U.S. patent application number 14/045529 was filed with the patent office on 2015-04-09 for sub-caliber shaped charge perforator.
This patent application is currently assigned to Baker Hughes Incorporated. The applicant listed for this patent is Baker Hughes Incorporated. Invention is credited to David Betancourt, William B. Harvey, Nathan C. Hogue, Ryan S. WHITE.
Application Number | 20150096434 14/045529 |
Document ID | / |
Family ID | 52775894 |
Filed Date | 2015-04-09 |
United States Patent
Application |
20150096434 |
Kind Code |
A1 |
WHITE; Ryan S. ; et
al. |
April 9, 2015 |
SUB-CALIBER SHAPED CHARGE PERFORATOR
Abstract
A shaped charge for use in perforating a wellbore that includes
a shaped charge case, a liner in the case, and explosive between
the liner and case. Detonating the explosive inverts the liner to
form a metal jet that forms a perforation in a side wall of the
wellbore. The outer diameter of the liner open end is set radially
inward from the inner diameter of the case opening to define an
annular gap. Providing a gap between the liner and case allows more
control of distribution of material of the liner into the jet.
Inventors: |
WHITE; Ryan S.; (Spring,
TX) ; Harvey; William B.; (Houston, TX) ;
Betancourt; David; (Cypress, TX) ; Hogue; Nathan
C.; (Hempstead, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Baker Hughes Incorporated |
Houston |
TX |
US |
|
|
Assignee: |
Baker Hughes Incorporated
Houston
TX
|
Family ID: |
52775894 |
Appl. No.: |
14/045529 |
Filed: |
October 3, 2013 |
Current U.S.
Class: |
89/1.15 |
Current CPC
Class: |
E21B 43/117
20130101 |
Class at
Publication: |
89/1.15 |
International
Class: |
E21B 43/117 20060101
E21B043/117 |
Claims
1. A shaped charge for use in perforating a wellbore comprising: a
case having an opening; a liner inserted into a space in the case
and having an open end and an apex; explosive disposed between the
liner and case; a hole in the apex of the liner; and a gap between
an outer diameter of the open end of the liner and inner diameter
of the opening in the case.
2. The shaped charge of claim 1, wherein the hole has a diameter
that ranges from about 10% to about 82% of an axial length of the
liner.
3. The shaped charge of claim 1, wherein an outer diameter of the
open end of the liner ranges from about 60% to about 75% of an
inner diameter of the opening of the case.
4. The shaped charge of claim 1, wherein the hole ranges from about
7% of the liner outer diameter to about 60% of the liner outer
diameter.
5. The shaped charge of claim 1, wherein the shaped charge is
selectively retained within a gun tube by a coupling that is
provided with the case.
6. The shaped charge of claim 1, wherein the shaped charge is
selectively disposed in the wellbore within a perforating
string.
7. The shaped charge of claim 1, further comprising a slot on an
end of the case opposite the opening that selectively receives a
detonating cord, and an initiator in a passage formed through the
case between the detonating cord and the explosive.
8. The shaped charge of claim 1, further comprising a protective
covering in the gap and over the explosive.
9. A shaped charge for use in perforating a wellbore comprising: a
case having an opening; a liner in the case; explosive between the
liner and case; and a gap defined by an outer diameter of the open
end of the liner and inner diameter of the opening in the case, and
having a liner diameter that ranges from about 60% to about 75% of
the inner diameter of the opening in the case.
10. The shaped charge of claim 9, further comprising a hole in an
apex of the liner.
11. The shaped charge of claim 10, wherein the hole has a diameter
that ranges from about 29% to about 82% of a length of the
liner.
12. The shaped charge of claim 9, wherein the case is fitted with a
coupling to selectively mount the shaped charge in a perforating
string, and wherein the perforating string is disposed in the
wellbore, and wherein detonating the explosive causes the liner to
form a metal jet that penetrates into a formation adjacent the
wellbore to form a perforation.
13. A method of perforating a wellbore comprising: a. providing a
shaped charge that comprises a case having an opening, a liner
inserted in the opening that comprises an apex, a hole in the apex,
and an open end with an outer diameter spaced radially inward from
an inner diameter of the opening to define an annular gap, and
explosive between the liner and the case; b. installing the shaped
charge in a perforating gun; c. deploying the perforating gun in
the wellbore; and d. detonating the explosive so that a detonation
wave is generated that collapses the liner to form a metal jet that
penetrates into a wall of the wellbore and perforates the
formation.
14. The method of claim 13, wherein the outer diameter of the liner
ranges from about 60% to about 75% of the inner diameter of the
opening.
15. The method of claim 13, wherein the hole ranges from about 15%
of the liner outer diameter to about 44% of the liner outer
diameter.
16. The method of claim 13, wherein the perforating gun is part of
a perforating string that is deployed on a line, and wherein a
detonating signal is transmitted from surface through the line and
to perforating gun.
17. The method of claim 13, wherein the shaped charge is mounted
into a gun tube that is inserted in the perforating gun.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present disclosure relates in general to a device for
perforating a wellbore. More specifically, the present invention
relates to a liner for a shaped charge having a liner inserted into
a case, where a gap exists between the respective outer and inner
diameters of the liner and case.
[0003] 2. Description of Prior Art
[0004] Perforating systems are used for the purpose, among others,
of making hydraulic communication passages, called perforations, in
wellbores drilled through earth formations so that predetermined
zones of the earth formations can be hydraulically connected to the
wellbore. Perforations are needed because wellbores are typically
lined with a string of casing and cement is generally pumped into
the annular space between the wellbore wall and the casing. Reasons
for cementing the casing against the wellbore wall includes
retaining the casing in the wellbore and hydraulically isolating
various earth formations penetrated by the wellbore. Sometimes an
inner casing string is included that is circumscribed by the
casing. Without the perforations oil/gas from the formation
surrounding the wellbore cannot make its way to production tubing
inserted into the wellbore within the casing.
[0005] Perforating systems typically include one or more
perforating guns connected together in series to form a perforating
gun string, which can sometimes surpass a thousand feet of
perforating length. The gun strings are usually lowered into a
wellbore on a wireline or tubing, where the individual perforating
guns are generally coupled together by connector subs. Included
with the perforating gun are shaped charges that typically include
a housing, a liner, and a quantity of high explosive inserted
between the liner and the housing. When the high explosive is
detonated, the force of the detonation collapses the liner and
ejects it from one end of the charge at very high velocity in a
pattern called a jet that perforates the casing and the cement and
creates a perforation that extends into the surrounding formation.
Each shaped charge is typically attached to a detonation cord that
runs axially within each of the guns.
SUMMARY OF THE INVENTION
[0006] Provided herein are embodiments for perforating a wellbore.
In one example, a shaped charge for use in perforating a wellbore
is described that includes a case having an opening, a liner
inserted into a space in the case and having an open end and an
apex, explosive disposed between the liner and case, a hole in the
apex of the liner, and a gap between an outer diameter of the open
end of the liner and inner diameter of the opening in the case. The
hole can optionally have a diameter that ranges from about 10% to
about 82% of an axial length of the liner. Optionally, an outer
diameter of the open end of the liner ranges from about 60% to
about 75% of an inner diameter of the opening of the case. In an
example, the hole ranges from about 7% of the liner outer diameter
to about 60% of the liner outer diameter. The shaped charge can be
selectively retained within a gun tube by a coupling that is
provided with the case. In an alternate embodiment, the shaped
charge is selectively disposed in the wellbore within a perforating
string. The shaped charge can further include a slot on an end of
the case opposite the opening that selectively receives a
detonating cord, and an initiator in a passage formed through the
case between the detonating cord and the explosive. A protective
covering may optionally be included in the gap and over the
explosive.
[0007] Also disclosed herein is a shaped charge for use in
perforating a wellbore that includes a case having an opening, a
liner in the case, explosive between the liner and case, and a gap
defined an outer diameter of the open end of the liner and inner
diameter of the opening in the case, and having a diameter that
ranges from about 60% to about 75% of the inner diameter of the
opening in the case. A hole may be included in in an apex of the
liner. In this example, the hole has a diameter that ranges from
about 29% to about 82% of a length of the liner. The case can be
fitted with a coupling to selectively mount the shaped charge in a
perforating string, and the perforating string can be disposed in
the wellbore. Further in this example, detonating the explosive
causes the liner to form a metal jet that penetrates into a
formation adjacent the wellbore to form a perforation.
[0008] A method of perforating a wellbore is also provided herein
that includes providing a shaped charge made up of a case having an
opening, a liner inserted in the opening that comprises an apex, a
hole in the apex, and an open end with an outer diameter spaced
radially inward from an inner diameter of the opening to define an
annular gap, and explosive between the liner and the case. The
method further includes installing the shaped charge in a
perforating gun, deploying the perforating gun in the wellbore, and
detonating the explosive so that a detonation wave is generated
that collapses the liner to form a metal jet that penetrates into a
wall of the wellbore and perforates the formation. In an example of
the method, the outer diameter of the liner ranges from about 60%
to about 75% of the inner diameter of the opening. In another
embodiment of the method, the hole ranges from about 15% of the
liner outer diameter to about 44% of the liner outer diameter. The
perforating gun of the example method can be a part of a
perforating string that is deployed on a line, and wherein a
detonating signal is transmitted from surface through the line and
to perforating gun. Further optionally in the method, the shaped
charge is mounted into a gun tube that is inserted in the
perforating gun.
BRIEF DESCRIPTION OF DRAWINGS
[0009] Some of the features and benefits of the present invention
having been stated, others will become apparent as the description
proceeds when taken in conjunction with the accompanying drawings,
in which:
[0010] FIG. 1 is a side sectional view of an example of a shaped
charge in accordance with the present invention.
[0011] FIG. 2 is a side sectional view of an example of a
perforating gun having the shaped charge of FIG. 1.
[0012] FIG. 3 is a partial side sectional view of a perforating
string in a wellbore made up of the perforating gun of FIG. 2.
[0013] While the invention will be described in connection with the
preferred embodiments, it will be understood that it is not
intended to limit the invention to that embodiment. On the
contrary, it is intended to cover all alternatives, modifications,
and equivalents, as may be included within the spirit and scope of
the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0014] The method and system of the present disclosure will now be
described more fully hereinafter with reference to the accompanying
drawings in which embodiments are shown. The method and system of
the present disclosure may be in many different forms and should
not be construed as limited to the illustrated embodiments set
forth herein; rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey its
scope to those skilled in the art. Like numbers refer to like
elements throughout.
[0015] It is to be further understood that the scope of the present
disclosure is not limited to the exact details of construction,
operation, exact materials, or embodiments shown and described, as
modifications and equivalents will be apparent to one skilled in
the art. In the drawings and specification, there have been
disclosed illustrative embodiments and, although specific terms are
employed, they are used in a generic and descriptive sense only and
not for the purpose of limitation. Examples exist wherein the term
"about" when used in conjunction with a cited value, defines the
scope of the cited value to range from a value that is less than
the cited value by an amount that is 5% of the cited value, and/or
greater than the cited value by an amount that is 5% of the cited
value. Ranges may be expressed herein as from about one particular
value, and/or to about another particular value. When such a range
is expressed, it is to be understood that another embodiment is
from the one particular value and/or to the other particular value,
along with all combinations within said range.
[0016] Shown in side sectional view is one example of a shaped
charge 10 that is made up of a shaped charge case 12 and having an
opening 13 on one end that opens up into a space within the case
12. A thin walled liner 14 shown inserted into the opening 13 and
having an apex A directed towards a closed end of the space within
the case 12. An open end 15 of liner 14, which is opposite apex A,
is a plane that is generally parallel with a plane in which the
opening 13 is disposed. The liner can be formed from a composition
of particles pressed and held together with a ductile or malleable
binder. A non-exhaustive list of particle material includes
tungsten, molybdenum, depleted uranium, hafnium, copper, bismuth,
tantalum, and combinations thereof. A non-exhaustive list of binder
materials includes bismuth, zinc, tin, uranium, silver, gold,
antimony, cobalt, copper, zinc alloys, tin alloys, nickel, copper,
tungsten, palladium, and combinations thereof.
[0017] An explosive 16 is shown provided in the space within the
case 12 and between an outer surface of the liner 14 and inner
surface of space. Examples of explosives include compositions sold
under trade designations HMX, HNS, RDX, HNIW, PYX and TNAZ. A hole
18 is shown formed through the liner 14 and proximate apex A.
Example holes 18 can have a shape that is curved, circular,
elliptical, and alike. A protective covering 20 is shown over the
portion of the explosive 16 exposed to hole 18. In the example of
FIG. 1, the outer diameter of the liner OD.sub.L is shown set
radially inward (with respect to axis A.sub.X) from an inner
diameter from the case ID.sub.C. The difference in length between
the OD.sub.L and ID.sub.C defines a gap G that circumscribes an
outer periphery of the liner 14 and adjacent its open end 15.
Optionally, a protective covering 22 is laid over the portion of
the explosive 16 and at the surface of gap G.
[0018] A detonating cord 24 is shown for providing detonation of
explosive 16 within case 12 where a booster charge 26 is shown
extending through the end of the case 12 and from the closed end of
space and to adjacent the detonation cord 24. A slot 25 is formed
in the end of the case 12 opposite its opening 13 and provides a
place for insertion and retention of the detonation cord 24.
[0019] In the example of FIG. 1, the offset between the outer
diameter of liner OD.sub.L and inner diameter of case ID.sub.C
defines what is sometimes referred to as a sub-caliber charge. In
this example, the liner outer diameter OD.sub.L can range from
about 60% to about 75% of the charge case inner diameter ID.sub.C.
Optionally, the diameter of hole 18 can have a value that ranges
from about 29% to about 82% of a length L of liner 14. An advantage
of the configuration of liner 14 is that more control of the
distribution of material of liner 14 into the jet is
accomplished.
[0020] Shown in FIG. 2 is a side sectional view of a plurality of
shaped charges 10 disposed within an annular gun tube 27, which is
in turn inserted within an annular gun body 28. The shaped charges
10 are oriented so the openings 13 of the cases 12 are oriented in
a direction generally radially outward from an axis of the gun tube
27. Further illustrated is the detonation cord 26 extending between
adjacent shaped charges 10, so that by forming a detonation wave in
one end of the detonation cord 26, the detonation wave can be
passed through each of the shaped charges 10 to which the
detonating cord 24 is attached. The combination of the shaped
charges 10 and gun tube 27 inserted with the perforating gun body
28 forms a perforating gun 29. In one example, a coupling 30 may be
provided on an outer surface of a shaped charge 10 (FIG. 1) for
maintaining the shaped charge 10 within gun tube 27.
[0021] Referring now to FIG. 3, a stack of perforating guns 29 is
shown coupled together to form a perforating string 31 which is
inserted within a wellbore 32. Operation of detonation of the
shaped charges 10 within the perforating string 29 can be
controlled within a surface truck 34 on surface. In this example,
signals generated within the surface truck 34 are sent via a line
36, from which the perforating string 29 is deployed within the
wellbore 32. Example embodiments of the line 36 include wireline,
slick line, coiled tubing, and cable. In the example of FIG. 3, the
line 36 is extended through a wellhead assembly 38 shown mounted at
the mouth of the wellbore 32. By sending a signal from surface
truck to wire line 36, detonating charges and detonating waves may
be initiated in the perforating cord 24 (FIG. 2) for initiating
detonation of explosive within the shaped charges 10 and that form
metal jets 39 that project into a formation 40 adjacent wellbore
32. By initiating and forming the metal jets 39 and directing them
into formation 40, perforations 42 are formed within formation 40
and for allowing fluid flow from formation 40 into wellbore 32.
[0022] The present invention described herein, therefore, is well
adapted to carry out the objects and attain the ends and advantages
mentioned, as well as others inherent therein. While a presently
preferred embodiment of the invention has been given for purposes
of disclosure, numerous changes exist in the details of procedures
for accomplishing the desired results. These and other similar
modifications will readily suggest themselves to those skilled in
the art, and are intended to be encompassed within the spirit of
the present invention disclosed herein and the scope of the
appended claims.
* * * * *