U.S. patent application number 13/745095 was filed with the patent office on 2013-07-25 for downhole tool with external housing torque transfer.
This patent application is currently assigned to National Oilwell Varco, L.P.. The applicant listed for this patent is National Oilwell Varco, L.P.. Invention is credited to David Alan GARCIA, Harry P. Hiebeler.
Application Number | 20130186689 13/745095 |
Document ID | / |
Family ID | 47758066 |
Filed Date | 2013-07-25 |
United States Patent
Application |
20130186689 |
Kind Code |
A1 |
GARCIA; David Alan ; et
al. |
July 25, 2013 |
DOWNHOLE TOOL WITH EXTERNAL HOUSING TORQUE TRANSFER
Abstract
A downhole tool comprises a first connector sub coupled to an
outer housing. A mandrel is disposed in the outer housing and is
coupled to a mandrel. The second connector sub is slidably engaged
with the outer housing so that torque loads are transferred from
the first connector sub to the second connector sub through the
outer housing independently of the mandrel.
Inventors: |
GARCIA; David Alan;
(Houston, TX) ; Hiebeler; Harry P.; (Houston,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
National Oilwell Varco, L.P.; |
Houston |
TX |
US |
|
|
Assignee: |
National Oilwell Varco,
L.P.
Houston
TX
|
Family ID: |
47758066 |
Appl. No.: |
13/745095 |
Filed: |
January 18, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61588887 |
Jan 20, 2012 |
|
|
|
Current U.S.
Class: |
175/57 ; 175/293;
175/296; 175/320 |
Current CPC
Class: |
E21B 4/14 20130101; E21B
31/1135 20130101 |
Class at
Publication: |
175/57 ; 175/320;
175/293; 175/296 |
International
Class: |
E21B 31/113 20060101
E21B031/113; E21B 4/14 20060101 E21B004/14 |
Claims
1. A downhole tool comprising: a first connector sub; an outer
housing coupled to the first connector sub; a mandrel disposed in
the outer housing; and a second connector sub coupled to the
mandrel and slidably engaged with the outer housing, wherein torque
loads are transferred from the first connector sub to the second
connector sub through the outer housing independently of the
mandrel.
2. The downhole tool of claim 1, further comprising a jar mechanism
disposed in an annulus between the outer housing and the mandrel,
wherein the jar mechanism selectively restricts relative axial
movement between the outer housing and the mandrel.
3. The downhole tool of claim 2, wherein the jar mechanism further
comprises: a seal body sealingly engaged with the mandrel; a cone
operable to sealingly engage a portion of the outer housing; and a
metering groove disposed between the seal body and the cone.
4. The downhole tool of claim 3, wherein the cone sealingly engages
a detent disposed on an inner surface of the outer housing.
5. The downhole tool of claim 1, further comprising: a plurality of
splines disposed on an outer surface of the second connector sub;
and a plurality of grooves disposed on an inner surface of the
outer housing and engaged with the plurality of splines.
6. The downhole tool of claim 1, further comprising a plurality of
ports that provide fluid communication across a wall of the outer
housing into an annulus between the outer housing and the second
connector sub.
7. A jar assembly comprising: a first connector sub; an outer
housing coupled to the first connector sub; a mandrel disposed in
the housing; a jar mechanism disposed in an annulus between the
outer housing and the mandrel, wherein the jar mechanism
selectively restricts relative axial movement between the outer
housing and the mandrel; and a second connector sub coupled to the
mandrel and slidably engaged with the outer housing.
8. The jar assembly of claim 7, wherein the jar mechanism further
comprises: a seal body sealingly engaged with the mandrel; a cone
operable to sealingly engage a portion of the outer housing; and a
metering groove disposed between the seal body and the cone.
9. The jar assembly of claim 8, wherein the cone sealingly engages
a detent disposed on an inner surface of the outer housing.
10. The jar assembly of claim 7, further comprising: a plurality of
splines disposed on an outer surface of the second connector sub;
and a plurality of grooves disposed on an inner surface of the
outer housing and engaged with the plurality of splines.
11. The jar assembly of claim 7, further comprising a plurality of
ports that provide fluid communication across a wall of the outer
housing into an annulus between the outer housing and the second
connector sub.
12. The jar assembly of claim 7, wherein the outer housing further
comprises: a pressure body that is coupled to the first connector
sub; and a torque body that is coupled to the pressure body and
slidably engaged with the second connector sub.
13. The jar assembly of claim 7, further comprising a shoulder
disposed on the mandrel, wherein the shoulder is operable to
contact the outer housing when the first connector sub moves away
from the second connector sub.
14. The jar assembly of claim 7, further comprising a shoulder
disposed on the second connector sub, wherein the shoulder is
operable to contact the outer housing when the first connector sub
is moving toward the second connector sub.
15. A method of operating a downhole tool comprising: coupling an
outer housing to a first connector sub; coupling a mandrel to a
second connector sub; disposing the mandrel within the outer
housing; and slidably engaging the second connector sub with the
outer housing so that torque loads are transferred from the first
connector sub to the second connector sub through the outer housing
independently of the mandrel.
16. The method of claim 15, further comprising: disposing a jar
mechanism in an annulus between the outer housing and the mandrel;
and operating the jar mechanism so as to selectively restrict
relative axial movement between the outer housing and the
mandrel.
17. The method of claim 16, wherein the jar mechanism uses
hydraulic fluid to restrict relative axial movement between the
outer housing and the mandrel.
18. The method of claim 16, wherein operating the jar mechanism
further comprises: sealingly engaging the mandrel with a seal body
disposed within the annulus between the outer housing and the
mandrel; and sealingly engaging the outer housing with a cone
disposed adjacent to the seal body, wherein a metering groove
restricts fluid flow between the seal body and the cone.
19. The method of claim 15, wherein torque loads are transferred by
a plurality of splines disposed on an outer surface of the second
connector sub that are engaged with a plurality of grooves disposed
on an inner surface of the outer housing.
20. The method of claim 15, wherein at least a portion of the
second connector sub is disposed within the outer housing.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Patent Application
Ser. No. 61/588,887, titled Downhole Tool with External Housing
Torque Transfer, which was filed Jan. 20, 2012, which is hereby
incorporated by reference in their entirety into the present
application, to the extent that it is not inconsistent with the
present application.
BACKGROUND
[0002] This disclosure relates generally to a downhole tool for use
in a wellbore. More particularly, this disclosure relates to a
downhole tool that can handle increased axial and rotational
loads.
[0003] A jar is a downhole tool used to deliver an axial impact
load. Jars are often utilized to apply an axial impact load when
the drill string becomes stuck in the wellbore. When a drill string
becomes stuck in a wellbore, applying or releasing tension at the
surface stretches or compresses the drill string causing energy to
be stored in the drill string. A jar operates by providing a
mechanism that allows for the energy stored in the drill string to
be quickly released and applied to the drill string as an axial
impact load.
[0004] Conventional jars operate by selectively constraining the
relative axial movement between an outer housing and an inner
mandrel. For purposes of this description, the inner mandrel is
coupled to the stuck portion of the drill string and remains fixed
while the outer housing moves axially in response to tension in the
drill string and activation of the jar. It is understood that in
other embodiments, the operation of the components is reversed and
the outer housing is fixed while the inner mandrel moves
axially.
[0005] As previous mentioned, when a tool becomes stuck, tension is
applied to or released from the drill string to store energy in the
drill string. Once the desired load is applied, the jar is "fired,"
and the outer housing is allowed to translate axially relative to
the inner mandrel and apply an impact load that is transferred to
the stuck portions of the drill string. Both mechanical and
hydraulic jars are available. Hydraulic jars utilize hydraulic
fluid to constrain the movement of the outer housing relative to
the mandrel. Mechanical jars utilize mechanical components, such as
springs or latches, to constrain the movement of the outer housing
relative to the mandrel.
[0006] Jars may be may be bi-directional, meaning they are capable
of delivering an impact blow in both the uphole and downhole
directions. Alternatively, a jar may be uni-directional, meaning it
is designed for and is capable of delivering an impact blow in
either the uphole or downhole direction, but not both. Regardless,
the common feature of each is that stored energy, created by
stretching or compressing the drill string, is used to accelerate
the outer housing of the hydraulic jar to deliver an axial impact
blow to the mandrel. Moreover, the higher the load applied to the
outer housing, the faster the acceleration of the outer housing and
the greater the impact force delivered to the mandrel.
[0007] Jars may be used with a variety of wellbore operations,
including drilling, fishing, and milling operations. Each of these
operations requires a different set of performance criteria. In
order to meet a wide variety of performance criteria, jars are
available in a wide range of configurations. Jars can also be
designed to work with drill pipe and on coiled tubing.
[0008] Providing jars for use with coiled tubing presents a number
of working constraints to conventional tool design. First of all,
due to the limited size of the coiled tubing, limited compressive
loads can be placed on the tubing by the rig operator. Essentially,
this means that downhole tools which require compressive force to
operate, such as a jar, must be capable of operating with the
limited compressive load capability of coiled tubing. Further,
coiled tubing operations often limit the outside diameter of the
jar and require a relative large inside diameter to allow the
passage of fluids and certain tools through the jar.
[0009] In addition, in coiled tubing application the overall length
of the downhole tool becomes significant since there is limited
space at the surface to accommodate the bottom hole assembly (BHA).
A typical BHA used for drilling or milling might include a drill
bit, a mud motor that provides torque to the drill bit, a jar, a
steering tool, and other tools and components depending on the
operation being performed. Therefore, the overall length of the jar
itself becomes particularly significant.
[0010] The operating envelope for coiled tubing, both in well depth
and conditions, is also expanding and further increasing the
performance requirements of the entire BHA, including the jar.
Higher torques applied by the mud motor and higher axial loads due
to longer, larger coiled tubing strings increase the loads applied
to and by the jar.
[0011] Thus, there is a continuing need in the art for jars that
are able to meet increased performance requirements as compared to
the prior art.
BRIEF SUMMARY OF THE DISCLOSURE
[0012] In certain embodiments, a downhole tool comprises a first
connector sub coupled to an outer housing. A mandrel is disposed in
the outer housing and is coupled to a mandrel. The second connector
sub is slidably engaged with the outer housing so that torque loads
are transferred from the first connector sub to the second
connector sub through the outer housing independently of the
mandrel.
[0013] In certain embodiments, a jar assembly comprises a first
connector sub coupled to an outer housing. A mandrel is disposed in
the housing. A jar mechanism is disposed in an annulus between the
outer housing and the mandrel and selectively restricts relative
axial movement between the outer housing and the mandrel. A second
connector sub is coupled to the mandrel and is slidably engaged
with the outer housing.
[0014] In certain embodiments, a method of operating a downhole
tool comprises coupling an outer housing to a first connector sub
and coupling a mandrel to a second connector sub. The mandrel is
disposes within the outer housing. The outer housing is slidably
engaged with the second connector sub so that torque loads are
transferred from the first connector sub to the second connector
sub through the outer housing independently of the mandrel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a more detailed description of the embodiments of the
present disclosure, reference will now be made to the accompanying
drawings.
[0016] FIGS. 1A-C are sectional views of a jar assembly shown in a
closed position;
[0017] FIGS. 2A-B are partial sectional views of a portion of the
jar assembly of FIG. 1.
[0018] FIGS. 3A-C are sectional views of the jar assembly of FIG.
1, shown in the full open position.
[0019] FIG. 4 is a partial isometric view of a portion of the jar
assembly of FIG. 1.
DETAILED DESCRIPTION
[0020] It is to be understood that the following disclosure
describes several exemplary embodiments for implementing different
features, structures, or functions of the invention. Exemplary
embodiments of components, arrangements, and configurations are
described below to simplify the present disclosure; however, these
exemplary embodiments are provided merely as examples and are not
intended to limit the scope of the invention. Additionally, the
present disclosure may repeat reference numerals and/or letters in
the various exemplary embodiments and across the Figures provided
herein. This repetition is for the purpose of simplicity and
clarity and does not in itself dictate a relationship between the
various exemplary embodiments and/or configurations discussed in
the various Figures. Moreover, the formation of a first feature
over or on a second feature in the description that follows may
include embodiments in which the first and second features are
formed in direct contact, and may also include embodiments in which
additional features may be formed interposing the first and second
features, such that the first and second features may not be in
direct contact. Finally, the exemplary embodiments presented below
may be combined in any combination of ways, i.e., any element from
one exemplary embodiment may be used in any other exemplary
embodiment, without departing from the scope of the disclosure.
[0021] Additionally, certain terms are used throughout the
following description and claims to refer to particular components.
As one skilled in the art will appreciate, various entities may
refer to the same component by different names, and as such, the
naming convention for the elements described herein is not intended
to limit the scope of the invention, unless otherwise specifically
defined herein. Further, the naming convention used herein is not
intended to distinguish between components that differ in name but
not function. Additionally, in the following discussion and in the
claims, the terms "including" and "comprising" are used in an
open-ended fashion, and thus should be interpreted to mean
"including, but not limited to." All numerical values in this
disclosure may be exact or approximate values unless otherwise
specifically stated. Accordingly, various embodiments of the
disclosure may deviate from the numbers, values, and ranges
disclosed herein without departing from the intended scope.
Furthermore, as it is used in the claims or specification, the term
"or" is intended to encompass both exclusive and inclusive cases,
i.e., "A or B" is intended to be synonymous with "at least one of A
and B," unless otherwise expressly specified herein. For the
purposes of this application, the term "real-time" means without
significant delay.
[0022] The present disclosure uses the directional and position
terms such as "upper," "up," "lower," and "down" as references only
with respect to other parts in the assembly and their relative
positions in the figures presented herewith. It is understood that
the embodiments shown and described herein can be operated in the
orientations shown or can be reversed without altering the
performance of the components.
[0023] Referring initially to FIGS. 1A-C, jar assembly 100 includes
an upper connector sub 102 that is coupled to an outer housing 104.
The outer housing 104 is formed from a pressure body 132 that is
coupled to a torque body 134 by threads 133. A lower connector sub
106 is slidably engaged with the torque body 134 so that the lower
connector sub 106 can move axially relative to the torque body 134
but is rotationally coupled to torque body 134. A mandrel 108,
including an upper mandrel 110 and a lower mandrel 112, is fixably
coupled to the lower connector sub 106 and extends upward through
the outer housing 104 and into the upper connector sub 102. Upper
seal 114 and lower seal 116 define a pressure chamber 118 defined
by the outer housing 104 and the mandrel 108. In operation, the
pressure chamber 118 is filled with a substantially incompressible
fluid, such as a hydraulic fluid.
[0024] Up seal body 120, down seal body 122, and cones 124 are
disposed within the pressure chamber 118 in the annulus between the
mandrel 108 and the outer housing 104. Each seal body 120, 122
sealingly engages the outer surface of the mandrel 108 via seals
126 and includes a metering groove 128 on a surface 129 that abuts
the cones 124. Pressure body 132 includes a reduced diameter
portion, or detent 130 along its inner surface that is sized to
sealingly engage the outer diameter of cones 124. As will be
discussed in detail to follow, the up seal body 120, down seal body
122, cones 124, and detent 130 form the jar mechanism that
restricts the movement of hydraulic fluid through the pressure
chamber 118 so as to restrain axial movement of the mandrel 108
relative to the pressure body 132 and fire the jar.
[0025] By way of example, the operation of jar assembly 100 will be
described with the jar assembly being run in the closed position
shown in FIGS. 1A-C and being used to apply an upward jarring force
to a stuck BHA. The lower connector sub 106 is coupled to a BHA
(not shown) and the upper connector sub 102 is coupled to the drill
string (not shown) that extends to the surface. In order to
energize the jar assembly 100, a tension load is applied to the
upper connector sub 102 by pulling on the drill string from the
surface. Because the lower connector sub 106 is coupled to the
stuck BHA, applying a tension load to the upper connector sub 102
will cause the upper connector sub 102 and the outer housing 104 to
move upward relative to the lower connector sub 106 and mandrel
108.
[0026] As shown in FIG. 2A and 2B, the outer housing 104 moves
upward relative to the mandrel 108 until up seal body 120 contacts
shoulder 136 of upper mandrel 110 and cone 124 engages the detent
130. The inner diameter of up seal body 120 is sealingly engaged
with the mandrel 108 and the outer diameter of the cone 124 is
sealingly engaged with the detent 130, so that flow 200 of
hydraulic fluid is directed through metering groove 128. Because
the hydraulic fluid is primarily incompressible, the axial movement
of the mandrel 108 relative to the outer housing 104 is restricted.
As fluid moves through the metering groove 128, the outer housing
104 will continue to move upward relative to the mandrel 108.
[0027] Limiting the flow of fluid through the metering groove 128
allows the stored energy in the drill string to be increased. In
order to control the flow of fluid and allow the desired load to be
generated, metering groove 128 may be a linear groove, a spiral
groove, or some other configuration that allows a controlled amount
of fluid to flow between the face of the cone 124 and the seal body
120. Certain groove configurations are shown in U.S. Pat. Nos.
5,906,239 and 7,814,995, both of which are incorporated by
reference herein for all purposes.
[0028] As tension is applied to the drill string and the BHA
remains stuck, the cone 124 slowly moves along the detent 130 as
fluid is allowed to pass through the metering groove 128. As the
cone 124 reaches the end 202 of the detent 130, the seal between
the cone and the detent is broken. Fluid flow across the detent 130
is no longer restricted and the jar assembly 100 is fired. The
outer housing 104 can now move freely relative to the mandrel 108
and the stored tension load in the drill string accelerates the
outer housing 104 upwards until the upper end 302 of the torque
body 134 impacts the shoulder 304 of the mandrel 108, as is shown
in FIGS. 3A-3C. The impact between the torque body 134 and the
shoulder 304 transfers the axial impact load into the lower
connector sub 106 and the connected BHA.
[0029] As the outer housing 104 moves upward, torque body 134 also
moves upward relative to the lower connector sub 106. The torque
body 134 is slidably coupled to the lower connector sub 106 though
any connection that allows relative axial movement but transmits
torque loads. For example, the torque body 134 may be coupled to
the lower connector sub 106 though a plurality of longitudinal
splines 308 (see FIG. 4) on the lower connector sub 106 that engage
corresponding grooves 306 on the inner surface of the torque body
134. The outer housing 104 may also include one or more fluid ports
310 through the wall of the torque body 134. Fluid ports 310
provide fluid communication that allows wellbore fluids and debris
to move into or out of the annulus 312 formed between the torque
body 134 of the outer housing 104 and the lower connector sub
106.
[0030] In other embodiments, the lower connector sub 106 and the
torque body 134 may be coupled by splines having any desired shape,
number, or configuration. Other torque-transferring couplings may
also be used including, but not limited to, pin in slot couplings
and faceted tubulars. By extending the torque body 134 into
slidable engagement with the lower connector sub 106, any residual
torque stored in the stuck BHA is transferred from the lower
connector sub 106 to the upper connector sub 102 via the torque
body 134 and pressure body 132, thus bypassing the mandrel 108. In
this manner, the stresses on the mandrel 108 are reduced because
the mandrel 108 is effectively isolated from any torque loads
transmitted through the jar assembly 100.
[0031] Isolating the mandrel 108 from torque loads may be
especially critical when the jar assembly 100 is used with a BHA
that includes mud motor. Often, when a BHA including a mud motor
becomes stuck, the mud motor stalls at its maximum torque
condition. Therefore, when the BHA becomes unstuck, a high torque
load is immediately applied to the drill string. As the performance
of mud motors increases the potential for damage to other
components increases. By isolating the mandrel 108 of jar assembly
100 from that torque load, higher axial loads can safely be applied
to the mandrel 108.
[0032] Telescopically extending the torque body 134 over the
outside of the lower connector sub 106 also allows for the overall
length of the jar assembly 100 to be reduced. The overall length of
the jar assembly 100 may also be reduced by optimizing the travel
of the jar during firing. Once the cone 124 disengages the detent,
the outer housing 104 accelerates until it impacts the mandrel 108.
By controlling the length of the outer housing 104 and the size and
placement of the detent 130, the jar assembly can be optimized by
placing the impact point at a distance where the impact force would
be maximized. This distance is dependent on the drill string with
which the jar assembly 100 would be used.
[0033] The jar assembly 100 can also be used to apply a downward
jarring force to the lower connector sub 106. With the jar assembly
100 in an open position, as is shown in FIGS. 3A-3C, the upper
connector sub 102 and outer housing 104 are lowered relative to the
lower connector sub 106, which is fixed in place. The outer housing
104 moves downward relative to the mandrel 108 until down seal body
122 contacts the shoulder 304 of mandrel 108 and cone 124 engages
the detent 130. The inner diameter of down seal body 120 is
sealingly engaged with the mandrel 108 and the outer diameter of
the cone 124 is sealingly engaged with the detent 130, so flow of
hydraulic fluid is directed through metering groove 128 that
restricts the flow of hydraulic fluid so that a compressive load
can be applied by releasing tension from the drill string.
[0034] As the drill string is placed in compression and the BHA
remains stuck, the cone 124 slowly moves along the detent 130 as
fluid is allowed to pass through the metering groove 128. As the
cone 124 reaches the end of the detent 130, the seal between the
cone and the detent is broken and the axial movement of the outer
housing 104 is no longer restricted. The compressive load in the
drill string moves the outer housing 104 downwards until the lower
end 314 of the torque body 134 impacts the shoulder 316 of the
lower connector sub 106. The impact between the torque body 134 and
the shoulder 316 transfers the axial impact load into the lower
connector sub 106 and the connected BHA. As with an upward jar, any
torque is transferred from the lower connector sub 106 to the upper
connector sub 102 via the torque body 134 and pressure body 132,
thus bypassing the mandrel 108.
[0035] The lower connector sub 106 and torque body 134
configurations shown herein can also be applied to other hydraulic
and mechanical jar systems as well as other downhole tools.
Isolating torque loads from axial impact loads and transferring
these loads through two separate components reduces the stress
applied to any single component and allows a downhole tool to
handle higher axial loads and higher torque loads.
[0036] While the disclosure is susceptible to various modifications
and alternative forms, specific embodiments thereof are shown by
way of example in the drawings and description. It should be
understood, however, that the drawings and detailed description
thereto are not intended to limit the disclosure to the particular
form disclosed, but on the contrary, the intention is to cover all
modifications, equivalents and alternatives falling within the
spirit and scope of the present disclosure.
* * * * *