US2793833A

US2793833A - Method for charging shot holes

Info

Publication number: US2793833A
Application number: US337835A
Authority: US
Inventors: Sr John P Daniel
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-02-19
Filing date: 1953-02-19
Publication date: 1957-05-28
Anticipated expiration: 1974-05-28

Description

May 28, 1957 J. P. DANN-1, sR

METHOD FOR CHARGING SHOT HOLES 3 Sheets-Sheet 1 Filed Feb. 19, 1955 m, wm m l A Mw. a D w D'. WQ J W. w w

May 28, 1957 J. P. DANIEL, SR

METHOD FOR CHARGING SHOT HOLES 3 Sheets-Sheet 2 Filed Feb. 19, 195s Fig. 4

John P. Da.n/'e/, Sr.

JNVENTOR.

May 28, 1957 J. P. DANIEL.. sR

METHOD FOR CHARGING SHOT HOLES I5 She'ets-Sheet 3 Filed Feb. 19. 1953 John P. Danie/,5r

INVENTOR.

BY ala/#wy Hmm United States Patent METHOD FOR CHARGING SHOT HOLES John P. Daniel, Sr., New Orleans, La.

Application February 19, 1953, Serial No. 337,835

Claims. (Cl. Z55-1.8)

This invention relates to a method and apparatus for constructing shot holes and particularly to an apparatus for drilling holes so that the shots may be placed therein and the drill cage removed before the shot is tired.

When making seismograph records it is customary to provide shot holes of variousdepths into the formation and to explode an explosive charge therein so that the propagation of the shock waves through the earth may be measured and recorded. This type of work is normally accomplished by two separate and independent crews. The first crew proceeds in `advance of the second crew and the operation of the iirst crew comprises the drilling of the necessary shot holes and the placing'of explosive charges therein. The second crew follows behind the first crew and connects up, tires the charges and records the shock waves. ln relatively hard formations the process is substantially this simple inasmuch as the shot holes may be readily drilled and the explosive charges placed therein with no other steps to be accomplished by the tirst crew.

However, when making seismograph records in soft formations, such as sand, swamp muck or other similar materials which will cave in, the operation is much more complicated. Heretofore it has been necessary for the first crew to drill the shot hole vand to leave the drill bit and drill string in the finished shot hole. Then the explosive charge is lowered into the interior of the drill string at the bottom thereof with the drill string maintaining the walls of the `shot hole and preventing the caving in of the surrounding formation while the charge is being placed. After the explosive charge has -been placed, the first crew then moves on in advance of the second crew who fires and records the explosive charges and the shock waves effected thereby under normal circumstances. After the explosive charges have been tired, it is then necessary for either the lirst crew to return or a third crew to follow the second crew and retrieve those portions of the drill strings which have not been destroyed, the lower portions of the drill strings and the bits being broken off by the firing of the shots. In many instances the cost of salvaging the drill stringis substantially equal to or in excess of the value of the drill string reclaimed. However, in certain states it is the law that the drill string must be removed. Since only one shot is fired in ea-ch shot hole, and since many such shot holes are formed, it will be readily apparent that seismographic operations in soft formations are `very expensive. v

The present invention relates to a method and apparatus by which the major portion of the toolvmay be salvaged for repeated use. y

This is accomplished according to the present invention by providing the drill string with a cutter head having a knockout or frangible portion or a removable drill cutter head which may be removed so as to provide an opening through which the charge may be placed while the detonator cable or wire will be extended upwardly through the drill tubing. After the charge has been pla-ced in the bottom of the hole the drill tubing may be pulled up and taken away so that the entire tubing may be used in another well thus salvaglng a major portion of the equipment. In order to support the detonator wire in the tubing during the removal of the string it is found that `a oat may 'be attached to the wire and the entire hole filled With water or other fluid so that the float will maintain the wire in position inside of the tubing so that the tubing may be raised over the float and even if the sides of the hole cave the detonator wire will be in position for connection to any suitable firing equipment.

lt is accordingly an object of this invention to provide an improved method of constructing shot holes.

it is lanother object of the invention to provide an improved tool for drilling shot holes.

It is a further object of the invention to provide a drill head having a knockout portion therein.

lt is a further object of the invention to provide a drill head which may be detachably connected to the end of a drill stem.

Other objects and many of the attendant advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawing in which:

Figure 1 is a sectional elevation of a shot hole with the tool elevated off of the bottom in knockout position;

Figure 2 is Ia view similar to Figure l with the knockout removed and explosive being lowered into position;

Figure 3 is a similar view with the hole ready to be shot;

Figure 4 is `an exploded perspective of one form ofA cutter hear laccording to the invention;

Figure 5 is an elevation of a modified tool according to the invention;

Figure 6 is a view similar to Figure l but showing the modied tool;

Figure 7 is a view showing the placing of the charge with the modilied tool; and y Figure 8 is a cross section of the tool taken substantially on the plane indicated by the line 8-8 of Figure 5.

In the exemplary embodiment according to Figure 1, the shot hole 10 is drilled into loose or caving formation 12 by means of a drill head 14 secured on the end of a hollow drill stem 16 which may be made of any desired number of links or joints so that the shot hole 10 may be of any desired depth.

In the modification according to Figures l to 4 inclusive, the drill head 14 is provided with a threaded collar 20 which may be threadedly engageable with the lower end of the tube 16 so that rotation of the tube 16 will rotate the head 14. A plurality of cutters 22 are provided on the head 14 and the head 14 is provided with an axial aperture 24 such as the continuation of the bore of the tubing 16 so that drill fluid or other material may readily be forced down the tubing 16 and ow outwardly through the passage 24. A knockout plug 26 provided with a small aperture 28 is mounted in the passage 24 to reduce the operating size thereof.

The knockout 26 is usually provided with a core member 30 which fits within the passage 24 and is provided with a ared skirt 32 for seating against the shoulder 34 provided by the counterbore 36 so that the plug 26 will be iirmly seated in the lowermost portion of the passage 24 and will maintain the opening 28 so that the iluid in the tubing may be expelled through the passage with,

. considerable velocity.

In order to maintain the knockout 26 in the passage 24 a frangible pin 38 may be placed in a bore in the head 14 which communicates with la bore 42 in the knockout 26.

In actuation or operation of the method with the tool according to Figures l to 4 the tool is operated so that the head 14 is driven into the earth by a rotary motion to produce a hole 10 of any desired depth. When the desired depth -of hole has been reached the tool will be raised upwardly a small distance from the bottom of the hole as shown in Figure l and the knockout weight 46 carried at the end f a cable 4S will be lowered through the tubing 16 with sufficient force to strike the knockout 26 and break the frangible pin 38 so that the knockout 26 will be removed from the passage 24 so that a relatively large a'xial opening will be produced through the drill head 14. The tool will then be raised a further distance from the bottom of the hole to provide a space 50 below the bottom of `the tool so that an exalosive charge 52 may be readily lowered through the aperture or passage 24 into the bottom of the hole.

In order to facilitate both the ring of the explosive charge 52 and the lowering thereof into the shot hole, a detonator wire or cable 54 is connected to the explosive charge 52 prior to the lowering thereof in the shot hole through the drill string or tubing 16. After the explosive charge has been lowered into the bottom of the shot hole through the tubing 1.6, the upper end of the detonator wirel 54 is connected to a float 56. The oat 56 is of a sufficiently small size so that it will pass through the passage 24 in the head 14 so that the entire drill string including the head 14 may be removed over the float. After the explosive charge 52 has been placed and the float 56 connected to the detonator wire 54, the hole lo may be filled with fluid 58 through substantially the surface of the ground lafter which the tubing 16 and the head 14 are withdrawn from the shot hole 10. Once the explosive charge 52 has been placed in the bottom of the hole 10, it is immaterial as to whether the walls of the hole 10 should cave in or otherwise be distorted inasmuch as the oat 56 will maintain the upper end of the detonator wire 54 readily accessible at the top of the hole 10. Thus when the second crew comes along, they may readily connect the upper end of the detonator wire 54 to a blasting machine 60.

In the modication according to Figures 5 to 8 inclusive, the tubing 62 has the end portion thereof slidably engaged within a drill head 64 having cutter points 66. The lower end of the tubing 62 is provided with drive lugs `68 which engage with kerf slots 70' in the head 64. The head,64 is detachably maintained in position on the end of tubing 62 by means of a frangible pin 74. The pin 74 is received within apertures '76 `and 78 of the head 64 and in apertures 80 yand 82 of the drill tube 62. ln the operation of this modification of the invention the stem 62 will be lowered into the hole and rotated to rotate the drill head 64. When the hole has been drilled to the desired depth the tool will be raised to the point where the head` 64 is elevated above the bottom of the hole and the weight 46 on the line 48 will be lowered into the tubing 62 where it will either encounter the frangible pin 74 and destroy it or hit the bottom of the head 64 so that the frangible pin 74 will be sheared off and the head 64 will be depositedin the bottom of the hole. After which the tubing 62 will, be elevated sulciently above the head 74 so that the explosive charge 52 may be readily placed between the bottom of the hole and the bottom of the tubing.

The explosive charge 52 is connected to the detonator Wire 54 in the same manneras that described above and the explosive charge 52 is then lowered through the tubing 62 into the bottom of the hole. The float 56 is then attached to the upper end of the detonator wire 54 after which the hole is filled with water so that the float 56 will maintain the detonator wire within reach from the surface at all times. After the float 56 has been placed in position, the tubing 62 will be removed and the explosive charge 52 in the bottom of the hole will be available for ring when the second -crew reaches the particular shot hole in question.

It will be apparent this invention provides a method by which the apparatus for constructing holes maybe readily recoveredv and used as often as desired without inuencing the explosion within the hole. l'n fact, should the walls of the hole cave in about the explosive charge 52 after the drill strings have been pulled, the shock waves resulting from the firing of the explosive charge 52 will be emitted under more nearly those conditions which are actually desired,

It will be apparent from ,the foregoing disclosure of the method yof charging shot holes that a great saving will result. In the first place, inasmuch as the major portion of the drilling tool including all of the drill string will be removed from the shot hole immediately after the placing of the charge, it is not necessary for the drilling crew to maintain a very large supply of tubing as in the prior methods of forming shot holes in soft formations where it was necessary to leave large quantities of tubing in the shot holes prior to their tiring. Secondly, it will be apparent that the cost of preparing a shot hole will be reduced inasmuch as a majority of the drilling equipment will be salvaged. Thirdly, since the salvage operation is performed by the same crew `as that which drills the shot holes and places the explosive charge therein, it will be necessary for only `one set up by the drilling crew so that the shot hole is both drilled and the drill string is removed therefrom with the same equipment during the same setup.

For purpose of exemplication the presently preferred embodiment of the invention has been shown and described according to the -best present understanding thereof. It will be apparent to those skilled in the 'art that changes and modifications may be made in the construction and arrangement of the parts thereof without departure from the true spirit and purpose of the invention.

What is claimed as new is as follows:

l. In the drilling of Shot holes with a drilling tool including a hollow drill string having a bit secured thereto, the bit having a flow passage communicating with the drill string to provide for circulation of drilling fluid through the drill string and bit, the method of charging a shot hole while the drilling tool remains in the shot hole comprising lifting the drilling tool `a slight distance above the bottom of the shot hole, removing a portion of the drilling tool to increasethe cross-sectional area of the how passage to permit the passage of an explosive charge through the drilling tool to a point therebelow, lowering an explosive charge 4into the drilling tool through the flow passage and into the shot hole beneath the drilling tool, and then withdrawing the remainder of the drilling tool from the shot hole prior to detonating the explosive charge.

2. In the ydrilling of shot holes with a drilling tool including .a hollow drill string having a bit secured thereto, the bit having a flow passage communicating with the drill string to provide for circulation of drilling fluid through vthe drill string and bit, the method of charging a shot hole while the drilling tool remains in the shot hole comprising lifting the drilling tool a slight distance above the bottom of the shot hole, removing a portion of the drilling tool to increase the cross-sectional area of the flow passage to permit the passage of an explosive charge through the drilling tool to a point therebelow, providing an explosive charge on one end of a detonator wire, lowering the explosive charge and detonator wire into the drill string, through the ow passage and into the shot hole beneath the drill string while retaining the other end of the detonator wire above the upper end of the shot hole, and then removing the drilling tool from the shot hole prior to detonating the explosive charge.

3. In the drilling of shot holes with Va drilling tool including a hollow drill string having a bit secured thereto, the bit having a ow passage communicating with the drill string to provide for circulation of. drilling fluid through the drill string and bit, the method of charging a shot hole while the drilling tool remains in the shot hole comprising lifting the drilling tool a slight distance above the bottom of the shot hole, removing a portion of the drilling tool to increase the cross-sectional area of the ow passage to permit the passage of an explosive charge through the drilling tool to a point therebelow, providing an explosive charge on one end of a detonator wire, lowering the explosive charge and detonator wire into the drill string, through the ow passage and into the shot hole beneath the drill string while retaining the other end of the detonator wire above the upper end of the shot hole, attaching a oat to the other end of the dentonator wire, placing liquid into the shot hole as is necessary to till the shot hole, removing the drilling tool and permitting the oat to be retained in an accessible position on the surface of the liquid to facilitate detonating the explosive charge.

4. In the drilling of shot holes with a drilling tool including a hollow drill string having a bit secured thereto, said bit having an enlarged passage therethrough, a plug positioned in the enlarged passage, said plug having a reduced flow passage communicating with the drill string to provide for circulation of drilling iluid through the drill string and bit, the method of charging a shot hole while the drilling tool remains in the shot hole comprising lifting the drilling tool a slight distance above the bottom of the shot hole, knocking out the plug to permit the passage of an explosive charge through the enlarged passage to a point below the bit, lowering an explosive charge into the drilling tool, through the enlarged passage and into the shot hole beneath the drilling tool, and then withdrawing the drill string and bit from the shot hole prior to detonating the explosive charge.

5. In the drilling of shot holes with a drilling tool including a hollow drill string having a bit releasably secured thereto, the method of charging a shot hole while the drilling ltool remains in the shot hole comprising lifting the drill string and bit a slight distance above the bottom of the shot hole, removing the bit from the drill string, lowering an explosive charge into the drill string and through the lower end thereof into the shot hole beneath the drill string, and then withdrawing the drill string from the shot hole prior to detonating the explosive charge.

References Cited in the tile of this patent UNITED STATES PATENTS 185,447 LeConte Dec. 19, 1876 2,048,677 Berteling July 28, 1936 2,146,645 Newman Feb. 7, 1939 2,184,514 Cleesattel Dec. 26, 1939 2,300,813 Savage Nov. 3, 1942 2,614,804 Carlisle Oct. 21, 1952 2,621,895 Toelke Dec. 16, 1952 2,665,886 Ellis Jan. 12, 1954 FOREIGN PATENTS 296,352 Great Britain Aug. 28, 1928