U.S. patent number RE28,641 [Application Number 05/495,545] was granted by the patent office on 1975-12-09 for retrievable subsurface well tools.
This patent grant is currently assigned to Baker Oil Tools, Inc.. Invention is credited to David V. Chenoweth.
United States Patent |
RE28,641 |
Chenoweth |
December 9, 1975 |
Retrievable subsurface well tools
Abstract
.Iadd.A retrievable well tool having a body structure on which a
downwardly tapering expander is disposed which can expand companion
normally retracted slips against the well casing, a pressure
differential from above or below the tool tending to hold the
expander in downward wedging relation to the slips to retain them
in anchored condition against the casing, relieving of the pressure
differential and elevation of the expander effecting release and
retraction of the slips from the well casing. .Iaddend.
Inventors: |
Chenoweth; David V. (Maui,
HI) |
Assignee: |
Baker Oil Tools, Inc. (Los
Angeles, CA)
|
Family
ID: |
27014722 |
Appl.
No.: |
05/495,545 |
Filed: |
August 7, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
394402 |
Sep 4, 1964 |
03361207 |
Jan 2, 1968 |
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Current U.S.
Class: |
166/120; 166/182;
166/237; 166/139; 166/187 |
Current CPC
Class: |
E21B
33/1291 (20130101); E21B 33/12955 (20130101); E21B
23/06 (20130101) |
Current International
Class: |
E21B
33/129 (20060101); E21B 23/00 (20060101); E21B
33/12 (20060101); E21B 33/1295 (20060101); E21B
23/06 (20060101); E21B 023/00 (); E21B
033/12 () |
Field of
Search: |
;166/138-140,120,122,134,182,216,217,187,212,237,48,214,119,239
;175/267-269 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Leppink; James A.
Attorney, Agent or Firm: Kriegel; Bernard
Claims
I claim:
1. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
responsive to movement of said body structure in one direction
relative to said normally retracted means for expanding said
normally retracted means outwardly, said expanding means including
chamber means containing a gas under pressure exerting a constant
force tending to retain said normally retracted means in expanded
condition; first releasable clutch means acting between said body
structure and normally retracted means for preventing such movement
of said body structure relative to said normally retracted means;
and second releasable clutch means acting between said body
structure and normally retracted means for preventing movement of
said body structure relative so said normally retracted means in
the opposite direction to lock said normally retracted means in its
outwardly expanded condition.
2. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
for expanding said normally retracted means outwardly and including
chamber means containing a gas under pressure exerting a constant
force tending to retain said normally retracted means in expanded
condition; first releasable clutch means acting between said body
structure and normally retracted means for preventing said normally
retracted means from being expanded outwardly; and second
releasable clutch means acting between said body structure and
normally retracted means for locking said normally retracted means
in its outwardly expanded condition.
3. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
responsive to longitudinal movement of said body structure in one
direction relative to said normally retracted means for expanding
said normally retracted means outwardly, said expanding means
including chamber means containing a gas under pressure exerting a
constant force tending to retain said normally retracted means in
expanded condition; first releasable clutch means acting between
said body structure and normally retracted means for preventing
such longitudinal movement of said body structure relative to said
normally retracted means; and second releasable clutch means acting
between said body structure and normally retracted means for
preventing longitudinal movement of said body structure relative to
said normally retracted means in the opposite direction to lock
said normally retracted means in its outwardly expanded
condition.
4. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
for expanding said normally retracted means outwardly and including
chamber means containing a gas under pressure exerting a constant
force tending to retain said normally retracted means in expanded
condition; a clutch member slidably relatively longitudinally on
said body structure and operatively connected to said normally
retracted means; a first clutch element movable laterally on said
clutch member into clutching engagement with said body structure
for preventing said normally retracted means from being expanded
outwardly; and a second clutch element movable laterally on said
clutch member into clutching engagement with said body structure
for locking said normally retracted means in its outward expanded
condition.
5. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
responsive to longitudinal movement of said body structure in one
direction relative to said normally retracted means for expanding
said normally retracted means outwardly, said expanding means
including chamber means containing a gas under pressure exerting a
constant force tending to retain said normally retracted means in
expanded condition; a clutch member slidable relatively
longitudinally on said body structure and operatively connected to
said normally retracted means; a first clutch element movable
laterally on said clutch member into clutching engagement with said
body structure for preventing such longitudinal movement of such
body structure relative to said normally retracted means; and a
second clutch element movable laterally on said clutch member into
clutching engagement with said body structure for preventing
longitudinal movement of said body structure relative to said
normally retracted means in the opposite direction to lock said
normally retracted means in its outwardly expanded condition.
6. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
for expanding said normally retracted means outwardly and including
chamber means containing a gas under pressure exerting a constant
force tending to retain said normally retracted means in expanded
condition; said body structure having first and second threaded
portions; a clutch member slidable relatively longitudinally along
said threaded portions and operatively connected to said normally
retracted means; a first threaded clutch element movable laterally
on said clutch member and being meshable with said first threaded
portion for preventing said normally retracted means from being
expanded outwardly; a second threaded clutch element movable
laterally on said clutch member into threaded mesh with said second
portion for locking said normally retracted means in its outwardly
expanded condition; the threads of said first portion and first
element being of opposite hand from the threads of said second
portion and second element.
7. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
responsive to longitudinal movement of said body structure in one
direction relative to said normally retracted means for expanding
said normally retracted means outwardly, said expanding means
including chamber means containing a gas under pressure exerting a
constant force tending to retain said normally retracted means in
expanded condition; said body structure having first and second
threaded portions; a clutch member slidable relatively
longitudinally along said threaded portions and operatively
connected to said normally retracted means; a first threaded clutch
element movable laterally on said clutch member and being meshable
with said first threaded portion for preventing such longitudinal
movement of said body structure relative to said normally retracted
means; a second threaded clutch element movable laterally on said
clutch member into threaded mesh with said second portion for
preventing longitudinal movement of said body structure relative to
said normally retracted means in the opposite direction to lock
said normally retracted means in its outwardly expanded condition;
the threads of said first portion and first element being of
opposite hand from the threads of said second portion and second
element.
8. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
for expanding said normally retracted means outwardly and including
chamber means containing a gas under pressure exerting a constant
force tending to retain said normally retracted means in expanded
condition; said body structure having first and second buttress
thread portions of opposite hand; a clutch member slidable
longitudinally along said threaded portions and operatively
connected to said normally retracted means; a first clutch element
movable laterally on said clutch member and having a buttress
thread meshing with the first threaded portion to prevent said
normally retracted means from being expanded outwardly; and a
second clutch element movable laterally on said clutch member and
having a buttress thread adapted to mesh with said second threaded
portion to lock said normally retracted means in its outwardly
expanded condition.
9. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
responsive to longitudinal movement of said body structure in one
direction relative to said normally retracted means for expanding
said normally retracted means outwardly, said expanding means
including chamber means containing a gas under pressure exerting a
constant force tending to retain said normally retracted means in
expanded condition; said body structure having first and second
buttress thread portions of opposite hand; a clutch member slidable
longitudinally along said threaded portions and operatively
connected to said normally retracted means; a first clutch element
movable laterally on said clutch member and having a buttress
thread meshing with said first threaded portion for preventing such
longitudinal movement of said body structure relative to said
normally retracted means; and a second clutch element movable
laterally on said clutch member and having a buttress thread
adapted to mesh with said second threaded portion to prevent
longitudinal movement of said body structure relative to said
normally retracted means in the opposite direction to lock said
normally retracted means in its outwardly expanded condition.
10. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
responsive to downward movement of said body structure relative to
said normally retracted means for expanding said normally retracted
means outwardly, said expanding means including chamber means
containing a gas under pressure exerting a constant force tending
to retain said normally retracted means in expanded condition;
first releasable means acting between said body structure and
normally retracted means for preventing such downward movement of
said body structure relative to said normally retracted means; and
second releasable clutch means acting between said body structure
and normally retracted means for preventing upward movement of said
body structure relative to said normally retracted means to lock
said normally retracted means in its outwardly expanded
condition.
11. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
responsive to downward movement of said body structure relative to
said normally retracted means for expanding said normally retracted
means outwardly, said expanding means including chamber means
containing a gas under pressure exerting a constant force tending
to retain said normally retracted means in expanded condition; said
body structure having first and second threaded portions; a clutch
member slidable longitudinally along said threaded portions and
operatively connected to said normally retracted means; a first
threaded clutch element movable laterally on said clutch member and
being meshable with said first threaded portion for preventing
downward movement of said body structure relative to said normally
retracted means; a second threaded clutch element movable laterally
on said clutch member into threaded mesh with said second portion
for preventing upward movement of said body structure relative to
said normally retracted means to lock said normally retracted means
in its outwardly expanded condition; the threads of said first
portion and first element being of opposite hand from the threads
of said second portion and second element.
12. In a well tool adapted to be set in a well bore: a body
structure; normally retracted means on said body structure; means
responsive to downward movement of said body structure relative to
said normally retracted means for expanding said normally retracted
means outwardly, said expanding means including chamber means
containing a gas under pressure exerting a constant force tending
to retain said normally retracted means in expanded condition; said
body structure having first and second buttress thread portions of
opposite hand; a clutch member slidable along said threaded
portions and operatively connected to said normally retracted
means; a first clutch element movable laterally on said clutch
member and having a buttress thread meshing with said first
threaded portion to prevent downward movement of said body
structure relative to said normally retracted means; and a second
clutch element movable laterally on said clutch member and having a
buttress thread adapted to mesh with said second threaded portion
to prevent upward movement of said body structure relative to said
normally retracted means to lock said normally retracted means in
its outwardly expanded condition.
13. In a well tool adapted to be set in a well bore: a body;
normally retracted packing means on said body; normally retracted
slip means on said body; means responsive to longitudinal movement
of said body in one direction for expanding said packing means and
slip means laterally outwardly, said expanding means including
chamber means containing a gas under pressure exerting a constant
force tending to retain said packing means and slip means in
expanded condition; first releasable clutch means acting between
said body and slip means for preventing said body from effecting
expansion of said slip means and packing means; and second
releasable clutch means acting between said body and slip means for
locking said slip means and packing means in their outwardly
expanded condition.
14. In a well tool adapted to be set in a well bore: a body;
normally retracted packing means on said body; normally retracted
slip means on said body; means responsive to downward movement of
said body for expanding said packing means and slip means laterally
outwardly, said expanding means including chamber means containing
a gas under pressure exerting a constant force tending to retain
said packing means and slip means in expanded condition; first
releasable clutch means acting between said body means and slip
means to prevent said body from effecting expansion of said slip
means and packing means; and second releasable clutch means acting
between said body and slip means for locking said slip means and
packing means in their outwardly expanded condition.
15. In a well tool adapted to be set in a well bore: a body;
normally retracted packing means on said body; normally retracted
slip means on said body; means responsive to downward movement of
said body for expanding said packing means and slip means laterally
outwardly, said expanding means including chamber means containing
a gas under pressure exerting a constant force tending to retain
said packing means and slip means in expanded condition; said body
having first and second threaded portions; a clutch member slidable
relatively longitudinally along said threaded portions and
operatively connected to said slip means; a first threaded clutch
element movable laterally on said clutch member and being meshable
with said first threaded portion for preventing said packing means
and slip means from being expanded outwardly; a second threaded
clutch element movable laterally on said clutch member into
threaded mesh with said second portion for preventing upward
movement of said body relative to said slip means to lock said slip
means and packing means in their outward expanded condition; the
threads of said first portion and first element being of opposite
hand from the threads of said second portion and second
element.
16. In a well tool adapted to be set in a well bore: a body;
normally retracted packing means on said body; normally retracted
slip means on said body; means responsive to downward movement of
said body for expanding said packing means and slip means laterally
outwardly, said expanding means including chamber means containing
a gas under pressure exerting a constant force tending to retain
said packing means and slip means in expanded condition; said body
having first and second buttress thread portions of opposite hand;
a clutch member slidable longitudinally along said threaded
portions and operatively connected to said slip means; a first
clutch element movable laterally on said clutch member and having a
buttress thread meshing with said first threaded portion to prevent
downward movement of said body relative to said slip means and
packing means to prevent said slip means and packing means from
being expanded outwardly; and a second clutch element movable
laterally on said clutch member and having a buttress thread
adapted to mesh with said second threaded portion to prevent upward
movement of said body relative to said slip means and packing means
to lock said slip means and packing means in their outwardly
expanded condition.
17. In a well tool adapted to be set in a well bore: a body;
normally retracted packing means on said body; means for expanding
said packing means laterally outwardly, comprising abutment means
for exerting an expanding force on said packing means; and chamber
means surrounding said body and containing a gas under pressure
charged into said chamber means at the top of the well bore for
exerting a continuous spring-like force on said abutment means to
hold said packing means expanded outwardly.
18. In a well tool adapted to be set in a well bore: a body;
normally retracted packing means on said body; an upper abutment
engaging said packing means; a lower abutment engaging said packing
means; means for relatively shifting said abutments toward each
other to expand said packing means laterally outwardly; chamber
means surrounding said body and operatively connected to one of
said abutments; said chamber means containing a gas under pressure
charged into said chamber means at the top of the well bore for
exerting a continuous spring-like force on said chamber means and
said one abutment to urge said one abutment toward the other
abutment.
19. In a well tool adapted to be set in a well bore: a body;
normally retracted slip means disposed around said body; expander
means around said body above and engaging said slip means; means
for relatively moving said expander means downwardly of said slip
means to expand said slip means relatively outwardly; packing means
above said expander means adapted to seal against the wall of the
well bore; means providing a downwardly facing transverse surface
on said expander means subject to the pressure of fluid in the well
bore above said packing means; and means providing a resultant
upwardly facing transverse surface on said expander means subject
to the pressure of fluid in the well bore below said packing means,
whereby a greater well bore pressure below said packing means and
above said packing means forces said expander means downwardly
within said slip means to retain said slip means expanded
outwardly.
20. In a well tool adapted to be set in a well bore: a body
structure; normally retracted packing means on said body structure;
means responsive to movement of said body structure in one
direction relative to said normally retracted packing means for
expanding said normally retracted packing means outwardly, said
expanding means including spring-like means exerting a constant
force tending to retain said normally retracted packing means in
expanded condition; first releasable clutch means acting between
said body structure and normally retracted packing means for
preventing such movement of said body structure relative to said
normally retracted packing means; and second releasable clutch
means acting between said body structure and normally retracted
packing means for preventing movement of said body structure
relative to said normally retracted packing means in the opposite
direction to lock said normally retracted packing means in its
expanded condition.
21. In a well tool adapted to be set in a well bore: a body
structure; normally retracted packing means on said body structure;
means for expanding said normally retracted packing means outwardly
and including spring-like means exerting a constant force tending
to retain said normally retracted packing means in expanded
condition; first releasable clutch means acting between said body
structure and normally retracted packing means for preventing said
normally retracted packing means from being expanded outwardly; and
second releasable clutch means acting between said body structure
and normally retracted packing means for locking said normally
retracted packing means in its outwardly expanded condition.
22. In a well tool adapted to be set in a well bore: a body;
normally retracted means on said body; means for expanding said
normally retracted means laterallly outwardly, comprising abutment
means for exerting an expanding force on said normally retracted
means; and chamber means surrounding said body and containing a gas
under pressure charged into said chamber means at the top of the
well bore for exerting a continuous spring-like force on said
abutment means to hold said normally retracted means expanded
outwardly.
23. In a well tool adapted to be set in a well bore: a body;
normally retracted means on said body; an upper abutment engaging
said normally retracted means; a lower abutment engaging said
normally retracted means; means for relatively shifting said
abutments toward each other to expand said normally retracted means
laterally outwardly; chamber means surrounding said body and
operatively connected to one of said abutments; said chamber means
containing a gas under pressure charged into said chamber means at
the top of the well bore for exerting a continuous spring-like
force on said chamber means and said one abutment to urge said one
abutment toward the other abutment. .Iadd. 24. In a well tool
adapted to be set in a well bore as defined in claim 19; said
downwardly facing transverse surface being disposed below said
packing means, passage means extending within said packing means
for conducting said pressure of the fluid in the well bore from
above said packing means to said downwardly facing transverse
surface; said upwardly facing transverse surface being adjacent to
the lower end of said packing means; said upwardly facing
transverse surface being greater in area than said downwardly
facing transverse surface. .Iaddend. .Iadd. 25. In a well tool
adapted to be set in a well bore: a body; normally retracted slip
means disposed around said body; expander means around said body
above and engaging said slip means; packing means above and
engageable with said expander means and adapted to seal against the
wall of the well bore; upper abutment means engaging the upper
portion of said packing means; said expander means including lower
abutment means engaging the lower portion of said packing means and
having a cylinder portion extending downwardly of said lower
abutment means, said lower abutment means having a portion
extending laterally inwardly of the inner wall of said cylinder
portion; means providing a first slidable seal between the inner
wall of said cylinder portion and said body to prevent the pressure
of fluid in the well bore below said packing from acting upwardly
on said lower abutment means portion; means providing a second seal
between said lower abutment means portion and said body; said first
and second seals providing a resultant downwardly facing transverse
surface on said lower abutment means of less area than an upwardly
facing transverse surface on said lower abutment means; said
upwardly facing surface being subject to the pressure of fluid in
the well bore below said packing means to force said expander means
downwardly within said slip means; means for conducting the
pressure of fluid in the well bore above said packing means to said
downwardly facing surface of said lower abutment means; and means
including means acting through said upper abutment means, packing
means, and lower abutment means for relatively moving said expander
means downwardly of said slip means to expand said slip means
relatively outwardly. .Iaddend. .Iadd. 26. In a well tool adapted
to be set in a well bore as defined in claim 25; said packing means
being initially retracted and being expanded laterally outwardly
into sealing engagement with the wall of the well bore upon
downward movement of said expander means within said slip means.
.Iaddend. .Iadd. 27. In a well tool adapted to be set in a well
bore: a body; normally retracted slip means disposed around said
body; expander means around said body above and engaging said slip
means; normally retracted packing means above and engageable with
said expander means and adapted to be expanded into sealing
engagement against the wall of the well bore; an upper abutment
engaging the upper portion of said packing means; a sleeve secured
to said upper abutment and extending downwardly through said
packing means and around said body; said expander means including a
lower abutment surrounding said sleeve and engaging the lower
portion of said packing means; said expander means also including a
cylindrical portion laterally spaced from said sleeve and secured
to and depending from said lower abutment; means providing a first
slidable seal between the inner wall of said cylinder portion and
said body to prevent pressure of fluid in the well bore below said
packing from acting upwardly on said lower abutment; means
providing a second seal between said lower abutment and said
sleeve; said first and second seals providing a resultant
downwardly facing transverse surface on said lower abutment of less
area than an upwardly facing transverse surface on said lower
abutment, said upwardly facing surface being subject to the
pressure of fluid in the well bore below said packing means to
force said expander means downwardly within said slip means; means
for conducting the pressure of fluid in the well bore from above
said packing means through the space between said sleeve and body
to said downwardly facing surface of said lower abutment; and means
including means acting through said upper abutment, packing means,
and lower abutment for relatively moving said expander means
downwardly of said slip means to expand said slip means relatively
outwardly and to expand said normally retracted means outwardly
into sealing engagement with the wall of the well bore.
Description
The present invention relates to subsurface well bore apparatus,
and more particularly to tools, such as anchors, well packers and
bridge plugs, adapted to be set in well bores.
An object of the invention is to provide an improved retrievabe
subsurface well bore apparatus, such as a well packer (including a
well packer capable of functioning as a bridge plug), having a
normally retracted packing structure to facilitate lowering and
elevating of the apparatus in the well bore, the apparatus being
capable of being set in the well bore and of holding pressure in
both longitudinal directions without the assistance of a tubing
string or other force applying device.
Another object of the invention is to provide a retrievable
subsurface well bore apparatus capable of being anchored in the
well bore against movement in both longitudinal directions, and in
which it is unnecessary for any parts to move in connection with
change in the direction in which the apparatus is to be anchored to
withstand fluid pressures acting thereagainst.
A further object of the invention is to provide retrievable
subsurface well bore apparatus capable of being anchored in a well
bore against movement in both longitudinal directions and of being
locked mechanically in its anchored position to prevent subsequent
relative movement of the anchoring parts until their retraction is
desired for the purpose of releasing the well apparatus from the
well bore.
An additional object of the invention is to provide improved
retrievable subsurface apparatus capable of being anchored in a
well casing against movement in both longitudinal directions in
which the apparatus can be easily released from the well casing
whenever desired. In a more limited sense, the apparatus includes a
reverse or downwardly tapering expander and companion slips in
which pressure differential from above the apparatus, as well as
from below the apparatus, tend to hold the expander in downward
wedging relation to the slips, so that bleeding off of the pressure
differential and elevation of the expander effects an easy release
and retraction of the slips from the well casing.
Yet another object of the invention is to provide an improved well
packer embodying a packing structure adapted to seal against a well
casing, in which the well packer embodies a mechanism for retaining
a setting or pack-off force on the apparatus despite loss of
packing material around the apparatus due to its extrusion or cold
flowing, and the like.
This invention possesses many other advantages, and has other
objects which may be made more clearly apparent from a
consideration of a form in which it may be embodied. This form is
shown in the drawings accompanying and forming part of the present
specification. It will now be described in detail, for the purpose
of illustrating the general principles of the invention; but it is
to be understood that such detailed description is not to be taken
in a limiting sense, since the scope of the invention is best
defined by the appended claims.
Referring to the drawings:
FIGS. 1a, 1b, 1c and 1d together constitute a combined side
elevational view and longitudinal section through a well apparatus
embodying the invention disposed in the well casing with the parts
in their relative positions for lowering the apparatus in the well
casing,
FIGS. 1b, 1c and 1d constituting lower continuations of FIGS. 1a,
1b and 1c, respectively;
FIGS. 2a, 2b, 2c and 2d are longitudinal sections corresponding to
FIGS. 1a to 1d disclosing the well packer anchored in packed-off
condition within the well casing, FIGS. 2b, 2c and 2d constituting
lower continuations of FIGS. 2a, 2b and 2c, respectively;
FIGS. 3a and 3b together constitute a longitudinal section through
the upper portion of the apparatus illustrated in FIGS. 2a and 2b
disclosing the release of the running-in and retrieving tool from
the well packer or bridge plug therebelow, FIG. 3b being a lower
continuation of FIG. 3a;
FIG. 4 is a diagrammatic view of the lock pin and slot arrangement
for releasably securing the running-in and retrieving tool to the
well packer or bridge plug;
FIG. 5 is a cross-section on an enlarged scale taken along the line
5--5 on FIG. 1b;
FIG. 6 is a cross-section on an enlarged scale taken along the line
6--6 on FIG. 1b;
FIG. 7 is a cross-section on an enlarged scale taken along the line
7--7 on FIG. 1c;
FIG. 8 is a cross-section on an enlarged scale taken along line
8--8 on FIG. 1d;
FIG. 9 is a cross-section on an enlarged scale taken along the line
9--9 on FIG. 1d;
FIG. 10 is an enlarged fragmentary longitudinal section through the
gas pressure bleeder portion of the apparatus;
FIG. 11 is a fragmentary enlarged longitudinal section through the
gas pressure inlet portion of the apparatus.
The invention is illustrated in the drawings as being embodied in a
well packer A, such as a bridge plug, adapted to be connected to a
running-in and retrieving tool B, which is, in turn, attached to a
tubular string C, by means of which the combination of apparatus is
lowered in a well casing D to a desired setting point. The
running-in and retrieving tool B is also used in connection with
release of the well packer from the well casing and its shifting to
another location therein, or its complete removal through the
casing to the top of the well bore.
The specific well packer A illustrated includes a mandrel or body
10 having a longitudinal passage 11 therein open at its lower end.
The mandrel includes an elongate lower section 12, the upper end of
which is threadedly secured to an upper section 13 having side
ports 14 therethrough establishing communication between the
central passage and the exterior of the mandrel or body 10. The
upper pin end 15 of the upper body section is threadedly secured to
a control head 16, there being a sleeve valve 17 slidable
longitudinally along the upper body mandrel section 13 from a lower
position, in which the ports 14 are opened, to an upper position
across the ports. The lower position is determined by engagement of
the lower end of the sleeve valve 17 with an upwardly facing body
shoulder 18, its upper position being determined by engagement of
its upper end with a downwardly facing shoulder 19 on the control
head. When in its upper position closing the ports 14, leakage of
fluid between the sleeve valve and the mandrel or body 10 is
prevented by opposed seal members 20, 21 mounted on the body
section 13 which slidably and sealingly engage the inner surface of
the sleeve valve 17.
An upper packing structure 22 surrounds the body, which is adapted
to seal against the wall of the well casing D. As specifically
disclosed, a plurality of packing sleeves 23, 24, 25 of pliant,
elastic material, such as rubber or rubber-like material,
encompasses an elongate sleeve 26 surrounding the body 10, the
upper end of the uppermost packing sleeve or element 23 engaging an
upper abutment 27 threadedly secured to the sleeve 26, there being
a gage ring 28 threaded on the upper abutment in engagement with
the upper packing element 23 to minimize the extent of extrusion of
the rubber packing material through the annular clearance space
between the gage ring 28 and the wall of the well casing D. The
upper packing element 23 contacts a spacer ring 29 which, in turn,
is engaged by the upper end of the intermediate packing element 24
that engages a lower spacer ring 30, the latter contacting the
upper end of the lower packing element 25 which engages a lower
abutment 31 having a lower gage ring 32 threadedly secured thereto.
The lower gage ring will also tend to minimize the extent of
extrusion or cold flowing of the lower packing sleeve 25 through
the annular clearance space between the gage ring and the wall of
the well casing D, as a result of shortening and compression of the
lower packing sleeve and its expansion against the wall of the well
casing, as described hereinbelow.
The lower end of the packing structure sleeve 26 has an external
flange 33 adapted to engage the lower end of the lower abutment 31,
which will limit the extent of separating movement between the
upper and lower abutments 27, 31, as shown in FIGS. 1b and 1c, in
which the packing elements 23, 24, 25 are retracted. However, the
upper abutment 27 can move toward the lower abutment 31 for the
purpose of exerting an axial force on the packing elements to
effect their shortening and lateral outward expansion and
compression against the wall of the well casing D, and also against
the periphery of the packing structure sleeve 26.
The packing structure sleeve 26 is spaced laterally from the
periphery of the mandrel or body 10, providing an annular passage
or space 36 therebetween through which fluid under pressure can
pass, the upper end of this passage communicating with upper ports
36 extending through the upper abutment 27 to its exterior. The
upper end of the passage 35 is closed by a bearing ring 37 disposed
within a counterbore 38 in the upper abutment and held therein by a
split snap retaining ring 39 located in a groove 40 in the upper
abutment and overlying the bearing ring. The bearing ring has inner
and outer seals 41 sealing against the periphery of the lower body
section 12 and also against the wall of the counterbore 38 to
prevent passage of fluid therebetween. This bearing ring is adapted
to be engaged by a lower pilot portion 42 on the upper body section
13 when the apparatus is to be set, to facilitate rotation of the
body 10 relative to the packing structure 22 and the remainder of
the apparatus surrounding the main body or mandrel of the tool, in
the manner described hereinbelow.
The lower end of the annular fluid passage 35 opens into a pressure
chamber 44 below the lower abutment 31. This pressure chamber is
defined by the lower abutment 31, an upper cylinder sleeve 45
threadedly attached thereto and depending therefrom in lateral
spaced relation to the body 10 of the tool, and an annular piston
46 which is slidable longitudinally along both the periphery of the
body and the inner wall of the upper cylinder sleeve. This piston
has inner and outer seal rings 47 sealingly engaging the periphery
of the body and the inner wall of the cylinder sleeve,
respectively. Its upward movement relative to the body 10 is
limited by its engagement with a two-piece stop ring 48 disposed in
a peripheral groove 49 in the body and extending substantially to
the wall of the cylinder sleeve 45. This stop ring is also
engageable with the lower end of the packing structure sleeve 26
when the apparatus is to be retracted or released from the well
casing, following its setting thereagainst.
The lower portion of the upper cylinder sleeve 45 is threadedly
secured to the upper cylinder head 50 of a cylinder 51 having a
cylinder sleeve 52 depending therefrom. The upper cylinder sleeve
45, head 50, and lower cylinder sleeve 52 encompass a connector
sleeve 53, the upper head 54 of which is disposed in an annular
chamber 55 defined between the upper cylinder sleeve 45 and body 10
of the tool, and which head 54 is also disposed between the
cylinder head 50 and the annular piston 46. The connector sleeve 53
extends within a reverse cone or expander 56 to which it is
suitably secured, as by means of a threaded connection 57, the
upper portion of the reverse cone or expander being constituted as
an annular piston 58 disposed within and adapted to slide
relatively along the wall of the lower cylinder sleeve 52. The
spaced relation between the lower cylinder sleeve 52 and the
connector sleeve 53 provides an annular chamber 59 adapted to
contain a gas under pressure, such as compressed air or nitrogen.
This gas can be introduced into the chamber through an inlet port
60 closed by a filler plug 61 threadedly secured within the
expander member 56. The gas can pass from the inlet port 60 through
an annular passage 62 between the connector sleeve 53 and the
expander 56, and through a longitudinal slot 63 cut through the
externally threaded portion of the connector sleeve (FIG. 11) to an
inlet port 64 extending through the expander member above its
piston 58. A one-way or check valve surrounds the port, being
disclosed in the form of an elastic O-ring 65 embracing the
exterior of the expander above the piston 58 and closing inwardly
to prevent gas from having retrograde movement through the inlet
port 64. However, it permits gas under pressure to flow through the
inlet port 64 into the chamber 59.
Leakage of gas from the chamber 59 is prevented by a suitable side
seal ring 66 on the piston sealingly engaging the wall of the lower
cylinder sleeve 52, by a seal ring 67 carried by the connector
sleeve 53 and engaging the upper portion of the expander 56, and by
an inner seal ring 68 on the cylinder head 50 slidably and
sealingly engaging the periphery of the connector sleeve 53. A
thread seal ring 69 is also mounted on the cylinder head 50,
engaging the upper cylinder sleeve 45 to prevent fluid leakage
through the threaded connection between the head and upper cylinder
sleeve. Leakage of fluid from the injection or inlet port 60 in a
downward direction between the connector sleeve and expander is
prevented by a suitable seal ring 70 mounted on the expander 56 and
engaging the periphery of the connector sleeve 53 below its inlet
port.
The connector sleeve 53 is relatively slidable with respect to the
cylinder 51 and is laterally spaced from the mandrel or body 10 to
provide an annular passage 72 therebetween which will allow fluid
pressure from below the apparatus to pass through such annular
passage into the chamber 55 above the connector head 54. Such fluid
under pressure cannot escape upwardly out of the chamber because of
the annular piston 46, and it cannot escape downwardly between the
upper cylinder sleeve and the connector head because of the
provision of a suitable seal ring 73 on the connector head which
slidably and sealingly engages the wall of the upper cylinder
sleeve 45. The connector head 54 and the cylinder head 50 are
disclosed in FIG. 1c as being in engagement with one another.
However, when the tool is set, the cylinder head moves downwardly
away from the connector head, as disclosed in FIG. 2c, the annular
chamber or space 74 between the two heads always containing air at
a pressure no greater than atmospheric, and actually much less than
atmospheric, since air is trapped between the head 50, 54 when the
tool is assembled at the top of the well bore. The increase in
volume of the chamber 74 as the cylinder head 50 moves downwardly
away from the connector head 54 will result in the air expanding
and having a lesser pressure than atmospheric.
A suitable gas at a desired pressure is ejected into the compressed
air or other gas chamber 59 through the inlet port 60 and through
the check valve controlled port 64 in the upper portion of the
expander 56. Such gas under pressure remains trapped in the
chamber, but may be bled therefrom when desired in the event the
tool is to be dismantled at the top of the well bore. Thus, a
bleeder port 76 is provided in the cylinder head that communicates
with the upper end of the chamber 59 which is normally closed by a
bleeder plug 77 threaded into the cylinder head 50. Such bleeder
plug can assume any desired form, the one disclosed more
specifically in FIG. 10 being a safety device to prevent the
pressure in the chamber from blowing the plug outwardly after it
has been unthreaded from the head. As shown in FIG. 10, the bleeder
plug includes an outer member 78 threaded into a radial bore 79 in
the cylinder head and having a suitable side seal ring 80 sealing
against the wall of the bore. An inner plug 81 is threaded within
the outer plug and carries a suitable seal ring 82 sealing against
the wall of the inner plug passage 83. As disclosed in FIG. 10, the
entire plug construction 77 is in a position closing the bleeder
port 76. When the gas under pressure is to be vented or bled from
the chamber 59 with the tool located at the top of the well bore,
the inner bleeder plug member 81 is first threaded outwardly, its
inner head engaging a companion shoulder 84 on the outer threaded
plug member 78, with the head disposed outwardly of lateral bleeder
ports 85 in the outer member to allow the compressed gas to flow
through the bleeder port 76 and through the radial ports 85 into a
passage 86 leading to the atmosphere. The inner plug 81 can be
rotated and threaded inwardly again to close the bleeder port 76,
i.e., being replaced in the position illustrated in FIG. 10.
The expander 56 has a plurality of longitudinal slots 87, the base
88 of each slot tapering in a downward and inward direction and
being engageable with a companion tapered inner surface 89 on a
slip 90 received within the slot. Each slip has opposed inclined
side tongues 91 slidable within companion side grooves 92 in the
expander (FIG. 8), the tongues and grooves being parallel to the
tapered surfaces 88, 89 of the expander and slip. The slips 90 are
mounted for joint longitudinal movement, but are capable of
partaking of generally radial inward and outward movement, by
providing lower inverted T-heads 93 on each of them which are
receivable within companion T-shaped slots 94 in the upper end of a
combined slip, drag block, and control unit housing 95. The lower
end of the connector sleeve 53 is capable of downward movement
within an upper counterbore 96 within such housing. The housing 95
has a plurality of circumferentially spaced generally radial
cavities 97 therein, each receiving a drag block 98 which is urged
outwardly into frictional engagement with the wall of the well
casing D by a plurality of helical compression springs 99 engaging
the housing portion forming the base 100 of the cavity and also
engaging the drag block itself. The radial outward movement of each
drag block is limited by engagement of upper and lower shoulders
101 thereon with the heads 102 of upper and lower stop screws 103
threadedly secured to the housing on opposite sides of the cavity
and overlying the shoulders.
The lower portion of the housing 95 forms part of a control unit
104 that determines the retention of the packer parts in retracted
position, their release to allow the packer to be anchored in
packed off condition in the well casing, the retention of the
packer or bridge plug in its packed-off and anchored condition, and
its release from such condition in the well casing and relocation
of its parts in their initial condition. Such housing includes a
lower housing section 105 threadedly secured to the lower portion
of the main housing section 106 thereabove, there being a suitable
gage ring 107 threaded on the lower end of the lower housing
section for insuring that the entire tool can be moved downwardly
in the well casing D to the desired setting point, and to prevent
any portions of the apparatus from becoming stuck in the well
casing.
The housing sections together provide a circumferential internal
groove 108, the lower side 109 of the groove tapering to a slight
extent in a downward and inward direction, the upper side 110 of
the groove tapering upwardly to a slight extent and in an inward
direction. Disposed within the groove are upper and lower clutch or
lock structures. The lower lock structure includes a plurality of
clutch segments or elements 111 having internal ratchet teeth 112
constituted by right-hand buttress threads adapted to mesh with
companion right-hand buttress or ratchet threads 113 on the lower
portion of the body or mandrel 10. The segments 111 are urged in an
inward direction, to hold the buttress threads 112 meshing with the
body threads 113, by a plurality of encircling helical tension
springs 114. The segments can move radially outward so that their
teeth 112 are free from engagement with the lower buttress threads
113 on the body, since there is adequate lateral clearance between
the outer surfaces of the clutch segments and the outer base
portion 115 of the groove 108 in which they are located. Rotation
of the segments 111 is prevented by a guide screw 116 threadedly
secured to each of them and slidably received within a
longitudinally extending slot 117 in the housing 95. The buttress
threads 112, 113 face in the direction shown in the drawings so
that the mandrel or body 10 can ratchet upwardly through the
segments 111, but cannot be moved downwardly, except as a result of
rotating the body 10 relative to the segments, rotation of the
segments being prevented or resisted by the frictional engagement
of the drag blocks 98 against the wall of the well casing D. The
right-hand buttress thread connection 112, 113 is preferably a
multiple pitch thread so that only a comparatively small number of
turns of the body 10 within the segments is required to effect full
downward unthreading of the body from the segments, whereupon the
body 10 is free to continue its downward movement without
rotation.
The control unit 104 of the mechanism also includes upper clutch
segments or elements 118 having downwardly facing ratchet teeth 119
in the form of multiple pitch buttress threads which are preferably
left-hand threads, and which are adapted to engage companion
buttress lefthand threads 120 extending longitudinally along the
body 10 thereabove. Encompassing helical springs 121 engage the
segments 118 and urge them inwardly, the segments being adapted to
be shifted radially outwardly upon downward movement of the body 10
and the left-hand buttress threads 120 therealong. Once the
left-hand buttress threads 120 are engaged with the internal
threads 119, the body 10 cannot move upwardly relative to the
segments unless the body is rotated in a right-hand direction. Such
rotation will not effect rotation of the segments 118 since the
latter are prevented from turning by guide screws 122 attached to
the segments and received within the longitudinal slots 117, the
guide screws allowing radial inward and outward shifting of the
segments, but preventing their rotation in view of the resistance
to rotation afforded by the drag blocks 98.
The left-hand threads 119, 120 are also preferably multiple pitch
threads, so that upon rotation of the body 10 a lesser number of
body turns is required to effect upward unthreading of the body
from the upper set of clutch segments 118, as described
hereinbelow.
The apparatus is adapted to be anchored in the well casing against
movement in both directions, despite the fact that only a single
set of slips 90 and a single reverse cone or expander 56 is
provided. To facilitate anchoring of the slips in the casing
against longitudinal movement in both directions, their external
wickers or teeth 130 are formed in a neutral position, that is,
they face neither upwardly nor downwardly, but will be embedded in
the casing D to resist movement longitudinally therealong as the
result of being subjected to pressure and other forces from below
the tool, as well as pressure and other forces from above the
tool.
In the use and operation of the packer portion of the apparatus so
far described, its parts are arranged in the relative positions
illustrated in FIGS. 1a to 1d, in which the lower right-hand
buttress threads 112, 113, are fully meshed, the slips 90 being in
their retracted position, as well as the packing structure 22. At
this time, the lower end 42 of the upper body section 13 is spaced
above the bearing ring 37. The well packer A is lowered in the well
casing D, as through use of the running-in and retrieving tool B,
or, if desired, the tubing string could be connected directly to
the packer body 10. The downward force imposed on the body 10 is
transmitted directly to the housing 95, because of the meshing of
the right-hand body threads 113 with the companion threads 112 of
the lower clutch segments 111, the segments tending to shift and
remain inwardly by virture of the engagement of the lower inclined
surfaces of the segments with the companion inclined side 109 of
the groove 108 in which they are located. In view of the coupling
of the body 10 to the housing 95 through the lower set of segments
111, as the body is moved downwardly, the body 95 is carried with
it, the drag blocks 98 sliding along the wall of the well casing.
The slips 90 are in their inward position, as disclosed in FIG. 1d,
and the downward pull exerted thereon by the housing 95 is
transmitted through their tongue and groove interconnections 91, 92
to the expander 56, shifting the latter downwardly and carrying the
connector sleeve 53 connected thereto with it. The connector head
54 of the connector sleeve engages the cylinder head 50 to pull the
cylinder 51 downwardly with it.
It is to be noted at this time that the lower end 52a of the lower
cylinder sleeve 52 is longitudinally spaced from a shoulder 56a on
the expander therebelow. The downward movement of the cylinder
sleeve 45 is transferred to the lower abutment 31, which engages
the flange 33 of the packing structure sleeve 26 to pull such
sleeve downwardly and the upper abutment 27 downwardly with it. At
this time the upper and lower abutments 27, 31 cannot move
relatively toward each other, particularly since the lower end of
the packing structure sleeve 26 is engaging the stop ring 48
secured to the body 10.
Prior to lowering of the well packer A in the well casing D, the
pressure chamber 59 will have been filled with a suitable gas, such
as air, to the desired pressure, which, for example, may be of the
order of 1200 p.s.i. Such gas under pressure actually functions as
a spring tending to hold the cylinder 51 in an upward position
relative to the connector sleeve 53.
It is further to be noted that during lowering of the apparatus in
the well casing, the upper segments 118 are disposed between the
right and left-hand body threads 113, 120, being in an ineffective
position, insofar as clutching action with respect to the body or
mandrel is concerned.
When the location in the well casing D is reached at which it is
desired to anchor the packer or bridge plug in packed-off
condition, the tubing string C is rotated to the right to rotate
the body 10 of the tool in the same direction. The drag blocks 98
resist and prevent rotation of the housing 95, so that right-hand
rotation of the body causes its right-hand threads 113 to feed
downwardly along the lower clutch or lock segments 111, until the
right-hand threads 113 completely unthread from the segment threads
112. Such downward unthreading releases the body 10 from the
housing 95 and permits the tubing string C to be lowered and
correspondingly lower the body, the lower end 42 of the upper
mandrel or body section 13 engaging the bearing ring 37, which will
then move the packing structure 22 as a unit, and the upper
cylinder sleeve 45, downwardly, the downward movement of the latter
being transferred through the cylinder head 50 and through the
compressed gas in the chamber 59 to the expander 56, the latter
shifting downwardly within the slips 90, which are prevented from
moving downwardly by virtue of the resistance offered by the drag
blocks 98 against the wall of the well casing.
The expander 56 moves down within the slips 90 to expand the latter
outwardly into firm engagement with the casing, after which the
expander is prevented from moving downwardly to any further extent.
A continued straight-line downward movement of the tubing C and
mandrel 10 will then effect a shifting of the packing structure 22
and the upper cylinder sleeve 45 downwardly as a unit, the cylinder
51 moving along the connector sleeve 53 until the lower end 52a of
the cylinder engages the expander shoulder 56a, the pressure of the
gas in the cylinder 59 being increased, in view of the decrease in
its volume. The downward thrust of the packing structure 22 and the
cylinder sleeves 45, 52 is then transmitted directly from the end
52a of the lower cylinder sleeve to the expander 56 and from the
expander through the slips 90 and its wickers 130 to the well
casing D.
An increase in downward force imposed on the tubing string C and
body 10 then effects a shifting of the upper abutment 27 towards
the lower abutment 31, since the expander prevents the latter from
moving downwardly any further, the upper abument moving toward the
lower abutment to shorten the packing elements 23, 24, 25 and
expand them outwardly into anchored engagement with the wall of the
well casing (FIGS. 2a to 2d). During downward movement of the body
10, after the right-hand buttress threads 113 have become
unthreaded and released from the clutch segments 111, the left-hand
threads 120 can ratchet downwardly freely through the upper clutch
segments 118. However, the body 10 cannot move upwardly relative to
the housing 95 since the coengagement between the external and
internal ratchet threads 120, 119 on the body and upper segments
prevents such movement. An upward force imposed on the upper
segments 118 causes them to be urged inwardly to remain in full
mesh with the left-hand threads 120 because of the inclined surface
on the upper segments engaging the companion upper side 110 of the
housing groove 108. Accordingly, the body 10 of the tool can move
downwardly relatively to the housing 95, but it cannot move
upwardly, retaining the slips 90 and packing structure 22 in an
outward expanded condition.
During the downward shifting of the cylinder 51 along the connector
sleeve 53, to bring the lower end 52a of the cylinder sleeve 52
into engagement with the shoulder 56a, the cylinder head 50 is
moved away from the connector sleeve head 54, as disclosed in FIGS.
2c, the gas under pressure in the chamber 59 constantly tending to
urge the cylinder 51 upwardly and the lower abutment 31 toward the
upper abutment 27 to retain the packing elements 23, 24, 25 sealed
off against the wall of the well casing D, as well as against the
packing sleeve 26. Thus, in the event of extrusion of packing
material, after the well packer or plug A has been set in the well
casing, the gas under pressure functions as a spring to retain a
substantial packed-off force on the packing elements and thereby
insure against leakage of the well packer.
The parts are now in the position illustrated in FIGS. 2a to 2d.
Pressure from above the well packer can enter the chamber 44
between the lower abutment 31 and the annular piston 46 by passing
through the ports 36 in the upper abutment into the annular passage
35 and around the lower end of the sleeve 26 into the chamber.
Thus, this chamber 44 will always have fluid under pressure in it
corresponding to the fluid pressure above the packer externally of
the tubing string C. On the other hand, pressure in the well casing
below the set packer can pass into the chamber 55 between the
annular piston 46 and the connector head 54, such fluid under
pressure passing upwardly through the annular space 72 between the
connector sleeve 53 and body 10 into such chamber.
The parts are so proportioned and arranged that pressure from below
the tool tends to force the expander 56 downwardly to hold it
wedged within its companion slips 90. Pressure from above the tool
is also exerting a force to hold the expander in wedging relation
within the slips to retain them anchored in the wall of the well
casing. As disclosed in FIGS. 2a to 2d, a predominance of a
pressure differential above the well packer acts downwardly on the
packing structure 27, such force being transmitted through the
lower abutment 31 and cylinder structure 51 directly to the
expander 56, because of the abutting of the end 52a of the lower
cylinder sleeve with the expander shoulder 56a. Thus, the pressure
from above assists in holding the slips 90 anchored against the
well casing and in retaining the packing elements 23, 24, 25
compressed in sealing relation against the wall of the well casing
D.
Following anchoring in packed-off condition of the well packer in
the casing, if a pressure differential is present below the well
packer A, such pressure can pass through the passage 72 between the
connector sleeve and body into the chamber 55 above the connector
head 54. The pressure is acting upwardly on the annular piston 46
which engages the stop ring 48 connected to the body 10. However,
the body cannot move upwardly because of the locking relation
between the left-hand buttress threads 120 and the upper clutch
segments 118, such upward force being transmitted through the
housing 95 to the slips 90, which are wedged outwardly by the
expander 56. The pressure in the chamber 55 is also acting in a
downward direction over the cross-sectional area of the connector
head 54, and the predominant fluid pressure below the tool is also
being exerted against the lowermost packing element 25 which has an
internal pressure equal to the predominant fluid pressure, such
internal pressure being exerted in a downward direction over the
abutment 31 and its gage ring 32. The lower annular area R of the
lower abutment 31 is subject to the lesser fluid pressure that
might exist above the packing structure 22, since such fluid
pressure enters the chamber 44 above the annular piston 46 through
the ports 36 and the annular passage 72. Because of the air in the
atmospheric chamber 74 between the connector head 54 and the
cylinder head 50, and the various elements on which the lower
pressure is acting, it can be demonstrated that there is a
resultant area R over which the pressure from below the well tool
is acting in a downward direction on the expander 56, which area is
quite substantial. Thus, the fluid pressure from below the
apparatus is urging the reverse cone or expander 56 downwardly to
retain it in wedged relation behind the slips 90, holding their
teeth 130 anchored against the wall of the well casing.
It is, therefore, apparent that despite the presence of only a
single set of slips 90 and a single companion expander 56, the well
packer apparatus A will remain anchored in packed-off condition
whether the pressure is exerted on the apparatus from below its
packing structure 22 or above its packing structure. The left-hand
thread and upper segment clutch mechanism 120, 119, 118 will hold
and lock in the packer parts in the positions illustrated in FIGS.
2a to 2d, relative upward movement of the body 10, which is
necessary to retraction of the well packer parts from the well
casing, being prevented. As a result, even if no down weight is
imposed on the apparatus A through the tubular string C, or for
that matter, if there is no upward force on the apparatus, it will
remain anchored in packed-off condition.
When the well packer is to be released from the well casing, the
pressure above and below the said packer is equalized, as in the
manner described hereinbelow. The tubular string C and the body 10
are then rotated several turns to the right while the tubing string
and body move upwardly, the packer body 10 threading upwardly with
respect to the upper segmental nut or clutch elements 118. Despite
the fact that the left-hand threads 120 are disposed within the
right-hand threaded lower clutch elements 111, the latter cannot
mesh therewith and are merely held in the outward position
disclosed in FIG. 2d. The upward threading of the body 10 elevates
the lower portion 42 of the upper section 13 from the bearing
member 37, which will remove the downward setting force on the
upper abutment 27, the packing elements 23, 24, 25 retracting
inherently from the well casing and shifting the abutment 27
upwardly. Even if such shifting does not occur, the stop ring 48
secured to the body will engage the lower end of the packing
structure sleeve 26 to shift it and the upper abutment upwardly
relative to the lower abutment 31, this upward movement continuing
until the sleeve flange 33 engages the lower end of the lower
abutment 31, which will then effect an elevation of the upper
cylinder sleeve 45 and of the cylinder 51 therebelow with respect
to the connector sleeve 53, until the cylinder head 50 engages the
connector head 54. Continued upward movement of the body 10 will
move the connector sleeve and expander 56 upwardly, the expander
shifting in an upward direction with respect to the slips 90 whose
upward movement is resisted and prevented by the frictional
engagement of the drag blocks 98 against the well casing. Because
of the tongue and groove interconnection 91, 92 between the
expander and the slips, the latter, as a result of moving
relatively downwardly of the expander, are shifted radially
inwardly to their retracted position.
Upon complete upward unthreading of the left-hand body threads 120
from the upper clutch segments 118, the body 10 is free to be
shifted upwardly without rotation, the right-hand buttress threads
113 then ratcheting upwardly through the lower segmented nut 111
and relocking the packer in its extended condition, as disclosed in
FIGS. 1a to 1d. The packer apparatus A is now in its retracted
position and can be shifted either downwardly or upwardly in the
well casing to a new setting location, or the packer can be
elevated and removed completely from the well casing, if
desired.
When the apparatus is to be dismantled, the bleeder plug 77 is
opened to vent the gas from the chamber 59, thereby preventing
sudden expansion of the gas and possible injury to persons and
property.
As disclosed in the drawing, the apparatus A is constituted as a
retrievable bridge plug. It can be lowered in the well casing and
can be removed therefrom by means of a running-in and retrieving
tool B, which can also control the opened and closed position of
the sleeve valve 17 relative to the body ports 14, which will
determine whether or not the passage 11 through the body is in open
or closed condition. As shown, the retrieving tool includes a
housing 150 adapted to telescope over the control head 16 and upper
body section 13 of the well packer or bridge plug, as well as over
its sleeve valve 17. This housing consists of an upper body portion
151 threadedly secured to an upper body sub 152 which is threadedly
connected to the lower end of the tubing string C that extends to
the top of the well bore. The lower end of the upper housing
section 151 is threadedly secured to the upper end of a lower
housing section 153 which carries a latch sleeve 154 that has the
purpose of shifting the valve sleeve 17 between open and closed
positions. This latch sleeve includes an upper circumferentially
continuous portion 155 and circumferentially spaced slots 156 (FIG.
5) that provide flexible spring-like arms 157 depending therefrom,
the intermediate portions of the latch arms having inwardly
directed latch fingers 158. These latch fingers have lower tapered
surfaces 159 adapted to engage a companion upper tapered surface
160 on the valve sleeve 17 and to be deflected outwardly thereof so
that the fingers are then disposed below an upper external flange
161 of the valve sleeve. The upper surfaces 162 of the fingers are
also tapered for engagement with a companion tapered surface 163 at
the lower end of the sleeve flange 161.
The latch sleeve 154 is adapted to occupy an upper position
relative to the housing 150 in which it engages a housing shoulder
183, and in which the lower ends 184 of the latch arms are located
above a restricted retaining bore 185 in the lower portion of the
housing. At this time, the latch arms 157 can flex outwardly
relatively freely within the housing so that the latch fingers 158
will readily snap over the flange 161 of the valve sleeve 17.
However, when the latch sleeve 154 occupies a lower position
relative to the housing 150, as determined by engagement of a latch
sleeve flange 165 with an upwardly facing shoulder 166 in the
housing, the lower ends 184 of the latch arms are confined within
the restricted bore 185 of the lower housing portion 153, thereby
preventing the lower ends 184 of the latch arms from deflecting
outwardly and requiring a greater deflecting force to shift the
latch fingers 158 laterally outwardly (FIG. 3b).
The ability of the housing 150 to move longitudinally with respect
to the control head 16, upper mandrel or body section 13, and
sleeve valve 17 is governed by a control lock device between the
housing and the control head. Thus, the control head 16 has one or
more control slots 170 therein (see FIG. 4 specifically), each slot
including a lower vertical leg portion 171 that terminates in an
upper hook or pocket portion 172 closed by an end wall 172a. Below
and adjacent to the hook portion the slot portion 171 communicates
with an inclined entry and withdrawal slot portion 173 defined by
an inclined surface 174 extending through the upper portion of the
control head. An opposed surface 175 above the hook portion 172a on
the sleeve converges in a downward direction relative to the
inclined surface 174 of the slot.
The housing carries a radial lock pin 176 for each slot 170, the
inner portion of which is received within the control slot 170.
This lock pin is mounted in a ring or sleeve 177 and also extends
into a longitudinal slot 178 in the upper body portion 151, the pin
being retained in its inward position by a retainer sleeve 179
encompassing the upper body portion enclosing its slot. A helical
compression spring 180 is mounted in the housing, its upper end
engaging the body sub 152 and its lower end engaging the lock pin
sleeve 177 so as to yieldably urge the lock pin 176 in a downward
direction.
In lowering the packer or bridge plug apparatus A in the well
casing, the running-in and retrieving tool B is disposed in the
position illustrated in FIG. 1a, in which the valve sleeve 17 is in
its lower port opening position, the lock pin being disposed in the
longitudinal leg 171 of the slot below the hook portion 172, the
lower end 181 of the housing engaging a shoulder 182 on the upper
body section 13 so as to push the body or mandrel 10 of the tool in
a downward direction and, through the right-hand body and clutch
segment portions 113, 111 of the apparatus, pull the parts of the
apparatus surrounding the body 10 in a downward direction. The
fluid in the well casing can by-pass around the well packer
apparatus A and can also flow upwardly through the central passage
11, out through the ports 14 and up through the housing 150 into
the tubing string C.
When the setting location in the well casing D is reached, the
tubing string C is rotated to the right, such right-hand rotation
being transmitted through the housing 150 to the lock pin 176, and
from the latter to the control head 16, the pin engaging a side
wall of the longitudinal slot 171. The control head 16, being
secured to the body 10 of the tool, transmits its rotation to the
latter so that its right-hand threads 113 unscrew in a downward
direction from the lower clutch segments 111, whereupon an
appropriate downward force can be imposed by the tubular string C
on the housing 150 and on the body 10 to effect full setting of the
well packer, in the manner described above, the parts being located
in the positions illustrated in FIGS. 2a to 2d, inclusive.
The running-in and retrieving tool B can now be released from the
well packer or bridge plug A, the latter remaining in its anchored
and packed-off condition in the well casing D. The tubing string C
is elevated, and during such elevation is turned to the right so
that the lock pin 176 shifts from the longitudinal slot 171 into
the diagonal slot 173, allowing the lock pin to move upwardly out
of the control head slot 170. Immediately following such upward
movement, the fingers 158 of the latch sleeve 154 engage the flange
161 on the valve sleeve 171, whereupon the housing 150 will move
upwardly relative to the latch sleeve to dispose the lower ends 184
of the latch arms within the restricted bore 185 of the housing to
increase the resistance to outward deflection of the latch arms.
Upward movement of the tubing string and running-in and retrieving
tool will now cause the fingers 158 to shift the valve sleeve 17
upwardly to the extent limited by its engagement with the
downwardly facing shoulder 19 on the control head, at which time
the sleeve has closed the ports 14, as disclosed in FIGS. 3a and
3b. Continued upward movement of the tubing string C and an
increase of the upward force will then cause the fingers 158 to be
cammed outwardly from engagement with the valve sleeve flange 161
because of the coengagement of their tapered surfaces 162, 163,
freeing the latch sleeve 154 from the valve sleeve 17 and allowing
the tubing string C and the retrieving device B to be elevated in
the casing string D to a desired extent, or removed entirely
therefrom at the top of the hole. The passage 11 through the well
packer is now closed so that it functions as a bridge plug. As
stated above, the bridge plug A will remain in anchored and
packed-off condition, despite the imposition of fluid pressure upon
it from above or below.
In the event it is desired to release and retrieve the bridge plug
or well packer A from the well casing, the running-in and
retrieving head B is lowered in the casing D, the housing 150
moving over the control head 16, and the lock pin 176 being
directed by the converging tapered surfaces 174, 175 on the control
head into the diagonal slot 173, shifting from the diagonal slot
into the longitudinal slot 171. The fingers 158 will engage the
upper end 160 of the valve sleeve flange 161, and the housing will
shift downwardly so that the lower ends 184 of the latch arms 157
are disposed out of the restricted housing bore 185. Accordingly, a
much lesser force is required to deflect the arms and their fingers
outwardly, such fingers riding past the flange 161 to a position
therebelow retracting inwardly. The latch sleeve 154 and housing
150 continue moving downwardly until a shoulder 190 on the latch
sleeve engages the tapered surface 160 at the upper end of the
valve sleeve 17, to shift the latter downwardly to its port opening
position illustrated in FIG. 1a, the downward force being
transmitted from the housing 150 to the upper end of the latch
sleeve flange 165 and from the latch sleeve to the valve sleeve 17.
The downward shifting of the valve sleeve is limited by engagement
of the lower end 181 of the housing with the shoulder 182 on the
upper mandrel or body section 13. At this time, the lock pin 176 is
disposed in the longitudinal leg 171 of the control head slot.
The opening of the ports 14 allows the pressure above and below the
well packer or bridge plug A to equalize whereupon the tubing
string C and housing 150 are rotated to the right, the rotation
being transmitted through the lock pin 176 and control head 16 to
the body 10 of the tool, to thread the left-hand buttress threads
120 upwardly within the upper thread 119 of clutch segments 118
until the slips 90 and packing structure 22 have been returned to
their initial position, and the right-hand body threads 113 are
again relocked in the lower segments 111, as described hereinabove.
The bridge plug A can now be either shifted downwardly to a new
location in the well casing, or shifted upwardly in the well casing
to a new location, or, if desired, removed entirely from the
latter. Upward movement of the tubing string C will move the
retrieving tool housing 150 upwardly, the lock pin 176 moving into
the hook portion 172 of the slot 170 at the upper end of its
longitudinal portion. Such upward movement will move the latch
sleeve 154 upwardly with the outer housing 150, but the pin will be
disposed in the hook portion 172, 172a of the slot 170 before the
fingers 158 can engage the valve sleeve flange 161. Upward movement
of the tubing string C will now carry the packer body 10 and the
entire apparatus upwardly with it, the body ports 14 remaining in
their open condition to facilitate elevation of the apparatus A
through the fluid in the well casing D, the fluid, of course, also
relatively by-passing around the exterior of the retracted bridge
plug parts. As stated above, the apparatus can be removed from the
well casing and the compressed gas bled from the pressure chamber
59.
It is, accordingly, apparent that a retrievable tool, such as a
well packer or bridge plug, has been provided which is capable of
holding pressure in both directions without the assistance of the
tubular string or other force applying means. It is unnecessary for
any parts to shift relative to one another in the event that the
pressure differential acting on the well packer shifts from a
position above the well packer to a position therebelow, or vice
versa. The parts remain locked in their holding and sealed and
packed-off condition because of the ratchet locks afforded by the
left-hand threads 120 in the upper segments 118. That is to say,
the upper clutch mechanism mechanically holds the tool in its set
condition. Inasmuch as only a reverse cone or expander 56 is used,
the tool is easy to retrieve, since the upper movement of the
expander tends to retract the slips 90. This is to be distinguished
from other tools that employ both upward and downward slips and
companion expanders, in which the upwardly holding slips and
expanders might tend to resist release from the well casing, and
may inadvertently effect setting of the upwardly holding slips
during the elevation of the well tool in the well casing.
The compressed gas chamber 59 functions as a spring to retain the
setting or packing force on the tool, despite loss of packing
material due to extrusion, and the like. However, this feature,
although capable of effectively insuring the retention of the
packer apparatus in sealed-off and set condition, need not be used,
in which event the lower abutment 31 would be secured directly to
the expander 56, as through the use of a suitable intervening
sleeve.
* * * * *