U.S. patent number 3,651,823 [Application Number 05/032,845] was granted by the patent office on 1972-03-28 for thermal sensing blow out preventer actuating device.
Invention is credited to James Leland Milsted, Sr..
United States Patent |
3,651,823 |
Milsted, Sr. |
March 28, 1972 |
THERMAL SENSING BLOW OUT PREVENTER ACTUATING DEVICE
Abstract
The present disclosure is directed to a fail safe device to
close an oil or gas well that has ignited during drilling or
workover operations working in conjunction with pressure
accumulators and blow out preventers. The apparatus is installed in
a line the upstream side of which is pressurized by the
accumulators and the downstream side of which is connected to
actuate the blow out preventer. The device has a pair of normally
closed check valves which are spaced apart but which may be moved
together to unseat the valves and permit the pressurized fluid from
the accumulators to actuate the blow out preventer. The movement of
the check valves by a fluid motor which while being under pressure
is restrained from unseating the valves by a thermally fusible
flowable barrier which when attaining flow temperature will permit
the fluid motor to actuate and unseat the normally closed check
valve and apply the accumulator pressure to actuate the blow out
preventer to close the well.
Inventors: |
Milsted, Sr.; James Leland
(Harvey, LA) |
Family
ID: |
21867128 |
Appl.
No.: |
05/032,845 |
Filed: |
April 29, 1970 |
Current U.S.
Class: |
137/72; 166/53;
251/1.1; 137/614.04; 175/24; 251/63.5 |
Current CPC
Class: |
E21B
35/00 (20130101); E21B 33/06 (20130101); E21B
34/16 (20130101); Y10T 137/87957 (20150401); Y10T
137/1797 (20150401) |
Current International
Class: |
E21B
33/06 (20060101); E21B 33/03 (20060101); E21B
35/00 (20060101); E21B 34/00 (20060101); E21B
34/16 (20060101); E21b 033/06 (); F16k
017/38 () |
Field of
Search: |
;251/1 ;137/72-74
;166/53 ;175/24 ;220/88R,89B |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Nelson; M. Cary
Assistant Examiner: Gerard; Richard
Claims
What I claim is:
1. For use with a volatile fluid well rig having a blow out
preventer thereon coupled to a source of fluid supply under
pressure to actuate a blow out preventer, a thermal sensing blow
out actuator actuating device comprising a first cylinder adapted
to be placed in communication with the pressure to actuate a blow
out preventer, a first piston in said first cylinder subject to
said pressure and communicating with a first normally closed check
valve carried by said piston, a second piston actuatable by said
first piston, thermally fusible means responsive to ambient
temperature conditions positioned to restrain movement of said
first and second piston means and being accessible to surrounding
ambient temperature to become flowable above 400.degree. F. to
escape and permit movement of said first piston, and a second
normally closed check valve mounted on a static part of said device
adapted to be placed in fluid circuit to actuate a blow out
preventer and positioned to be engaged by said first normally
closed check valve so that upon said first normally closed check
valve engaging the second normally closed check valve both check
valves are unseated to permit the fluid supply to actuate a blow
out preventer upon flow of the fusible means.
2. For use with a volatile fluid well having a blow out preventer
supplied with actuating fluid from a source under pressure through
a main conduit under control of a hand-actuated valve in the
conduit, an automatic heat-triggered device adapted to be placed in
a by-pass conduit connected to the main conduit at opposite sides
of the hand-actuated valve and in communication at an initial end
with the pressure fluid source and at the discharge end with a blow
out preventer, comprising
a. a pair of normally closed check valve means adapted to be placed
in communication with a by-pass conduit,
b. fluid-pressure motive means adapted to be subjected to the
pressure in a by-pass conduit to be automatically moved thereby and
relatively to the last-mentioned valve means to engage and open
said check valve means when so moved, and
c. a normally solid blockading material in the path of movement of
the motive means subject to melting at elevated temperatures to
automatically permit movement of the motive means to open said
check valve means.
3. For use with a pressurized fluid charged line for actuating blow
out preventers on a volatile fluid well, a thermal sensing blow out
preventer actuating device comprising, two normally closed check
valves positioned with their central axis on the same center line
but physically separated so that each normally remains closed but
which when opened will pass actuating fluid, fluid motor means in
fluid circuit with and subjected to the pressure of the charged
line and being connected to said normally closed check valves for
opening same, and a fusible flowable barrier means responsive to
ambient temperature conditions positioned to normally restrain the
fluid motor constantly subjected to charged pressure from opening
said check valves to pass pressure actuating fluid through the line
until a rise in ambient temperature renders the barrier flowable
and permits the fluid motor to actuate and open said check valves
to pass the pressurized actuating fluid.
4. The apparatus of claim 3 wherein the fluid motor comprises a
cylinder, a piston having an open ended hollow rod one end of which
is in communication with the pressurized fluid at the head end of
the cylinder and the other end of which is connected to one of said
normally closed check valves, fusible flowable barrier engaging
means on said piston rod positioned to engage said barrier and
restrain linear motion of said piston rod against the pressurized
fluid until said barrier becomes flowable which permits movement of
one of said check valves against the other of said check valves to
unseat both valves and to pass the pressurized fluid through the
piston rod and both of said check valves upon flowing of the
fusible barrier.
5. The apparatus of claim 4 wherein the fusible barrier is of an
epoxy resin which becomes flowable above 400.degree. F.
6. The apparatus of claim 5 wherein the fusible barrier comprises
rods of epoxy resin which is flowable above 400.degree. F. in at
least one pair of telescopic tubes one of each pair of which is
connected to a static part of the device and the other of each of
which is connected to the barrier engaging means of the piston rod
of said motor and wherein at least one of said tubes of each pair
has openings through the wall thereof to permit escape of the epoxy
when it reaches flow temperature against the head pressure acting
on the piston rod.
7. The apparatus of claim 5 wherein the fusible barrier is a zone
of epoxy resin which is flowable above 400.degree. F. about the
piston rod and which is engaged by an annular projection carried by
said piston rod and wherein a plurality of openings are provided
through the cylinder wall in the area of the barrier so that upon
said barrier becoming flowable the annular projection on said rod
will force the flowable epoxy through the openings and permit the
piston rod to shift under its pressurized head causing the two
check valves to unseat and pass the pressurized fluid to actuate
the blow out preventer.
Description
The present invention is directed to the quick shutdown or closing
of an oil or gas well when a fire occurs and which will happen
automatically actuating the blow out preventers when a
predetermined temperature rise on the rig occurs.
Another object of the present invention is the provision of a quick
closing thermally responsive device which has fail safe features
which will insure against the fortuitous and untimely closing of a
well.
Another object of the present invention is the provision of a pair
of normally closed check valves in a fluid pressurized line to
actuate the blow out preventer which valves are actuated by a fluid
motor under the influence of the liquid pressure which actuates the
blow out preventer but which motor is restrained from acting on the
valves by a thermally fusible flowable barrier.
A still further object of the present invention is the provision of
an automatic blow out preventer actuator which will function to
close the well when temperatures because of fire prevent human
beings from operating the normal manual control valves.
A still further object of the invention is the provision of a fluid
motor restraining device in the form of an epoxy resin which when
cold will have the strength to resist accumulator pressure but
which when heated to 400.degree.F. will become flowable and permit
the fluid motor to unseat normally closed valves to actuate the
blow out preventer.
With the foregoing and other objects in view, the invention will be
more fully described hereinafter, and will be more particularly
pointed out in the claims appended hereto.
In the drawings wherein like symbols refer to like or corresponding
parts throughout the several views.
FIG. 1 is a schematic view of an oil well drilling rig showing the
Christmas Tree, blow out preventers, accumulators and manual remote
operating stations for the blow out preventer actuating controls as
well as locating the apparatus of the present invention with
respect thereto.
FIG. 2 is a fragmentary perspective view of the four way control
valve manual operation on the accumulator platform.
FIG. 3 is a hydraulic schematic of the operation of the four way
valve of FIG. 2.
FIG. 4 is a vertical section taken through the apparatus of the
present invention with the two normally closed check valves in
their mated open position.
FIG. 5 is a side elevational view of the apparatus of FIG. 4.
FIG. 6 is a vertical section taken through a modified form of
apparatus constructed in accordance with the present invention.
Referring now for the moment to FIG. 1, an oil well rig is shown
having a Christmas Tree arrangement 10 with the blow out preventers
11, 12 and 13 thereon. The motive fluid for actuating the blow out
preventers comes from a source of hydraulic accumulators 14 which
will bring up the hydraulic lines to a pressure adequate to assure
operation of the blow out preventers.
The overhead rig structure of 15 has a manual remote control
station 16 for operating the control valves for closing the blow
out preventers.
In the oil well rig structure 15 the apparatus of the present
invention is shown schematically as being located at 17 and which
is shown being coupled to the hydraulic accumulator pressurized
source at one side and to the blow out preventers downstream of the
apparatus.
Referring now to FIGS. 4 and 5, the thermo-sensing blow out
preventer actuating device 17 has an end portion 18 having a bore
19 therethrough. An O-ring seal 20 permits of hydraulic
communication between the bore 19 and the bore 21 and the cylinder
housing 22. A cylinder chamber 23 is provided in which is mounted a
piston 25 having a rod 26 which is provided with a hollow bore 24
therethrough. The piston rod 26 has a projection 27 annularly
thereabout. The operating end of the piston rod 26 has connected
thereto a normally closed check valve 28 which is in axial
alignment with a normally closed check valve 29 carried by the
upper casement 30. The upper casement 30 has an opening 31
therethrough. This structure provides for a fluid path straight
through the device obstructed only by the two normally closed check
valves 28 and 29. The fluid path is through bore 19, bore 21, bore
24 through the piston rod 25 and 26 up to the check valve 28. The
fluid passage on the downstream side of the check valves is shown
at 31 and from 31 goes directly to the fluid operating connection
of the blow out preventers. The two normally closed check valves 28
and 29 are arranged such that upon mating the two valves 28, 29
each valve unseats the other to permit the head of the fluid
pressure to go from the end 18 through the end 30 of the
thermo-sensing blow out preventer actuating device 17.
The annular extension 27 carried by the piston rod extension 26 is
position to engage a ring 32 which forms a base for a pair of
telescopic tubes 33 and 34. The walls of the tubes 33 have openings
35 therethrough and the tube chambers are normally filled with an
epoxy resin of sufficient volume to cause the two normally closed
check valves 28 and 29 to be separated; however, upon the epoxy
resin attaining a temperature in excess of 400.degree.F. the resin
will become flowable and will flow through the openings 35 allowing
the fluid motor piston 25 to move the rod 26 and thereby cause the
valve 28 to mate with the valve 29 opening both valves and allowing
the pressurized fluid from the accumulators 14 to actuate the blow
out preventers and to thereby seal off the well 12. The upstream
side of the unit 17 is in communication with the pressure fluid
from the accumulators 14 and upon the opening of the check valves
28, 29 the fluid will flow through line 37 to the blow out
preventer 13 to seal the well.
Referring now to FIG. 6, 40 designates a modified form of
thermo-sensing blow out preventer actuating device in which a
cylinder 41 has a fluid chamber 42 in communication with the
pressurized fluid from the accumulators 14 through opening 43.
Within the cylinder 41 is a piston 44 having a rod 45 with an open
bore 46 therethrough. The other end of the hollow piston rod 45 has
connected thereto a normally closed check valve 47 which can only
be unseated by mating it with a complemental normally closed check
valve 48 carried by a static portion 49 of the cylinder 41 so that
upon unseating of both valves 47 and 48 fluid will flow through the
unit 40 and be communicated to actuate the blow out preventer 13
through line 50.
Carried on the piston rod 45 is an annular projection 51 which
engages a thermal sensing fusible flowable barrier 52 of an epoxy
resin which will flow only upon the resin being heated to over
400.degree.F. at which time the head pressure upon the piston from
the accumulators 14 will cause the projection 51 to force the
flowable epoxy through the openings 53 in the cylinder walls
thereby permitting the hollow piston rod 45 to cause mating and
unseating of the two normally closed check valves 47, 48 which will
permit the pressurized fluid to pass from the accumulators to
actuate the blow out preventers to seal the well. In this
embodiment the check valves 47, 48 are identical to the check
valves 28, 29 of FIGS. 4 and 5.
The parts 18, 22 and 30 are retained in operative relationship by
assembly bolts 36, and nuts 37.
In both embodiments the cylinder walls 22 and 41 respectively have
high velocity check valves 54 which leak until a velocity is
applied at which time they hold pressure. This prevents hydraulic
fluid that might leak past the piston seal ring from causing a
hydraulic lock when the piston head moves toward the check valve
operating position.
While I have given as an example an epoxy resin which will become
flowable at 400.degree.F. or over for a form of thermally fusible
flowable barrier it will be appreciated by those skilled in that
art that any fusible flowable solid which will liquify or become
flowable may be employed whether it be metallic or plastic so long
as it has strength in its solid state to overcome the hydraulic
head and keep the valves 28, 29 and 47, 48 apart and closed but
which will upon being heated become flowable allowing the hydraulic
head to move the piston rod a length sufficient to mate the
normally closed valves thereby unseating them and allowing the
hydraulic head pressure to flow to the blow out preventer and seal
off the well.
While drilling or during workover the devices 17 or 40 may be
mounted anywhere on the drilling or workover rig, probably about 20
feet above the floor, in the derrick 15. A line A is installed from
the pressure accumulator 14 to one end of the unit 17. Another line
B is installed from the downstream side of the unit 17 to the blow
out preventer 13. Both lines A and B are in parallel to the
operating valves at the remote station 16 and are connected to
supply operating fluid to the blow out preventer.
The output line 31 of unit 17 and output line 50 of unit 40 may be
connected to the piston operator 56 attached to the handle 57 of
the four-way control valve 58. Normally the piston 56 is used to
shift positions of the four-way valve 58 remotely. The four-way
control valve 58, shown in FIGS. 2 and 3 are shown diagramatically
at 16 in FIG. 1 and over ridden to actuate the blow out preventer
by the unit 17 when a rise in ambient temperature occurs by a fire
which due to heat intensity makes it impossible for a human being
to actuate the valve 58 to close the blow out preventers 11, 12 and
13.
* * * * *