U.S. patent number 3,739,723 [Application Number 05/174,088] was granted by the patent office on 1973-06-19 for perforating gun.
This patent grant is currently assigned to Harrison Jet Guns, Inc.. Invention is credited to John R. Hakala.
United States Patent |
3,739,723 |
Hakala |
June 19, 1973 |
PERFORATING GUN
Abstract
A shaped charge assembly for a tubular oil well perforating gun
includes a channel member having spaced apertures in the web
thereof with shouldered shaped charges extending through the
apertures with the shoulders engaging the web of the channel
member. A spring clip engages the edges of the channel and the apex
of the charge to secure the charge in the aperture and to maintain
a ribbon detonator in contact with the apex of the charge.
Inventors: |
Hakala; John R. (Fort Worth,
TX) |
Assignee: |
Harrison Jet Guns, Inc.
(Houston, TX)
|
Family
ID: |
22634778 |
Appl.
No.: |
05/174,088 |
Filed: |
August 23, 1971 |
Current U.S.
Class: |
102/310;
175/4.6 |
Current CPC
Class: |
F42B
3/26 (20130101); E21B 43/117 (20130101) |
Current International
Class: |
F42B
3/26 (20060101); E21B 43/11 (20060101); E21B
43/117 (20060101); F42B 3/00 (20060101); E21b
043/117 () |
Field of
Search: |
;102/20 ;175/4.6 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pendegrass; Verlin R.
Claims
What is claimed is:
1. A perforating gun comprising:
an elongated barrel having a passageway therethrough,
a channel member mounted in said passageway having a plurality of
spaced charge receiving apertures through the channel web,
a shaped charge positioned in at least one of said apertures, and
including a projecting portion engaging the channel member adjacent
the aperture,
a spring clip for engaging the apex of said charge and said channel
member to secure said charge in the aperture of said channel
member, and
means for detonating said charge.
2. The gun of claim 1 wherein said shaped charge includes a housing
having a shoulder thereon for engaging a surface of said channel
member surrounding said apertures with a portion of said housing
extending through said aperture.
3. The gun of claim 2 wherein said means for retaining said charges
in said apertures comprises:
a spring clip having flanges engaging said channel member and a
strap portion interconnecting said flanges which engages the rear
portion of said shaped charge.
4. The gun of claim 1 wherein said elongated barrel has a plurality
of thinned portions in the wall thereof at spaced locations aligned
with the mouth of said shaped charges.
5. The gun of claim 4 wherein said charge carrier member
comprises:
an elongate structural channel, the web thereof containing said
plurality of spaced charge carrying apertures, said structural
channel having reinforcing flanges thereon.
6. The gun of claim 1 wherein the exterior of said housing for said
shaped charge and said clip member have cooperative means thereon
for forming a first passageway, the gun further comprising:
a second passageway containing an explosive leading from said first
passageway through said housing to said shaped charge,
a charge detonator interconnecting said plurality of said shaped
charges through said first passageway.
7. The gun of claim 1 wherein said spring clip has substantial
width and thickness to absorb reactive force of explosion of said
shaped charge to protect the inner wall of said barrel in the
region of the charge apex.
8. A perforating gun comprising:
an elongated barrel having a passageway therethrough,
a channel member mounted in said passageway and including a channel
web having a plurality of spaced charge receiving apertures formed
through it and flanges extending from the web in a predetermined
direction,
a shaped charge positioned in at least one of said apertures and
having an apex and a mouth facing in the same direction as the
channel flanges,
a spring clip for engaging the apex of said shaped charge and
including flanges for retentively engaging the flanges of said
channel member to secure said charge in the aperture of said
channel member, and
means for detonating said charge.
9. A perforating gun comprising:
an elongated barrel having a passageway therethrough,
a channel member mounted in said passageway and including a channel
web having a plurality of spaced charge receiving apertures formed
through it and a pair of flanges extending in a predetermined
direction,
a shaped charge positioned in at least one of said apertures and
including an apex facing in the predetermined direction,
a spring clip for engaging the apex of said charge and including
flanges for engaging the surface of the channel web opposite the
flanges to secure the charge in the aperture of the channel
member,
spacing means interposed between said shaped charge and the channel
web, and
means for detonating the charge.
10. The perforating gun according to claim 9 wherein the shaped
charge includes a shoulder and wherein the spacing means comprises
a resilient O-ring positioned between the shoulder and the surface
of the channel web facing in the direction of the flanges.
Description
BACKGROUND OF THE INVENTION
This invention relates to guns for perforating oil well casings and
more particularly to apparatus which facilitates loading and
supporting explosive charges in a perforating gun.
Heretofore, shaped explosive charges of the cone type have been
employed in an elongated perforating gun barrel. The shaped charges
loaded in a gun barrel are directed radially outward from the
barrel. In some instances shaped charges are secured in a port in a
barrel by force applied through a port closing plug which engages
the mouth of a shaped explosive charge. In other cases, shaped
charges are positioned in a barrel to face wall sections of the
barrel that have been externally thinned. Loading and positioning
the charge in such barrels is achieved by this invention. Since the
gun barrel and associated apparatus are expendable, minimization of
cost while maintaining reliability is essential.
By the present invention shaped charges can be positively and
reliably positioned in a perforating gun and at the same time can
be interconnected with a detonator.
SUMMARY OF THE INVENTION
In accordance with the present invention, a perforating gun
comprises an elongated hollow casing which receives a charge
carrier channel with a plurality of spaced charges secured in
apertures therein. Flat spring clips engage the channel edges and
the apex of each charge to retain each charge in an aperture along
with means for detonating the charges.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention
reference may be had to the following description taken in
conjunction with the accompanying drawings, wherein:
FIG. 1 is an elevation view of a perforating gun having charges
supported therein in accord with the present invention;
FIG. 2 is an enlarged longitudinal sectional view of a portion of
the gun of FIG. 1;
FIG. 3 is a view similar to that of FIG. 2 rotated 90.degree.
therefrom;
FIG. 4 is a sectional view taken along section line 4--4 of FIG.
3;
FIG. 5 is an elevation view of the retention clip utilized with the
present invention; and
FIG. 6 is a sectional view similar to that of FIG. 4 showing an
alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in conjunction with a
preferred embodiment. It is to be understood that various changes,
alterations and substitutions of equivalents can be made to the
embodiments disclosed without departing from the concept of the
invention. It is intended that the invention as disclosed be
limited only by the definition contained in the appended claims.
Where appropriate for clarity, like numerals will be employed in
the several FIGURES to indicate the same or similar structure.
Referring first to FIG. 1, a detonator gun 10, in accord with the
present invention, is of the jet perforating type. The gun 10 is
lowered into a well bore 12, and upon energization of an electrical
circuit activated at the ground level, fires a detonator which in
turn causes the shaped charges to explode. The gun 10 is attached
to a suspension cable 14 via cable head 16. Electrical circuit
connections are run along the cable and through the cable head to
be connected to a detonator. The gun includes an intermediate gun
section or barrel 18 and a bottom closure member 20. The barrel 18
is of hollow construction and contains a plurality of shaped
charges. The exterior of the barrel 18 is thinned at regularly
spaced zones 22. The purpose of the thinned zones 22 is to provide
preselected locations in the barrel 18 through which the blast from
the shaped charges can pass. Thinned zones 22 minimize dissipation
of projectile energy in breaking out of barrel 18. Burrs on the
exterior of the casing 18 extending beyond the perimeter of barrel
18 are minimized thereby aiding removal of the spent gun barrel
through lubricators at the well head. Also prevented is total
rupture or separation of barrel 18.
Referring to FIGS. 2, 3 and 4, enlarged views of the casing, charge
and charge carrying member are shown. FIG. 3 is rotated 90.degree.
from FIG. 2. FIG. 4 is a cross sectional view of FIG. 3 taken along
section line 4--4. A structural channel 24 is suspended inside
barrel 18. The width of the channel 24 is slightly less than the
I.D. of barrel 18. The channel member 24 hangs in barrel 18,
suspended from head 16 on fasteners (not shown) extending through
holes 28 in the upper portion of the channel 24. The upper portion
of barrel 18 has internal threads by which it is connected to the
head 16. A plurality of spaced apertures 32 are provided in the web
of channel 24. A shaped charge 34 extends through the apertures 32.
Shaped charge 34 has formed as an integral part thereof an annular
shoulder 36 which abuts the outer surface of the web of channel
24.
A spring clip 38 extends around the apex of charge 34 and engages
the flanges of channel member 24. The coaction of the clip 38 and
the shoulder 36 abutting the channel member 24 retains the shaped
charge 34 securely in the apertures 32. The clips 38 are formed
from spring steel which has a high shcok resistance. In addition,
clips 38 have a sufficient width and thickness to withstand the
reactive forces generated when the shaped charge 34 is detonated.
The clip 38 absorbs retroblast energy to a degree shielding barrel
18 from such reactive forces.
Barrel 18 has a plurality of thinned zones 22 in the outer wall
thereof which are adjacent the mouth of each shaped charge 34.
Thinned zones 22 are readily formed by grinding the exterior
surface of the barrel 18. The thinned zones 22 are located so that
the charges will rupture the barrel 18 at desired locations. In
addition, the thinned zones 22 will provide less material for the
formation of burrs caused by the explosion. Burrs extending beyond
the barrel perimeter, rupture of the casing, or inordinate bulging
of the barrel 18 will render it difficult, if not impossible, to
pass barrel 18 through lubricators employed for entering the gun
into the well bore. It should be realized that it is necessary to
withdraw the gun including barrel 18 after firing so that the well
may be completed.
Retention at the shaped charge 34 is best seen in FIG. 4. The
charge 34 is of conventional construction in that it contains a
conical shaped body of explosive with a metallic inside liner of
conical shape whose bore faces the gun wall. A passageway 44 is
provided in the rear portion of charge 34 communicating with a slot
46 in the rear of the charge 34. The passageway 44 contains
detonating material. A ribbon detonator 48 extends through slot 46
in each of the charges 34. The detonator 48 is connected to a cap
42 near the cable head 16 (FIG. 1). The cap 42 is detonated by use
of a conventional blaster (not shown). Clip 38 coacts with
detonator 48 and charge 34 to retain the detonator 48 in intimate
contact with the material in passageway 44. The detonator may be of
the type sold under the trademark "Primacord". By its use a
plurality of charges 34 can be exploded sequentially upon
detonation of the cap 42.
A preferred form of the spring clip 38 is shown in FIG. 5. The clip
38 has a rounded central portion 50 which engages the apex of
charge 34 to force the detonator 48 into slot 46. The forwardly
extending sides 52 of clip 38 engage the sloping sides of the
charge 34. Flanges 54 are provided to engage the channel 34. The
flanges 54 have circular indentations 56 therein which engage the
cylindrical portion of the wall of charge 34 extending from the
bore of the conical portion.
FIG. 6 illustrates an alternate embodiment of the present
invention. The shaped charge 34 is the same as in the unit of FIG.
4. There is coaction of the spring clip 38 with the rear portion of
the charge 34. In this embodiment, however, the channel 24 has been
rotated 180.degree. such that the flanges thereof extend in the
direction of the cone apex. The flanges on clip 38 thus engage the
outer surface of the web of the channel 24. An "O" ring 58 is
interposed between the inner surface of the web of channel 24 and
annular shoulder 36 of the charge 34. This form of the invention
can be utilized alone or can be utilized in conjunction with the
embodiment shown in the previous FIGURES. If, for example, it is
desired to direct the explosion from the shaped charges in two
different directions, charges are alternately reversed. Half the
charges would be mounted in the manner shown in FIG. 4 and half in
the manner shown in FIG. 6. Appropriate thinned zones would thus be
provided in the opposite side of the barrel 18 to provide selective
rupture thereof. It will be noted that the thinned zone 60 provided
in the barrel 18 is somewhat different from that shown in previous
FIGURES. The thinned zone is provided by grinding away a portion of
barrel 18 along an entire longitudinal wall. The direction of the
charge is aligned with the flat portion 60 such that the wall can
rupture in the flat portion 60, thus providing a minimum of
burring, bulging and random rupturing of the casing walls 18.
Gun casings and channel members can be manufactured in uniform
relatively short sections which may then be joined if desired to
perforate longer sections of the bore hole. It has been found that
sections 10 feet long are convenient for transport storage and use.
The apertures 32 in the channel 24, and thus the thinned portions
22 in the wall of casing 18 have been provided on 3 inch centers.
The length of the gun can be increased by multiples of the 10 foot
sections by utilizing suitable connectors for the casings and the
longitudinally disposed web members. It is, of course, to be
understood that the gun of the present invention can be
manufactured in any desired length and can be tailored to fit a
particular application.
The advantages of the present invention are apparent to those of
ordinary skill in the art. Among these advantages are easy loading,
minimum time consumption in loading and operating the gun,
relatively simple manufacturing procedures for the component parts
thereof and simple and efficient interconnection of a plurality of
charges with a detonator.
* * * * *