U.S. patent number 3,731,742 [Application Number 05/125,173] was granted by the patent office on 1973-05-08 for well flow controlling method, apparatus and system.
This patent grant is currently assigned to Otis Engineering Corporation. Invention is credited to Albert W. Carroll, Phillip S. Sizer.
United States Patent |
3,731,742 |
Sizer , et al. |
May 8, 1973 |
WELL FLOW CONTROLLING METHOD, APPARATUS AND SYSTEM
Abstract
A method, apparatus, and system for controlling flow of well
fluids from a well in response to sensing of a leak in the
connections between the components of the well head or fire at the
well head for closing off all flow from the well upon the
occurrence of such condition. Encompassed is modification of
existing installations to carry out the method with a minimum of
added equipment or well work-over. Sensing mechanisms responsive to
leakage between adjacent connected components of the well head for
actuating the closure and responsive to heat from fires at the well
head are disclosed. The method, apparatus and system are adapted
for multiple string installations and for new installations without
modification. The system is also adapted for use with down-hole
flow control devices in the well flow conductor.
Inventors: |
Sizer; Phillip S. (Dallas,
TX), Carroll; Albert W. (Dallas, TX) |
Assignee: |
Otis Engineering Corporation
(Dallas, TX)
|
Family
ID: |
22418517 |
Appl.
No.: |
05/125,173 |
Filed: |
March 17, 1971 |
Current U.S.
Class: |
166/375; 166/53;
166/72; 137/629; 166/66.4; 166/386 |
Current CPC
Class: |
E21B
33/047 (20130101); E21B 33/04 (20130101); E21B
34/16 (20130101); E21B 34/066 (20130101); E21B
35/00 (20130101); Y10T 137/86936 (20150401); E21B
2200/04 (20200501) |
Current International
Class: |
E21B
33/04 (20060101); E21B 34/06 (20060101); E21B
35/00 (20060101); E21B 33/047 (20060101); E21B
33/03 (20060101); E21B 34/00 (20060101); E21B
34/16 (20060101); E21b 043/00 () |
Field of
Search: |
;137/312
;166/53,72,85,86,87,315 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Ebel; Jack E.
Claims
What is claimed and desired to be secured by Letters Patent is:
1. A method of controlling flow from a well having a bore
penetrating a producing formation and a flow conduit disposed
therein for conducting well fluids from such formation to a well
head Christmas tree having a plurality of elements connected in
sealing communication with each other therein and connected in flow
communication with the upper end of said flow conduit, comprising
the steps of: disposing flow controlling means in the flow conduit
operable to control fluid flow therethrough; holding said flow
controlling means open to permit flow of well fluids through the
flow conduit; sensing at positions separated from said flow conduit
a condition of the sealing connections of the elements of the well
head Christmas tree which would permit undesired leaking of well
fluids from within the flow conduit and said Christmas tree through
said connections to the atmosphere exteriorly of said flow conduit
and Christmas tree; and closing said flow controlling means in
response to the sensing of such condition.
2. A method of controlling flow from a well having a bore
penetrating a producing formation and a well flow conduit disposed
therein having one end thereof in flow communication with said
formation and the other end thereof connected to a Christmas tree
having a plurality of elements connected in sealing communication
with each other and a flow line connected with said Christmas tree
establishing a flow path for conducting well fluids from the
formation to the surface, comprising: disposing normally closed
flow controlling valve means said flow path below said Christmas
tree; holding said flow controlling valve means open by remote
control fluid pressure to permit flow of well fluids through said
flow path; establishing a closed control fluid pressure chamber in
said Christmas tree separate from said flow path and communicating
with one or more of the connections between adjacent components of
the Christmas tree; maintaining said remote control fluid pressure
in said closed pressure chamber in said Christmas tree for
detecting a condition of said one or more connections between
adjacent components of said Christmas tree which would release said
control fluid pressure from said closed pressure chamber separate
from said flow path to indicate a condition which would result in
the undesired escape of well fluids from said flow path; and
controlling closing of said flow controlling valve means by
releasing the pressure of said control fluid in said closed
pressure chamber between said adjacent components of said Christmas
tree and acting on said valve means.
3. A well flow controlling system for use in a well having a flow
conductor extending from the surface to the producing formation for
conducting well fluids from the producing formation to the surface,
a well head Christmas tree having a plurality of components
connected in sealing communication with each other connected to the
upper end of and communicating with the flow conductor and
providing a flow path for receiving and conducting the well fluids
from the flow conductor to the surface flow lines, flow controlling
valve means disposed in the flow conductor operable between open
and closed positions to control flow through the flow conductor,
and remote control means at the surface for controlling actuation
of said flow controlling valve means and including: sensing means
separate from the flow path through the Christmas tree connected
with the connection between two or more adjacent components of said
well head Christmas tree for detecting a condition of said
connection between said adjacent components of said Christmas tree
which would result in permitting undesired leakage of fluids from
the flow path therethrough; and means operatively connecting said
sensing means with said remote control means for controlling
operations of said valve to cause the valve to be moved from open
to closed position upon the occurrence of such condition.
4. Apparatus for controlling flow from a well having a bore
penetrating a producing formation and in which a tubing string is
hung from a hanger at the surface and communicates at its lower end
with the producing formation, and to which a Christmas tree having
a plurality of components connected in sealing flow communication
with each other is connected for flow communication with the tubing
string to provide a flow path from the tubing to the surface flow
lines, said apparatus including: a normally closed safety valve;
means for supporting said safety valve at said tubing hanger for
controlling flow of fluids from the tubing string through the flow
path through the components of the Christmas tree; means for
releasably holding said safety valve in open position; remote
control means for controlling deactivation of said means for
releasably holding said safety valve in open position and operable
for deactivating said holding means to permit movement of said
safety valve from open to closed position; and sensing means
separate from the flow path through the components of said
Christmas tree operatively connected with at least one connection
between adjacent components of said Christmas tree for detecting a
condition of the connection between said adjacent components
thereof which would result in permitting undesired leakage of well
fluids from the flow path therethrough; and means operatively
connecting said sensing means with said control means for actuating
said control means to deactivate said means for releasably holding
said valve in open position to permit said valve to move to a
normally closed position to cut off flow of well fluids from the
tubing string to the flow path through the components of the
Christmas tree.
5. Apparatus of the character set forth in claim 4 wherein said
means for releasably holding said safety valve in open position
comprises: a control fluid pressure applied to said safety valve
from a remote point; and said control means comprises: a closed
pressure chamber in said Christmas tree separate from the flow path
therein and communicating with the connections between one or more
of the components of the Christmas tree; said closed separate
pressure chamber having control fluid pressure confined therein and
communicating with said control fluid applied to said safety valve;
and said sensing means for sensing a condition of said connections
which would result in permitting undesired leakage of well fluid
from said flow path includes means operative upon sensing such
condition of said connections to release said control fluid
pressure from said closed separate chamber to reduce the control
fluid pressure applied to the safety valve and permit the safety
valve to move from open to closed position.
6. An apparatus of the character set forth in claim 4 wherein the
means for supporting the safety valve at the tubing hanger
comprises: a tubular valve receptacle formed in the tubing hanger
and having locking and sealing surfaces therein engageable by said
safety valve for closing off flow through the tubing string when
said safety valve is closed, said safety valve being removable from
said receptacle without disturbing the tubing hanger or tubing
string.
7. Apparatus of the character set forth in claim 4 wherein said
means for holding said valve in open position comprises an
electromagnetic operated means in the valve; said remote control
means comprises a source of electric power connected with said
electromagnetic means in said valve; and said sensing means
comprises a switch for controlling supply of power to said
electromagnetic means and disposed in operative connection with at
least one connection between adjacent components of said Christmas
tree to sense and be operated as a result of movement of such
connection between the components of the Christmas tree which would
permit a leak of fluids from the flow path therethrough.
8. Apparatus of the character set forth in claim 4 wherein said
sensing means comprises: heat sensitive means engaged with at least
one connection between adjacent components of said Christmas tree
and responsive to a temperature of said connection above a
predetermined temperature for actuating the control means for
deactivating the means releasably holding the valve in open
position to release said means and permit the safety valve to
close.
9. Apparatus of the character set forth in claim 4 wherein said
normally closed safety valve comprises: down-hole flow control
safety valve means connected in the tubing string substantially
below the surface of the well and operable by remote control fluid
means from the surface of the well.
10. Apparatus of the character set forth in claim 4 wherein:
down-hole flow control safety valve means is connected in the
tubing string substantially below the surface of the well and
operable by remote control fluid means from the surface of the
well, and actuation of said down-hole safety valve means is also
controlled by said control means controlling actuation said safety
valve supported at said tubing hanger, whereby both said down-hole
safety valve and said safety valve supported at the tubing hanger
are actuated by a common control means and responsive to a common
sensing means.
11. A method of controlling flow from a well of the character set
forth in claim 1, wherein the step of sensing the condition at the
well head Christmas tree which would permit undesired leaking of
well fluids from said Christmas tree to the atmosphere comprises:
confining a a body of control fluid pressure in a closed chamber in
said Christmas tree separated from the flow path through said
Christmas tree; exposing said separate body of control fluid
pressure to the connections between adjacent components of the well
head; communicating said control fluid pressure of said separate
chamber with a body of control fluid under pressure acting on said
flow controlling means in the flow conduit and operable when the
pressure of said confined body of control fluid pressure in said
chamber in said well head Christmas tree is reduced by conditions
at said con-nections between adjacent components of said Christmas
tree opening said closed chamber to reduce the pressure of the
control fluid acting on said flow controlling means to permit the
flow controlling means to move to closed position to shut off flow
through the well flow conductor.
12. A method of controlling flow from a well of the character set
forth in claim 1, wherein the steps of sensing the condition at the
connection between adjacent components of the well head Christmas
tree which would permit undesired leaking of well fluids from said
Christmas tree to the atmosphere comprises: sensing at the
connection between adjacent components of the well head Christmas
tree movement of said adjacent components with respect to each
other opening the flow path through said Christmas tree to the
atmosphere; and transmitting a signal from said connection movement
sensing means to the flow controlling means in the well for causing
the same to close.
13. A method of controlling flow from a well of the character set
forth in claim 1, wherein the flow controlling means is installed
in the well flow conduit at the well flow conduit hanger
immediately below the Christmas tree.
14. A system of the character set forth in claim 3, wherein: the
flow controlling valve disposed in the conductor is disposed in the
hanger for the well flow conductor below the flow path through the
Christmas tree.
15. A well flow controlling system of the character set forth in
claim 3, wherein the sensing means connected with the well head
Christmas tree comprises: a closed chamber in said Christmas tree
separated from the flow path therethrough and communicating with
the connection between adjacent components of the well head
Christmas tree; and means confining control fluid under pressure in
said chamber and communicating with the means for control-line
operation of the valve means, whereby a leak occurring in said well
head chamber will actuate said confining means to release control
fluid from said chamber to reduce the pressure of the control fluid
to cause the flow controlling valve means to move to closed
position.
16. A flow control system of the character set forth in claim 3,
wherein the sensing means comprises: means disposed between the
coupling means connecting adjacent components of the well head
Christmas tree for sensing movement of said components with respect
to each other to cause activation of the means con-trolling
operation of the valve to cause the valve to move to closed
position.
17. A system of the character set forth in claim 3, wherein the
flow controlling safety valve means is responsive to operating
means for controlling movement of said valve means to closed
position upon the occurrence of the undesired conditions at the
Christmas tree.
18. A system of the character set forth in claim 3, wherein the
sensing means includes: temperature responsive means engaged with
the connection between adjacent components of the Christmas tree
and operable by elevated temperatures for actuating the control
means for controlling operation of the safety valve means to cause
the safety valve means to move from closed to open position upon
the occurrence of predetermined temperature at the well head
Christmas tree.
19. A system of the character set forth in claim 16, wherein the
sensing means also includes: a temperature responsive means in
engagement with the connection between adjacent components of the
Christmas tree and operable in response to temperature elevated
above a predetermined temperature for actuating the control means
for controlling operation of the safety valve means to cause the
safety valve means to move from closed to open position upon the
occurrence of said predetermined elevated temperature at the well
head Christmas tree.
20. A method of controlling flow from a well having well casing
penetrating to a producing formation and a flow conduit disposed
therein for conducting well fluids from such formation to a well
head Christmas tree having a plurality of separate components
connected together in sealing communication providing a flow path
therethrough connected in flow communication with the upper end of
said flow conduit and having surface flow lines connected thereto,
comprising: closing the upper end of the flow conduit below the
well head Christmas tree; disconnecting the well head Christmas
tree from the well casing and upper end of the flow while the flow
conduit is closed; providing sensing means at one or more
connections between adjacent components of the Christmas tree
separated from the flow path therethrough for sensing conditions at
said connection which would result in opening said flow path to
permit undesired escape of well fluids from said flow path;
inserting a tubular spacer means on the upper end of said well
casing and the upper end of said well flow conduit to communicate
with the flow path of the well head Christmas tree; connecting the
well head Christmas tree to the spacer means; removing the closure
from the flow conduit; installing a flow controlling safety valve
in the flow conduit below the well head Christmas tree operable to
control fluid flow through the flow conduit; holding said flow
controlling safety valve open to permit flow of well fluids through
the well conduit; operatively connecting said sensing means with
said holding means for deactivating said holding means upon said
sensing means sensing an undesirable condition at a connection
between components of the well head Christmas tree; and closing
said flow controlling safety valve in response to the sensing of
such condition and deactivation of said holding means.
21. A method of the character set forth in claim 20 including the
step of sensing a condition of movement between adjacent connected
components of the Christmas tree resulting in opening the
connection between the components of the well head Christmas tree
at the surface which would permit undesired leaking of well fluids
from said Christmas tree to the atmosphere and closing said flow
controlling safety valve in response to such condition.
22. A method of controlling flow from a well having well casing
penetrating to a producing formation and having a tubing head at
its upper end with a hanger for supporting a flow conduit disposed
in said casing therein for conducting well fluids from such
formation to a well head Christmas tree connected to said tubing
head and having a flow path therethrough connected in flow
communication with the upper end of said flow conduit and having
surface flow lines connected thereto, comprising: closing the upper
end of the flow conduit at the hanger below the well head Christmas
tree; disconnecting the well head Christmas tree from the tubing
head and upper end of the flow conduit while the flow conduit is
closed; inserting a tubular spacer member on the upper end of said
tubing head for flow communication with the upper end of said well
flow conduit and disposed to communicate with the flow path of the
well head Christmas tree; connecting the well head Christmas tree
to the spacer; removing the closure from the hanger for the flow
conduit; installing a flow controlling safety valve in the hanger
for the flow conduit below the well head Christmas tree operable to
control fluid flow through the flow conduit; establishing a closed
pressure chamber in said spacer member and hanger for the upper end
of the flow conduit separate from the flow path through said
Christmas tree and communicating with one or more of the
connections between the tubing head and the spacer member and the
well head Christmas tree thereabove; holding said flow controlling
valve means open by remote control fluid pressure to permit flow of
well fluids through said flow path; maintaining said control fluid
pressure also in said pressure chamber for detecting a condition of
said one or more connections which would result in undesired escape
of well fluids from said flow path; and closing said flow
controlling safety valve upon reduction of the pressure of said
control fluids in said chamber and acting on said safety valve to
close off flow of well fluids through said flow conduit.
23. A method of the character set forth in claim 22, including
positioning the well flow controlling safety valve in sealing
engagement with the bore of the spacer means above the well casing
and below the Christmas tree and sealing with the upper end of the
well conduit below said spacer means for defining said closed
pressure chamber and directing control fluid pressure into said
chamber and to said safety valve to control the operation of said
safety valve.
24. A method of controlling flow from a well having well casing
penetrating to a producing formation and a tubing head connected to
the upper end of said casing with a hanger therein connected to the
upper end of a flow conduit disposed in said casing for conducting
well fluids from such formation to a well head Christmas tree
having a plurality of separate components connected together in
sealing communication to provide a flow path therethrough and
connected in flow communication with the upper end of said flow
conduit and having surface flow lines connected thereto,
comprising: closing the upper end of the flow conduit at the hanger
below the well head Christmas tree; disconnecting the well head
Christmas tree from the tubing head and hanger supporting the flow
conduit while the flow conduit is closed; inserting a tubular
spacer means on the upper end of said tubing head and the hanger at
the upper end of said well flow conduit to communicate with the
well flow conduit and with the flow path of the well head Christmas
tree; connecting the well head Christmas tree to the spacer means;
providing sensing means at each of the connections between the
tubing head, the spacer means and each of the components of the
Christmas tree separated from the flow path therethrough for
sensing conditions at each of said connections which would permit
undesired escape of well fluids from said flow path; removing the
closure from the flow conduit; installing a flow controlling safety
valve in the hanger and the upper end of the flow conduit below the
well head Christmas tree operable to control fluid flow through the
flow conduit; holding said flow controlling safety valve open to
permit flow of well fluids through the well conduit; operatively
connecting each of said sensing means with said holding means for
deactivating said holding means upon any one of said sensing means
sensing an undesirable or unsafe condition at any one of the
connections between the tubing head, at spacer means, or any of the
components of the well head Christmas tree; and closing said flow
controlling safety valve in response to the sensing of such
condition and deactivation of said holding means.
Description
This invention relates to methods, apparatus and systems for
controlling flow of well fluids from a well, and more particularly
to such a system responsive to undesirable or unsafe conditions
occurring at the well head.
It is one object of the invention to provide improved methods,
apparatus and systems for controlling flow of well fluids from a
well.
It is an important object of the invention to provide improved
methods, apparatus and systems for controlling flow of well fluids
from a well particularly responsive to undesirable or unsafe
conditions occurring at the well head.
It is a further object of the invention to provide means for
shutting off flow of well fluids from a well through a well flow
conductor by valve means located in the flow conductor below the
master valve.
Still another object of the invention is to provide methods,
apparatus and systems for controlling flow of well fluids from a
well through the well flow conductor to cut off such flow in
response to undesirable or unsafe conditions occurring in or at the
well head flow control system and particularly in the Christmas
tree of the well head.
Still a further object of the invention is to provide methods,
apparatus and systems of the character described which are
responsive to the development of leaks in the connections between
the components of the Christmas tree or well head system above the
tubing hanger, or which are responsive to fire at such well head or
Christmas tree, for closing off flow of the well fluids from the
well through the flow conductor in the flow conductor below the
master valve.
A particularly important object of the invention is to provide a
method and system for controlling flow of well fluids from a well
through the well flow conductor by means of a flow controlling
safety valve disposed in the well flow conductor at the upper end
of the tubing or in the tubing hanger below the master valve, and
which is biased to an open position by control fluid pressure
applied to the valve to move the same to the open position, and
wherein the control fluid is confined in an area within the well
head at the connection between adjacent components of the well
head, whereby separation or leaking of the connections will release
the pressure of the control fluid to cause the valve to move to
closed position to cut off flow upon the occurrence of such a
leak.
It is also an object of the invention to provide sensing means
responsive to separating movement of the connections between
adjacent components of the well head for relieving the control
means which is normally holding the safety valve in open position
to permit the same to close upon the occurrence of such a
movement.
A further object of the invention is to provide a sensing device
for use in a system in practicing the method of the invention which
is responsive to heat such as a fire in or adjacent the well head
for releasing the control means normally holding the safety valve
in open position to permit the valve to move to closed position
automatically upon the occurrence of such a fire or the presence of
such heat.
A further object of the invention is to provide a control valve
which is normally held open by control fluid pressure and which
will automatically move to closed position upon release of such
control fluid pressure and wherein seal means is provided between
the valve and the flow conductor in which the valve is located
which is responsive to heat to provide a metal to metal seal
between the valve and the flow conductor in the event of a fire or
other similar high temperature condition occurring which would
otherwise damage or destroy such sealing means.
Additional objects and advantages of the invention will be readily
apparent from the reading of the following description of a device
constructed in accordance with the invention, and reference to the
accompanying drawings thereof, wherein:
FIG. 1 is a schematic view of a well installation, partly in
elevation and partly in section, showing a down-hole flow control
valve connected in the flow conductor or tubing string of the
well;
FIG. 2 is a fragmentary schematic view showing the tubing hanger of
the well of FIG. 1 plugged and the Christmas tree thereabove
disconnected therefrom;
FIG. 3 is a view similar to FIG. 2 showing an adaptor member or
spool connected between the tubing head and the Christmas tree
thereabove for carrying out the method of the invention;
FIG. 4 is an enlarged schematic view similar to FIG. 3 showing a
flow controlling safety valve anchored in the tubing hanger and
sealing with the spacer spool or adaptor of FIG. 3 in condition for
operation permitting flow of fluids from the well;
FIG. 5 is a view similar to FIG. 4 showing the valve closed to
prevent flow from the tubing string upon the occurrence of a leak
between the tubing head and the adaptor flange thereabove;
FIG. 6 is a view similar to FIG. 5 showing a control fluid manifold
system in which both the down-hole flow control-ling safety valve
and the tubing hanger mounted flow controlling safety valve are
each connected to a common source of control fluid responsive to
loss of such pressure to close both valves, if desired;
FIG. 7 is a view similar to FIG. 6 showing a further leak sensing
structure arrangement connected with the control fluid
manifold;
FIG. 7-A is an enlarged fragmentary sectional view of the sensing
device used between coupled components of the Christmas tree to
sense leaks or separating movement of such components;
FIGS. 8-A and 8-B are enlarged vertical sectional views, partly in
elevation and partly in section, of the tubing hanger mounted flow
controlling safety valve and control fluid conduit used in the
system in practicing the method of FIGS. 4 through 7;
FIG. 9 is a fragmentary sectional view of a sensing device disposed
between adjacent flanges of the well head for sensing spreading
movement of the flanges, and/or for sensing application of heat
thereto;
FIG. 9-A is a fragmentary vertical sectional view taken on the line
9-A - 9-A of FIG. 9;
FIG. 10 is a view similar to FIG. 9 of a modified sensing device in
which the separating movement of the flanges is sensed by an
electrical microswitch or electrical means;
FIG. 10-A is a fragmentary vertical sectional view taken on the
line 10-A - 10-A of FIG. 10;
FIG. 11 is a horizontal cross-sectional view taken between the
flanges of a well head connection showing the disposition of a
plurality of sensors, such as are shown in FIGS. 9 and 10, between
the flanges to sense separating movement or heat applied to the
flanges;
FIG. 12 is an enlarged fragmentary vertical view, partly in section
and partly in elevation of a modified form of support for the flow
controlling safety valve and the modified adaptor for conducting
control fluid to the safety valve for controlling actuation of such
valve;
FIG. 13 is a schematic view similar to FIG. 1 showing a multiple
zone well having parallel flow conductors or tubing strings hung
therein from the tubing head and each provided with a flow
controlling safety valve in the tubing hanger and upper end of the
tubing for separately controlling flow through each of the flow
conductors;
FIG. 14 is a fragmentary sectional view similar to FIG. 4 showing a
modified form of tubing hanger and tubing head arranged to receive
the flow control safety valve of the system and also further
illustrating a sensing mechanism for detecting leaks between the
flanges of adjacent coupling members between the components of the
well head or Christmas tree;
FIG. 15 is an enlarged view, partly in elevation and partly in
section, of an electrically controlled safety valve and sensing
mechanism for use in practicing the method; and,
FIG. 16 is a view, similar to FIG. 15, showing a modified for of
electrically controlled safety valve and sensor.
In the drawings, FIG. 1 illustrates schematically a typical
producing well installation. The usual casing string C extends
downwardly from the surface through the usual producing zone Z from
which well fluids flow into the casing through the perforations E
into the bore of the casing where they will flow upwardly to the
lower inlet end of a tubing string or flow conductor T which is
sealed at its lower end with the casing by the usual packer P.
A down-hole flow controlling safety valve device V is connected in
the tubing string and is of the type generally shown in the patent
to John V. Fredd, U.S. Pat. No. 3,007,669, which is normally biased
to a closed position and which is moved to an open position by
means of control fluid pressure conducted thereto through a control
fluid conductor line L extending inwardly through a gland fitting
member G in an exit bushing B connected to the upper end of the
casing head A with the usual annular seal ring R sealing between
the casing head A and the bushing B. A tubing head H is connected
to the upper end of the exit bushing B by bolts in the usual
manner, and a seal ring R2 is disposed between the flanges of the
bushing and the tubing head to seal therebetween. A tubing hanger
or support S is threaded into the bore of the tubing head or
otherwise suitably supported in said bore, and the upper end of the
string of tubing T is connected to the hanger or support in the
usual manner.
Above the tubing head H is the usual master valve M for controlling
flow from the well through the bore of the tubing and through the
Christmas tree X in the usual manner, the master valve being
connected by flanges in the usual manner to the upper end of the
tubing head and to the flow cross K thereabove. The usual seal
rings R3 and R4 are disposed between the flanges of the master
valve and the tubing head and between the master valve and the flow
cross, respectively. The usual wing connections W1 and W2 are
connected to the flow cross in the customary manner and a swab
valve or crown valve Y is connected to the upper end of the cross
and a bull plug and pressure gauge may be connected to the upper
end of the crown valve in the customary manner, if desired. The
casing head A has a lateral inlet and outlet port provided with a
flow line and casing wing valve A1, also in the customary
manner.
The down-hole flow controlling safety valve V is preferably
installed at a depth several hundred to several thousand feet, or
possibly more, in the well to provide means for closing off flow
through the tubing string T in the event of the occurrence of any
dangerous or undesirable conditions at the surface, as when a ship
strikes the platform of a marine type installation, or bombs, or
fire or other catastrophes occur at the well head, which are sensed
by sensing means at the surface as set forth in the patent to
Sizer, U.S. Pat. No., Re. 26,149. The control fluid in the control
fluid line L will then be released and the valve permitted to move
to closed position in the manner set forth in the patent to Fredd,
U.S. Pat. No. 3,007,669, or Sizer, Re. 26,149.
However, in any installation, a slight leak can occur between the
flange connections of the several elements or components of the
Christmas tree X, as a result of the deterioration or damage of the
seal rings R, R2, R3, R4, etc., or in the event of a fire which
weakens the bolts holding the flanges together and permits the same
to stretch and the flanges to separate to permit well fluids to
flow outwardly between the flanges past the seal rings. In such
event, the volume of flow of the fluids from the well through the
tubing string may not be sufficient to cause the valve V to close
and the sensing mechanism at the surface may not sense such a
condition to relieve the pressure acting on the sub-surface safety
valve to cause the valve to close.
To provide means for positively closing off the flow of fluids
through the tubing string from the producing formation to the
surface through the Christmas tree in the event the flanges
separate or there is other damage to the Christmas tree resulting
in a slight lateral leak, which is the type that may be ignited and
burn with a small but damaging flame, that the method, the
apparatus and system of this invention is directed. Also, this
method, and the apparatus and system used in carrying out the
method, provide for an early and prompt closing off of flow through
the conductor upon the occurrence of a fire or heat applied to the
Christmas tree, as well as leaks between the flanges of the various
components of the Christmas tree, and other undesirable or unsafe
conditions.
Tubing hangers are currently in use which provided with internal
annular locking and sealing recesses and surfaces for receiving and
anchoring a plugging tool in place in the bore of the hanger
sealing with the hanger or the upper end of the tubing string
immediately therebelow to close off the bore of the tubing string
and prevent flow upwardly therethrough. These plugs, however, must
be inserted and removed each time it is desired to so close off
flow. Tubing hangers and plugging tools of the type just described
are illustrated in the patent to John V. Fredd, U.S. Pat. No. Re.
25,289. Also, when the plug is in place, the well cannot be
produced until the plug is removed.
The method of this invention is directed toward providing an
automatically operable remotely controlled flow controlling safety
valve disposed in the tubing hanger or the tubing head within the
upper end of the tubing string for closing off flow through the
tubing string. This valve installation and the method of
controlling flow of fluids from the well through the tubing string
without completely re-working the well is an important feature of
this invention.
In carrying out the method and effecting the installation of the
system for controlling the well, the well head plug J is installed
in the tubing hanger S in the manner set forth in the aforesaid
patent to Fredd, U.S. Pat. No. Re. 25,289, and the Christmas tree
above the tubing head H is disconnected and lifted, as shown in
FIG. 2, to permit installation of an adaptor or spool D, as shown
in FIG. 3. The adaptor spool has flanges at its ends by means of
which it is connected to the flange at the upper end of the tubing
head H and to the lower end of the master valve at the lower end of
the Christmas tree X, as shown in FIG. 3. The adaptor spool is
provided with a control fluid flow conduit and connection Q by
means of which control fluid may be directed into the bore of the
adaptor and into the upper end of the bore of the tubing hanger or
support S, as will hereinafter be more fully set forth. In the seal
ring R3 is disposed between the lower end of the adaptor D and the
upper end of the tubing head, while a seal ring R5 is disposed
between the flanges at the upper end of the adaptor D and the lower
end of the master valve M of the Christmas tree X. After the
adaptor has been connected between the tubing head and the
Christmas tree, and a control fluid line L2 has been connected to
the flow passage and outlet connection Q, as shown in FIG. 4, with
a valve N2 therein connected therein for controlling fluid from a
control fluid manifold unit U, the closure plug or well head plug J
is removed from its position in the tubing hanger S, and a flow
controlling safety valve V2 is installed therein, as shown in FIG.
4, the valve being locked in place by means of a locking and
sealing mandrel assembly I of the type illustrated in detail in
FIGS. 8-A and 8-B.
The locking and sealing mandrel assembly I has sealing members that
engage the bore wall of the adaptor D above the flange and the
inner end of the control fluid inlet Q and the lower packing
members which seal between the mandrel and the bore wall of the
tubing hanger S below the locking recesses in the bore of said
tubing hanger, whereby control fluid from the line L2 passing
through the inlet passage Q is directed to the flow controlling
safety valve V2 to control actuation thereof in the manner set out
in the patent to Fredd, U.S. Pat. No. 3,007,669, or in the
application for patent to William W. Dollison, Ser. No. 786,149,
filed Dec. 23, 1968 now U.S. Pat. No. 3,583,442, issued June 8,
1971. The details of construction of the locking and sealing
mandrel assembly and the valve V2 will be described more fully
hereinafter in connection with FIGS. 8-A and 8-B. However, the
valve V2 is shown in open condition in FIG. 4 and in closed
position in FIG. 5.
Control fluid from the control line L2 enters into the bore of the
adaptor D between the lower flange of the adaptor and the upper
flange of the tubing head A and passes downwardly in the annular
space between the locking and sealing mandrel to the valve V2 where
it acts on the valve to move the same to the open position shown in
FIG. 4 to permit well fluids to flow upwardly from the well with
the valve anchored in place in the tubing head in the manner
illustrated. However, should the pressure of the control fluid in
the annular space between the packing members of the locking and
sealing mandrel and the bore wall of the adaptor D and tubing head
H within the seal ring R3 be released or reduced sufficiently, the
valve will automatically move to the closed position as shown in
FIG. 5 to close off all flow through the tubing string below the
hanger S. Such a condition might arise, as shown in FIG. 5, by
stretching of the means holding the lower flange of the adaptor D
connected with the upper flange of the tubing head H, causing
slight separation of the flanges, and so permit the control fluid
confined within the inner diameter of the seal ring R3 to escape
outwardly and reduce or release all pressure in such annular space
and so permit the valve V2 to close. The connecting bolts might
have been caused to stretch by heat or by over tension or wear or
the like, or the seal ring R3 may have been damaged as a result of
corrosion or impacts, dents or the like, which would cause the same
to leak and release the control fluid to cause the valve to close.
Such a small leak would not ordinarily be sufficient to cause the
down-hole safety valve flow controlling safety valve V to close in
the usual installation, because the sensing members connected with
the control line L at the surface would not ordinarily sense such a
leak to release the pressure of the control fluid in the line L to
permit the valve to close.
Also, such a lateral leak between the flanges of the connected
components of the Christmas tree may be sufficiently small enough
in volume not to cause actuation of the down-hole safety valve V,
but when the leaking fuel is ignited it would cause serious damage
to the platform or surrounding well, which could result in further
damage to the Christmas tree connections and turning the well loose
to permit uncontrolled flow. Therefore, the well head safety valve
V2 provides for immediate and complete closure of the flow passage
from the producing formation through the tubing string T in the
event of loss of pressure of the control fluid present in the
control line L2 for any reason, whether by leakage or any other
condition sensed by the manifold U controlling the supply of
control fluid to the well head safety valve V2.
Various types of monitoring equipment may be provided in the
manifold U for sensing various conditions which would release the
control fluid pressure in the line L2 to permit the valve V2 to
close upon the development of any undesired condition for which the
sensors or monitoring devices are provided. In addition, upon the
occurrence of a leak in the connections between the tubing head H
and the Christmas tree elements or components thereabove, which
will release the control fluid pressure present in chamber formed
in the annular space between the mandrel of the locking and sealing
device I and the bore wall of the adaptor D and the tubing head H,
such a leak will automatically and promptly relieve the control
fluid pressure acting on the tubing head or hanger safety valve V2
and cause the same to be moved to closed position to shut off flow
through the tubing string and prevent further escape of well
fluids.
The pressure of the control fluid is ordinarily created and
maintained by means of a small pump which builds up and acts to
provide a constant source of pressure to maintain the safety valve
in the open position even though there may be a very small leak in
the control fluid lines or in the chamber of the system. Thus, any
leak reducing or completely relieving the control fluid pressure
acting on the valve V2, downstream of a small restrictive orifice
in the control fluid line L2 between the manifold and the adaptor
D, will prevent the pump from completely replacing the fluid and
permit the valve to close, in which event the pump is automatically
shut off by a pressure valve or throttle or switch controlling the
supply of fuel or power to the pump. As an alternative, the
reservoir of control fluid at the pump may be very small so that it
would be exhausted upon the occurrence of a small leak, and the
valve will then close upon the exhausting of the pressure. The pump
will be cut off in either event, upon exhausting of the fluid from
the reservoir or the closing of the valve.
Manifestly, the down-hole safety valve V may be connected in the
same manifold with the tubing head safety valve V2, if desired.
Such a manifold arrangement is illustrated in FIG. 6, wherein the
control fluid manifold U2 is connected by a line L3 wherein the
control unit U is connected by means of a control fluid line L3
with the control fluid line L leading to the down-hole safety valve
and with the control fluid line L2 leading to the tubing head
safety valve V2. A venting valve N3 is also connected to the line
L3, while the valve N is connected in the control fluid L
controlling the supply of control fluid under pressure through the
line L to the down-hole safety valve V, in the same manner as the
valve N2 controls the supply of control fluid pressure to the line
L2 to the tubing head safety valve V2. With the valves N and N2
open permitting application of the control fluid pressure to the
two safety valves V and V2, any leak in the system which reduces or
relieves the control fluid pressure acting on the valve would cause
the valves to be moved to closed position shutting off flow through
the tubing string. Also, the valve N3 may be opened to reduce the
control fluid pressure acting on the safety valves to cause them to
close, if desired.
Further, it is believed apparent that the seal ring R5 between the
upper flange of the adaptor D and the lower flange of the master
valve M may be of the type shown in FIG. 7-A, having a vertical
flow passage formed therein and connecting the ring grooves of the
flanges of the Christmas tree components between which it is
positioned to permit control fluid pressure to be supplied to the
ring grooves above and below the seal ring R5, whereby any
separation of the flanges will cause leakage of the control fluid
through the grooves in the flanges above or below the ring R5 and
reduce or completely relieve control fluid pressure in the manifold
to cause actuation of the tubing head safety valve V2.
Such a well head installation is shown in FIG. 7 wherein the
control fluid manifold U is connected by means of the control fluid
line L3 to the control line L2 and the valve N2 leading to the
surface tubing head safety valve V2, and may be also connected by
means the control fluid line L and the valve N to the down-hole
safety valve V in the manner illustrated in FIG. 6. Similarly, the
line L3 may be connected to a line L4 and valve N4 leading to the
seal ring R5. Thus, if the pressure within the grooves of the
flanges in which the seal ring R5 is disposed is reduced or
relieved, the control fluid pressure acting on the safety valves V
and V2 will be reduced or relieved and cause the valves to close
immediately and shut off flow through the tubing string.
The seal ring R5, as shown in FIG. 7-A, comprises an annular metal
ring 10 having convex upper and lower annular surfaces 11 and 12,
respectively, adapted to fit in the tapered grooves 13 and 14,
respectively, of the flanges of the components of the Christmas
tree between which the rings are disposed in sealing position. A
flexible V-type packing ring or sealing ring 15 is suitably bonded
or affixed to the inner annular periphery of the ring 10 and is
adapted to engage the opposed surfaces of the flange 16 and 17 of
the Christmas tree components to seal therebetween to prevent
escape of well fluids in the event the flanges become separated as
by elongation of the bolts for any reason. Also, this seal ring 15
will prevent contact of the well fluids with the metal seal ring 10
to reduce or prevent corrosion of the ring by the chemicals present
in the well fluids. The control fluid line L4 from the valve N4 is
connected to the outer periphery of the seal ring body 10 by
soldering or brazing or otherwise securing the inner end of the
line L4 in a radial aperture 18 formed in the outer medial portion
of the ring and communicating with the vertical bore 19 therein.
Control fluid pressure thus will be confined in the annular space
in the grooves 13 and 14 and any reduction in pressure in either of
the annular areas will reduce the pressure in the other and reduce
or relieve the pressure present in the control line L4 to permit
the tubing head safety valve V2 to close. Also, if the down-hole
safety valve V is connected to the line L with the manifold, the
release of pressure in the grooves 13 and 14 will cause the
down-hole valve to close as well.
As shown in FIG. 7, a ring R5 such as is shown in FIG. 7-A may be
disposed between the flanges of the master valve and the flow
cross, and a control fluid line L5 connected thereto after passing
through the valve N5. Similarly, a valve ring R5 may be disposed
between any other component of the Christmas tree and connected by
means of a control fluid line L6 having a valve N6 therein, if
desired. Thus, any separation of the flanges or connections of the
components of the Christmas tree for any reason, whether by
elongation, heat or by deterioration of the seal provided by the
seal rings R5, R5, or any other seal ring between two components,
will permit the pressure of the control fluid to be reduced or
relieved and the valves to be closed upon such occurrence.
A modified form of sensing device adapted to be disposed between
the adjacent flanges of connected components of the Christmas tree
is shown in FIGS. 9 and 9-A, wherein a rectangular body member 20
having an enlarged flange 21 on its outer end is provided with a
control fluid passage 22 extending inwardly centrally of said body
from a threaded inlet opening 23 in the flange 21 to which the
control fluid line may be connected. The lower surface 25 of the
body is upwardly and inwardly inclined and engages the inclined
surface 26 of a lower closure member 27 which closes the inlet or
bore 22 of the body 20. The two members are pressed together firmly
in a wedge fit by driving or pressing the body member 20 inwardly
along the inclined upper surface 26 of the closure member 27
between the upper flange 28 and the lower flange 29 of two
interconnected components of the Christmas tree of the well. The
inclined surfaces provide a tight seal closing the inner end of the
bore 22 when the flanges are clamped together and the members are
driven into position therebetween. Should any spreading occur
between the flanges 28 and 29, the inclined surfaces will quickly
separate and permit the control fluid in the bore 22 to escape and
release control fluid pressure to actuate the safety valve V or V2,
or both, with which the control fluid line L4 is connected.
The wedge closure member 27 may be formed of a low temperature
melting or fusible metal, such as "Cerrometal" or the like, which
when subjected to a predetermined temperature will melt and flow to
release the control fluid present in the bore 22 of the body 20 of
the sensor 19. Thus, the sensor 19 is not only responsive to
separating movement of the flanges 28 and 29, but will likewise
sense elevated temperatures such as may result from a fire adjacent
the Christmas tree, to cause the safety valves V or V2 to close
upon the occurrence of such an event.
A plurality of the sensor members 19 will be positioned at
circumferentially spaced points around outside the seal ring R
between the two adjacent flanges, so that any movement of the
flanges which causes separation will actuate one or more of the
sensors 19 to release the control fluid confined in the bore 22
thereof. The control fluid line L4 will be connected to each of the
sensors 19 as shown in FIG. 11, and the sensors will be disposed
between the usual bolts 30 connecting the flanges. It will,
therefore, be seen that the sensing members 19 will release control
fluid present in the bores 22 thereof upon separation of the
flanges 28 and 29 to cause actuation of the valves V and V2 by
releasing the pressure present in the control fluid line L4
connected to the control fluid lines L and L2 leading to the
valves.
A further sensing device 35 is shown in FIGS. 10 and 10-A in which
a rectangular housing 36 of dielectric or non-conductive material
is disposed between the flanges 37 and 38 and confined tightly
therebetween, being positioned at circumferentially spaced points
around the seal ring between the flanges in the same manner as the
device of FIGS. 9 and 9-A, as shown in FIG. 11. Within the housing
36 is a normally biased open electrical microswitch 40 having a
fixed base conductor 41 provided with a contact point 42 and an
elongate leaf spring conductor arm 45 mounted at its inner end
between insulator spacers 43 and 44 and having a contact 46 on its
outer end portion disposed to engage the contact 42 of the
stationary arm or conductor. The leaf spring conductor 45 normally
biases the contact 46 away from the contact 42 to open the switch.
A pressure button or plunger 47, having a head 48 and a reduced
body 48a, is movable in an aperture 49 in the housing or case 36
and is pressed upwardly by the lower flange 38 to the position
shown in FIG. 10, wherein the leaf spring contact arm 45 is moved
toward the stationary conductor 41 to bring the contacts 42 and 46
into engagement and establish a circuit between the conductors. The
length of the button or plunger 47 is such that the contacts are
moved into engagement when the flanges are drawn together in the
usual manner. However, should the flanges separate in the manner
already described for any reason, the leaf spring conductor 45 will
move the lower contact 46 away from the contact 42 and break the
circuit between the conductors 41 and 45. The ends of the
conductors 41 and 45 adjacent the insulating spacers or separators
43 and 44 are connected to suitable electrical conductor wires 48
and 49, respectively, leading to a source of electrical power and
to a solenoid valve N3A or the like connected to the control
manifold U. When the contacts are separated, the circuit is broken
and the solenoid valve is permitted to move to release the control
fluid from the control fluid lines L and L2 and permit the safety
valves V and V2 to close. The solenoid valve is deenergized when
the contacts are separated and the valve is actuated in the usual
manner to open the valve and release the control fluid pressure.
The electrical sensors 35 may be disposed between any two adjacent
flanges of any two adjacent components of the Christmas tree on the
well to sense the separation of the flanges and cause the safety
valves to close.
The button 47 may have a low temperature fusible body 48a and a
dielectric head 48, whereby at a predetermined temperature the body
48a will melt and permit the switch to open.
Details of the tubing head H with the hanger or support S secured
therein and supporting the tubing string T, and having the adaptor
D connected thereto is shown in FIG. 8-A. Also shown in detail is
the construction of the tubing head flow controlling safety valve
V2 and the locking and sealing mandrel I. The lower flange of the
master valve M is shown connected to the upper flange of the
adaptor or spool D, while the tubing head is connected at its lower
end to the upper end of the exit bushing B.
The tubing hanger or support S is shown as threaded into the lower
end of the bore of the tubing head H in the usual manner and
consists of an elongate tubular body 50 having a downwardly and
outwardly inclined seating surface 51 intermediate its ends spaced
above the external annular threaded enlarged lower portion 52 of
said body. A seal ring 53 is provided in the sealing surface 51 for
sealing between the support body and the tubing head H. The upper
reduced portion of the body extends upwardly in the reduced upper
portion of the bore 55 of the tubing head in the usual manner. The
lower portion of the bore 56 of the hanger is enlarged in diameter
and provided with internal annular threads 57 by means of which the
upper end of the tubing string T is threadedly connected to the
hanger for suspension from the tubing head. The upper portion of
the bore 56 of the hanger is provided with a pair of internal
annular locking and seating recesses 58 above a sealing surface
extending between said recesses and the threaded portion 56 of the
hanger. This hanger is similar to that shown in the patent to John
V. Fredd, Re. 25,289, and the hanger is adapted to receive a well
head plug J similar to the plug illustrated in that Fredd patent
for closing the upper end of the bore of the tubing against flow
therethrough in the manner already described.
The adaptor spool member D comprises a tubular body 60 having a
substantially cylindrical bore 61 which is reduced at its lower
portion to provide a sealing surface 62 therein. The lower flange
63 of the adaptor is connected to the upper flange 64 of the tubing
head H, and the sealing ring R3 or R5 is adapted to be disposed in
the sealing grooves formed in the opposing faces of the flanges.
The upper flange 65 of the adaptor member is connected to the lower
flange 66 of the master valve at the lower end of the Christmas
tree and a suitable sealing ring R5 is disposed in the annular
grooves formed in the opposed faces of the flanges for sealing
therebetween. The flanges 65 and 66 and the flanges 63 and 64 are
drawn together by bolts (not shown) in the usual manner to engage
the sealing rings R3 and R5 to seal between the components of the
Christmas tree and to provide a continuous passageway through the
Christmas tree connected in flow communication with the upper end
of the tubing head H. The inlet opening and passage Q in the
adaptor D consists of an elongate passage 70 opening at its lower
end to the lower face of the flange 63 within the sealing ring
groove in the lower face of such flange in which the sealing ring
R3 is disposed. The upper end of the passageway communicates with
an enlarged opening 71 having an enlarged threaded outer portion 72
formed therein in a boss 73 on the exterior of the adaptor, by
means of which the control line L2 may be connected to said
adaptor.
The tubing head flow controlling safety valve V2 is similar to that
illustrated in the patent application of William W. Dollison, Ser.
No. 786,149, filed Dec. 23, 1968, now U.S. Pat. No. 3,583,442,
issued June 8, 1971, and comprises an elongate tubular housing 80
having an internal thread in its upper end by means of which it is
connected to the lower end of the mandrel 90 of the locking and
sealing device I. The lower end of the bore of the tubular housing
80 is reduced in diameter to provide an upwardly facing shoulder 81
engaged by the lower end of a helical coil spring 82. An elongate
tubular valve piston and seat member 85 is slidable longitudinally
in the bore of the housing 80 and has a piston member 86 near its
upper end provided with an O-ring or other suitable sealing ring 87
externally thereon for sealing between the piston and the bore wall
of the housing. The spring 82 bears against the lower surface of
the piston 86 and biases the member 85 upwardly in the housing. An
external annular enlarged closure head member 88 is formed on the
lower end of the tubular seat and piston sleeve 85 and has a
beveled seat 88a at its upper end disposed to engage a
complementary beveled stop surface or seat 88a at the lower end of
the housing 80 when the valve is moved to closed position. An
equalizing port 88b is formed in the wall of the sleeve 85 above
the seat 88a to permit easy opening of the valve in the manner set
forth in the aforesaid patent application. The sleeve 85 below the
closure head 88 is reduced in diameter to provide an external
annular groove 89 above an external annular flange and seat member
100 at the lower end of said sleeve 85 against which the ball
closure member 110 of the valve seats. A pair of connecting links
105 have hooks at their upper ends engaged in the external annular
recess 89 and inwardly projecting pins 102 engaging in
complementary recesses in the ball closure member 101, whereby the
ball closure member is moved with the sleeve 85. The ball will
pivot about the pins 102 engaged in the recesses in the ball, and
rotation of the ball is effected by means of pins 103 on opposite
sides of the ball engaged in angularly disposed slots 104 formed in
the outer periphery of the ball. The pins 103 are carried by a
slidable sleeve 106 mounted in the enlarged lower portion of the
bore of a valve cage 107 which is provided with internal threads
108 at its upper end by means of which it is connected to the lower
end of the housing 80. A thimble 109 is threaded into the lower
internally threaded end of the bore of the cage 107 and provides a
downward stop for the ball closure member for positioning the
transverse flow passage 110a of the ball closure member in
alignment with the longitudinal flow passage 112 in the bushing.
The upper end of the bushing also serves as a stop for the sleeve
106. When the flow passage 110a of the ball valve closure 110 is in
alignment with the flow passage 112 in the bushing it is also in
alignment with the longitudinal flow passage or bore 85a in the
elongate tubular sleeve 85, whereby fluids may flow through the
ball closure member upwardly through the sleeve and then upwardly
through the locking and sealing device I. A stabilizing pin 105 is
also provided in the sleeve 106 to guide the movement of the links
101 on the opposite sides of the ball closure for guiding the same
in their vertical movement and to assure rotation of the ball
closure member 110.
When the piston 86 is moved downwardly by fluid pressure applied to
the upper end thereof against the force of the spring 82, the
tubular sleeve 85 is moved downwardly and the ball is rotated to
the open position shown in FIG. 8-B. When the pressure acting on
the piston 86 is reduced or relieved, the spring 82 will move the
tubular sleeve upwardly and lift the ball closure member 110 to
cause rotation thereof to the closed position as shown in FIG.
5.
The anchoring and sealing assembly I comprises the elongate tubular
mandrel 90 having an external annular packing assembly 91 confined
thereon between the upper end of the valve housing 80 and an
external annular flange 92 formed on the mandrel. An O-ring or
other seal member 93 seals between the locking and sealing mandrel
90 and the upper end of the housing 80 of the valve. Likewise, the
upper reduced end 85c of the tubular piston sleeve 85 has a sliding
fit in the lower portion of the bore 90a of the mandrel 90 and an
internal annular sealing ring 94 in the bore of the mandrel seals
between the valve sleeve and the mandrel to provide a control fluid
pressure chamber 95 in the upper portion of the bore of the valve
housing below the lower end of the mandrel by means of which
control fluid may be confined to act on the piston 86. Control
fluid is directed into the chamber 95 through one or more
longitudinally extending flow passages 96 formed in the mandrel and
extending from the lower end thereof to the upwardly facing stop
shoulder 97 against which the locking dogs 120 are confined and
which limits downward movement of an elongate expander and locking
sleeve 127 on the upper reduced portion of the mandrel above said
shoulder.
The locking dogs 120 are disposed in radial windows 122 formed in a
dog carrier sleeve 123 threaded at its lower end onto the upper end
of the large lower portion of the mandrel below the shoulder 97 and
above the flange 92. The lower ends of the windows 122 are in
substantial alignment with the upwardly facing shoulder 97 and
provide a further support for the locking dogs at that point.
Suitable lateral flanges (not shown) on the dogs limit outward
movement of the dogs from the sleeve and suitable springs (not
shown) bias the dogs outwardly of the windows to a position at
which the downwardly facing abrupt stop shoulder 125 on the dogs
will engage the upwardly facing stop shoulder 58a in the locking
and positioning recesses or grooves 58 of the tubing hanger. The
exterior faces of the dogs conform to and are complementary with
the configuration of the locking and stopping recesses or grooves
58. The lower portion of the expander and locking sleeve 127 is
slidable on the upper reduced portion of the locking and sealing
mandrel 90 and within the enlarged lower portion of the bore of the
dog carrier sleeve. An external annular packing assembly 130 is
mounted on the upper portion of the dog carrier sleeve confined
thereon between an upwardly facing shoulder 131 and the downwardly
facing lower end of a retaining ring nut 132 threaded onto the
upper end of the sleeve. An internal seal ring 133 is disposed in a
suitable annular groove in the bore of the expander sleeve 127 and
seals between the expander sleeve and the exterior of the reduced
upper neck portion 98 of the mandrel 90. A retaining nut 99 is
threaded or silver soldered or otherwise suitably secured to the
upper end of the neck 98 of the mandrel and the upper portion of
the bore of the expander sleeve 127 is enlarged to slide along the
outer surface of the nut 99 at the upper end of the mandrel. The
upper portion of the expander sleeve is formed with longitudinal
slots or slits 128 providing a plurality of upwardly extending
resilient fingers 129 on the upper end of the expander sleeve which
are contractible to permit the enlarged external flange shoulders
129a to enter the reduced lower end of the bore of the detent
locking sleeve 150 past the internal annular stop flange 155 at the
lower end of the sleeve for assembly of the parts together. A
radial aperture is formed in each of the fingers and a detent
locking ball member 135 is disposed in each of the openings and is
adapted to engage the downwardly facing beveled shoulder 99a at the
lower end of the nut 99 to lock the locking sleeve 127 in its lower
position.
An internal annular seal ring 137 is disposed in a suitable
internal annular groove in the bore of the dog carrier sleeve below
the external packing assembly 130 and seals between the dog carrier
sleeve and the external surface of the expander sleeve 127, while
the ring 133 disposed in a suitable internal annular groove in the
expander sleeve 127 seals between mandrel neck 98 and the base of
the expander sleeve, whereby fluid pressure within the bore of the
adaptor member D and the tubing head H below the packing assembly
130 is confined between the mandrel 90 and the adaptor and tubing
head.
The detent locking sleeve 150 has the central portion of its bore
reduced to fit closely around the nut 99 at the upper end of the
mandrel and the lower portion of its bore is enlarged therebelow to
slide over the upper end of the external bosses or flanges 124a on
the fingers 129 at the upper end of the expander sleeve to press
the locking detent ball 135 inwardly of the apertures 134 below the
shoulder 99a at the lower end of the locking nut to hold the
expander sleeve in the lower position in which the dogs are locked
in expanded locking position in the recesses 58. Near the lower
portion of the enlarged lower bore of the detent locking sleeve is
formed an internal annular recess which is disposed to be aligned
with the detent balls 135 to permit the balls to move outwardly in
the apertures 134 to pass the shoulder at the lower end of the nut
99 to permit retraction of the expander sleeve upwardly from
engagement with the locking dogs. The internal annular flange 155
at the lower end of the detent locking sleeve engages the
downwardly facing shoulder at the lower end of the bosses 129a on
the fingers 129 at the upper end of the expander sleeve to lift the
expander sleeve when the detent locking sleeve is moved upwardly. A
fishing tool recess 156 is formed in the upper end of the bore of
the detent locking sleeve 150 for engagement by suitable retrieving
tool by means of which the sleeve may be lifted to lift the locking
sleeve and release the dogs 120 to permit the tool to be retrieved
from its position in the tubing hanger.
To install the device the locking sleeve is secured by means of a
shear pin 160 to the dog carrier sleeve 123. The shear pin extends
through aligned apertures 161 and 162 in the dog carrier sleeve and
expander sleeve, respectively, and when so disposed holds the
expander sleeve in the upper position out of engagement with the
locking dogs. When the anchoring and sealing device I has been
lowered through the Christmas tree until the downwardly facing stop
shoulder 125 on the dogs 120 engages the upwardly facing stop
shoulder 58a in the locking recess grooves 58, downward force
applied to the locking detent sleeve 150 moves the same downwardly
to move the shoulder 153 at the lower end of the internal flange
provided by the reduced central bore 154 into engagement with the
upper ends of the fingers 129 to force the expander sleeve
downwardly and shear the shear pin 160. Further downward force
applied to the detent locking sleeve will then move the expander
sleeve downwardly between the dogs to hold the same locked in
expanded holding position. When downward movement of the expander
sleeve has been limited by engagement of the lower end thereof with
the upwardly facing shoulder 97 on the mandrel, the balls 135 are
disposed beneath the downwardly facing shoulder 99a on the head 99
at the upper end of the mandrel neck and the detent locking sleeve
150 may move downwardly to move the locking surface 152 provided by
the enlarged bore below the shoulder 153 into engagement with the
balls to move the balls inwardly below the downwardly facing
shoulder 99a and lock the expander sleeve in its lower locking
position. Thus, the anchoring and sealing device is disposed in
anchored sealed position within the bore of the tubing hanger S and
the bore of the adaptor D. The upper packing 130 will seal against
the sealing surface 62 in the adaptor and the lower packing 191
will seal against the sealing surface 59 in the bore of the tubing
hanger.
Control fluid passing inwardly through the passageway 70 into the
annular space within the seal ring R3 and in the bore of the
adaptor D and the tubing head H will be confined between the upper
packing 130 and the lower packing 91 exteriorly of the mandrel 90
and will pass downwardly through the elongate longitudinal passage
96 in the mandrel into the chamber 95, where it will act on the
piston 86 to move the valve seat and piston tube 85 downwardly to
move the ball closure member 110 of the valve to open position
against the force of the spring 82.
It will be noted that the upper end of the locking and sealing
assembly I is disposed below the master valve M so as not to
interfere with the operation thereof. It is also preferable that
the adaptor spool or member D be of such longitudinal dimensions
that should the anchoring device and valve member V2 be disposed in
the tubing hanger with the detent locking sleeve is in its upper
position, the upper end of such sleeve is nevertheless still
disposed below the closure member of the master valve and will not
interfere with operation of the master valve to close off flow
therethrough.
When the valve V2 is closed, the bore of the tubing is closed at
the tubing hanger S and any leakage in the connections between the
components of the well head Christmas tree thereabove will be
terminated. The structures described are those effective to carry
out the method by use in the system of the invention.
A slightly modified form of means for supporting the tubing head
valve in the tubing hanger is shown in FIG. 12, wherein a slightly
different form of tubing hanger S1 is disposed in modified form of
tubing head H1. The hanger S1 is commonly known as the "bollweavel"
type hanger and has an enlarged external downwardly tapered upper
end portion 202 which is designed to seat in a downwardly tapered
bore 203 in the tubing head. Seal rings 200 are disposed in
external annular grooves 201 formed in the tapered surface 202 of
the hanger S1 and seal between the hanger and the tapered bore 203
of the tubing head H2. Suitable hold down screws 207 are threaded
through the flange at the upper end of the tubing head and engage
an inwardly inclined locking surface 208 at the upper end of the
external annular flange or head of the hanger. A packing gland and
nut 205 seals around each of the hold down screws. The bore of the
hanger is enlarged at its lower end and threaded as at 206 to
receive the upper end of the tubing string T in the usual manner.
The central portion of the bore of the hanger is reduced in
diameter and provided with interval threads 209 having a modified
downwardly facing buttress shape, each having a downwardly facing
stop shoulder inclined inwardly and upwardly and a longer inclined
downwardly and inwardly lower stop surface, for receiving a
complementary externally threaded sleeve 210 having modified
buttress threads 211 thereon which may be rotatably threaded into
said interval buttress threads 209 and secured in place thereby.
The sleeve 210 has O-ring seal members 212 disposed in external
annular recesses 213 above the threads which seal in the bore 214
of the hanger above the threads in said bore. The upper portion of
the bore of the hanger is enlarged and provided with internal
threads 215 for engagement by handling pipe or the like in the
usual manner.
The locking sleeve 210 has an internal annular thread in the lower
portion of its bore into which the externally threaded upper end
180a of the housing 180 of the valve V3 is threaded. An internal
annular seal ring 113 is disposed in a suitable internal annular
groove in the sleeve below the threads for sealing between the
sleeve and the housing. The locking sleeve 210 forms an upper
continuation of the valve housing 180 and the upper portion of its
bore is enlarged to provide a cylinder in which the piston 286 of
the tubular valve seat and piston sleeve 285 of the valve is
slidable. The external annular seal ring 287 in the piston seals
between the piston and the bore wall of the cylinder, and the upper
reduced end 285c of the sleeve 285 is slidable in a sub 218
connected to the upper end of the sleeve 210 by a reduced
externally threaded depending portion 218a which is threaded into
internally threaded upper end of the locking sleeve. A locking
screw 220 is threaded through the locking sleeve and into a recess
in the sub to hold the same securely locked together with the
inclined seating surfaces 221 and 222 on the locking sleeve and the
sub, respectively, in sealing engagement with each other. An
internal annular seal ring 223 is disposed in a suitable internal
annular groove 224 in the base of the reduced lower end of the sub
and seals between the sub and the reduced upper end or neck 285c of
the tubular valve seat and piston member 285. The O-ring may be
confined between non-extrusion rings of the usual type, if desired.
The locking screw permits rotation of the sub 218 and the locking
sleeve 210 to effect rotation of the buttress threads on the
exterior of the locking sleeve into the corresponding interval
buttress threads 209 in the bore of the tubing hanger.
A connector and packing bushing 230 is threaded into the upper
enlarged upper portion of the bore of the sub 218 and a locking
screw 231 is threaded through the sub and engages the packing
bushing 230 to prevent disengagement of the threads and to permit
rotation of the members in the manner already set forth. An
external annular flange 233 at the upper end of the bushing 230
clamps or confines an external seal assembly 235 on the bushing
between the upper end of the sub 218 and the shoulder 234 at the
lower end of the flange 233.
The bore of the bushing is internally threaded at 241 to provide
means for connecting handling tubing or rods thereto for rotation
of the locking sleeve to engage the buttress threads and the
corresponding threads in the hanger. A pair of diametrically
opposed slots 240 are provided in the upper end of the bushing for
engagement with a key pin carried by the rod, by means of which the
device is lowered into and locked in place in the tubing
hanger.
The buttress threads in the bore of the tubing hanger and the
external buttress threads on the locking sleeve are left hand turn
so that when the device is to be removed from the tubing hanger the
usual threaded rod or tubing may be inserted into the threads 241
at the upper end of the bushing 230, which are right hand threads,
and the tubing or rods rotated in a right hand or clockwise
direction to cause the disengagement of the buttress threads by
such rotation.
The external seal member 235 seals against a sealing surface 250
formed in the bore of a spacer flange 251, connected in the same
manner as the adaptor sleeve or spool D previously described
between the upper flange at the upper end of the tubing head H1 and
the lower flange at the lower end of the Christmas tree, usually
the lower flange of the master valve M.
An angular flow passage 252 is formed in the flange, extending
horizontally inwardly from the outer periphery of the flange and
upwardly from the lower surface thereof within the sealing ring
groove 253 in such surface in which the sealing ring R3 is
disposed. The outer end of the horizontal portion of the passage is
enlarged at 254 and threaded to provide means for connection of the
control fluid line L2 thereto for conducting control fluid into the
bore of the tubing head above the hanger.
The locking sleeve has a lateral flow passage 210a formed in the
wall thereof communicating with a cylinder or chamber 295 formed in
the bore of the sleeve above the piston 286 whereby the control
fluid from the passage 252 will act on the upper end of the piston
286 to bias the elongate valve seat and piston sleeve 285
downwardly against the force of the spring 282 to open the valve
therebelow connected with said sleeve.
The operation of the valve is similar to that already described and
the spacer flange or spacer member 251 corresponds in function to
the adaptor member D of the forms previously described. Otherwise,
the valve assembly V3 is held in place by means of the buttress
threaded connection between the externally threaded sleeve 210 and
the internally threaded bore of the tubing hanger S1.
In FIG. 13, a multiple producing zone of flow string well
installation is shown wherein two strings of tubing are disposed in
the casing and communicate with a lower zone Z1 below a lower
packer P1 and an upper zone Z2 communicating with the casing
between the lower packer P1 and an upper packer P2. The tubing
string T1 communicates with the lower zone below the lower packer
and the tubing string T2 communicates with the upper zone between
the packer P1 and the packer P2. Down-hole control valves V and V4,
which correspond to the down-hole valve previously described, are
connected in the tubing strings T1 and T2, respectively, and are
operated in the same manner.
An exit bushing or fixture B1 is connected to the casing head A1
and control fluid lines L and L1 extend downwardly through suitable
packing glands G in the exit bushing B1 to the down-hole valves for
conducting control fluid to such valves for actuating the same in
the manner already described. The control fluid manifold and valves
of this Figure are identical to those of FIG. 4.
The tubing strings T1 and T2 are connected at their upper ends to
separate hangers S3 and S4, respectively, in a multiple string
tubing head H4. Each of the tubing strings communicate with
separate flow passages through the adaptor spool D2 and the flow
courses are separated from each other by suitable annular seal
rings R7, R8, R9 and R10. The master valves M1 are connected to the
upper end of the adaptor in the usual manner and the Christmas tree
includes the usual dual string cross X1 and flow wings and
valves.
A tubing head flow controlling safety valve V2 is disposed in each
of the hangers S3 and S4, the safety valve being identical to that
shown in FIGS. 8-A and 8-B and anchored in place in the hangers in
the same manner. Control fluid is directed into each of the flow
passages in which the valves are anchored in sealing position in
the same manner as in the device of FIG. 4 and acts on each of the
valves identically with that previously described. The seal rings
R7, R8, R9 and R10, prevent communication of the control fluid in
one of the flow passages with that in the other so that each of the
valves is separately controlled if desired.
Control fluid manifolds U5 and U6 are connected to the control
fluid inlets Q5 and Q6, respectively, of the adaptor spool D2 for
supplying control fluid to control actuation of the valves. If
desired the control fluid manifolds U5 and U6 may be connected to
the control unit manifolds U by a suitable connecting line L10 so
that the down-hole valves and the tubing head safety valves are
connected together in the same manner as were the valves of FIGS. 6
and 7. Also, it is believed readily apparent that sensing devices
may be disposed between the flanges of the connected components of
the Christmas tree of this system as well as those previously
described.
In FIG. 14 a modified form of tubing hanger is shown, wherein the
body 350 is threaded as at 352 into the bore of a tubing head H5.
The tubing head has a lateral control fluid inlet passage 370
formed in its wall which has its outer portion enlarged and
threaded to receive the control fluid line L11 from the flow
control fluid unit U7. External annular seal rings 351 and 353 are
mounted in suitable external annular grooves on the hanger body 350
and seal between the hanger and the bore wall of the tubing head H5
above and below the lateral inlet 370. The bore 355 of the hanger
has internal annular locking and stop grooves 358 formed therein
for anchoring and locking and sealing mandrel of a flow control
valve V2 (not shown) in place in the hanger.
Below the locking and locating grooves 358 the bore of the hanger
is slightly reduced in diameter to provide upper and lower sealing
surfaces 360 and 361, respectively, above and below an internal
annular recess 362 formed in the bore between said sealing
surfaces. A lateral inlet port 365 is formed in the wall of the
hanger communicating with the internal annular recess 362 in the
bore of the hanger and with the inlet port 370 in the tubing head
H5 for conducting control fluid pressure into said groove for
controlling actuation of the safety valve supported therein.
In this installation the anchoring and positioning grooves and keys
are located above the sealing surfaces and a slightly modified form
of tubing head and hanger are utilized. Otherwise the device
functions in the same manner in carrying out the method and system
of the invention.
The upper flange 364 of the tubing head H5 has a radially inwardly
extending conduit 366 formed therein having its inner end portion
367 inclined upwardly to communicate with the annular ring groove
368 in the upper face of the flange in which the seal ring R55 is
seated. The seal ring R55 is similar to that illustrated in FIG.
7-A. However, only the vertical bore or passage 309 is formed in
the ring body 310, and the inner end 367 of the flow passage 366
communicates with the bottom of the annular recess 368 in which the
ring R55 is disposed. The ring R55 does not have a lateral port
communicating with the control fluid line, but instead the
passageway 366 communicates with the annular groove 368 in which
the ring is disposed, and through the vertical passage 309 with the
groove 369 in the lower face of the lower flange 66 of the master
valve. In this form of the device, as in the device of FIG. 7-A,
any leakage between the flanges and the seal ring R55 will reduce
the pressure of the control fluid present in the port passage 366
and, acting through the control line L11, will cause actuation of
the tubing head safety valve to closed position.
If desired, other sensing devices may be connected between the
flanges of other components of the Christmas tree and a control
fluid line L12 may be connected to the control fluid line L10 and
L11 leading to the down-hole valve, for actuation of both the
down-hole safety valve and the well head safety valve.
A still further modification of the flow controlling safety valve
is shown in FIG. 15, wherein the valve closure member and seat are
the same as those of the forms previously described. However, in
this form of the device the valve is shown as mounted on a tubular
member 400 which may be the lower end of a locking device or the
tubing hanger of the well tubing head. The ball valve is shown as
being movable mechanically to an open position by a prong or the
like (not shown) and latched in such open position by means of a
ball detent mechanism 401 disposed within the housing 480 and
acting on the elongate tubular valve seat and piston member 485 to
hold such tubular member in the lower position in which the ball
closure member 410 is turned to the open position, as shown. When
the detent mechanism 401 is released, the spring 482 will bias the
sleeve 485 upwardly to move the closure member 410 to closed
position, the spring being confined between the upper end of the
housing sub 507 and a split ring 508 mounted in an external annular
groove 509 on the exterior mid-portion of the sleeve.
The detent mechanism 401 comprises a plurality of detent latching
balls 425 which are disposed in lateral apertures 426 in the upper
portion of an upwardly extending retainer sleeve 427a extending
upwardly from an internal annular flange 427 in the mid-portion of
the bore of the housing 480 and through which the enlarged external
surface 485a of the sleeve 485 is slidable. An upwardly facing
shoulder 428 formed on the external surface of the tubular seat
sleeve 485 of the ball valve is engaged by the balls to hold the
sleeve in the lower position shown in FIG. 15 when the balls are
engaged with the seat. The balls are positively held inwardly in
locking engagement with the seat by a locking detent or latching
sleeve 429, the lower end of which has an internal annular
releasing recess 430 formed therein into which the balls may move
to permit the shoulder 428 to pass the balls when the sleeve is
moved upwardly to position the recess in alignment or registry with
the balls.
The upper portion of the locking sleeve 429 is reduced in both
internal and external diameter to provide a core supporting stem or
neck 435 slidable along the reduced upper end of tubular sleeve 485
and having an iron or other similar magnetic solenoid core sleeve
436 mounted in an external annular groove 437 formed along the
exterior of the neck. The iron core sleeve may be split and
suitably secured by welding or otherwise to the exterior of the
neck. The locking sleeve 429 is biased downwardly toward the
locking position shown in FIG. 15 by a helical coil spring 431
which is confined between the upwardly facing shoulder 432 at the
lower end of the reduced neck 435 and the lower end of an
electro-magnetic solenoid coil 440 confined within an enlarged bore
441 in the upper portion of the housing 480 of the valve.
Electrical conductor wires 442 and 443 lead from the electrical
coil 440 upwardly through a conduit 444 to a point exteriorly of
the flow path of the well head and to a source of power 445 which
may be a monostable multivibrator for supplying sufficient power to
activate the solenoid detent latch sleeve. A sensing switch
mechanism 450, which is a sensing mechanism similar to the sensing
mechanism 35 of FIGS. 10 and 10-A, but is a normally closed switch
held open by a plunger 451 disposed in a housing similar to the
housing 36 of such sensing mechanism, is yieldable to permit the
switch to move to its normally closed position to energize the coil
440 and cause the core 436 to move upwardly therewithin and lift
the detent locking sleeve 427 to position the recess 430 in
registry with the balls, whereupon the spring 482 will move the
sleeve 485 upwardly to close the ball valve closure member 410.
Thus, the valve is triggered by the electromagnetic solenoid type
operating mechanism for moving the locking sleeve with respect to
the detent balls 425 to release the sleeve for movement to closed
position.
Still another form of the valve is shown in FIG. 16, wherein the
elongate tubular valve seat sleeve 585 has a soft iron or other
magnetic material solenoid core sleeve 536 secured on the exterior
thereof in an external annular recess 537 formed on the upper
portion of the sleeve. The electro-magnetic solenoid coil 540 is
mounted in an internal annular recess 541 in the valve housing 580,
similarly to the coil 440 of the form last described, and acts on
the soft iron solenoid core 536 to draw the same downwardly to the
position shown in FIG. 16 and move the valve seat sleeve 585 and
the valve closure member 510 connected therewith to the open
position. The coil 540 is connected by electrical conductors 542
and 543 to a source of electric power and a normally open switch
550, identical to that of FIG. 10, which is held open by a plunger
551 similar to that of the sensing device 35 of FIG. 10. The power
unit 545 continues to supply energy to the solenoid coil 540 to
hold the solenoid core 536 downwardly and retain the valve seat
sleeve in the lower position and the valve closure open. When the
button 551 is destroyed or the flanges between which it is
positioned separate, the switch 550 is moved to its normally open
position to cut off or disconnect the supply of power to the coil
540 and permit the sleeve 585 to be moved upwardly to the upper
position by the helical coiled spring 582. In the upward position
the ball closure member 510 is closed.
In this form of the device, the tubular member 500 at the upper end
of the housing also may be either the lower end of an anchoring and
sealing device I or the lower end of a tubing hanger in the tubing
head.
The electrically controlled flow control safety valves of FIGS. 15
and 16 show modifications of the valve adapted for using the
sensing mechanisms of FIG. 10 and 10-A, though others may be used
equally well.
It will be seen that improved methods, apparatus and systems for
controlling flow of well fluids from a well flow conductor have
been shown and described, and particularly that such methods,
apparatus and systems are adapted to detect and control such flow
when undesired and unsafe conditions occur in the flow path and
connections of the well head Christmas tree.
The foregoing description of the invention is explanatory only, and
changes in the details of the constructions illustrated may be made
by those skilled in the art, within the scope of the appended
claims, without departing from the spirit of the invention.
* * * * *