US3280742A

US3280742A - Loading and anchoring adaptor for positioning geophysical explosive charges

Info

Publication number: US3280742A
Application number: US399000A
Authority: US
Inventors: John J Babb
Original assignee: Delta Exploration Co Inc
Current assignee: FIRST CITY NATIONAL BANK OF HOUSTON A NATIONAL BANKING ASSOCIATION; Delta Exploration Co Inc
Priority date: 1964-09-24
Filing date: 1964-09-24
Publication date: 1966-10-25
Anticipated expiration: 1983-10-25

Description

Oct. 25, 1966 J. J. BABB 3,280,742

LOADING AND ANCHORING ADAPTOR FOR POSITIONING GEOPHYSICAL EXPLOSIVE CHARGES 2 Sheets-Sheet 1 Filed Sept. 24, 1964 INVENTOR JOHN 3. BABE BY WCLSO'K,

ATTORNEYS 1966 J. J. BABB 3,280,742

LOADING AND ANCHORING ADAPTOR FOR POSITIONING GEOPHYSICAL EXPLOSIVE CHARGES Filed Sept. 24, 1964 2 Sheets-Sheet 2 1 INVENTOR JOHN 3. BABE United tates atent Ofitice 3,280,742 LOADING AND ANCHORING ADAPTQR FOR POSITIONING GEOPHYSICAL EXPLOSIVE CHARGES John J. Babb, Jackson, Miss, assignor to Delta Exploration Company, Inc., Jackson, Miss, a corporation of Mississippi Filed Sept 24, 1964, Ser. No. 99,000 7 Claims. (Cl. 102-2L8) This invention relates generally to geophysical exploration and more particularly to devices for loading, positioning and anchoring explosive charges in geophysical boreholes preparatory to detonation.

In normal geophysical exploration methods of the subsurface, it is generally necessary to drill relatively small diameter boreholes to depths of fifty to three hundred feet. Once these holes are drilled, explosive charges are placed in them at suitable depths and then exploded to produce reflected sound waves which can be detected on the surface by geophones for identifying the particular waves and timing their length of travel from the source. A major problem in this type of operation is the placement of the charges at the desired depth in the borehole. The charges normally come commercially packed in elongated metal cylinders which are adapted to be screwed together end-toend to form a charge of desired weight and/or length. The topmost charge is normally the primer of high explosive while the remaining charges are of a low grade explosive. In the primer cylinder, there is a small longitudinal well into which the blasting cap is placed with its electrical lead extending upwardly through an adaptor which is screwed into the top recess of the primer mainly to hold the blasting cap in place by securely binding the electrical leads of the cap.

In loading the charges into a borehole, the problem generally encountered is that the hole is not perfectly straight and may at times have certain small irregularities that will prevent the descent of a relatively long line of the end-to-end explosive charges. This necessitates that a suitable loading device be employed such as a plurality of wooden loading poles each interconnected at their ends in a flexible manner, yet in a manner so that a longitudinal force upon the upper end of the line of poles will be transmitted to the lowermost pole that is immediately adjacent the line of charges.

In prior art devices, the loading and positioning of the explosive charge containers is accomplished by placing about the primer can an elongated basket or bell-shaped positioning device which protrudes downwardly around the primer container to eifectively guide the chain of explosive containers down the borehole. At the upper end of the loading basket is an elongated cylinder and to which a loading pole is adapted to be placed so that the crew at the top of the borehole may exert sufiicient force to remove the chain of explosives to the desired level. Between the loading basket and the upper end of the primer container is a normally high impact plastic shield which screws into a threaded well at the top of the primer container for maintaining the blasting cap in its receiving the recess on the top of the primer container. A suitable slot is provided in this shield so that the electrical blasting lead may be inserted therethrough and passed upwardly to the top of the borehole.

. Such prior art devices have the disadvantages of being larger in their external configuration than the maximum diameter of the explosive charge containers and therefore they require a borehole of greater diameter than should ordinarily be required. Further, the electric blasting lead is passed from the plastic shield in such a manner as to lie alongside the elongated cylindrical part of the basket which subjects it to abrasion from sidewalls of the borehole. Since it is readily apparent that the basket is able to rotate about the primer can relative to the fixed shield, it should be noted that the blasting lead is in a rather precarious position if such an event takes place. Upon the relative rotation of the basket to the shield, the blasting lead is likely to be positioned beneath a sharp corner of the basket which will readily cut the lead at such times as pressure is applied to the loading poles to force the chain of charges downwardly in the borehole. In the normal prior art basket, the soft brass of which these devices are made are often deformed or pushed tightly against the charge making the release of the charge within the hole very difficult. In order to facilitate the release of the charge, the basket is usually enlarged causing the charges to be angled to one side by pulling on the blasting cap lead that comes out of one side of the shield.

Therefore, an object of this invention is the positioning of a loading and anchoring adaptor which accurately places explosive charges in the desired location of a borehole.

Another object of this invention is the provision of a loading and anchoring adaptor in which the electric blasting cap leads are protected from abrasion against the borehole wall that would tend to cut or injure the leads.

Another object of this invention is the provision of a loading and anchoring adaptor which when it is necessary to tamp the explosive charge assembly, such tamping will not injure or cut the electric blasting cap leads.

A further object of this invention is the provision of a loading and anchoring adaptor from which loading poles may be easily removed.

Another object of this invention is the provision of a loading and anchoring adaptorin which the diameter of the adaptor does not exceed the diameter of the explosive charge train.

A further object of this invention is the provision of a loading and anchoring adaptor which is easy to manufacture and is sufliciently low in cost as to be considered an expendable item that may be consumed with the explosive charges.

Other objects, advantages and capabilities of the inven tion will become apparent from the following description, taken in conjunction with the accompanying drawings showing only a preferred embodiment of the invention.

In the drawings:

FIGURE 1 is a side elevation view of the loading and anchoring adaptor of the present invention shown in proper operative relation within a borehole as it positions a suitable number-of explosive charges;

FIGURE 2 is a representation in perspective of a loading adaptor commonly known in the prior art;

FIGURE 3 is a perspective view of the loading and anchoring adaptor of the present invention;

FIGURE 4 is a vertical section view of the present invention taken along lines 44 of FIGURE 3;

FIGURE 5 is a horizontal section view taken alon lines 5-5 of FIGURE 4;

FIGURE 6 is a horizontal section view of the present 3 invention taken along lines 6-6 of FIGURE 4; and

FIGURE 7 is an exploded perspective view of the various parts used with the present invention in making up an integral explosive charge.

Referring to the drawings wherein like reference characters designate corresponding parts throughout several figures, the loading and anchoring adaptor of the present invention is represented by the numeral 10 and preferably formed of a high impact plastic. Comprising the adaptor 10 at its upper end, is an upwardly extending elongated tubular member 11 which has an internal hollow loading pole recess 12 of sufficient diameter to accept a loading pole 13. At the uppermost end of the tubular member 11 is an enlargement 14 which serves as a reinforcing collar.

The lower portion of the adaptor 10 may be considered the shield 15 and is generally a relatively solid member except as will be hereinafter noted. The shield 15 may be considered as extending from the bottom 16 of the loading pole receiving recess 12 to the base 17 onto which is fixedly positioned the lower tubular threaded shaft 18. The maximum diameter of the shield 15 is preferably the same diameter as that of the cans of explosive charges which will be used in the present adaptor, however, the maximum diameter of the threaded shaft 18 is less than that of the shield 15 thereby providing a shield lip 19. Extending transversely of the longitudinal length of the adaptor and generally through its axis is a flat, elongated anchor receiving aperture 21. Adapted to be placed within this aperture is an anchor 22 of suitable flexible spring steel material which, when in position, will be bent upwardly about each side of the adaptor to effectively become a force opposing any withdrawal of the explosive charges once they are in the borehole. Such an arrangement is clearly shown in FIGURE 1.

It is anticipated that in the normal installation, the lower tubular threaded shaft 18 will be threaded into the commonly used cylindrical explosive container 23 which has at one end recessed internal threads 24 and at the other end an externally projecting member 25. The externally projecting member 25 is adapted to interconnect with similar containers 23 to form an end-to-end arrangement for insertion into the borehole. Depending from the base recess 26 of the primer explosive container 23 is a blasting cap recess 27 into which is placed blasting cap 28 at such time as it may be desired to fully charge the explosive train that will be inserted into the borehole.

As is the normal procedure, the blasting cap 28 has been fitted with a blasting lead 29 prior to the insertion of the cap into the recess 27. Located about the periphery of the shield 15 is the first longitudinal projecting blasting wire receiving groove 31 which extends from the topmost portion of ,the shield and terminates at the bottom of the shield in such a manner that an opening 31a is provided into the base cavity 32 through the side wall of the threaded shaft 18. A reentrant blasting lead receiving groove 33 is located on the periphery of the shield in a manner similar to the first receiving groove 31. However, in this case the reentrant groove 33 is not provided with access to the base cavity 32. Also located about the periphery of shield 15 is an exit groove 34 for the blasting lead 29. As in the case of the reentrant groove 33, the exit groove 34 projects from the top of the shield 15 to its lowermost portion without communicating with the base cavity 32. The

longitudinal grooves

31, 33 and 34 all project toward the center longitudinal axis of the adaptor 10 a distance that is just short of intersecting the side walls of the loading pole tubular member 11.

In assembling the adaptors of the present invention, it is merely necessary to place the top end of the blasting cap 28 with its associated blasting cap wire 29 into the base cavity 32. After this, the blasting cap wire 29 is placed within the first groove 31 in such a manner that the lead 29 passes from the base cavity 32 through the communicating slot 31a upwardly and out of the groove 31. The lead is then bent over and laid into the reentrant groove 33, brought out of the bottom thereof and wound closely adjacent the shield lip 19 within the annular cavity 36 that is formed between the shield lip 19, the container ledge 37 and lip 38. The lead 29 follows the annular cavity 36 until it intersects exit groove 34 where it is then brought upwardly through this gro'ove for connection with a suitable detonator. The adaptor 10 with the blasting cap and lead in position is then placed in suitable operative relation with respect to the primer explosive container 23. Specifically, the blasting cap 28 is placed within recess 27 of the primer and the adaptor 10 is then screwed into the base recess 26. Normally, the explosive charge is then completed by the addition of additional containers 23a containing a low grade explosive. The end of the explosive train is then capped by a pointed guide member 39 which helps to guide the explosives through the borehole.

To position the explosive charges within the borehole, the explosive containers and adaptor 10 would be inserted into the hole with the blasting cap lead 29 trailing behind out of a hole and held by an operator at ground level. To force the charges to the suitable location of the borehole, a loading pole 13 would be inserted into the receiving recess 12 and pressure applied to move the entire array deeper into the earth.

If it is necessary to continue to apply pressure to force the array deeper, then additional loading poles 13 are interconnected in the manner shown in FIGURE 7 so as to obtain the desired depth required for proper seismic detonation.

As can be seen, the present invention has shown where a noval loading and anchoring adaptor may be used to position seismic charges in such a manner that prevents the disadvantages from occurring that have been pointed out hereinabove that relate to the prior art. Specifically, this invention prevents abrasion or cutting of the blasting cap lead 29 when the seismic array is being lowered or tamped through the borehole. From the above description, it is seen that at no time will the adaptor 10 move relative to the blasting cap lead 29 and the primer explosive container 23 in such a manner that will tend to sever the electrical leads within the blasting cap lead 29. Further, an extremely important feature of the invention is that the lead 29 is kept within the maximum effective diameter of the adaptor 10 at all times and cannot possibly be subjected to abrasion.

While I have particularly shown and described one particular embodiment of the invention, it is distinctly understood that the invention is not limited thereto but that modifications may be made within the scope of the invention and such variations as are covered by the scope of the appended claims.

What is claimed is:

1. In a seismic array wherein a plurality of tubular explosive charge containers including a blasting lead and blasting cap are to be connected together in an end-to-end array with threadedly mating male and female elements prior to introduction into a borehole, the combination of a unitary one-piece loading and anchoring adaptor which comprises an upper tubular member, a lower shield member, the upper tubular member having an elongated body, the uppermost portion of the tubular member having an enlarged reinforcing collar protruding therefrom, longitudinal blasting lead receiving grooves projecting inwardly from the outer periphery of the lower shield, a lower tubular threaded shaft of less diameter than the diameter of the shield projecting downwardly from .the base of the shield member, the lower tubular threaded shaft being adapted to mate with the female element of the topmost charge container to define a base recess between the charge container and the base of the lower shield member.

2. In a seismic array wherein a plurality of tubular explosive charge containers including a blasting lead and blasting cap are to be connected together in an end-to-end array with threadedly mating male and female elements prior to introduction into a borehole, the combination of a unitary one-piece loading and anchoring adaptor which comprises an upper tubular member, a lower shield member, the upper tubular member having an elongated body, the uppermost portion of the tubular member having an enlarged reinforcing collar protruding therefrom, an elongated aperture of rectangular cross section projecting through the shield transverse to the longitudinal axis of the adaptor, longitudinal blasting lead receiving grooves projecting inwardly from the outer periphery of the lower shield, a lower tubular threaded shaft of less diameter than the diameter of the shield projecting downwardly from the base of the shield member, the lower tubular threaded shaft being adapted to mate with the female element of the topmost charge container to define a base recess between the charge container and the base of the lower shield member.

3. In a seismic array wherein a plurality of tubular explosive charge containers including a blasting lead and blasting cap are to be connected together in an end-toend array with threadedly mating male and female elements prior to introduction into a borehole, the combination of a unitary one-piece loading and anchoring adaptor which comprises an upper tubular member, a lower shield member, the upper tubular member having an elongated body, the uppermost portion of the tubular member having an enlarged reinforcing collar protruding therefrom, an elongated aperture of rectangular cross section projecting through the shield transverse to the longitudinal axis of the adaptor, anchor means positioned in the aperture and adapted to maintain the seismic array in the borehole, the anchor means comprising an elongated rectangular shaped strap having its opposite ends projecting through the anchor aperture and terminating exteriorly of the adaptor beyond the peripheral extent thereof, longitudinal blasting lead receiving grooves projecting inwardly from the outer periphery of the lower shield, a lower tubular threaded shaft of less diameter than the diameter of the shield projecting downwardly from the base of the shield member, the lower tubular threaded shaft being adapted to mate with the female element of the topmost charge container to define a base recess between the charge container and the base of the lower shield member.

4. In a seismic array wherein a plurality of tubular explosive charge containers including a blasting lead and blasting cap are to be connected together in an end-toend array with threadedly mating male and female elements prior to introduction into a borehole, the combination of a unitary one-piece loading and anchoring adapter which comprises an upper tubular member, a lower shield member, the upper tubular member having an elongated body, the uppermost portion .of the tubular member having an enlarged reinforcing collar protruding therefrom, longitudinal blasting lead receiving grooves projecting inwardly from the outer periphery of the lower shield, a lower tubular threaded shaft of less diameter than the diameter of the shield projecting downwardly from the base of the shield member, a shield lip being formed between the lower tubular shaft and the outer periphery of the shield, the lower tubular threaded shaft being adapted to mate with the female element of the topmost charge container to define a base recess between the charge container and the base of the lower shield member.

5. In a seismic array wherein a plurality of tubular explosive charge containers including a blasting lead and blasting cap are to be connected together in an end-to-end array with threadedly mating male and female elements prior to introduction into a borehole, the combination of a unitary one-piece loading and anchoring adaptor which comprises an upper tubular member, a lower shield member, the upper tubular member having an elongated body, the uppermost portion of the tubular member having an enlarged reinforcing collar protruding therefrom,

longitudinal blasting lead receiving grooves projecting inwardly from the outer periphery of the lower shield, 21 lower tubular threaded shaft of less diameter than the diameter of the shield projecting downwardly from the base of the shield member, a shield lip being formed between the lower tubular shaft and the outer periphery of the shield, the lower tubular threaded shaft being adapted to mate with the female element of the topmost charge container to define a base recess between the charge container and the base of the lower shield member, the longitudinal grooves comprising a first blasting lead re ceiving groove communicating with the interior base recess of the lower tubular threaded shaft, a reentrant blasting lead receiving groove and an exit blasting lead receiving groove communicating with the shield lip.

6. In a seismic array wherein a plurality of tubular explosive charge containers including a blasting lead and blasting cap are to be connected together in an end-toend array with threadedly mating male and female elements prior to introduction into a borehole, the combination of a unitary one-piece loading and anchoring adaptor which comprises an upper tubular member, a lower shield member, the upper tubular member having an elongated body, the uppermost portion of the tubular member having an enlarged reinforcing collar protruding therefrom, longitudinal blasting lead receiving grooves projecting inwardly from the outer periphery of the lower shield, a lower tubular threaded shaft of less diameter than the diameter of the shield projecting downwardly from the base of the shield member, a shield lip being formed between the lower tubular shaft and the outer periphery of the shield, the lower tubular threaded shaft being adapted to mate with the female element of the topmost charge container to define a base recess between the charge container and the base of the lower shield member, the longitudinal grooves comprising a first blasting lead receiving groove communicating with the interior base recess of the lower tubular threaded shaft, a reentrant blasting lead receiving groove and an exit blasting lead receiving groove communicating with the shield lip, whereby the blasting lead is adapted to be received in the base recess and threaded through the first groove back through the reentrant groove to be laid upon the shield lip and then returned through the exit groove.

7. In a seismic array wherein a plurality of tubular explosive charge containers including a blasting lead and blasting cap are to be connected together in an end-to-end array with threadedly mating male and female elements prior to introduction into a borehole, the combination of a unitary one-piece loading and anchoring adaptor which comprises an upper tubular member, a lower shield member, the upper tubular member having an elongated body, the uppermost portion of the tubular member having an enlarged reinforcing collar protruding therefrom, an elongated aperture of rectangular cross section projecting through the shield transverse to the longitudinal axis of the adaptor, anchor means positioned in the aperture and adapted to maintain the seismic array in the borehole, the anchor means comprising an elongated rectangular shaped strap having its opposite ends projecting through the anchor aperture and terminating exteriorly of the adaptor beyond the peripheral extent thereof, longitudinal blasting lead receiving grooves projecting inwardly from the outer periphery of the lower shield, a lower tubular threaded shaft of less diameter than the diameter of the shield projecting downwardly from the base of the shield member, a shield lip being formedbetween the lower tubular shaft and the outer periphery of the shield, the lower tubular threaded shaft being adapted to mate with the female element of the topmost charge container to define a recess between the charge container and the base of the lower shield member, the longitudinal grooves comprising a first blasting lea-d receiving groove communicating with the interior base recess of the lower tubular threaded shaft, a reentrant blasting lead receiving groove and an exit blasting lead receiving groove communicating with References Cited by the Examiner 5 UNITED STATES PATENTS 2,535,196 12/1950 Counterrnan 102-24 Joslin 102-218 McMacklin et al. 86-21 Silverman 10221.6 Kihlstrom et al. 102-30 BENJAMMIN A. BORCHELT, Primary Examiner.

V. R. PENDEGRASS, Assistant Examiner.

Claims

1. IN A SEISMIC ARRAY WHEREIN A PLURALITY OF TUBULAR EXPLOSIVE CHARGE CONTAINERS INCLUDING A BLASTING LEAD AND BLASTING CAP ARE TO BE CONNECTED TOGETHER IN AN END-TO-END ARRAY WITH THREADEDLY MATING MALE AND FEMALE ELEMENTS PRIOR TO INTRODUCTION INTO A BOREHOLE, THE COMBINATION OF A UNITARY ONE-PIECE LOADING AND ANCHORING ADAPTOR WHICH COMPRISES AN UPPER TUBULAR MEMBER, A LOWER SHIELD MEMBER, THE UPPER TUBULAR MEMBER HAVING AN ELONGATED BODY, THE UPPERMOST PORTION OF THE TUBULAR MEMBER HAVING AN ENLARGED REINFORCING COLLAR PROTRUDING THEREFROM, LONGITUDINAL BLASTING LEAD RECEIVING GROOVES PROJECTING INWARDLY FROM THE OUTER PERIPHERY OF THE LOWER SHIELD, A LOWER TUBULAR THREADED SHAFT OF LESS DIAMETER THAN THE DIAMETER OF THE SHIELD PROJECTING DOWNWARDLY FROM THE BASE OF THE SHIELD MEMBER, THE LOWER TUBULAR THREADED SHAFT BEING ADAPTED TO MATE WITH THE FEMALE ELEMENT OF THE TOPMOST CHARGE CONTAINER TO DEFINE A BASE RECESS BETWEEN THE CHARGE CONTAINER AND THE BASE OF THE LOWER SHIELD MEMBER.