U.S. patent application number 15/983936 was filed with the patent office on 2018-11-22 for unloader valve assembly.
The applicant listed for this patent is Michael Jenkins. Invention is credited to Michael Jenkins.
Application Number | 20180334884 15/983936 |
Document ID | / |
Family ID | 64269950 |
Filed Date | 2018-11-22 |
United States Patent
Application |
20180334884 |
Kind Code |
A1 |
Jenkins; Michael |
November 22, 2018 |
UNLOADER VALVE ASSEMBLY
Abstract
An unloader valve assembly includes a cylindrical housing
defining an annular space, an inner wall thereof including a port
that enables fluid communication between the annular space and a
location outside the inner wall of the housing. A mandrel having a
tubular configuration is positioned inside the housing, the mandrel
defining a central bore for receiving fluid and includes a mandrel
port enabling fluid communication between the central bore and the
annular space. A piston encircling the mandrel is movable along an
axis defined by the central bore. A spring is situated between the
inner wall of the housing and the mandrel and movable between an
extended configuration urging the piston downwardly and a
compressed configuration being urged upwardly by the piston.
Inventors: |
Jenkins; Michael; (Raceland,
LA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Jenkins; Michael |
Raceland |
LA |
US |
|
|
Family ID: |
64269950 |
Appl. No.: |
15/983936 |
Filed: |
May 18, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62508022 |
May 18, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 34/10 20130101;
E21B 33/14 20130101; E21B 34/14 20130101; E21B 2200/05 20200501;
E21B 33/129 20130101; E21B 2200/06 20200501 |
International
Class: |
E21B 34/14 20060101
E21B034/14; E21B 33/129 20060101 E21B033/129; E21B 33/14 20060101
E21B033/14; E21B 34/10 20060101 E21B034/10 |
Claims
1. An unloader valve assembly for engaging, via a seal mandrel
assembly, a cement retainer assembly that is deployed inside a
casing of a well bore and that is attached to the casing with slips
and having a sliding sleeve initially in a closed configuration not
allowing fluid to flow into proximity of the cement retainer
assembly from a check valve assembly having a flapper at an open
configuration, the sliding sleeve being slidably movable to an open
configuration upon downward urging of the seal mandrel assembly
into engagement with the cement retainer allowing fluid to flow
from the check valve assembly into the casing, said unloader valve
assembly, comprising: a housing that includes an inner wall having
a cylindrical configuration defining an annular space; wherein said
inner wall of said housing includes a port that enables fluid flow
between said annular space and a location outside said inner wall
of said housing; an upper adapter coupled to an upper end of said
housing and operable to engage the check valve assembly; a lower
adapter coupled to a lower end of said housing and operable to
engage the seal mandrel assembly; a mandrel positioned inside said
interior space of said housing and inwardly displaced from said
inner wall of said housing, said mandrel having a tubular
configuration defining a central bore for receiving a flow of
fluid; wherein said mandrel includes a mandrel port operable for
fluid communication between said central bore and said annular
space; a piston encircling said mandrel that is movable along an
axis defined by said central bore when urged to move; a spring
having an upper end operably coupled to said upper adapter and a
lower end operably coupled to said piston, said spring being
situated between said inner wall of said housing and said mandrel
and movable between an extended configuration urging said piston
downwardly and a compressed configuration being urged upwardly by
said piston.
2. The unloader valve assembly as in claim 1, wherein said spring
is naturally biased toward said extended configuration so as to
urge said piston downwardly to bear against said lower adapter.
3. The unloader valve assembly as in claim 1, wherein a volume of
said annular space is increased when said piston is urged upwardly
in said annular space and said spring is moved toward said
compressed configuration.
4. The unloader valve assembly as in claim 3, wherein said annular
space has a volume sufficient to contain an entire volume of fluid
displaced by penetration of the seal mandrel assembly into the
cement retainer assembly.
5. The unloader valve assembly as in claim 2, wherein a pressure
increase in said central bore is communicated through said mandrel
port and bears against a bottom of said piston so as to urge said
piston upwardly to compress said spring toward said compressed
configuration.
6. The unloader valve assembly as in claim 5, wherein fluid in said
central bore is allowed to flow from said central bore through said
port in said inner wall of said housing to said location outside
said housing as said piston is urged upwardly.
7. The unloader valve assembly as in claim 6, wherein said piston
moves upwardly in unison with fluid being displaced by penetration
of the seal mandrel assembly into the cement retainer assembly.
8. The unloader valve assembly as in claim 1, wherein: said upper
adapter is coupled to said housing in a threaded engagement; said
lower adapter is coupled to said housing in a threaded
engagement.
9. An unloader valve assembly, comprising: a housing that includes
an inner wall having a cylindrical configuration defining an
annular space; wherein said inner wall of said housing includes a
port that enables fluid flow between said annular space and a
location outside said inner wall of said housing; an upper adapter
coupled to an upper end of said housing and operable to engage a
check valve assembly; a lower adapter coupled to a lower end of
said housing operable to engage a seal mandrel assembly; a mandrel
positioned inside said interior space of said housing and inwardly
displaced from said inner wall of said housing, said mandrel having
a tubular configuration defining a central bore for receiving a
flow of fluid; wherein said mandrel includes a mandrel port
operable for fluid communication between said central bore and said
annular space; a piston encircling said mandrel that is movable
along an axis defined by said central bore; and a spring having an
upper end operably coupled to said upper adapter and a lower end
operably coupled to said piston, said spring being situated between
said inner wall of said housing and said mandrel and movable
between an extended configuration urging said piston downwardly and
a compressed configuration being urged upwardly by said piston.
10. The unloader valve assembly as in claim 9, wherein said spring
is naturally biased toward said extended configuration so as to
urge said piston downwardly such that said piston bears against
said lower adapter.
11. The unloader valve assembly as in claim 9, wherein a volume of
said annular space is increased when said piston is urged upwardly
in said annular space and said spring is moved toward said
compressed configuration.
12. The unloader valve assembly as in claim 9, wherein a pressure
increase in said central bore is communicated through said mandrel
port and bears against a bottom of said piston so as to urge said
piston upwardly so as to move said spring toward said compressed
configuration.
13. The unloader valve assembly as in claim 5, wherein fluid in
said central bore is allowed to flow from said central bore through
said port in said inner wall of said housing to said location
outside said housing as said piston is urged upwardly.
14. The unloader valve assembly as in claim 9, wherein: said upper
adapter is coupled to said housing in a threaded engagement; said
lower adapter is coupled to said housing in a threaded
engagement.
15. An unloader valve assembly for placement in a casing of a well
bore, comprising: a seal mandrel assembly situated in the casing; a
check valve assembly having a flapper member positioned in the
casing for insertion of a fluid into the casing; a cement retainer
assembly positioned inside the casing lowerly adjacent said seal
mandrel assembly and coupled to a wall thereof with slips and
having a sliding sleeve initially in a closed configuration not
allowing fluid to flow into proximity of the cement retainer from
said check valve when said flapper is at an open configuration,
said sliding sleeve being slidably movable to an open configuration
upon downward urging of said seal mandrel assembly into engagement
with said cement retainer assembly allowing fluid to flow from the
check valve assembly into the casing; a housing situated within the
casing between said check valve assembly and said seal mandrel
assembly and that includes an inner wall having a cylindrical
configuration defining an annular space; wherein said inner wall of
said housing includes a port that enables fluid flow between said
annular space and a location outside said inner wall of said
housing; an upper adapter coupled to an upper end of said housing
and operable to engage said check valve assembly; a lower adapter
coupled to a lower end of said housing and operable to engage said
seal mandrel assembly; a mandrel positioned inside said interior
space of said housing and inwardly displaced from said inner wall
of said housing, said mandrel having a tubular configuration
defining a central bore for receiving a flow of fluid; wherein said
mandrel includes a mandrel port operable for fluid communication
between said central bore and said annular space; a piston
encircling said mandrel that is movable along an axis defined by
said central bore when urged to move; a spring having an upper end
operably coupled to said upper adapter and a lower end operably
coupled to said piston, said spring being situated between said
inner wall of said housing and said mandrel and movable between an
extended configuration urging said piston downwardly and a
compressed configuration being urged upwardly by said piston.
16. The unloader valve assembly as in claim 15, wherein a volume of
said annular space is increased when said piston is urged upwardly
in said annular space and said spring is moved toward said
compressed configuration.
17. The unloader valve assembly as in claim 16, wherein said
annular space has a volume sufficient to contain an entire volume
of fluid displaced by penetration of said seal mandrel assembly
into an upper bore of said cement retainer assembly so as to
displace fluid therefrom.
18. The unloader valve assembly as in claim 17, wherein said fluid
displacement causes a pressure increase in said central bore that
is communicated through said mandrel port and bears against a
bottom of said piston so as to urge said piston upwardly to
compress said spring toward said compressed configuration.
19. The unloader valve assembly as in claim 18, wherein said piston
moves upwardly in unison with fluid being displaced by penetration
of the seal mandrel assembly into the cement retainer assembly.
20. The unloader valve assembly as in claim 15, wherein fluid in
said central bore is allowed to flow from said central bore through
said port in said inner wall of said housing to said location
outside said housing as said piston is urged upwardly.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority and benefit of
provisional patent application U.S. Ser. No. 62/508,022 filed May
18, 2017 titled Unloader Valve which is incorporated in its
entirety herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to downhole oil and gas equipment and
in particular to that of a valve that enables seal mandrels to
enter closed bores which are normally impractical due to the
incompressibility of fluid. The aforementioned condition is
commonly referred to as being "fluid locked".
[0003] It is common practice to install plugs, packers, barriers,
and retainers at various depths within a well bore. These devices
are used for a myriad of remedial services for oil and gas wells.
Frequently, devices are set in the casing of a wellbore and act as
plugs where such devices contain a sliding sleeve that will require
shifting to selectively open and shut off a communicative flow path
from above to below the plug. As an example, a loosely defined
rudimentary system for the purpose of squeezing cement below a plug
is illustrated herein in conjunction with the invention to
demonstrate its' functionality.
[0004] A particular type of plug or barrier is commonly referred to
as a "cement retainer." The cement retainer is deployed with its'
sliding sleeve in the closed position and within the casing to a
desired depth then locked to the casing via grippers called
"slips." At the same time as the slips are set, an elastomer is
expanded against the inside wall of the casing thus shutting off
communication from above or below the cement retainer. A subsequent
deployment into the casing is required with a mandrel connected by
pipe to the surface. Such mandrel is designed to seal within the
upper bore of the cement retainer and shift the sleeve to the open
position upon contact with the sleeve. With the sleeve in the open
position, the seals of the mandrel shut off communication around
the outside of the mandrel while the expanded elastomer of the
cement retainer shuts off communication around the outside of the
cement retainer. Cement pumped through the pipe from the surface,
exits through the open sleeve and fills the area of the casing
located below the cement retainer. The remedial operation of
squeezing cement below the retainer normally takes place within a
well that has no pressure, therefore, the top of the pipe at
surface can be open to the atmosphere when the mandrel is stabbed
into the upper bore of the cement retainer preventing a condition
referred to as "fluid lock". In some circumstances, remedial cement
squeezing is advantageous within a well bore that is pressurized.
The pipe must be closed at the top to contain the pressure. In
addition, check valves that prevent back flow into the pipe are
commonly installed near or directly above the mandrel A small
volume of fluid is trapped between the check valves and the bore of
the cement retainer when the seals of the mandrel contact the upper
bore of the cement retainer creating a fluid lock condition. Due to
the limited compressibility of fluids, pressure increases while
additional penetration is attempted to reach and shift the sleeve
within the cement retainer. Unless the pressure can be relieved,
the mandrel may be prevented from reaching the sleeve to accomplish
shifting of the sleeve to the open position.
[0005] Therefore, it would be desirable to have a a valve that
enables seal mandrels to enter closed bores of plug elements, such
as a cement retainers, and displace trapped fluids so as to
overcome the fluid lock problem often encountered in a well boring
process.
SUMMARY OF THE INVENTION
[0006] The invention disclosed herein advantageously eliminates the
fluid lock condition by providing a space for displacement of
trapped fluid thus allowing the mandrel to reach and successfully
shift a sleeve within a cement retainer. The cement retainer system
used as an example herein is not intended to limit the invention to
use with such system. Many circumstances exist that can create a
fluid lock condition whereby this invention can be employed to
alleviate such a condition. The aforementioned features and
functions will be fully defined in the detailed description of the
disclosure.
[0007] Therefore, a general object of this invention is to provide
a valve assembly for use in drilling a well bore that eliminates
the fluid lock condition by providing a space for displacement of
trapped fluid thus allowing the mandrel to reach and successfully
shift a sleeve within a cement retainer.
[0008] Other objects and advantages of the present invention will
become apparent from the following description taken in connection
with the accompanying drawings, wherein is set forth by way of
illustration and example, embodiments of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a side cross-section view of an unloader valve
according to a preferred embodiment of the present invention.
[0010] FIG. 2 is a side cross-section view of the unloader valve
installed in a typical arrangement with associated devices to
perform cementing through a typical cement retainer and prior to
mandrel seal contact with the upper bore of the cement
retainer.
[0011] FIG. 3 is side cross-section view of the unloader valve and
associated devices with the sleeve within the cement retainer fully
shifted sleeve by contact with the mandrel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] An unloader valve assembly according to a preferred
embodiment of the present invention will now be described with
reference to FIGS. 1 to 3 of the accompanying drawings.
[0013] Referring to FIG. 1, the unloader valve assembly 10 is
comprised of upper adapter 101, housing 116 having a cylindrical
configuration (which may also be referred to merely as "cylinder"),
lower adapter 123 (which may also be referred to as a bottom
adapter), mandrel 104, piston 110, spring guide 108, and spring
103, the connections and combinations of which will be described
below in more detail.
[0014] Still referring to FIG. 1, upper adapter 101 includes upper
thread 100 for securing associated tools and/or pipe. Upper adapter
is coupled to an upper end of housing 116 and is operable to
receive and engage a check valve assembly as described later. Lower
thread 102 of upper adapter 101 secures upper adapter 101 to
housing 116 and seal 115 encircles mandrel 104. Housing 116 is
secured by thread 113 (i.e. a threaded arrangement) to lower
adapter 123 encircling piston 110, spring guide 108, mandrel 104,
and spring 103. As described in more detail later, lower adapter
123 may be configured and capable of operably engaging a seal
mandrel assembly as will be described more fully below with
reference to FIG. 5.
[0015] Spring 103 may be a compression spring as will be described
later. Spring 103 includes an upper end or portion operably coupled
(meaning there may be intermediate structures) to upper adapter 101
and includes a lower end or portion operably coupled to piston 110,
spring 103 being positioned between the inner wall of housing 116
and mandrel 104. The spring 103 may be a compression spring and is
movable between and extended configuration and operable to urge or
force piston 110 downwardly (i.e. away) and a compressed
configuration when urged upwardly by movement of piston1 110.
Spring 103 is normally biased toward the extended configuration,
i.e. away from being compressed. The side wall (which will also be
referred to as inner wall) of the housing 116 defines port 105,
port 105 being operable for communication of fluid between the
annular space 121 and a location outside of the annular space 121.
Lower adapter 123 includes thread 124 (i.e. a threaded arrangement)
for securing associated tools. Seal 122 seals against the bore of
housing 116. Spring 103 is normally biased toward an extended
configuration that covers port 105 but is movable to a compressed
configuration in housing 116 that leaves port 105 open. Port 105 is
in fluid communication with the annular space 121 described later
in more detail.
[0016] Piston 110 encircles a lower portion of mandrel 104. Piston
110 includes an inner seal 119 that encircles piston 110 and seals
against the outer diameter of mandrel 104 and outer seal 109 of
piston 110 seals against the bore of housing 116. The lower most
section of piston 110 includes ports 111 that define a path of
communication between central bore 114 and annular space 121. The
lower adapter 123 includes upper end 112 and lowerly adjacent ports
111.
[0017] An upper end of piston 110 has an upward facing shoulder
118. Spring guide 108 abuts upward facing shoulder 118 of piston
110 and the bottom of spring 103, i.e. is intermediate the two
structures. Mandrel 104 is confined within the lower bore of upper
adapter 101 extending to the upper bore of lower adapter 123.
Mandrel 104 may also have a tubular configuration defining the
central bore 114 operable to transfer a flow of fluids.
[0018] It is understood that central bore 114 defines an imaginary
linear axis about which many components encircle, such as piston
110 encircles mandrel 104 and is movable (e.g. slidable) therealong
and along the imaginary linear axis. The mandrel 104 includes
mandrel port 120 which provides a path of communication between
central bore 114 and annular space 121. The unloader valve 10
includes spring 103 that encircles mandrel 104 and is confined
between the lowermost shoulder of upper adapter 101 and upward
facing shoulder of spring guide 108, spring 103 selectively urging
piston 110 downward to abut the upper most shoulder of lower
adapter 123 as will be described further below.
[0019] Referring to FIG. 2, unloader valve assembly 10 is attached
by its upper adapter thread 100 to a representative flapper style
check valve 300 and by its lower adapter thread 124 to a
representative seal mandrel assembly 500. Seal mandrel assembly 500
is shown suspended and positioned partially within the upper bore
605 of a representative and rudimentary cement retainer assembly
600. Check valve assembly 300 is secured by thread 201 to pipe 200
extending to the surface. Cement retainer assembly 600 is shown
anchored to the wall 402 of casing 400 by its slips 601 and 607 and
seal element 606 seals against the bore 402 of casing 400 shutting
off communication around cement retainer assembly 600. Sliding
sleeve 603 within cement retainer assembly 600 is shown in the
closed position with seals 604 and 608 straddling port 609 in the
lower sidewall of cement retainer assembly 600 shutting off
communication between the upper bore 401 of casing 400 and lower
bore 403. Collet fingers atop the sliding sleeve 603 maintain the
closed position of sliding sleeve 603. The flapper 301 of check
valve assembly 300 is shown in the open position as fluid is pumped
in a path of circulation through central bore 114 and around the
end of seal mandrel assembly 500 and upward into the bore 401 of
casing 400.
[0020] Referring to FIG. 3, flapper 301 of check valve assembly 300
is shown urged by a torsion spring (not shown) to a closed position
as a result of fluid circulation ceasing prior to seals 501 of seal
mandrel assembly 500 entering upper bore 605 of cement retainer
assembly 600. Upon initial contact between seals 501 of seal
mandrel assembly 500 and upper bore 605 of cement retainer assembly
600, fluid is trapped between flapper 301 of check valve assembly
300 and the closed sliding sleeve 603 of cement retainer assembly
600 (FIG. 2). Continued lowering of pipe 200 urges seal mandrel
assembly 500 further into the upper bore 605 of cement retainer
assembly 600 which displaces the fluid within bore 605 which causes
a pressure increase within central bore 114. The pressure increase
acts against the bottom of piston 110 through port 120 of mandrel
104 so as to urge piston 110 upward compressing spring 103. Piston
110 moves upward in unison with the displaced fluid as seal mandrel
assembly 500 continues to penetrate the bore 605 of cement retainer
assembly 600. Fluid above piston 110 is permitted to exhaust
through port 105 in the sidewall of housing 116 as piston 110 moves
upward. The annular space 121 created by the upward movement of
piston 110 is sufficient in volume to contain the entire volume of
fluid displaced by the penetration of seal mandrel assembly 500
into the upper bore 605 of cement retainer assembly 600.
[0021] Referring to FIG. 1, upward movement of piston 110 is abated
by contact of upward facing shoulder 107 of spring guide 108 when
contacting downward facing shoulder 117 of mandrel 104 thus
preventing possible communication between central bore 114 and port
105 of housing 116 however. Whenever piston 110 is displaced upward
prior to contact between downward facing shoulder 117 and upward
facing shoulder 107, annular space 121 is greater in volume than
the displaced volume of fluid created by the penetration of seal
mandrel assembly 500 into the bore 605 of cement retainer assembly
600.
[0022] Referring to FIG. 3, the upward moving piston 110 of
unloader valve assembly 10 advantageously allows the seal mandrel
assembly 500 to fully penetrate bore 605 of cement retainer
assembly 600 and contact sliding sleeve 603 of cement retainer
assembly 600 shifting the sliding sleeve 603, thus opening a path
of communication through ports 609 of cement retainer assembly
600.
[0023] It is understood that while certain forms of this invention
have been illustrated and described, it is not limited thereto
except insofar as such limitations are included in the following
claims and allowable functional equivalents thereof.
* * * * *