CA1154749A

CA1154749A - Device for controlling the orientation of bore holes

Info

Publication number: CA1154749A
Application number: CA000367657A
Authority: CA
Inventors: Heinz Wallussek; Martin Wiebe; Thomas Roder
Original assignee: Bergwerksverband GmbH
Current assignee: Bergwerksverband GmbH
Priority date: 1980-01-05
Filing date: 1980-12-29
Publication date: 1983-10-04
Also published as: AT373358B; GB2066878A; CH653406A5; FR2473105A1; SE441376B; GB2066878B; AU536279B2; FR2473105B1; ATA581A; BR8008612A; AU6586080A; SE8008775L

Abstract

ABSTRACT OF THE DISCLOSURE
A device for controlling the inclination of underground bore holes is in form of a drill guide rod having an outer element and an inner element which rotates coaxially in the outer element.
Strip-shaped members can be pivoted out from the outer element in the same manner as the ribs of an umbrella, and electrical in-clinometers in the rod furnish the signals which control the time and degree of such pivoting.

Description

1 This invention relates to the field of drilling.
~ ore particul~rly, the invention concerns a device for controlling the orientation of bore holes.
In man~ instances, particularly in ~ining operations~
it is highly desirable and sometime$ vital~ to be able to drive a bore hole as close as possible ~o the intended spot. For exampler this is eYidently desirable when the bore hole is being driven to gain access to a new underground area of coal or another substance to be mined. On the other hand, the ability to be able to drive a bore hole directly to a chosen spot may become a matter of life and death if one or more workers are trapped under-ground and the bore hole is being driven to either supply them with air, food and/or medicine/ or else to physically remove them to safety through the bore hole.
The problem with the prior art is that it is not effective.
It is known to incorporate in the drill string a rigid guide rod which is located behind the drill bit and is intended to stabilize the drill string, which it does in fact do. Such guide rods cannot, however, prevent a deviation of the bore hole from its intended path, as it occurs during the course of drilling.
Even less, of course, can these rods correct such a deviation once it occurs. And finally, if a deviation does occur no one will know of its details until the drill target is or should be reached and it is found that the bore hole does not come out where intended.
A proposal has been made to provide these guide rods with pendulum controls to cause them to more or less automatically maintain the ~ore hole "on target". Such controls are~ however, quite complicated and eY~pensive. Moreover, they are susceptible to malfunctions due to errors in setting or operating malfunctions in the control itself. This will then again lead to borehole deviations which can be detected only when the drllling operation is completed and it is discovered that the bore hole does not

-2-~s~9 1 come out where intended. Also, these controls ha~e a certain inertia factor which in itself may ~ive rise ~o bore hole deviations.
It is an object of the invention to overcome the disadvantages of the prior art.
A more particular o~ject is to pro~ide an imp~oved device ~or controlling the orientation of bore holes.
A concomitant object is to prc~ide a device of the type uncler discussion which permits not only control (i.e.~
monitoring) of the bore hole orientation, but the correction of any deviations which may be occurring.
In keeping with these and other objects, one aspect of the invention resides in a device of the type under discussion which includes a drill guide rod including an outer fixed part, an inner part turnable relative to the outer fixed part, elect-rically operating inclinometers on or in the outer part, and adjustable orientation-correcting elements on the outer part.
A device according to the inYention permits constant monitoring of the bore hole orientation via the inclinc~meters and, if deviation of the bore hole from the prescribed path is deteetedr the execution of appropriate corrections via the eorrecting elements. These can be extending outwardly from the outer part by different selectable distances, in dependence upon the degree and direction of detected bore hole deviation.
A monitoring eable may extend from the inclinometers through the drill string to the control panel or stand of the drilling machine, so that the inelinometer signal ean be monitored at the stand and appropriate eounter-measures taken from there. Monitoring and correcting is adYanta~eously earried out step wise in the drill pauses because vibrations and other error sources are then excluded. However~ both functions can also be carried out while drilling is in progress.

-3 7'~9 1 It is advantageous for the correcting elements to be mounted at the head of the guide rod and to be pivotable outwardly from t~e same ~ia hydraulic cylinders mounted in the upper part of the rod. In this manner the correcting elements can be moved out from the rod in the s-ame pattern in which the ribs of an umbrella mo~e away from its stem when the umbrella opens. Moreover~ even the slightest mo~ement of the cylinders will be reflected by a correspondin~ movement of the correcting elements, and the parts needed for effecting and controlling this movement can be positioned in such a manner as to be largely protected against contamination and/or damage.
The inclinometers may have magnetic (solenoid) valves j associated with them and these valves will then control the supply of hydraulic fluid to the c~linders. The valves ma~ be so set that they effect movement of the correcting elements which are analogous to the signals received from the inclinometers.
Erroneous measurements can be avoided ana better results obtained if the inclinometers are arranged crosswise. This permits erroneous indicat;~ons to be readily detected at the control panel and to be negated by appropriate countermeasures.
It is advantageous if the required hydraulic operating pressure is produced directly in the rod. For this purpose the inner turnable part of the rod ma~ carry an eccentric via which the requisite operating pressure is p~oduced. Pressure-limited hydraulic accumulators may be connected between the pressure generator and the cylinders so that hydraulic ackuation of the cylinders is possible even during pauses in the drilling activity.
To avoid the need for having to r~n an electric supply cable throug~ the drill string, and to permit the generation of an adequate supply voltage in the guide rod itself, it is advan-tageous to mount a gear on the shaft of a generator which is ~54~

1 connected with the outer stationary rod par~J and to ha~e this gear mesh with a secon~ gear which is pxovided on the inner rotatable part of the rod. A shrink fitting of the gear onto the inner rod is ad~isable to aYoid slippa~e. To avoid pro-jecting parts it is adYantageous to ar~an~e the generator within the outer stationary pa,rt of the rod.
Accordin~ to a further em~odiment of the invention the inner wall of the outer stationary- part of the rod may be constructed as the stator, and the s~urface of the turnable inner part as the rotor of the generator. The stator is preferably constituted by a tubular sleeve which is rigidly connected with the stationary outer part~ and the rotor by permanent magnets which are fixedly connected with the turnab,le inner part. This embodiment requires very little Space and is therefore especially well suited for the intenaed applications.
The novel features which are consid,ered as charac-teristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its constructions and its method of operation ! together with additional 2Q objects and advantages thereof~ will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
FIG. 1 is a device according to the invention, shown in axial section;
FIG. 2 is a fragmentary axial sectional view of another embodiment of the invention; and FIG~ 3 ;`s a view similar to FIG, 2 but showing still another embodiment.
The deYi,ce illustrated in FIG, 1 is a drill guide rod 1 to be incorporated in a drill string behind the drill bit.

~5--~S~749 1 It has a rotary inner part 3 and a stati,onary o~ter part 4. A
flushing passage 22 extends throu~h the center of xod 1, for supply of drilling fluid to the not illustratecl drill bit.
Rod 1 has a head portion 2 and a plurality o~ angularly spaced (only two vi,sible~, bore hole orientation correcting ' elements 9~ which are firmly connected to part 4 at the head portion ' 2, by means of mounts which allow the lower ends tadjacent end , portion 7 of rod l) of the elements 9 to tilt outwardly away from ', the rod 1. Hydraulic cylinders lQ~ 11 are mounted in the upper '' lO part of rod l which when extended/ pivot the elements 9 outwardly away from part 4. Limiters 12 prevent movement of the elements 9 outwardly from rod 1 heyond a predetermined extent. Springs 13 associated with the limiters return the ~lements 9 to their (,illustrated) starting position when the cylinders 10, 11 are not supplied with hydraulic fluid.
, The operation of cylinders lQ, 11 is controlled by magnetic (,solenoid) valves 16, 17 (known per se) which control the flow of fluid to and from the c~linders. The valves are in turn controlled by signals received from electrically operated inclinometers 14 (known per se~. In addition to furnishing their signals to the valves 16l 17 the inclinometers also supply the signals (via an appropriate cable or in another suitable manner~
to the drilling machine control panel.
The hydraulic operating pressure required for the hydraulic control is produced ~y the rotating part 3 of the rod l, in the illustrated em~odiment by an eccentric 23 which is provided thereon. Pressure-limited hydraulic accumulators 20 are provided which permit the cylinders lO, 11 to operate during pauses in the drilling operation; the required fluid is then withdrawn from reservoir 18 via pressure generator 19.

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1 In the embodiment of FIG. 1 t~e electric energy for the inclinometers 14 and the val~es 16, ~7 is supplied via the cable 15 which also functions as the monitorin~ and control cable. The inclinometers 14 may be directly coupled with the cylinders 10~ 11 but in that case a si~ht control of the bore hole path from the control panel is not possible without addition-al equipment.
In the embodiment of FIG~ 2 the inclinometers and valves 16, 17 are supplied with el~ctricity which is generated in situ. For thi5 purpose a generator 25 is provided which~ for the sake of simplicity! may be mounted on the outer stationary part 4 of rod 1. It has an input shaft 26 carrying a gear 27 which meshes with another gear 28 on -the rotary inner part 3 of rod 1. Gear 28 may be shrunk onto the inner part 3, or it may be directly formed in the material of part 3 to keep from sub-jecting part 3 to additional external forces. Taps 29 on the housing of the generator 25 furnish the supply voltage for elements 14, 16 and 17.
In the embodiment o~ FTG. 3, finally~ the generator is so constructed as to require no projecting parts at all~ Its stator 30 is ~ormed by a tubular sleeve which is firmly connected with the stationary part 4. The rotor 31 is formed by permanent magnets which are connected for rotation with the inner part 3.
The supply votage is tapped off the terminals 32.
A particular advantage of the present invention results from the fact that any deviation of a bore hole can be easily determined and corrected by appropriate countermeasures. The additional expenses and time losses associated with deviating bore holes are thus avoided, to say nothing of the consequences 3Q for health and life of trapped personnel. The correction can ~59L7~g 1 even be effected automatically and eYerythin~ can be ~onitored and supervised fro~ the drillin~ ~ach~ne ~ontrol panel~ If~ as in the em~.odiments. of FIGS e 2 and 3, the supply voltage for the electrical equipment is generated in the de~ice itself, then such generation can be effected withDut the need for supplying additional ener~y.
While the ln~ention ha$ ~een ill~strated and described as embodied in a b.ore~hole monitoring and ~orrecting device, it is not intended to be limited to the aetails shown, since various modifications .and structuxal changes may be maae without departing ~ in any way from the splrit of the present invention.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Device for controlling the orientation of bore holes, particularly in underground coal mining applications, comprising a drill guide rod adapted to be included in a drill string rearwardly of the drill bit and including an outer elongated element and an inner elongated element coaxial with and turnable in said outer element; inclinometer means on at least one of said elements and operative for generating signals when inclination of said rod indicates deviation from a predetermined bore hole path; correcting means including a plurality of strip-shaped correcting members pivotally mounted on said outer element; a plurality of cylinder-and-piston units arranged for engaging said members and pivoting them outwardly away from said outer element to a selectable extent; a generator to be driven by said inner element; and magnetic valves supplied from said generator and controlled by signals received from said inclinometer means to thereby control the operation of said cylinder-and--piston units so as to pivot said strip-shaped correcting members.

2. Device as defined in claim 1, said inclinometer means comprising a plurality of electrically operated inclin-ometers.

3. Device as defined in claim 1, said members being movable to and arrestable in a plurality of positions relative to said outer element.

4. Device as defined in claim 3, said guide rod having a head portion and a body portion longitudinally spaced from said head portion, and said members being pivotably mounted on said head portion and extending lengthwise of said rod.

5. Device as defined in claim 4, said cylinder--and-piston units including hydraulic fluid lines, said magnetic valves being provided in said fluid lines and operatively connected to said inclinometers to control the flow of hydraulic fluid to and from said units in response to signals generated by said inclinometers.

6. Device as defined in claim 2, wherein said inclinometers are arranged transversely to said guide rod.

7. Device as defined in claim 4; further compris-ing pressure-generating means in said guide rod and operative for pressurizing the hydraulic fluid for said cylinder-and--piston units; and further comprising pressure-limited hydraulic accumulators interposed between and connected with said pressure-generating means and said cylinder-and-piston units.

8. Device as defined in claim 1, said generator having a drive shaft carrying a first gear, and said inner element having a second gear which rotates with it and which meshes with said first gear so as to turn said drive shaft.

9. Device as defined in claim 8, said inner element being adapted to be connected to and rotate with the drill string, and said second gear surrounding said inner element and being shrink-fitted onto the same.

10. Device as defined in claim 1, wherein said generator is located within said outer element.

11. Device as defined in claim 1, said generator including a stator formed by an inner circumferential surface of said outer element, and a rotor formed by an outer circumfer-ential surface of said inner element.

12. Device as defined in claim 11, said outer element including an inserted tubular sleeve rigidly con-nected therewith and having said inner circumferential surface, and said inner element including a plurality of permanent magnets rigidly connected with said inner elements and together having said outer circumferential surface.

13. Device for controlling the orientation of bore holes, particularly in underground coal mining applications, comprising a drill guide rod adapted to be included in a drill string rearwardly of the drill bit and including an outer elongated element and an inner elongated element co-axial with and turnable in said outer element; inclinometer means on at least one of said elements and operative for generating signals when inclination of said rod indicates deviation from a predetermined bore hole path, said inclino-meter means including a plurality of electrically operated inclinometers; and pivotably adjustable correcting means on one of said elements and operative for correcting the devia-tion indicated by said signals.

14. Device for controlling the orientation of bore holes, particularly in underground coal mining applications, comprising a drill guide rod adapted to be included in a drill string rearwardly of the drill bit and including an outer elongated element and an inner elongated element co-axial with and turnable in said outer element; inclinometer means on at least one of said elements and operative for generating signals when inclination of said rod indicates deviation from a predetermined bore hole path; pivotably adjustable correcting means on one of said elements and operative for correcting the deviation indicated by said signals; and an eccentric mounted on said turnable inner element of said guide rod.

15. Device for controlling the orientation of bore holes, particularly in underground coal mining applications, comprising a drill guide rod adapted to be included in a drill string rearwardly of the drill bit and including an outer elongated element and an inner elongated element co-axial with and turnable in said outer element; inclinometer means on at least one of said elements and operative for generating signals when inclination of said rod indicates deviation from a predetermined bore hole path; and pivotably adjustable correcting means on one of said elements and operative for correcting the deviation indicated by said signals; and a generator on said outer element and operative to be driven by rotation of said inner element.

16. Device for controlling the orientation of bore holes, particularly in underground coal mining applications, comprising a drill guide rod adapted to be included in a drill string rearwardly of the drill bit and including an outer elongated element and an inner elongated element co-axial with and turnable in said outer element; inclinometer means on at least one of said elements and operative for generating signals when inclination of said rod indicates deviation from a predetermined bore-hole path; pivotably adjustable correcting means on one of said elements and operative for correcting the deviation indicated by said signals; and an electrical generator including a stator formed by an inner circumferential surface of said outer element, and a rotor formed by an outer circumferential sur-face of said inner element.