CN114109242A - Drilling and manufacturing technology and well completion method for large-diameter deep well - Google Patents

Abstract

The patent discloses a drilling and construction technology and a well completion method for a large-diameter deep well, wherein the diameter of the large-diameter deep well is a vertical well with the diameter more than 5m and less than 20m, and the depth of the large-diameter deep well is more than 20m and less than 150 m; the drilling technology mainly comprises the following steps: pre-reinforcing the inner hole wall of the soft soil layer by adopting solidified soil, carrying out rotary drilling or grab bucket hole leading and soil taking and deslagging, forming a well by using a large-diameter drill bit, and protecting the wall of the hole formed by the deep well by adopting slurry; the major diameter deep well completion process mainly comprises the following steps: pre-reinforcing the hole wall of a soft soil area, arranging a locking hole well wall, building a drilling platform, rotary excavating a pilot hole, taking earth and discharging slag, forming a hole by a large-diameter drill bit, manufacturing and circulating wall protection slurry, prefabricating the well wall and the well bottom, floating and sinking the well wall, cementing the well and discharging slurry to form the well. The method has the advantages of green, environment-friendly, safe and reliable social benefits, capability of reducing the manufacturing cost and shortening the construction period, and great economic value.

Description

Drilling and manufacturing technology and well completion method for large-diameter deep well

Technical Field

The invention relates to the technical field of civil engineering, in particular to a vertical channel construction technology and a vertical channel construction method for deep underground space development.

Background

In deep space development, vertical channels such as a jacking pipe and a tunnel shield working well, an underground garage, a deep diving well and the like need to be built. The conventional methods comprise an open caisson method, a foundation pit open cut construction method, a drilling method and a vertical shield method, which have the defects that the open caisson method has great influence on the surrounding environment, the quality of the cast-in-place well wall is difficult to ensure, and when a hard stratum is met, the open caisson is difficult to sink or cannot sink; the foundation pit open cut construction method has the advantages of high cost, long construction period, high construction labor intensity, high construction safety risk and high water leakage probability after the underground continuous wall is constructed; the well drilling method is suitable for deep wells with the depth of more than 100 meters, but the deep wells with the depth of less than 100 meters are commonly used at present, the construction preparation period of the method is long, the measure cost is high, and the total cost is high; the vertical shield method is a novel construction technology, and has the advantages of high construction machine-class cost, high total construction cost and longer construction period. In some gravel formations, hard clay formations, pebble formations and rock formations, the current drilling method and open caisson method cannot be applied. Other deep well construction methods also have significant drawbacks.

Therefore, the engineering industry needs to provide a method which is suitable for different stratums, has small influence on the surrounding environment, can quickly form a well, can reduce the construction cost of engineering, can overcome the defects of the traditional deep well construction method, accelerates the construction speed and realizes the aim of green construction of the ultra-large diameter deep well.

Disclosure of Invention

The technical problem to be solved by the patent is to overcome the defects of the existing method for drilling and manufacturing the deep well, solve the difficult problems of rapid construction pore-forming and large-diameter hole wall stabilization, reduce the engineering cost and influence on the surrounding environment, and provide the method for drilling and manufacturing the large-diameter deep well.

In order to achieve the purpose, the technical scheme adopted by the patent is as follows:

the diameter of the large-diameter deep well is more than 5m and less than 20m, and the depth of the large-diameter deep well is more than 20m and less than 150 m;

the drilling technology mainly comprises the following steps: pre-reinforcing the inner hole wall of the soft soil layer by adopting solidified soil, carrying out rotary drilling or grab bucket hole leading and soil taking and deslagging, forming a hole by using a large-diameter drill bit, and protecting the wall of the hole formed by the deep well by adopting slurry;

the major diameter deep well completion process mainly comprises the following steps: pre-reinforcing the hole wall of a soft soil area, arranging a locking hole well wall, building a drilling platform, guiding holes by rotary digging or grab bucket, taking soil and discharging slag, forming holes by a large-diameter drill bit, manufacturing and circulating wall protection slurry, prefabricating the well wall and the well bottom, floating and sinking the well wall, cementing the well and discharging slurry to form the well.

The pre-reinforcing of the hole wall is an annular wall body, and is usually made by mutually overlapped multi-shaft stirring piles, RJP or TRD and CSM methods; the pre-reinforced cementing material is cement or soil hardening agent.

The fore shaft well wall is a reinforced concrete well wall or a steel structure assembled well wall.

The drilling platform is of an assembled steel structure.

The prefabricated well wall and the well bottom are a reinforced concrete prefabricated well wall, a steel plate well wall or a duct piece assembled concrete well wall; the connection between the upper section well wall and the lower section well wall adopts end plate welding; the assembly of the duct piece assembly type concrete well wall is closed by adopting bolt connection and filling rubber water stop strips.

The prefabricated well bottom is shaped like a pan bottom.

The floating sinking well wall is characterized in that the prefabricated well wall floats and sinks to the bottom of the well through the difference between the water filling amount in the sealed space in the well wall and the self weight of the well wall and the buoyancy of slurry outside the well wall.

The well cementation is that curing agent slurry is injected into a gap between the outer side of the well wall and the well wall, and the slurry in the gap is replaced, so that the well wall and the stratum of the well wall are bonded together.

The well completion method of the large-diameter deep well comprises the following steps:

the first step is as follows: pre-reinforcing the hole wall of the soft soil area,

the second step is that: setting a locking well wall, setting up a drilling platform,

the third step: drilling a guide hole in a rotary manner, taking soil and discharging slag, and prefabricating a well wall and a well bottom at the same time; and manufacturing and circulating wall protection slurry;

the fourth step: after the rotary drilling guide hole is drilled to the bottom, a large-diameter drill bit is adopted to rotate to form a hole;

the fifth step: cleaning holes and removing slag;

and a sixth step: hoisting and assembling the prefabricated well wall, and then floating and sinking into the well hole;

the seventh step: and injecting gelled slurry into a gap between the prefabricated well wall and the borehole wall, and replacing slurry to fix the well wall.

Eighth step: pumping out the counterweight water in the well wall to complete the well.

Has the advantages that: the prefabricated pedestal pile structure consisting of the enlarged pile end and the pile body and the pile sinking method have the characteristics of convenient pile body assembly, reliable quality, quick pile sinking method and the like, thereby realizing the technical progress of the pedestal pile and having the advantages of cost reduction and environmental protection.

Drawings

The invention is further described with reference to the following figures and detailed description.

FIG. 1 is a schematic view of a rotary drilling guide hole for taking earth and discharging slag.

Fig. 2 is a schematic diagram of a large diameter drilling tool for reaming and cleaning holes.

FIG. 3 is a schematic diagram of wall preparation.

FIG. 4 is a schematic diagram of a borehole wall bottom preparation.

Fig. 5 is a schematic view of floating and sinking.

FIG. 6 is a schematic view of the borehole wall outer gap filling and fixing.

FIG. 7 is a process flow diagram of a well completion method.

FIG. 8 is a schematic view of the windowing and windowing of the top pipe at the bottom of the well wall or the inlet and outlet of the shield.

FIG. 9 shows a well wall formed by assembling prefabricated pipe segments.

FIG. 10 connector distribution on prefabricated duct pieces

In the figure: 1-shaft, 11-shaft locking opening, 12-shaft construction platform; 13-mud pit; 14-a slurry conveying pipe; 15-rotary drilling rig or grab bucket machine; 16-barrel drilling tool; 17-a large-diameter drill bit, 18-a drill rod, 2-foundation soil and 21-a hole wall reinforcing body; 22-a fixed well wall filling layer, 3-a well wall, 31-a precast concrete well wall, 32-a precast steel well wall, 33-a precast well bottom, 4-a precast concrete well bottom, 35-a pipe piece (ring), 36-a hanging ring, 37-a steel plate, 4-mud, 41-clear water, 5-a lifting rope, 51-a grouting pipe, 52-a grouting pipe, 53-a water pipe, 6-an assembly type steel structure well wall, 61-a jacking pipe or a shield inlet and outlet windowing, 62-an advance reinforcement reserved drilling hole, 7-a blind tenon, 71-a groove of a sealing strip, 72-a sealing strip, a notch of a 73-blind tenon, 74-a bolt hole channel, 75-a bolt and 76-an orifice of the bolt.

The specific implementation mode is as follows: in order to make the technical means, the creation characteristics 2, the achievement purpose and the efficacy of the invention easy to understand, the patent is further described below with reference to the specific figures.

As can be seen from fig. 1, 2 and 3, a large-diameter deep well shaft 1 is drilled in a soft soil stratum 2, the wall of a well-forming hole needs to be pre-reinforced 21 by solidified soil, then a shaft locking opening 11 and a shaft construction platform 12 are manufactured and installed, a barrel type drilling tool 16 of a rotary drilling rig 15 is firstly used for drilling holes and taking earth and discharging slag by utilizing the positioning and guiding of the platform 12 and the locking opening 11, and meanwhile, wall protection mud 4 is conveyed into the shaft 1 from a mud pit 13 by a mud conveying pipe 14, as shown in fig. 1;

during drilling of the borehole, the borehole wall 3 is prefabricated on site or at the factory, as shown in fig. 3 and the well;

the large-diameter drill bit forms a hole, and the wall of the deep-well formed hole is protected by slurry 4;

when the drilled hole reaches the designed depth, a large-diameter drilling machine is used for driving a large-diameter drill bit 17 through a drill rod 18 to carry out hole sweeping and hole cleaning, as shown in FIG. 2;

after hole cleaning is finished, a floating sinking technology is adopted, the prefabricated well wall 32 and the prefabricated well bottom 33 are assembled to form a closed cylinder, the well wall 3 is slowly lowered through the lifting rope 5 under the combined action of buoyancy of slurry 4, clean water 41 in the well wall and the self weight of the prefabricated well wall 32, water 41 is injected into the well wall 1 through a water pipe 53, as shown in figure 5, meanwhile, slurry outside the well wall 3 is discharged through a slurry pumping pipe 52, and the prefabricated well wall bottom 33 is stably and underground placed at the bottom of the well hole 1.

After the well wall 3 is put in place, a cementing operation is required, i.e. the slurry between the well wall 3 and the well bore 1 is replaced by a curing agent slurry to form a filling layer 22, so that the well wall 3 and the well bore wall 21 are bonded together, as shown in fig. 6. And finishing the drilling construction of the ultra-large diameter deep well. The following detailed description is directed to several key technologies

Key technology, namely well completion method of large-diameter deep well completion technology

The process steps for drilling a large diameter deep well are shown in figure 7. The concrete main points are as follows:

(1) pre-reinforcing the hole wall of the soft soil area to form a reinforcing body 21;

(2) arranging a locking well wall 11;

(3) setting up a drilling platform 12;

(4) a hole of the rotary excavator 15 and the grab bucket 15 are used for taking soil and discharging slag, as shown in figure 1;

(5) the large-diameter drill bit 17 is used for forming holes, and wall protection slurry is manufactured and circulated, and simultaneously, a well wall 31 and a well bottom 33 or 4 are prefabricated, as shown in figures 2, 3 and 4;

(6) floating the sinking well wall 3, as shown in fig. 5;

(7) the post-wall pack 22 is completed with cementing and drainage as shown in figure 6.

Key technology II, method for reinforcing soft soil hole wall of well and keeping hole wall stable caused by large-diameter deep well drilling

The key of the technology is to keep the stability of the hole wall in the large-diameter deep well drilling process, therefore, the hole wall in the soft soil stratum region needs to be pre-reinforced, and the pre-reinforcing method mainly comprises the following steps:

(1) the construction is carried out by adopting the mutually overlapped multi-shaft mixing piles along the outer side line of the drilled and dug hole, and the continuous cement soil pile wall 21 is connected, so that the strength of the hole wall reinforcing body 21 reaches over 800KPa, and the stability of the hole wall of a soft soil area is ensured, as shown in figure 1.

(2) The hole wall reinforcing body 21 is made of RJP or TRD and CSM stirring walls and is used for some ultra-deep well bores.

(3) The cement or the soil hardening agent is adopted in the pre-reinforced cementing material, or the soil hardening agent is adopted to replace the cement to reinforce the hole wall 21, so that the defects that the solidified soil formed by reinforcing the soft soil by the cement is low in strength and cannot be formed are considered, and the soil reinforced by the soil hardening agent has better soft soil reinforcing performance.

Key technology III, prefabricating and assembling method of well wall

The well wall 3 is divided into a prefabricated concrete well wall 31 and a prefabricated reinforced concrete well wall 32, and a well wall bottom 33 needs to be manufactured to form a closed well wall structure, as shown in fig. 3 and 4.

When the working surface is limited on site, the well wall 3 needs to be manufactured in a factory, and for the well wall 3 with large diameter, the pipe pieces need to be manufactured in the factory according to the figure 9, and then the pipe pieces are assembled into the well wall on site. In the prefabricated tube piece are the rebate 7, the groove 71 for the sealing strip, the sealing strip 72, the rebate 73 for the rebate and the bolt hole 74 as shown in figure 10. The discrete segments are assembled into the desired well wall structure 31 using the operating space provided by the bolts 75 and bolt apertures 76.

Key technology four, method for windowing and perforating on well wall

After the clean water 41 in the well wall is pumped out, people and equipment can go down to the bottom of the well by using the lifting device. As a working well for shield, jacking and deep tunneling, it is necessary to use a lower well window of a deep well, as shown in FIG. 8.

The position 61 needing windowing is pre-designed to be an assembled steel structure well wall 6, the well wall at the position is connected through bolts, a pre-reinforcing reserved drilling hole 62 is reserved in the position, and after the outer stratum is reinforced and waterproof, windowing can be performed safely.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are given by way of illustration of the principles of the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (10)

1. A drilling technology and a well completion method for a large-diameter deep well are characterized in that the diameter of the large-diameter deep well is a vertical well with the diameter more than 5m and less than 20m, and the depth of the large-diameter deep well is more than 20m and less than 150 m; the drilling technology mainly comprises the following steps: pre-reinforcing the inner hole wall of the soft soil layer by adopting solidified soil, carrying out rotary drilling or grab bucket hole leading and soil taking and deslagging, forming a well by using a large-diameter drill bit, and protecting the wall of the hole formed by the deep well by adopting slurry; the major diameter deep well completion process mainly comprises the following steps: pre-reinforcing the hole wall of a soft soil area, arranging a locking hole well wall, building a drilling platform, rotary excavating a pilot hole, taking earth and discharging slag, forming a hole by a large-diameter drill bit, manufacturing and circulating wall protection slurry, prefabricating the well wall and the well bottom, floating and sinking the well wall, cementing the well and discharging slurry to form the well.

2. The drilling and construction technology of a large diameter deep well as claimed in claim 1, wherein the wall of the hole is pre-consolidated into a ring wall, and the hole is usually made by mutually overlapped multi-shaft mixing piles, RJP, or TRD and CSM methods.

3. The drilling and construction technique for large diameter deep wells as claimed in claim 1, wherein the pre-consolidated cementitious material is a cement or soil hardening agent.

4. The drilling and construction technology for the large-diameter deep well as claimed in claim 1, wherein the well wall of the locking notch is a reinforced concrete well wall or a steel structure assembly type well wall.

5. The drilling and construction technique for large diameter deep wells as claimed in claim 1, wherein the drilling platform is fabricated steel construction.

6. The drilling and manufacturing technology of the large-diameter deep well as claimed in claim 1, wherein the prefabricated well wall and the well bottom are a reinforced concrete prefabricated well wall, a steel plate well wall or a duct piece assembled concrete well wall; the connection between the upper section well wall and the lower section well wall adopts end plate welding; the assembly of the duct piece assembly type concrete well wall is closed by adopting bolt connection and filling rubber water stop strips.

7. The drilling and manufacturing technique for large diameter deep wells as claimed in claim 1, wherein the prefabricated bottom hole is in the shape of a pan bottom.

8. The drilling and manufacturing technique for the large-diameter deep well as claimed in claim 1, wherein the floating and sinking well wall is characterized in that the difference between the water filling amount in the sealed space in the well wall and the self weight of the well wall and the buoyancy of slurry outside the well wall enables the prefabricated well wall to float and sink to the bottom of the well.

9. The drilling and construction technique for a large diameter deep well according to claim 1, wherein the cementing is carried out by injecting a curing agent slurry into the space between the outside of the well wall and the wall of the well, displacing the slurry therein, and bonding the well wall to the formation of the wall of the well.

10. A well completion method for a large-diameter deep well is characterized by comprising the following steps:

the first step is as follows: pre-reinforcing the hole wall of the soft soil area,

the second step is that: setting a locking well wall, setting up a drilling platform,

the third step: drilling a guide hole in a rotary manner, taking soil and discharging slag, and prefabricating a well wall and a well bottom at the same time; and manufacturing and circulating wall protection slurry;

the fourth step: after the rotary drilling guide hole is drilled to the bottom, a large-diameter drill bit is adopted to rotate to form a hole;

the fifth step: cleaning holes and removing slag;

and a sixth step: hoisting and assembling the prefabricated well wall, and then floating and sinking into the well hole;

the seventh step: and injecting gelled slurry into a gap between the prefabricated well wall and the borehole wall, and replacing slurry to fix the well wall.

Eighth step: pumping out the counterweight water in the well wall to complete the well.

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