U.S. patent number 3,785,436 [Application Number 05/265,655] was granted by the patent office on 1974-01-15 for well packer.
Invention is credited to Philip E. Davis, Jr..
United States Patent |
3,785,436 |
Davis, Jr. |
January 15, 1974 |
WELL PACKER
Abstract
A well packer adapted to be used for cementing operations and
the like in a well, wherein the packer includes hold-down slips to
hold the packer sealing means and packer slips in the set position,
and such hold-down slips are actuated by fluid from the annulus so
as to be isolated from the bore of the packer mandrel to keep the
hold-down slips free of cement or other fluids in such bore which
might cause a malfunctioning of the hold-down slips.
Inventors: |
Davis, Jr.; Philip E. (Houston,
TX) |
Family
ID: |
23011355 |
Appl.
No.: |
05/265,655 |
Filed: |
June 23, 1972 |
Current U.S.
Class: |
166/120;
166/130 |
Current CPC
Class: |
E21B
23/06 (20130101); E21B 33/12 (20130101); E21B
23/006 (20130101); E21B 33/12955 (20130101) |
Current International
Class: |
E21B
33/12 (20060101); E21B 23/00 (20060101); E21B
23/06 (20060101); E21B 33/1295 (20060101); E21b
023/06 () |
Field of
Search: |
;166/120,129,130,134,138 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Brown; David H.
Attorney, Agent or Firm: Pravel, Wilson & Matthews
Claims
I claim:
1. A well packer for use in a well, comprising:
a mandrel having a central bore forming the central bore of the
packer and adapted to be connected to a tubing string for lowering
into a well pipe;
packer sealing means on said mandrel for sealing engagement with
the pipe to seal off the annulus between the tubing string and the
well pipe;
hold-down slips integrally connected with said mandrel for
longitudinal movement together and with the tubing string at all
times and for gripping engagement with the well pipe for preventing
a premature release of said packer sealing means;
said mandrel having no passages therethrough above said sealing
means;
fluid by-pass means with said mandrel for by-passing annulus fluid
around said sealing means; and
valve means mounted on said mandrel for closing said fluid by-pass
means above said sealing means after said packer sealing means is
in sealing engagement with the well pipe.
2. The packer set forth in claim 1, including:
packer slip means on said mandrel;
a releasable J-slot connection means connecting said packer slip
means to said mandrel and being releasable upon a rotation of said
mandrel relative to said slip means; and
friction means engageable with the well pipe for preventing
rotation of said slip means upon a rotation of said mandrel for
releasing said J-slot connection means.
3. The packer set forth in claim 1, wherein said valve means
includes an annular valve seal, and also including:
an annular valve sleeve mounted above said packer sealing means for
communicating with said fluid by-pass means and having an inner
bore of a diameter to receive said annular valve seal in sealing
engagement therewith.
4. The packer set forth in claim 1, including:
packer slip means slidably mounted on said mandrel for supporting
said mandrel in the well pipe; and
said hold-down slips having fluid passage means for communicating
with said fluid by-pass means when said valve means has closed off
said by-pass means above said sealing means for thereby directing
the fluid from below said sealing means through said by-pass means
to said hold-down slips for actuating same.
5. The packer set forth in claim 4, including:
means separating the bore of said mandrel and the tubing string
from said hold-down slips for thereby isolating said hold-down
slips from the fluid in said bore.
6. The packer set forth in claim 4, including:
support means for said valve means and said hold-down slips having
connection with said mandrel for movement therewith to and from the
position of said valve means wherein said by-pass means is closed
off above said sealing means.
7. The packer set forth in claim 4, wherein:
said hold-down slips includes a plurality of gripping slips for
engagement with the well pipe to prevent an inadvertent release of
said sealing means and said packer slip means from their set
positions in engagement with the well pipe; and
said fluid passage means includes a plurality of fluid passages
from said by-pass means to said gripping slips for providing
alternate flow routes for fluid to each of said gripping slips in
the event one or more of the fluid passages becomes plugged.
8. A well packer for use in a well, comprising:
a mandrel having a central bore forming the central bore of the
packer and adapted to be connected to a tubing string for lowering
into a well pipe;
packer sealing means on said mandrel for sealing engagement with
the pipe to seal off the annulus between the tubing and the well
pipe;
hold-down slips mounted with said mandrel for longitudinal movement
together and with the tubing string at all times and operable by
fluid pressure from externally of the tubing string for gripping
engagement with the well pipe;
means separating said hold-down slips from the bore of said mandrel
and the tubing string; and
fluid passage means communicating said hold-down slips with fluid
in the annulus between the tubing and the well pipe for actuating
same after the sealing means have been set in engagement with the
well pipe.
9. The packer set forth in claim 8, including:
packer slip means on said mandrel for gripping engagement with the
well pipe for supporting said mandrel in the well.
10. The packer set forth in claim 8, including:
fluid by-pass means with said mandrel for by-passing fluid in the
annulus around said sealing means; and
valve means mounted on said mandrel for closing said fluid by-pass
means above said sealing means after said packer sealing means is
in sealing engagement with the well pipe.
11. The packer set forth in claim 10, wherein:
said hold-down slips includes a plurality of gripping slips for
engagement with the well pipe to prevent an inadvertent release of
said sealing means and said packer slip means from their set
positions in engagement with the well pipe; and
said fluid passage means includes a plurality of fluid passages
from said by-pass means to said gripping slips for providing
alternate flow routes for fluid to each of said gripping slips in
the event one or more of the fluid passage becomes plugged.
12. The packer set forth in claim 10, wherein said valve means
includes an annular valve seal, and also including:
an annular valve sleeve mounted above said packer sealing means for
communicating with said fluid by-pass means and having an inner
bore of a diameter to receive said annular valve seal in sealing
engagement therewith.
Description
BACKGROUND OF THE INVENTION
The field of this invention is well packers, particularly well
packers of the squeeze-type.
So far as is known, well packers such as the one shown in U. S.
Pat. No. 3,428,123, having hold-down slips have been actuated by
fluid directed from the bore of the packer mandrel which sometimes
creates a problem in operating such hold-down slips especially when
such fluid is a cement or similar fluid that is thick and is
subject to hardening, or is a solid carrying fluid such as used for
sand fracing.
SUMMARY OF THE INVENTION
The present invention relates to a well packer which has a fluid
by-pass for by-passing fluid in the annulus around the packer
sealing means to prevent the packer from floating as it is run into
the hole. Hold-down slips are provided with the packer and are
actuated by fluid in the annulus from the area below the packer so
as to isolate the hold-down slips from the fluids in the tubing for
thereby preventing cement and the like from causing a
malfunctioning of the hold-down slips. The packer is relatively
short in length and is easily and automatically set, preferably by
right hand rotation. Well pressure and possible corkscrewing of the
tubing supporting the packer will not open the by-pass after the
hold-down slips are set. Also, with the packer of this invention,
tubing shortening or shrinkage due to temperature reductions will
not release the packer or the hold-down slips when pressure is
maintained in the tubing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1B and 1C are vertical sectional views, partly in
elevation, showing the upper, intermediate and lower portions,
respectfully, of the well packer of this invention in the normal
runing-in position;
FIG. 2 is a cross-sectional view taken on line 2--2 of FIG. 1A;
FIG. 3 is a cross-sectional view taken on line 3--3 of FIG. 1A;
FIGS. 4A and 4B are partial sectional views, partly in elevation,
illustrating the apparatus of FIGS. 1A-1c after the packer slips
have been set, but prior to the setting of the packer sealing
means; and
FIG. 5A and FIG. 5B are partial sectional views, partly in
elevation, illustrating only the upper portions of the well packer
of this invention as illustrated in FIGS. 1A-1C, but showing the
packer sealing means and the hold-down slips in their set positions
in the well pipe.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of the well packer of this invention is illustrated
in FIGS. 1A, 1B and 1C, showing the upper, intermediate and lower
portions of such packer, respectively. The packer is lowered into a
well pipe P on a tubing string T. Broadly, the packer of this
invention includes gripping slips G, packer sealing means S and a
hold-down means or slips H. As will be explained in detail, a
by-pass for fluid is provided so that the fluid in the annulus 10
between the well pipe P and the tubing string T may flow around the
sealing means S during the running in of the packer so as to
prevent a floating or buoyancy of the packer as it is run into the
well pipe P. Also, the flow through such by-pass means is
controlled by a valve means V, as will be explained in detail so as
to close off such by-pass and direct the fluid from below the
sealing means S through the by-pass to the hold-down slips H for
actuating same to thereby lock the packer in the set position with
the slips G and the sealing means S in their set positions in the
pipe P.
Considering the invention more in detail, the packer of this
invention includes a mandrel 12 which extends for substantially the
full length of the packer and which has its upper end connected at
threads 12a or other suitable connecting means to an adapter sub 14
which has the hold-down slips H therewith. The adapter sub 14 is
connected by threads 14a or other suitable means to the lower end
of the tubing string T which extends to the surface of the well in
the known manner.
A lower tubular packer body 15 (FIG. 1C) is disposed at the lower
end of the packer and is provided with a J-slot 16 having a J notch
16a, and an outlet slot 16b leading from the J-slot 16a. A
connecting pin 12b is secured to or is integral with the mandrel 12
and is adapted to extend into the J-slot 16 so as to connect the
body 15 and the mandrel 12 together when the pin 12b is in the J
portion 16a as illustrated in FIG. 1C. Upon a righthand rotation of
the mandrel 12 relative to the body 15, the pin 12b moves
automatically out of the J-slot 16a and upwardly until it enters
the slot 16b at which time the mandrel 12 may move downwardly
relative to the body 15 as the pin 12b moves in the slot 16b, for a
purpose to be hereinafter described.
The packer body 15 is provided with a wedge or expander 15a, which
is preferably annular and has a downwardly and inwardly inclined
expander surface or surfaces 15b therewith for engagement with pipe
gripping slips 18 having gripping teeth 18a on the external surface
thereof for gripping engagement with the interior of the pipe P for
supporting the packer in the pipe P as will be more evident
hereinafter. A plurality of such gripping slips 18, preferably
three in number are circumferentially spaced with respect to each
other and are disposed in windows 20a of a sleeve 20 and above the
shoulder 15c at the upper end of the body 15. Each of such slips 18
has inner downwardly inclined surfaces 18b which are adapted to
coact with the inclined surfaces 15b so as to urge the slips 18
radially outwardly into the gripping engagement with the pipe
P.
The sleeve 20 is secured to the body 15 by a plurality of retaining
screws 20b or other suitable securing means. The upper ends of the
gripping slips 18 are also confined with their upper ends by
retaining screws 20c or other suitable securing means. Leaf springs
20c are secured to the sleeve 20 by screws 20d or other suitable
securing means and each of such springs 20c is adapted to fit into
a longitudinal groove 18c for applying resilient force to the
gripping members 18 to maintain them in their inward retracted
postion with the surfaces 18b constantly in contact with the
surfaces 15b. Upon an outward radial movement of the gripping
members 18 by reason of the wedging action with the expander member
15a, the springs 20c yield to permit such radial movement.
Suitable friction means such as the flexible bow springs 22 (FIG.
1C) are secured to the body 15 by screws 22a or other suitable
securing means, and the lower ends 22b are free to slide as the
springs 22 resiliently engage the inner wall of the pipe P. The
lower ends 22b of the friction springs 22 are confined by a keeper
ring 20e which is connected to the sleeve 20 by a plurality of
screws 20f or other suitable securing means. It should be
understood that any other suitable friction means such as friction
blocks or shoes of conventional construction may be used in place
of the bow springs 22 so long as the friction means constantly
engages the inner wall of the pipe P. It will be understood that
normally there will be a plurality of such friction means 22 so as
to tend to also centralize the packer within the pipe P.
The upper end of the packer body 15 is connected at upper threads
15d (FIG. 1B) to a sleeve 23 which is connected by threads or other
suitable means to a metal ring 24. A plurality of openings 15e are
formed in the upper portion of the packer body 15, and it is to be
noted that the body 15 is formed with a larger internal diameter as
indicated at 15f as compared to the inner diameter of the body 15
therebelow to thereby serve as a portion of a by-pass channel or
passage, as will be more evident hereinafter. The sleeve 23 also is
spaced from the mandrel 12 so as to form an annular passage 25
which is a continuation of the passage above the by-pass openings
15e and it communicates with a passage 25a within the bore of a
telescoping tube 27 which is a part of the packer seal means S. A
plurality of packer rings 30 formed of rubber or other suitable
resilient material (FIGS. 1A and 1B) are mounted on the tube 27,
preferably with metal rings 31 therebetween.
A seal setting sleeve 35 is threaded or is otherwise connected to
the upper end of the tube 27 at threads 35a and such sleeve 35 is
disposed above the upper packer seal member 30 for engagement
therewith. The sleeve 35 has its inner bore spaced radially from
the external surface of the tube 12 so as to form a continuation of
the passage 25 as indicated at 35b, which is thus a continuation of
the by-pass passage 25 therebelow. The sleeve 35 has a lower
shoulder 35c which is adapted to be engaged by the upper ends of a
plurality of spacer rods 36 which are welded to the mandrel 12 and
are movable therewith to effect a release of the packer sealing
means S, as will be explained hereinafter. As seen in FIG. 3, the
rods 36 are welded or are otherwise affixed to the mandrel 12 and
are circumferentially spaced so that they do not interfere with the
annular passage means 25a between the mandrel 12 and the inner
surface of the sleeve 27.
The actuating sleeve 35 has an upper annular surface 35d which is
adapted to be engaged by an annular shoulder 14a on the sub 14 for
applying downward force to the sleeve 35 to set the packer as will
be explained. Also, the sleeve 35 is provided with a counterbore or
enlarged diameter 35e at its upper end which serves to provide a
sealing surface against which a valve seal ring 37 of the valve V
is adapted to engage for shutting off the by-pass of fluid upwardly
through the open upper end of the sleeve 35 during the running-in
of the packer in the pipe P. Thus, when the valve seal 37 which is
made of any suitable sealing material such as chevron packing, is
out of engagement with the internal cylindrical surface 35e, a
by-pass of fluid inwardly and around the sealing means S is
permitted so as to prevent a floating or buoyancy of the packer as
it is lowered into the well. The hold-down slips H include a
plurality of gripping slips 40 having gripping teeth 40a which are
adapted to engage and grip with the inside surface of the pipe P. A
plurality of such gripping members 40 are preferably provided in a
circumferential arrangement, usually three in number and each is
mounted in a pocket or recess 14b in the sub 14. Each gripping
member 40 acts like a piston and it preferably includes a ring 40b
therewith formed of rubber or similar material which is in sealing
engagement with the inside of the recess 14b so that fluid pressure
acting on the rear surface 40c of each gripping member 40 urges
same outwardly into gripping engagement with the pipe P. The fluid
pressure is supplied to the recesses 14b by a plurality of
longitudinally extending passages 14c (FIG. 1A) which are in
communication with lateral passages 14d (FIG. 2). Each of the
longitudinal passages 14c communicates with one of the lateral
passages 14d, and each lateral passage 14d is in communication with
at least two of the pockets 14b as seen in FIG. 2. Since all of the
pockets 14b are thus interconnected by the passages 14d, fluid may
be supplied to all of the gripping members 40 through only one of
the longitudinal passages 14c, should one or more of the other
longitudinal passages 14c become plugged with some foreign
matter.
The gripping members 40 are retained in position and are normally
held in the retracted position by retaining screws 45 which are
screwed into the adapter 14. Also, leaf springs 46 are connected to
the adapter 14 by screws 46a and these assure the gripping members
40 are retained in their retracted position until a sufficient
fluid pressure is applied from the passages 14c and 14d to urge the
gripping members 40 outwardly against the resistance of such
springs 46.
In the operation or use of the well packer of this invention, it is
lowered into the well pipe P on the tubing string T, with the
releasable connecting pin 12b in the J portion 16a of the J-slot 16
(FIGS. 1A-1C). The slips G, the packer sealing means S and the
hold-down slips H are all in the retracted position out of
engagement with the inner wall or surface of the well pipe P. The
friction springs 22 or other friction means are in contact with the
inner surface or wall of the well pipe P as the packer is lowered
into the pipe P to the desired location therein. It is to be noted
that during the lowering of the packer P, the well fluid externally
of the packer by-passes the packer sealing members 30 by flowing
upwardly through the by-pass ports 15e and the inner by-pass
passage which includes the passage spaces 25, 25a and 35b, as
previously explained. The valve V is in the open position so that
it does not restrict the by-pass of such fluid around the sealing
means S and therefore, there is no tendency for the well packer to
float or be buoyed up by the well fluid as a result of restriction
at the packer sealing means S. Such by-pass therefore facilitates
the rate of lowering of the packer even though the well pipe P is
full of fluid.
When the packer has reached the desired elevation in the pipe P,
the lowering of the packer is discontinued and the tubing string T
is rotated in a righthand direction to thereby also rotate the
mandrel 12 in a righthand direction which automatically moves the
connecting pin 12b upwardly along the guide of the J-slot portion
16a until it reaches the vertical open slot 16b, at which time the
weight of the tubing string T and the mandrel and the parts
therewith cause the mandrel 12 to move downwardly relative to the
rest of the packer so that the pin 12b moves downwardly and out of
the slot 16b as illustrated in FIG. 4B.
The sub 14 likewise moves downwardly with the mandrel 12 so as to
move the valve V into the closed position (FIG. 4A), bringing the
shoulder 14a into contact with annular surface or shoulder 35d to
thereby apply the weight of the tubing string to the sleeve 35 and
through the packer sealing means S to the expander 15a for causing
the expander 15a to move downwardly relative to the gripping
members 18 which are held against downward movement by the friction
springs 22. The coaction between the inclined surfaces 15b and 18b
causes an outward radial movement of the gripping members 18 to set
the slips by engaging the gripping teeth 18a with the inner surface
of the wall or pipe P (FIG. 4B).
It should be noted that although the valve V is closed at the time
of the setting of the slips G, and the by-pass inwardly of the
sealing means S is thus closed off, there is still fluid pressure
in the tubing externally of the hold-down slips H which tends to
equalize the pressure on each side thereof so that the hold-down
slips H do not set to any extent at that time. However, upon a
continued downward movement of the tubing string T after the slips
G are set, the sealing means S is then set in its sealing position
(FIG. 5B). The sealing means S is thus set in its sealing contact
with the inside surface of the pipe P because the downward movement
of the packer body 15, sleeve 23 and ring 24 are prevented after
the expander 15a had wedged gripping slips 18 into their set
position. The inner tube 27 telescopes and moves downwardly from
the position shown in FIG. 1B to the position shown in FIG. 5B with
its lower shoulder 27a displaced below the shoulder 24a of the ring
24.
After the packing rings 30 have been compressed into their sealing
or set position shown in FIG. 5B, the fluid pressure in the well
externally of the packer can no longer communicate with the
exterior of the hold-down slips H and therefore the only fluid
pressure acting on the gripping members 18 of the hold-down slips H
is from the by-pass fluid entering the ports 15e from below the
packer sealing means S. Such fluid pressure acts to urge the
gripping members 40 outwardly into gripping engagement with the
inside surface of the pipe P. It is to be noted that the gripping
teeth 40a are disposed so that they bite into the wall of the pipe
P at an angle to resist upward movement of the gripping members 40
so as to thereby prevent an inadvertent release of the packer
sealing means S and the packer slips G from their set position.
It is also to be noted that the hold-down means 40 is actuated by
the fluid pressure in the annulus of the well between the tubing
string T and the pipe P rather than by the fluid within the bore of
the tubing string T or the mandrel 12. Such manner of operation
reduces the danger of introducing cement or the heavier fluids into
the passages 14c and 14d which communicate with the rear of the
gripping members 40 for actuating same, thereby reducing the
possibility of the lines 14c and 14d becoming plugged by the cement
or other heavy fluids which are normally present in the bore of the
tubing string T, particularly during cementing operations.
By reason of construction of the valve V, even though the tubing
string tends to corkscrew or twist, the valve V will not
inadvertently become opened after it has been closed and the
hold-down slips H have been set. Well pressures may increase in the
tubing string T and below the sealing means S without unsetting or
releasing the valve V so that the packer is not prematurely
released. Similarly, even though there is shrinkage or shortening
of the tubing due to temperature reductions or other changes which
might cause other packers to release, the packer of this invention
will not release under such circumstances.
To release the packer from its set position to remove same from the
well, the hold-down means H is first released by bleeding off the
tubing pressure so as to be zero or equalized internally and
externally of the gripping members 40. In some cases, pressure is
applied in the annulus above the hold-down gripping members 40 to
equalize the pressure acting thereon. After the pressure has thus
been equalized on the gripping members 40, the tubing string T is
raised upwardly to initially cause the upper ends of the rods 36 to
engage the shoulder 35c so as to exert the lifting force on the
sleeve 35 as the tubing string T is moved upwardly to thereby
relieve the pressure on the sealing rings 30 from the sleeves 35 as
the tubing string T is pulled upwardly. The release of the contact
between the shoulders 14a and 35d also relieves the weight from the
sealing means S to allow the resiliency of the sealing members 30
to act to urge them upwardly and release same from their set
position.
Continued upward movement of the tubing string T and the mandrel 12
also causes an upward travel of the telescoping sleeve 27 and an
engagement of the shoulder 27a with the shoulder 24a to thereafter
lift the tube 23 and the packer body 15 therebelow upwardly to pull
the expander or wedge section 15a upwardly relative to the gripping
slips 18 to thereby release the expanding force on the gripping
slips 18. The resiliency of the leaf springs 20c thus returns the
gripping members 18 to their retracted position so that they may
then be withdrawn upwardly in the well.
It is to be noted that the pin 12b is guided into the vertical
slots 16b by a curved surface 15g on the lower portion of the
packer body 15 so that the pin 12b returns to the J-slot 16 and may
be reset with the pin 12b in the J portion 16a after the packer
slips G have been released, if desired. The resetting is
accomplished by a slight amount of lefthand rotational movement of
the tubing string T after the slips G have been released to their
set position and then the packer can be moved upwardly or
downwardly in the well as desired to any suitable elevation.
Although this invention has been described for setting by a right
rotation, it will be understood that the J-slot 16 can be reversed
for setting by left hand rotation if desired. It should also be
understood the packer may be of the pin type or isolation type,
wherein slips such slips G are not employed. In such cases, the
packer sealing means S is held down solely by the slips H.
The foregoing disclosure and description of the invention are
illustrative and explanatory thereof, and various changes in the
size, shape, and materials as well as in the details of the
illustrated construction may be made without departing from the
spirit of the invention.
* * * * *