U.S. patent application number 09/770111 was filed with the patent office on 2001-08-09 for well completion system with an annular bypass and a solid stopper means.
Invention is credited to Wilkins, Robert Lee.
Application Number | 20010011593 09/770111 |
Document ID | / |
Family ID | 27375759 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010011593 |
Kind Code |
A1 |
Wilkins, Robert Lee |
August 9, 2001 |
Well completion system with an annular bypass and a solid stopper
means
Abstract
A well completion system having a spool tree body defining a
vertical bore extending therethrough. The vertical bore defines an
annular recess adjacent to the lateral production fluid outlet port
in the spool tree body. A tubing hanger is connected to the spool
tree body. The tubing hanger defines a vertical production bore
extending therethrough and has at least a lateral production fluid
flow port. The tubing hanger is positioned within the vertical bore
such that the lateral production fluid flow port in the tubing
hanger is in flow communication with the lateral production fluid
outlet port in the spool tree body. There is a removable plug that
seals the vertical production bore extending through the tubing
hanger above the lateral production fluid outlet port in the spool
tree body. A stopper means seals the vertical bore extending
through the spool tree body above the removable plug. A workover
port extends laterally through the spool tree body and penetrates
into the vertical bore above the stopper means. A tubing annulus
fluid flow port extends laterally through the spool tree body from
beneath the second sealing means from a tubing annulus. The
workover port and the tubing annulus fluid flow port are
interconnected via an external loop line containing at least one
valve.
Inventors: |
Wilkins, Robert Lee;
(Houston, TX) |
Correspondence
Address: |
Wendy K. B. Buskop
Buskop Law Group PC
Suite 500
1717 St. James Place
Houston
TX
77056
US
|
Family ID: |
27375759 |
Appl. No.: |
09/770111 |
Filed: |
January 24, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09770111 |
Jan 24, 2001 |
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09087791 |
May 29, 1998 |
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09770111 |
Jan 24, 2001 |
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08892185 |
Jul 14, 1997 |
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09770111 |
Jan 24, 2001 |
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08746212 |
Nov 6, 1996 |
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Current U.S.
Class: |
166/368 ;
166/348; 166/75.13; 166/86.1; 166/89.1; 166/95.1 |
Current CPC
Class: |
E21B 33/035 20130101;
E21B 34/04 20130101 |
Class at
Publication: |
166/368 ;
166/348; 166/86.1; 166/89.1; 166/95.1; 166/75.13 |
International
Class: |
E21B 033/035; E21B
034/04 |
Claims
We claim:
1. A well completion system comprising: a spool tree body having an
inside surface defining a vertical bore extending therethrough, and
having at least a lateral production fluid outlet port connected to
a valve; wherein the vertical bore defined by the inside surface of
the spool tree body defines an annular recess therein extending
circumferentially around the bore and being positioned adjacent to
the lateral production fluid outlet port in the spool tree body; a
tubing hanger defining a vertical production bore extending
therethrough and having at least a lateral production fluid flow
port, said tubing hanger positioned within the vertical bore at a
position at which the lateral production fluid flow port in the
tubing hanger is in flow communication with the lateral production
fluid outlet port in the spool tree body; a removable plug sealing
the vertical production bore extending through the tubing hanger
above the lateral production fluid outlet port in the spool tree
body; a stopper means sealing the vertical bore above the removable
plug; wherein the tubing hanger is sealed to the vertical bore
above the lateral production fluid outlet port by a first sealing
means and below the lateral production fluid outlet port by a
second sealing means; a workover port extending laterally through
the spool tree body and penetrating into the vertical bore above
the stopper means; and a tubing annulus fluid flow port extending
laterally through the spool tree body from beneath the second
sealing means and extending from a production tubing annulus
defined by a wellhead casing tubular having an inner diameter and a
production tubular having an outer diameter; wherein the workover
port and the tubing annulus fluid flow port are interconnected via
an external loop line containing at least one valve.
2. A system as in claim 1, further comprising a pressure monitor
and bleed port having an inner diameter of about one half inch,
said pressure monitor and bleed port extending laterally through
the spool tree body in flow communication with a chamber defined
between the tubing hanger first sealing means the removable plug
and the stopper means, said pressure monitor and bleed port being
connected to a valve means and monitor/bleed line.
3. A system as in claim 2, wherein the pressure monitor and bleed
port defines an inner diameter of about one half inch.
4. A system as in claim 1, wherein the workover port comprises a
bypass bore extending generally longitudinally through the spool
tree body from the workover port to the external loop line.
5. A system as in claim 1, wherein the removable plug is a wireline
plug and the stopper means is a solid plug.
6. A system as in claim 5, wherein the solid plug contains at least
one opening closed by a wireline plug.
7. A system as in claim 1, wherein the spool tree body is fixed and
sealed to a wellhead housing.
8. A wellhead as in claim 1, wherein the lateral production fluid
outlet port in the tubing hanger is up to 180 degrees out of
alignment with the corresponding lateral production fluid outlet
port in the spool tree body.
Description
[0001] This new application is a continuation in part application
of pending Ser. No. 09/087,791, filed May 29, 1998 and examined in
Group Art Unit 3672 by Examiner W. Neuder. This application is also
a continuation in part of Ser. No. 08/892,185 filed Jul. 14, 1997,
now abandoned and a continuation of Ser. No. 08/746,212 filed Nov.
6, 1996, now abandoned.
BACKGROUND OF THE INVENTION
[0002] A basic function of a wellhead system is to provide for
fluid flow into the well and/or out of the well. The outer end of
the required pathway(s) is outside of the outermost well barrier.
The inner end of the pathway(s) is either the wellbore or one of
the annular spaces between the concentric tubes or tubular
bodies.
[0003] Conventionally, wells in oil and gas fields are built up by
establishing a wellhead housing, and with a drilling blow out
preventer stack (BOP) installed, drilling down to produce the well
hole while successively installing concentric casing strings, which
are cemented at the lower ends and sealed with mechanical seal
assemblies at their upper ends. In order to convert the cased well
for production, a tubing string is run in through the BOP and a
hanger at its upper end landed in the wellhead. Thereafter, the
drilling BOP stack is removed and replaced by a Christmas tree
having one or more production bores containing actuated valves and
extending vertically to respective lateral production fluid outlet
ports in the wall of the Christmas tree.
[0004] This arrangement involves several problems. Any operations
down hole have been limited to tooling which can pass through the
production bore, which is usually no more than five inches in
diameter, unless the Christmas tree is first removed and replaced
by a BOP stack. However this involves setting plugs or valves,
which may be unreliable by not having been used for a long time,
down hole. The well is in a vulnerable condition while the
Christmas tree and BOP stack are being exchanged and neither one is
in position, which is a lengthy operation. Also, if it is necessary
to pull the completion, consisting essentially of the tubing string
on its hanger, the Christmas tree must first be removed and
replaced by a BOP stack. This usually involves plugging and/or
killing the well.
[0005] An existing subsea well completion system commonly called a
spool tree, or horizontal tree, or side valve tree typically
comprises a wellhead housing, a spool body and connector which
latches and seals to the wellhead housing, the spool body having an
inside cylindrical surface defining a vertical bore extending
throughout having a least a lateral production fluid outlet port
connected to a valve. A tubing hanger which lands, locks and seals
inside the spool body. The tubing hanger defines a vertical
production bore extending there through and has a least a lateral
production fluid flow port which can align with the lateral
production fluid port in the spool body. The tubing hanger seals to
the spool body above and below the lateral production fluid outlet.
The tubing hanger suspends the weight of production tubing which
extends to the bottom of the well for purposes of transporting well
fluids back to the well completion equipment.
[0006] A removable plug, commonly operated by wireline means, seals
the vertical production bore extending through the tubing hanger
above the lateral production fluid outlet. A removable stopper
means, commonly referred to as a tree cap, seals the vertical bore
through the spool tree body above the tubing hanger. Such a
removable stopper may include internal provisions for a removable
wireline plug which would seal a production through bore which
would align with the production through bore in the tubing hanger.
This facility would provide for wireline access to the production
tubular without the need to first recover the tree cap.
[0007] A work over port, typically 1.5 to 2 inches in diameter,
extends laterally through the spool body and penetrates into the
spool vertical bore below the tree cap spool bore seals and above
the tubing hanger uppermost spool bore seals.
[0008] A tubing annulus fluid flow port, typically 1.5 to 2 inches
in diameter, extends laterally through the spool body and
penetrates into the spool vertical bore, commonly referred to as
the tubing annulus, below the tubing hanger lowermost spool bore
seals.
[0009] The work over port and the tubing annulus fluid flow port
are typically interconnected via an external loop line containing
at least one valve.
[0010] In one embodiment, the arrangement described for the annulus
work over port and the annulus fluid port offers certain
advantages. Installation of a tubing hanger and tree cap is
accomplished through a BOP stack which latches and seals to the top
of the spool body. This provides for additional well control during
the installation process.
[0011] The tubing hanger is installed into the wellhead using a
specialized running tool commonly referred to as a tubing hanger
running tool which includes a vertical tubular member which extends
back to the an overhead drilling an installation vessel.
[0012] At some point after installation of the tubing hanger but
prior to removal of the tubing hanger running tool, it may become
necessary to circulate quickly large volumes of fluid between the
main vertical production bore through the tubing hanger and the
production tubing annulus surrounding the production tubing.
[0013] The circulation of fluids is as described herein. BOP
sealing rams are closed on the tubing hanger running tool extension
tubular. Fluid port outlets in the BOP below the sealing rams are
interconnected to external tubulars which extend back to the
drilling vessel. These external tubulars are commonly referred to
as choke or kill lines.
[0014] Communication between the production tubing and the
production tubing annulus near the bottom of the well may be
accomplished by means of a sealable sliding sleeve which can be
opened and closed exposing communication ports between the
production tubing and the production tubing annulus. Alternatively,
other specialized devices can be used to create communication holes
between the tubing and annulus.
[0015] Circulation is finally accomplished by pumping fluids down
the production tubing, through the lowermost production tubing
sliding sleeve, back up the production tubing annulus, into the
spool body annulus fluid flow port, through interconnecting
external annulus piping, through the annulus work over port back
into the annulus formed by the spool body inside surface and BOP
inside surface above the tubing hanger, into the BOP choke/kill
lines, and finally back to the surface. Likewise, this process can
be performed in reverse by pumping down the choke/kill lines and
taking returns through the vertical production tubular.
[0016] This arrangement for circulating fluids into the production
tubing annulus is considered advantageous in that it provides for
circulation of fluids around the sealed tubing hanger and
eliminates the need to have a dedicated bore through the tubing
hanger body expressly for this purpose. This however, can only be
done prior to installation of the tree cap. After the tree cap has
been installed above the tubing hanger, the capability to circulate
the production tubing and the production tubing annulus as
described above through the BOP is eliminated as the work over port
has been sealed off above by the tree cap to the spool tree body
bore sealing means.
[0017] As described above, a removable wireline plug may be
installed in the tree cap. The purpose of this wireline plug is to
allow access to the primary production bore for purpose of
performing certain wireline operations in the production tubular
downhole. This may be accomplished with a BOP stack installed on
the wellhead or by means of a lightweight work over BOP stack or
subsea lubricator installed on top of the spool body. In either
case, access to the annulus for purposes of circulating the
production tubing and production tubing annulus from the overhead
work over vessel is eliminated as described above. Annulus
circulation can only be achieved by first removing the tree cap to
allow access to the annulus work over port in the spool body.
[0018] The object of this invention to provide an improved means to
allow access to the production tubing annulus for purposes of
circulation as described above with the tree cap installed above
the tubing hanger. This is accomplished by routing the lateral work
over annulus port into the bore of the spool body above the tree
cap to spool body bore sealing means yet below the uppermost BOP
stack to spool body uppermost sealing surface.
[0019] With this arrangement, access to the annulus for purposes of
circulation is provided at all times, with or without the tree cap
installed. Therefore, annulus circulation can be provided through a
conventional BOP stack or through a work over BOP or a subsea
lubricator system without the need to first recover the tree
cap.
[0020] Existing designs assume there will be no need to access the
annulus for purposes of circulation when strictly preforming
wireline operations. However, this does not account for certain
coil tubing operations which may require circulation capabilities
in certain scenarios.
OBJECTS OF THE INVENTION
[0021] It is an object of the present invention to provide a well
completion system that has an annular bypass port around the tubing
hanger and the tree cap.
[0022] It is a further object of the present invention to provide a
well completion system that can be used to circulate fluids while
the tree cap is in place.
[0023] It is yet another object of the present invention to provide
a well completion system that can be used with a solid tree cap
assembly.
[0024] Another object of this invention to provide an improved
means to allow access to the production tubing annulus for purposes
of circulation with the tree cap installed above the tubing
hanger.
SUMMARY OF THE INVENTION
[0025] In accordance with the present invention, a well completion
system comprises a wellhead housing, a spool tree body fixed and
sealed to the housing, and having at least a lateral production
fluid outlet port connected to an actuated valve, and a tubing
hanger landed within the spool tree body at which a lateral
production fluid outlet port in the tubing hanger is in flow
communication with that in the spool tree body.
[0026] With this arrangement, the spool tree body, takes the place
of a conventional Christmas tree but differs therefrom in having a
comparatively large vertical through bore without any internal
valves and at least large enough to accommodate the tubing
completion. The advantages which are derived from the use of such
spool tree are remarkable, in respect to safety and operational
benefits.
[0027] Thus, in workover situations the completion, consisting
essentially of the tubing string, can be pulled through a BOP
stack, without disturbing the spool tree body and hence the
pressure integrity of the well, whereafter fill production casing
drift access is provided to the well through the large bore in the
spool tree body. The BOP can be any appropriate workover BOP or
drilling BOP of opportunity and does not have to be one specially
set up for that well.
[0028] The present invention provides for a well completion system.
The system comprises a spool tree body with an inside surface that
defines a vertical bore extending therethrough and has at least a
lateral production fluid outlet port connected to a valve. A tubing
hanger lands in, latches to and seals to the spool tree body. The
tubing hanger defines a vertical production bore extending
therethrough and has at least a lateral production fluid flow port.
The tubing hanger is positioned within the vertical bore such that
the lateral production fluid flow port in the tubing hanger is in
flow communication with the lateral production fluid outlet port in
the spool tree body.
[0029] A removable plug seals the vertical production bore
extending through the tubing hanger above the lateral production
fluid outlet port in the spool tree body. A stopper means seals the
vertical bore extending through the spool tree body above the
removable plug.
[0030] The tubing hanger is sealed to the vertical bore above the
lateral production fluid outlet by a first sealing means and below
the lateral production fluid outlet port by a second sealing
means.
[0031] A workover port extends laterally through the spool tree
body and penetrates into the vertical bore above the stopper means.
This allows for fluid to be injected down the production bore and
flow back out of the annular space through the tubing annulus fluid
flow port through the workover port to an opening in the spool tree
body above the tree cap. Using this system allows operations to be
carried out while fluid is flowing through the annular spaces. This
arrangement also allows for the use of a solid tree cap when this
is desirable for safety or stability purposes.
[0032] A tubing annulus fluid flow port extends laterally through
the spool tree body from beneath the second sealing means from a
production tubing annulus. The production tubing annulus is defined
by a wellhead casing having an inner diameter and a production
tubular having an outer diameter.
[0033] The workover port and the tubing annulus fluid flow port are
interconnected via an external loop line containing at least one
valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a cross-sectional view of the well completion
system.
DETAILED DESCRIPTION
[0035] In FIG. 1, a well completion system 10 is shown that can be
used in a variety of subsea drilling operations. The system 10
comprises a spool tree body 20 with an inside surface 22 that
defines a vertical bore 30 extending therethrough and has at least
a lateral production fluid outlet port 40 connected to a valve 50.
A tubing hanger 60 is connected to the spool tree body 20. The
tubing hanger 60 defines a vertical production bore 70 extending
therethrough and has at least a lateral production fluid flow port
80. The tubing hanger 60 is positioned within the vertical bore 30
such that the lateral production fluid flow port 80 in the tubing
hanger 60 is in flow communication with the lateral production
fluid outlet port 40 in the spool tree body 20. Preferably, the
spool tree body 20 is fixed and sealed to a wellhead housing
230.
[0036] A removable plug 90 seals the vertical production bore 70
extending through the tubing hanger 60 above the lateral production
fluid outlet port 40 in the spool tree body. A removable stopper
means 100 seals the vertical bore 30 extending through the spool
tree body 20 above the removable plug 90. The removable plug 90 can
be a wireline plug and the stopper means 100 can be a solid plug.
The solid plug may contain at least one opening closed by a
wireline plug.
[0037] The tubing hanger 60 is sealed to the vertical bore 30 above
the lateral production fluid outlet port 40 by a first sealing
means 110 and below the lateral production fluid outlet port 40 by
a second sealing means 120.
[0038] A workover port 130 extends laterally through the spool tree
body 20 and penetrates into the vertical bore 30 above the stopper
means 100. In a preferred embodiment, the workover port 130 can be
connected to the external loop line 160 by a bypass bore 220
extending generally longitudinally through the spool tree body
20.
[0039] A tubing annulus fluid flow port 140 extends laterally
through the spool tree body 20 from beneath the second sealing
means from a production tubing annulus 150. The production tubing
annulus 150 is defined by a wellhead casing tubular 222 having an
inner diameter and a production tubular 224 having an outer
diameter. The workover port 130 and the tubing annulus fluid flow
port 140 are interconnected via an external loop line 160
containing at least one valve 170.
[0040] A pressure monitor and bleed port 180 extends laterally
through the spool tree body 20 in flow communication with a chamber
190 defined between the first sealing means 110 of the tubing
hanger, the removable plug 90 and the stopper means 100. The
pressure monitor and bleed port 180 is connected to a valve means
200 and an isolation line 210. The pressure monitor and bleed port
180 is used to monitor the pressure in the tubing annulus and bleed
the pressure when the tree cap is being seated on and connected to
the tubing hanger. This is a secondary means for monitoring and
controlling the pressure in the tubing annulus. The pressure
monitor and bleed port 180 defines an inner diameter of about one
half inch which prevents its use as a workover port.
* * * * *