JPS5925071B2 - Expanded borehole boring method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In the formation of bore holes in the ground, more particularly expanded bore holes, such as blast holes used in bench mining or quarrying, a pilot hole is drilled to a predetermined depth and then a pilot hole is drilled to a predetermined depth. It has become common practice to enlarge the holes to form larger chambers for receiving explosives.

Such boreholes are also useful in connection with in-situ fracturing in chemical mining and coal gasification technology.

Oil well dimensions or other bores like gas wells
When poling a hole into the ground, it may be necessary or desirable to extend the well or bore a certain distance.

Therefore, the hole included in the telescopic drill focus
The opener developed.

Some of the telescoping drill pints included a pilot pint in combination with a telescoping canter to drill the Habaylot hole and expansion chamber.

In the case of poling, where a liquid or mud is used as the poling fluid to cool the drill and flush away cuttings from the bore hole, the poling fluid can be circulated all the way down through the drill pipe or conduit. Typically, the fluid returns through the annular space between the pipe and the borehole to clean out cuttings from the hole force.

In some borehole poling operations, air or gas is used as the poling fluid to cool the tip and remove cuttings from the borehole in the formation of blast holes and other boreholes. .

However, effective removal of cutting debris by air requires relatively high pumping speeds compared to liquid poling fluids.

According to the most authoritative sources, 5,000 feet per minute (15
An air pumping speed of the order of 24 m) is required.

Therefore, when a large bore hole is being drilled using air 12 as the polling fluid, such air pumping speeds in the outer annulus of the drill pipe are difficult to achieve and limited by the size available in the polling rig. would require more compressor capacity than is economically practicable.

Additionally, even though the added compressor may provide sufficient air to displace the cuttings through the borehole annulus, the velocity of the air returning to the expansion chamber or the reduced annulus above the borehole. At the exit, the drill pipe becomes extremely noisy and the integrity of the drill pipe and expansion borehole is compromised due to the abrasive nature of the force, cuttings, and dust.

Particularly in the case of blast holes, shoulder erosion at the beginning of the expansion chamber is undesirable because it reduces the blast effectiveness.

In order to supply the polling fluid 4 at an appropriate pumping rate, so-called reverse circulation of the polling fluid was attempted.

This reverse circulation involves circulating air downward through the borehole annulus and then upwardly through the pinto and drill pipe, where the velocity within the relatively small bore of the pipe is determined by the cross-sectional area of the flow path. It's small so it's very expensive.

Furthermore, it has been attempted in poling operations where there is a circulation of the poling fluid in so-called double concentric pipe strings.

In this double concentric pipe string, a concentric inner pipe and an outer pipe are provided, both pipes having connections that provide a flow path through the entire bore of the central pipe, providing full communication with the annular space between them. .

Maintaining proper flow area while applying force to the wrench area or tool slot for assembling and disassembling connections is a dual task. This is a problem with concentric drill pipe.

When the telescoping, pivot-coupling canter support arm on the drill bit is expanded outward by air pressure to initiate an expanded borehole, the air-cooled cutter pins create a very large force on the air flow into the cutter.
Inadequate pressure exists to achieve canter expansion for a reasonably short time of poling, resulting in the formation of a long tapered sidewall over which the rear or outer surface of the pivoting cutter arm is dragged. and wear out.

It is desirable to maintain an expanding force on the arm carrying the cutter and not to deprive the cutter of sufficient cooling air during the initial stages of bore home expansion.

Currently available refrigerated telescoping cutters have complex structures that allow air flow through the cutter support arm and are inadequate in cleaning and cooling the air acting on the canter element.

In the formation of blast holes in mining or quarrying operations,
Two-pass (two-pass) where a pilot hole is first drilled with a first drill pin and drill string, and then, in a second pass, the pilot hole is expanded with a telescoping bit that moves along the second drill string. ) method has been found to produce superior blasthole geometry if borehole expansion is continued substantially at the bottom of the pilot hole.

The annular borehole space outside the drill string is
When drilling a pilot hole, where the cross-sectional flow area is not large, the poling fluid or air is typically circulated downward through the drill string and then into the annulus. It can be circulated upwards and the pumping rate of the fluid or air in the annular space is suitable.

However, later on, when the second hole expansion pass is being performed, the bore hole expansion increases the total annular flow area so much that existing compressors are no longer able to provide the required air pumping rates. .

Even if telescoping beats expanded by countercirculation are used via double concentric pipe strings, different fittings assembly in the rig is required to supply air through the annulus.

On the other hand, the Pilot Pinto was powered by a double pipe rig that could not be used in conjunction with a double pipe rig fitting to supply air through the double pipe annulus.

η. Therefore, in the case of the existing installation, two separate pipe strings would be required for the pilot polling path and the extended polling path.

The bottom part is somewhat half-finished? When forming a blast hole in a two-pass manner to provide an expansion chamber with (It is desirable that there be relatively little cutting debris or accumulated dust.) Accumulated debris can reduce the blast effect and interfere with force bench removal or effective fragmentation.

However, cutting chips and dust remaining in the holes are still a problem.

The present invention is directed to improved reverse circulation pilot hole and expanded hole polling that overcomes the above problems.

More specifically, the present invention utilizes the two-pass method and reverse circulation with a double concentric pipe string during bore hole expansion polling, and also utilizes a double concentric pipe string during polling of two pilot holes. However, it concerns the formation of expanded bore holes or blast holes.

In accordance with the present invention, a double concentric pipe string is constructed from a plurality of pipes having threaded pins and box ends to provide a sealed connection or joint t-' between the ends.

During polling of the pilot hole, one pipe utilized in the pipe string has a crossover structure that closes off the central pipe above the pilot bit and allows air to flow between the central pipe and the outer knob. to the pilot bit air passage.
The return flow of air thereby rises entirely within the annular space between the pipe string and the borehole wall.

A sealed swivel structure provides a polling air source between the center pipe and the outer pipes and includes a rotating mandrel connected to the pipe string by one of the sealed double pipe joints.

Also, according to the invention, the telescoping bit for expanding a bore hole has a piston-cylinder structure, which is supplied with air from the spatial force between the central pipe and the outer pipe, and which supports the inner body and the outer arm. Outward expansion of the canter arm is achieved in response to longitudinal movement of the arm support relative to the body rotary drive mandrel.

During initial movement of the arm support and expansion of the canter arm, a relatively small portion of the total air pressure is released from the piston-cylinder structure and flows through passages in the arm support to the canter, cooling it and increasing the air pressure. The majority of the canter is maintained in the piston-cylinder structure, thereby achieving full expansion of the canter.

When the canter is in its fully inflated state, the canter is mechanically locked in the inflated state and an additional passageway mechanism is opened allowing a large amount of air to pass through the piston-cylinder structure.
It flows through the ra kantha.

Furthermore, another passageway mechanism in the cutter support is also opened;
Air from the piston-cylinder structure flows through the outer cutter support body to a nozzle directed in the direction of the cutter, thereby blowing away cuttings from the cutter and aiding in cooling the cutter, while the cutter is It is fully inflated and mechanically locked in the inflated state.

A simple structure is provided to conduct air through the piston-cylinder structure, force and counter support body and arms.

, having a fluid passageway connected to an additional passageway in the support body by a flexible connecting conduit that allows the arm to pivot.

The arm passage leads to a bearing support for a roller canter rotatable on the support, and air flows through the bearing and bearing race.

Adequate return airflow through the central pipe during borehole Q expansion? To ensure this, a mechanism is provided for inducing such a return air flow.

More particularly, there is a venturi mechanism associated with the discharge conduit or conduit of the top drive unit for rotating the drill pipe.

This venturi mechanism has an air population, which is connected to the pipe
Air is supplied separately from the blast of air supplied to the string.

Effective extrusion or removal of cutting debris is ensured by force.

Additionally, the venturi mechanism can advantageously induce a continuous air flow through the central pipe, thereby removing residual cuttings and dust that settles within the hole when the extended poling is completed. Remove.

Such residue a(/'i) can be force-removed by continuous rotation of the expansion roller without applying any thrust to the drill pipe.

More particularly, the present invention provides for drilling a pilot hole into a formation by rotating a pilot pinto over a double pipe string having an outer fluid passageway defined between an inner pipe and an outer pipe; The polling fluid is circulated through the force hole to allow the polling fluid and cuttings to flow out of the force hole through the space between the pipe string and the wall, and then the circulation of the polling fluid is stopped and the pipe string and pilot pin are removed from the bore hole. , replace the pilot bit with a borehole expansion pint with a canter that can expand to a gauge exceeding that of the pilot pint, and pilot the expansion pint along the drill pipe.
expanding the expansion bit cutter by moving it to a selected position within the hole and fully supplying poling fluid to the expansion pin through the outer fluid passage of the drill pipe; and rotating the drill pipe and expansion pin to expand the expansion bore. The entire hole is drilled, while two portions of poling fluid and formation cuttings are removed through the inner fluid passage defined by the inner pipe, and then the supply of poling fluid is completely stopped, the extended focus cutter is retracted, and the drilling fluid and formation cuttings are removed through the inner fluid passage defined by the inner pipe. Expansion pinto includes a method of drilling an expansion borehole into a geological formation, consisting of a total expansion borehole force and an extraction force.

The present invention has many other advantages and objects that will become apparent from consideration of the modes and methods in which it may be carried out.

The forms and methods are illustrated and described herein with reference to the accompanying drawings, which form a part of this specification.

Although such forms and methods are described in detail below for the purpose of illustrating the general principles of the invention, it is to be understood that such detailed description is not to be taken in a limiting sense.

Referring to figures 1a, lb and 2a, 2b, the pilot bore hole PH (1a, l
The device for initially drilling a hole in Figure b) is shown schematically.

Drill pinto B is a rotating drill Pipe string P
The drill pipe string P is fixed to the lower end of the bit B, and the drill pipe string P is rotated by a suitable rotating drive unit (D), so that as the drill pipe P is rotated, the cutter C on the bit B is inserted into the bore or pilot hole PH. ' is progressively drilled, and in the case of air poling, poling fluid is supplied via supply conduit 10 and fiber St from a suitable poling fluid source such as an air compressor.

As shown in the figure, the drill pipe string Pfl-1 is a double concentric drill pipe having an inner pipe IP and an outer pipe OP, which are connected at a joint J and are connected to each other through an annular joint between the two pipes. It is constructed of suitable lengths or sections defining a space Ak, so that the polling fluid or air is supplied through the pipe 107:l to the swivel S and the annular space Ak to the crossover unit CO, where the annular space A communicates through a transverse passage 11 with a hollow bore 12 at the lower end of the crossover unit.

The bit BU is connected to the lower end of the crossover unit by a conventional threaded connection 13 and has a central through-hole 142.
through which the polling fluid or air passes through the crossover unit passage 12 and exits through the bore hole PH through the bore hole PH, forming an annular space defined between the bore hole wall and the drill pipe shaft 9772. 15
through and return to the surface or the starting end of the borehole.

The flow of polling fluid or air is at the angle C of bit B.
Clean or pump the cuttings from the borehole as cooling and force-poling progresses.

Drill knobs and bores, as they are commonly known.
The velocity of the air rising through the annular space 15 between the hole walls is 5 per minute to pump the cutting sound from the bore hole force.
It must be on the order of 000 feet (152477?).

When the gauge of the bit B is much larger than the diameter of the drill pipe string P, as shown in FIG. 1b, the annular cross-sectional area of the annular space 15 allows a sufficient velocity of air flow.

For example, if air is supplied at 1300 SCFM through the compressor power drill pipe string annulus A', the drill pipe diameter *53/4 inch (46wn) and the pinto gauge is 7'7/ /8
inches (2,-Q, Orrvn), and the borehole is a large protrusion or extension, which is a regular one.The air returns through the annular space 15 and is rumored to have a yielding speed of 8,000 feet per minute. -1 knee<2438mm)k
In other words, the minimum speed necessary to take out the cutting chips must be exceeded at full power.

For this purpose, drill pipes of ordinary or double concentric type are used.
As a polling fluid supplied throughout the string,
Bore hole polling, typically using air containing other gases, is widely used for polling bore holes into various geological formations, including bore holes for blasting or other mining operations, and for well bore poling. has been used.

As not seen in Figure 2 at Zb, a drill pipe string P without a crossover structure CCI is coupled to a telescoping cutter-type hole opener or bore hole expansion bit EB, and the pin) EB is provided with a canter Ck at the lower free end. having a pivot-coupled cutter support arm 16;
As the telescoping cutter pivots outward and polling progresses, the cutter moves into the expanded bore hole or chamber E.
Form H.

If air is to be supplied to the drill pipe string P through the swivel Sk in order to pump out the cutting debris from the enlarged bore hole or chamber EH, as explained in connection with Figures 1a and lb. , the pumping speed will be below the required minimum value φ.

For example, expansion bore hole EH has a diameter of 13 inches (
330mm) and polling air is 1300SCF
The air velocity i in the expanded borehole if supplied with M
H is slightly greater than 1,700 feet per minute (518,777).

According to the present invention, as shown by the arrow,
Air passes through the swivel St to the inner pipe IP and the outer pipe 741
It is fed into the annular space A between 02 and flows down into the borehole and then into the inner pipe IP, through which it flows up and out of its top force.

Assuming that the bore of the inner pipe is 2 inches (50,8 mm) in diameter and that all of the air supplied through the annulus Ak at 1300 SCF'M is returned to the surface through the 2 inch bore, the pumping rate is This would be on the order of 60,000 feet (18,288 m ) per minute.

Therefore, if only 10% of the air entering the borehole returns through the inner pipe, the pumping speed will still be on the order of 6000 feet per minute (1828,8 m), which is more than enough to pump the cuttings. The required minimum speed is exceeded.

As is known, a panfur can also be used between the drill pipe string P and the wall of the borehole PH to ensure adequate air flow up the middle of the drill pipe string.

However, according to the present invention, the upward flow of air in the central pipe is enhanced by providing a mechanism V for drawing all the air through the inner pipe In, as seen in FIG. 2a.

The drive unit DU has an inner drive pipe 11 driven by a transmission driven by a suitable motor, such as a hydraulic motor M, as shown.

Fluid and cuttings ascend into a drive pipe 17 into a discharge chamber 17a in the drive unit housing, with the pipe 17 engaging a banking 17b.
This prevents dust from entering the drive unit housing.

The outlet coupling 19 is connected to the housing with a fastener 19a and is connected to the force housing chamber 17a and the force discharge hose 19b''! The flow path is set with i.

Venturi mechanism V is associated with discharge hose 19b to direct flow through the hose and thus direct upward flow in the center of the drillpipe string.

The venturi is attached to the discharge 1, hose 19b, and includes the sword through passage 1g a-: @... Ujifugu 19ck.

The flange 19e of the housing 19cf has an annular space or passageway 19f', which is supplied with air via an artificial conduit 19gk.

The annular gap 19h opens downstream from the annular passage 19f into the flow path 19d to reduce the pressure in the flow path 19d downstream of the gap, thereby allowing air to be supplied in a swivel structure and connecting to the inner pipe. Annular space Ak between outer pipes
As the flow flows down through the pinhole and into the borehole, the borehole force induces fluid flow upstream through the inner drill pipe and through the discharge hose.

The venturi or vacuum generating mechanism vV'i provides another advantage when the borehole expansion is completed and the polling air supply is stopped.

When the poling operation is completed, the borehole contains a certain amount of cuttings and dust, which rises in the annular space inside the borehole outside the drill pipe and then settles to the bottom of the hole. It is.

Continuous application of air to the venturi induces flow into the discharge conduit, which subsequently draws the air up into the central pipe and lifts the cuttings from the bottom of the borehole.

During vacuum operation, by rotating the drill pipe P, the cutter on the bit can stir the cutting sound at the bottom of the hole.

3a, 3b, 3c and 4, the swivel structure S is shown in detail.

Internally, the swivel structure includes an elongated body or mandrel 20 having a central passage 21 therethrough.

At its upper end, the body 20 has an externally threaded pin 22 which fits into an internally threaded box 23 of the rotary drive member 17, which is rotated by the drive unit D as described above.

The rotary drive member has a central passageway 25 therethrough that communicates with the swivel passageway 21 and the discharge conduit and venturi mechanism V.

At its lower end, the swivel body or mandrel 20 has an internally threaded box part 26 which is connected to an externally threaded pin 2γ to form a joint J.

A tubular outer body section 28 is placed around the mandrel 20 at the body portion and force welded thereto at appropriate locations to firmly connect the inner and outer body sections.

As shown, the outer body section 28 has a top weld 29 securing it to the upper portion of the inner body section.
A suitable number of longitudinally and circumferentially spaced welds 30 formed in holes in the outer body section are also provided for joining the body sections.

Outer body section 28 over inner body section
Prior to assembly, the inner body section is provided with a number of circumferentially spaced, longitudinally extending milling inserts 31, the slots 31 extending further downwardly to slots 32 spaced apart in the direction (Fig. 3c)
These melons 14 communicate with each other to allow air to flow downwardly between the mandrel body sections.

As seen in Figure 3c, slot 32 is slot 3
1, 33, but deeper, thereby having approximately the same effective airflow area.

The narrow width of the slots 320 defines outwardly opening wrench slots 34 at a number of circumferentially spaced locations in the swivel body that extend longitudinally of the body and allow for force and downward direction. A shoulder 35 is provided by which vertical support and holding tools can be applied to the body by means of a polling rig, as is known.

The wrench slot 34 is partially formed with an outer front 36 formed on the exterior of the inner body portion 20 and preferably a weld bead 37 is formed around the interface of the body portion within the wrench front 34.

An outer swivel housing structure 38 is disposed around the rotatable swivel body structure, and the housing structure is not powered within a suitable support arrangement to enable downward movement of the swivel assembly during polling operations. It is adapted to be held as such.

Support devices are not shown, as this is not critical to the invention, and various support devices may be used, as is well known in the use of this type of device.

More particularly, the outer fixed swivel structure 38 includes a central annular member 39 which is coupled to suitable axially spaced inner side ring seals 40 disposed about the rotatable inner body structure. , 41.

Seals 40, 41 are preferably elastomeric seals adapted to leak-tightly seal the force and air inlet conduits 107) to the swivel assembly.

As can be seen in FIG. 3a, the conduit 10 opens into an annular space 42 which has an annular groove 43 formed in opposed relation in the cylindrical wall of the outer body section 28 of the swivel member and swivel mandrel. 44.

A number of circumferentially spaced radial boats 45 are formed between the annular space 42 and the longitudinally extending channel tubes or slots 31 of the mandrel.

An upper bearing mechanism 46 and a lower bearing mechanism 47 are rotatably supported within the inner mandrel structure and the entire outer swivel structure.

The upper bearing mechanism 46 includes an inner bearing race 48 that seats on a shoulder 49 that is provided on the outer mandrel body section 28 and that engages an inward force bearing element or roller 51.
It has two upwardly sloped races or surfaces 50.

Outer race member 51' is engaged by bearing rollers 51 and engages within a seat 52 provided within a double bearing retainer and seal sleeve 53.

This sleeve 53 is connected to the central swivel housing member 3.
9 is provided on an annular flange 55 extending upwardly. The flange has an inner seal ring structure 56 in slidable sealing engagement with the outer cylindrical surface of the mandrel body section 20, thereby protecting the bearing mechanism 46 from the forces of erosive debris. There is.

The lower bearing mechanism 47, on the other hand, has an inner race 5γ which is seated in a seat 58 provided on the mandrel body structure and which is engaged by a downward force bearing element or roller 60. Bearing rollers 60 also engage outwardly sloping raceways 61 under the opposing upward force of outer bearing races 62 disposed within seats 63. However, the seat 63 is provided with a lower bearing retainer sleeve 64.

This sleeve 64 is the mandrel housing central member 3.
6 to a downwardly extending annular flange 66 provided at 9.
It has a circumferentially extending and inwardly projecting lower flange 67 which is threadedly coupled at 5 and which flange 67 is in slidable sealing engagement with the outer cylindrical surface of the mandrel structure. It carries a mating internal seal assembly 68, thereby preventing the ingress of foreign material into the lower bearing assembly.

As described above, the outer swivel housing structure 38 (respective of the dimensions of the swivel mandrel structure can be easily assembled and the respective bearing retainer sleeves 53, 64 and the center) of the mounting member 39. Can be easily disassembled for repair by separating the screw connections.

Additionally, when the bearing retainer sleeve 53, 64 is removed, the seal ring 40, 4'l can be repaired or replaced by moving the central housing member axially upward from the 39-karat gold swivel mandrel. .

Referring to Figures 5a and 5b as well as Figures 6 and 7, a typical joint J is shown.

Each joint J includes a box end γ0 and a pin end 11.

The box end TO is comprised of an inner tubular member 7271) having a suitable number of circumferentially spaced, longitudinally extending milling channels 73 and a through central channel 74. .

At its lower end, the member 72 has a downwardly outwardly tapered internal thread 15 adapted to receive an external thread 76 of the pin section.

At its upper end, the bonk member 72 has an annular seat 11 which surrounds the ufMu 74 and extends below the elongated pipe section 79.
8, the pipe section γ9 is welded to the box member 72 at a circumferentially continuous weld 80.

Arranged in place of one of the pipes 19 is an elongated outer pipe 81 defining with it an annular space At, which pipe has a suitable number of circumferentially spaced welds 8 in a radial opening 83.
2 is welded to the upper end of the box member 72.

A connector sleeve 84 extending below the hatchet is welded to the box member 72, and this sleeve is connected to the box member T.
2 and provides a shoulder 85 for the downwardly directed tube section that projects below the lower end 86 of the threaded box section.

Sleeve 84Vi is welded to box member 12 by a suitable number of circumferentially spaced welds 81 provided within a radial opening 88 thereof.

Additionally, a circumferentially continuous weld 89 is provided between opposing ends of the upper pipe section 81 and the downwardly extending sleeve 840.

The outer connector sleeve 84 and the inner box member are also joined near their lower ends by a weld 90 at the junction of the lower end of the inner box member T2 and the inner periphery of the connector sleeve 84 above the lower end shoulder 85. Extending in the circumferential direction.

As seen in FIG. 5b, the upper end of each pipe, each having a pin end 71k of a joint J, is connected to an upwardly force-inwardly tapered pin section 91 with an external thread 16 provided on the pin section 92. The pin body section 92 has a longitudinally extending through bore or fluid passageway 93 adapted to align with the passageway 74 in the camp ring's bonk end γ0.

At its lower end, pin body section 92 has an internal annular seat 94 that receives a cylindrical end section 95 that extends above central pipe 79 and that receives pipe 1
9 is welded to the pin body section 92 by a circumferentially continuous weld 96.

The outer periphery of pin body section 92 is formed with a number of circumferentially spaced, longitudinally extending slots 97 adjacent its upper end, with slots 91 being relatively narrower but deeper. longitudinally extending slot 98
, and the slots 98 communicate with a further longitudinally extending slot 99 at their lower ends.

Slot 97 communicates with an annular space 100 between the lowermost end of box end 86 and an upwardly facing surface or shoulder 101 of the upper end of outer pin connector sleeve 102 .

The lower slot 99 communicates with the annular space A between the lower pipe 81 and the inner pipe 79 of the underlying unit.

As in the case of Slon) 32.33 described above, the cross-sectional area of slots 9T and 99 is relatively thicker than slot 98, which has a narrower circumferential length;
has substantially the same cross-sectional airflow area.

The outer pin sleeve 102 is force-fitted to the upper end of the sleeve 102 and the upper outer edge of the pin body 92 by a suitable number of circumferentially spaced welds 103 formed within the radial opening 104 of the sleeve 1020. The inner pin body section 92 is welded to the inner pin body section 92 by a weld 105 .

As seen in FIG. 7, relatively narrow circumferentially spaced slots 98 (ri, circumferentially spaced I or radially opposed wrench slots 106 may be formed in the body 92). These slots 106 extend circumferentially and provide a substantially segmented longitudinally extending opposing shoulder 107 that is engageable with conventional retention and support members of the polling rig. and provides a downward horizontal surface 108.

By holding the pin end by a projection on the rig that engages in a wrench slot, it can be rotated by an overlying pipe fan rig to form a threaded connection between the pin and the box.

Referring to FIG. 5a, at the upper end 91a of pin 91, a q-type sealing mechanism is provided for engagement with box body section 72. As shown in FIG.

More specifically, the upper end 91a of the pin section 91
has a circumferentially extending annular groove 91bi in which is disposed an annular elastomer or other sealing ring 91c, which always projects outwardly or upwardly from surface 91a.

Seal ring 91cU, when configuring the joint,
It resiliently seals into engagement with a downwardly directed shoulder 9'ld provided within the box body section 12.

This seal arrangement abuts the pin section and the box section at shoulders 101 and 85, forming a complete fluid-tight seal between the inner and outer pipes, with the resilient sealing ring 91c extending from the annular space A to the central passageway through the inner pipe. Prevent inward airflow.

Referring to Figures 8a and 8b, crossover assembly CO is shown in detail.

This assembly includes an elongated central section including a through channel 110 and an upper inner body section 111, having a threaded pin end 112 engaged with a box screw 75 at the lower end of the pipe section above the inner body section 111 (ri). .

At its lower end, the inner body section 111 has an annular seat 113 that receives an end protrusion 114 of a lower elongated crossover body section 115, the body section 115 being connected to the body section by a circumferentially continuous weld 116. It is welded to 111.

The upper body section 111 has a milled elongated slot 11γ? The slots 117 open at their lower ends into the annular space A between the inner body section 115 and the outer tubular body section 118 and are welded to the upper outer body section 120 at the outer tubular body section 118 (fi 119) and are Section 120 provides an upwardly facing shoulder 121 that, when threaded, is engageable with downwardly facing shoulder 85 of the upper pipe section.

As mentioned above, the pin 112 has an annular elastically deformable or elastomeric seal on its upper end surface.
It carries a ring 122 which prevents air flow from the annular space A into the central passageway through the assembly.

The upper outer body section 120 is connected to the inner body by a suitable number of welds 123 formed within holes 124 thereof.
Welded to section 111 , a lower outer body section 118 is also welded to inner body section 111 by a suitable number of welds 125 formed in holes 126 in body section 118 below weld 119 .

At the lower end of the crossover assembly CO, a crossover connector member 127 is joined to the inner tubular body member 115 and the outer tubular body member 118, and the member 127
There is a hole in the internally threaded box 128 connected to the externally threaded bottle 129 of Vi Pit I-B.

The crossover connector member 127 is an annular seat) 131
The seat 130 receives a downwardly extending cylindrical end portion 132 of the inner body section 115, and the two portions are welded in a circumferentially continuous weld 133.

As shown, connector body 130 is an upper body
The lower end of fluid passage 110 in the center of the section? It's closed.

Outer tubular body section i i aa, body section 1 surrounding cylindrical crossover body 130
It was formed in the hole 135 in the section 18.

It is rigidly coupled to crossover connector member 121 by a number of circumferentially spaced welds 134 .

Another circumferentially continuous weld 136 is provided between the lower end of body section 118 and crossover connector member 127.

A number of circumferentially spaced elongated milled slots 137 on the sides of the crossover body 130
is in communication with the annular space A and is also a crossover body 13
0 and communicates with a number of radial boats 139 formed between the force slot 131 and the central bore 140 of the body 130 .

The bore 140 opens downwardly into a central passage 141 passing through the pinto B', so that air flowing downward through the annular space Ak enters the bit B and is discharged into the borehole as with respect to FIG. 1a. Ru.

Referring to 10a, 10b t 10ck,
A retractable canter hole opener housing or hole expansion bit of the present invention is shown.

The bit EB includes an elongated tubular body 150 that threadably engages a thread 75 at the lower end of the drill pipe section 150.
The pin has an upper pin end 151 in shoulder contact at 2 and carries an elastomeric or elastic sealing ring 15.1 engageable in the box 70 at its upper end, and the outer channel and an inner passageway 154 passing through the body of the hole opener bit.

A number of elongated milling slots 155 are provided at circumferentially spaced positions along the pinto body 150, the slots 155 communicating with the annulus of the drill pipe string through a connection at the upper end of the body, and communicating with the annulus of the drill pipe string through a connection at the upper end of the body.
The outer body sleeve or member 156 of the body extends over the body member 1 in a pyramid-to-pyramidal relationship to the slot 155.
Welds 147 formed in holes 148 at 56 are welded at a number of circumferentially spaced locations.

At the lower end, fluid passageway 155 connects outer body member 156
The piston chamber 15 is provided with a piston-cylinder mechanism 159 through a lateral opening 157 (FIG. 11) located in the piston chamber 15.
It communicates with 8.

This piston and cylinder mechanism 159 is arranged between the position shown in Figures 10b and 10c, where the canter arm 16 is retracted, and the position shown in Figures 15a and 15b, where the canter arm 16 is expanded. The canter arm support structure 160 is adapted to be displaced longitudinally upward relative to the inner drive or mandrel section 161.

The outer, canter arm support structure 160 includes elongated closure strips 164 at circumferentially spaced locations that are machined 61 J and welded into the elongated sheet 165.
A tubular member 162 having an elongated fluid passageway or slot 163 sealed therein.

There are additional passage tubes or slots 166 at alternate angularly spaced locations at member 162, the passages 166 being welded into seats 167' in member 162 that are somewhat shorter than passages 163. It is sealed with an elongated closure strip 167.

As will be described below, the passage 163 is adapted to supply air to the canter C on the canter arm 16, and the passage 163 is adapted to supply air to the canter C on the canter arm 16.
6 communicate with passageways 168 in the lower end section 169 of the outer body member 162 and these passageways 168 communicate with the nozzles 1
70, these nozzles 110 are carried within the lower end of the body and are oriented in the direction of the cutting edge of the bit, so that the air emitted from the nozzles is blown onto the cutter, thereby cutting the cutting edge. Remove debris and focus? Maintain cold operating conditions.

A respective canter support arm 16 is carried by a lower end section 169 of body member 162 in a plurality of circumferentially spaced slots 171 .

Bibond pins 172 extend through the upper end 173 of canter support arm 16 into alignment bores 174 on either side of the slot.

As seen in FIG. 14, the pin is held in place by a suitable threaded member 176 which engages the stopper 115 at one end and is threaded into the forceps body.

As previously mentioned, air in the passageway 163 of the body member 162 is adapted to be directed toward the canter C.

By force, the bore 1γ at the lower end of the passage 163 (/'i
A flexible, preferably metallic, fluid connector 178 opens into the bore 177 and communicates with a finning 179 connected within the bore 177 and another fin communicating with an elongated passageway 181 formed in the canter support arm 16. 180.

In the illustrated embodiment, the arm 16 is a three-part construction, including a bibond end 16a and a canter support end 16bk, which portions are provided with a fluid passageway of 181 Ω by a weld 16c.
It is joined with a tubular insert 16d which provides continuity.

The air supplied to the passage 181 is fed to a canter (as described later).
J- adapted for cooling.

Inner body or drive member 161 (/i outer member 162
A tubular member 18 at its lower end extends reciprocally within the shaft.
2, the member 182 is disposed within the seat at the lower end of the body member 161 and has a split retainer ring 1.
The retainer ring 185 also has a head 183 held in place by a suitable device such as a ball 1.
86 and ball 1811111
The outer periphery of the J retainer ring 185 engages in opposing arcuate surfaces provided around the inner peripheral wall of the seat 184.

Tubular member 182 extends downwardly within the center of outer body section 162 through bushing 18γ and bore 189 provided in web 190 at the lower end of outer body member 169 by bushing 187V'i snap ring 188. held within.

A fluid passageway 191 extends through tubular member 182 and communicates with central passageway 154 through inner bit body member 161.

Because the air flowing through tubular member 182 exerts a force on cutting chips and abrasive dust, member 182 is preferably provided with a wear-resistant ring insert 192 at its lower end.

In operation of the structure to expand the cutter support arms outwardly from the position force of FIG. 10c to the position dimension of FIG. The downward force provided inside the 16
It is adapted to engage with a cam surface 194 extending inwardly in an arcuate manner.

At the lower end of the cam surface 194 is a locking surface 195, which locks the arm 1 as seen in FIG. 15b.
6 is fully pivoted and inflated, it engages projection 193 to mechanically ring the arm in the inflated position until reverse movement of the bit body member occurs.

Upon such reverse movement of the focus body members, the outwardly projecting force-upward shoulders 196 provided on the tubular members 182 cause the upper ends 173 of the respective support arms 16 to
15b, thereby moving the support arm 16 from the expanded position force of FIG.
The focus structure can be taken out onto the hole force drill pipe by rotating the cylinder at the retracted position c.

As previously mentioned, the inner bit body member 161 is a rotary drive member adapted to rotationally drive the outer focus body member 162 in response to the rotation of the drill pipe string, thereby causing the focus canter to center around the axis of the focus. It is rotated, that is, rotated on its own axis.

Rotational drive between the focus body members is provided as shown in FIG.

That is, as shown, on each side of the inner body member 161 there are chord-like flat portions 198 disposed in opposing relation, such that the flat portions 198 carry forces and forces carried within the outer body member 162.
It can be slidably engaged with a segment-shaped torque transmission member 199 that is fixed in place by welding or the like.

As previously mentioned, the piston-cylinder mechanism 159 forming the piston chamber 158 includes the canter arm 16.
acts to move outer body structure 160 upwardly relative to inner body structure 161 when it is to be inflated.

Referring to FIG. 10b, the piston-cylinder mechanism 159 includes an upper tubular head 200 carried by an outer body member 162.
00 is secured within the upper end of the outer body member 162 by means such as a retaining screw 201 extending into an aperture or groove 202 formed around the outer periphery of the outer body member 162.

An outer seal ring 203 is disposed between the body member 162 and the outer periphery of the head 200, and an inner side seal
The ring is also carried by the head of piston ring 203'U in slidable sealing engagement with the outer cylindrical surface of upper outer body member 156.

Another wiper or resilient seal 204 is carried at the upper end of the head 200 and slidably engages the cylindrical outer surface of the sword body member 156.

Additionally, a suitable grease can be applied to the sliding connection between the head 200 and the body member 156.
06, lubricant is supplied to the annular space 205 above the piston ring seal 203' and to the wiper ring seal 204.

Below the head 200, another head member or hari lug 207 is carried by the inner body member 161, and this ring 2
0γ is arranged around the outer periphery of the body member 161, and the sword
A stop ring 208 is seated on and held in place by a number of circumferentially spaced retaining screws 209 threaded into the force body member 161.

Static seal ring 210 connects body member 161 and ring 2
07, a sliding resilient ring seal 211 is carried by ring 207 adjacent its lower end and is in sliding sealing engagement within the inner cylindrical surface of outer body member 162. .

The air supplied through the swivel to the annular space A between the inner and outer pipe sections can flow downwardly through the respective 234214 to reach the air passages 155 provided in the focusing mandrel.

A boat 151 at the lower end of passageway 155 provides communication between passageway 155 and piston chamber 158 such that air pressure within the piston chamber is maintained between the outer circumference of pinto mandrel 156 and the inner circumference of outer body member 162. Acting upwardly across the annular cross-sectional structure of the head 200, the outer body member and hence the focus support arm 16 is moved toward the inner body member and the cam member 1 on the mantle tube 182.
Apply upward force to 93 to raise it.

Such upward movement causes the focusing arm 16 to gradually expand outward.

That is, the rotation of the drill pipe causes the canter C to form a downwardly directed upper shoulder within the expanded borehole EH.

A suitable number of small boats 213 spaced apart in the circumferential direction are connected to the head 20.
Piston chamber 158 and outer body member 1 directly below
62 and an air passage 163, whereby a portion of the air supplied to the piston chamber passes through the passage 16.
3 and then through the flexible connector 17i to the air passage 181 of the bit arm 16.

As shown in FIG. 11, the canter arm passage 181 is adapted to supply air to the cutter C.

Passage 181U communicates with bore 181b via passage 181ak, from which air flows through another passage 181c which extends over a journal or mount 220 for rotating conical cutter element 221. , the canter element is supported by a suitable hard cutting insert 1' 222k arranged in a suitable cutting pattern as is well known.

Between the canter journal or mount 220 and the conical canter element 221 is a suitable roller bearing 223 that engages an opposing bearing surface 224 of a conical member 2250 on the mount.

Furthermore, a ball bearing element 226 is disposed on the mount 220 and between the opposing arcuate seats 227 and 228 in the conical cutter element 221;
These balls are first fed through the bore 1aibi and are rotatably held by the canter element 221 on the mount.

Pub ring. After the balls 226 are installed, they are held in place by these two retainers 229, and the retainers 229
9 is placed within bore 181b and provides an inner arcuate surface 230 that corresponds to surface 227 in the force mount and is secured in place by welder B 231 next to retainer 229.

Additionally, an end bearing or sleeve 232 is disposed between the reduced end of mount 220 and the end bore in conical member 221.

The air passage 181cU opens through the inner end of the mount 220, and all the air supplied through the passage 181 flows out between the cutter cone and the mount and flows through the bearings 232, 226,
223, all of which can be passed through.

As previously mentioned, the relatively small boat 213 leading from the piston chamber 158 to the fluid passageway 163, which connects the cutter, provides sufficient flow to effectively cool the cutter during the initial drilling operation. , but Kanta is the 15th
After expanding outward to the position shown in Figure b and being mechanically locked in this position, it is desirable to supply a large amount of air to the canters to cool them.

Accordingly, referring again to Figure 10b, an additional fluid boat 213a is provided in the body member 162 and in communication with the air passageway 169.

These boats 213aU, the lower side ring seal 21 between the sleeve 20γ and the inner circumference of the body member 162
1 and the upper side link seal 212 initially closed.

When the body member 162 is moved upwardly to the position shown in FIG. 15a, the relatively large boat 213a
i; is moved upwardly into the upper side link seal 212 and then communicates with the piston chamber 158, thereby providing additional air to the passageway and canter in the cutter support arm.

Further, as shown in FIG. 10b, body member 162 has additional circumferentially spaced bows 1-213b' in communication with passageway 166, and the lower end of body section 169 on side passageway 1661. Nozzle 1 in
It is familiar to 70.

These additional boats 213b are also initially located between lower seal 211 and upper seal 212 between body member 162 and sleeve 201 such that communication between these boats 213b and fluid passageway 155 is initially blocked.

Again, when the outer body of the bit moves upwards and the force bit arm 16 is fully expanded, these additional bows 213b also communicate with the piston chamber 158, so that A portion of the air supplied to the piston chamber is allowed to flow to the nozzle 170 and is directed towards the cutter, as seen in FIG.・Blows away cutting debris and maintains full cooling power.

Be sure to install a pilot hole PHk as shown in Figure 1.
In using the apparatus described above for forming and then forming expanded bore holes EHk, each component of the apparatus preferably includes a compressor for supplying air to the polling operation, so that each component can be configured into a string during the polling operation. The components are carried by a polling rig having suitable supports for holding them together and their engagement and support tools that allow each component to be rotated together.

First, the crossover CO is assembled with the usual poling pinto B and swivel S, along with the intermediate double concentric pipes of force and appropriate length.

When polling air is supplied to conduit 10, the pipe
Rotation is applied to the string.

Air flows down into the annular space A of the pipe string,
Are you doing a crossover? It traverses to reach the central bint passage and then returns to the surface through an annular space 15 k outside the drill pipe.

This is a more or less standard borehole polling operation, except for the convenience of double concentric pipe and a crossover, and can also be done using regular drill pipe instead of double concentric pipe.

After the pilot hole PH is drilled to the desired depth,
The polling string is removed from the borehole and the focus crossover assembly is removed.

A telescoping pin EB is then applied to the pipe string and lowered into the bore hole in the order in which it is to begin forming the expansion chamber or hole EH.

Air is simultaneously supplied to the polling fluid conduit and the venturi v to rotate the drill pipe string and initiate the cutting action of cutter C against the pilot hole wall.

The cuttings, together with the portion of the air that circulated through the telescoping arm to the canter C, flow back upwards through the central pipe, assisted by the induced flow created by the venturi device V.

The flow of polling air to the cutter C is initially limited by the relatively small boat 213 communicating between the canter expansion piston chamber 158 and the canter, resulting in a high air pressure that forces the cutter outward. The cutter arm 16 is moved forcefully to rapidly cut into the formation to prevent the outer surface of the cutter arm 16 from being dragged across the formation at the cut shoulder.

When the cutter is fully expanded and thrust into position by the camming action of the mandrel on the force-support arm, more air can be circulated through the cutter to cool and clean the knife. , the remainder of the air is injected in the direction of the bit through the nozzle 110 and further
4-Clean and cool.

The poling operation is then continued until the expansion hole is drilled to the same depth as the original pilot hole, such as in the no-pass blast hole formation method of the aforementioned patent application.

At one point, the circulation of air in the drill pipe and the application of the Bolins thrust can be terminated, while the supply of air to the venturi continues.

Cuttings and dust carried upward by the air returning to the surface through the annulus will settle to the bottom of the borehole.

The continuous rotation of the drill pipe allows the cutter to collect settled dust and swarf, and the air flow flowing down through the annular space and then up through the center of the drill pipe is acts under the influence of to keep the pores relatively clean.

[Brief explanation of drawings]

Figures 1a and lb both show the double drill pipe of the present invention.
Pilot bore into the formation using a string
A diagram illustrating the poling of holes is constructed, with Figure 1b being a downward extension of Figure 1a. Figures 2a and 2b both illustrate the retractable bit of the present invention and Figure 1a, which utilizes reverse circulation in the double pipe string.
, lb constitutes a schematic diagram showing the expansion of the pilot bore hole, and Figure 2b is a downward extension of Figure 2a. Figures 3a and 3b together constitute an enlarged longitudinal section through the swivel structure, with figure 3b being a downward extension of figure 3a. FIG. 3c is a sectional view taken along the line 3cm3c of FIG. 3b. FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3a. Figures 5a and sb together constitute an enlarged cross-sectional view taken along line 5--5 of Figure 1 showing a typical double pipe joint If, and Figure 5b is a downward extension of Figure 5a. FIG. 6 is a sectional view taken along line 6-6 of FIG. 5a. FIG. 7 is a sectional view taken along line 7-1 in FIG. 5b. In Figures 8a and 8b, both pilot bore holes?
A cross-over unit in a double pipe string used for drilling (f) constitutes an enlarged cross-sectional view taken along line 8-8 in Fig. 1, and Fig. 8b is a downward extension of Fig. 8a. Figure 9 is a sectional view taken along line 9--9 of Figure 8b. Figures 10a, 10b and 10c all show the retractable pit used to expand the bore hole with the cutter in the retracted state; Figure 2; A 1o-io line cross-sectional view of the entire configuration,
10b and 10c are downward extensions of FIG. 10a. FIG. 11 is a sectional view taken along line 11-11 in FIG. 10b. FIG. 12 is a sectional view taken along line 12-12 of FIG. 10b. FIG. 13 is a sectional view taken along line 13-13 in FIG. 10c. FIG. 14 is a sectional view taken along line 14-14 in FIG. 10c. Chapter 15a. Figure 15b constitutes a cross-sectional view corresponding to Figures 10b and 10c, together showing the cutter expanded as in Figure 2. FIG. 16 is a bottom view of the retractable bit showing the fully expanded cutter of FIG. 15b. Figure 17 is part 1 of Figure 16 showing one detail of the air-cooled canter.
7-17 is an enlarged cross-sectional view. F...Geological formation, B...Drill bit,
P...Drill pipe, D...Rotary drive unit, C...Kanta, PH...
Pilot hole, S...Swivel, 10.
... Air supply conduit, IP ... Inner pipe, OP ... Outer pipe, J ... Joint 5, A ... Annular space, CO ...Crossover unit, V...Venturi, E
B...Bit, 16...Cutter arm, 20...Mandrel, 158...
Piston chamber, EH...expansion hole, 170
······nozzle.

Claims (1)

[Claims] 1. An outer fluid passage defined between an inner pipe and an outer pipe? Nonoiront on double pipe string with
Pi-Pilot into the formation by rotating
The hole is drilled and the poling fluid is circulated through the hole while the hole is being drilled, and the poling fluid and cutting waste are removed.
To drain the hole force through the entire space between the pipe string and the bore hole wall; stop the circulation of the poling fluid and remove the bore hole force from the pipe string and the pilot bit: Replacing the pilot bit with a borehole expansion pint with an inflatable cutter at: the bottom of the pilot hole and moving the expansion pit along the drill pipe at a selected location within the pilot hole spaced from the force above. Expanding the expansion bit canter by supplying polling fluid with the expansion bore hole through the outer fluid passageway of the drill pipe: rotating the drill pipe and expansion pin hole toward the bottom of the pilot hole; drilling a hole, while removing a portion of the poling fluid and formation cuttings through the inner and outer fluid passages defined by the inner pipe; ceasing the supply of poling fluid; retracting the expansion bit canter: the drill pipe and the expansion; Extracting the expansion borehole force: A method of poling an expansion borehole in the formation, taking into account each of the above process forces. 2. The method of claim 1, including expanding all of said boreholes by substantially the same extension distance as said boreholes. 3. The method of claim 1, including directing the flow of poling fluid through the inner fluid passageway from a borehole force. 4. The method of claim 1, comprising directing the flow of poling fluid through the inner fluid passageway from a bore annealing force by reducing the pressure within the inner fluid passageway. 5. The method of claim 1, including directing the flow of poling fluid through the inner fluid passageway from borehole forces by venturi-reducing the pressure within the inner fluid passageway. 6 Bore hole force directing the flow of poling fluid through the inner fluid passage, and after stopping the supply of poling fluid and before retraction of the canter of the expansion bit, the inner fluid passage force causes fluid and cutting. 2. The method of claim 1, further comprising full vacuum cleaning the borehole while continuing to direct the flow of debris. 1 restricting the flow of polling fluid through the cutter from the outer fluid passage force while inflating the canter, and subsequently directing a portion of the polling fluid from the outer fluid passage force to the cutter after inflation of the cutter; 2. A method as claimed in claim 1, including directing the method into the borehole in the direction of . 8. restricting the flow of poling fluid through the canter from the outer fluid passage force while inflating the bore hole; and expanding the bore hole to a distance substantially the same as the pilot hole. 2. The method of claim 1, including directing a portion of the poling fluid from the outer fluid passageway force into the borehole toward the cutter after inflation of the lid.