added to its front end in sequence and then sleeved onto the head of the drill bit 1.

[0027] f. Then, the casing 2 is extracted sequentially until the last part is extracted, and the clamped drill string 1 is sealed using the variable diameter sealing device 7.

[0028] g. Then remove the gripped drill bit 1 in sequence, and finally close the butterfly valve.

Claims

1. A drill-and-loop retrieval device for high-pressure soil layers, characterized in that: The process employs a casing with a central opening and a seamless steel pipe casing to retrieve the gripped drill bit. Packing seals at both ends are fixed to the gripped drill bit. A butterfly valve sealing device, a variable diameter sealing device, and a casing sealing device with a grouting port pass through the gripped drill bit and are sequentially fixed to the tunnel segments, ensuring an effective seal between the gripping device and the tunnel segments at each step, preventing water and soil from entering the tunnel from the external high-pressure soil layer. Both ends are welded to the gripped drill bit using annular fixing points to prevent packing displacement, sealing the gap between the casing and the gripped drill bit, and preventing bentonite slurry leakage during pilot hole retrieval. The casing sealing device is secured by flange compression, sealing the casing and preventing water, soil, and pilot hole bentonite slurry leakage. The variable diameter sealing device initially seals the casing and later seals the gripped drill bit. After casing retrieval is complete, the casing is removed first, and after all casings are removed, the variable diameter sealing device seals the gripped drill bit, which is then sequentially removed.

2. The drill-and-loop extraction device for high-pressure soil layers according to claim 1, characterized in that: The grouting port is located on the casing sealing device. Bentonite grout enters the casing with a central opening through the grouting port, and then is conveyed forward into the seamless steel casing, which serves to remove sand and soil between the casing and the drill bit and to protect the borehole wall.

3. The drilling and retrieval device for high-pressure soil layers according to claim 1, characterized in that: Every two strokes the central perforated sleeve travels, it retracts to the outside of the packing seal, and then an additional seamless steel pipe sleeve is sequentially slipped forward.

4. The drill-and-loop extraction device for high-pressure soil layers according to claim 1, characterized in that: The butterfly valve sealing device is sealed after all the drilling tools have been removed from the valve to prevent water and soil from entering.

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