Note: Descriptions are shown in the official language in which they were submitted.
ROD ANNULAR BLOWOUT PREVENTER HYDRAULIC SUPPLY SYSTEM
[0001] BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0002] The present invention relates to blowout preventer systems and to
oil well blow out
preventers. More specifically, the present invention relates to an improved
system for inflating a bladder type
rod blow out preventer on a well head using hydraulic pressure from the
reservoir of the hydraulic pumping
system.
[0003] A blowout preventer device is a required safety device on an oil rig
that prevents the
uncontrolled release of high pressure well fluid from an oil well. These
devices are exposed to extremely
high pressure, as well as erratic fluctuations in pressure. These devices are
fail-safe mechanisms that prevent
the escape of wellbore fluid and allow fluid to be added or removed from the
wellbore as desired by
operators. Additional functions include regulating and monitoring the wellbore
pressure, and shutting off the
well altogether in the event of an emergency or failure of the well.
[0004] Common types of blowout preventers include ram-type
preventers and rod annular
blowout preventers. Both of these designs allow the rods to be moved up or
down through the blowout
preventer device, and are used to close the annulus around the rods in the
event of a blowout. Ram-type
preventers require a ram block to be sized and shaped appropriately for the
rods being enclosed in order to be
effective when closing the well, and must be changed accordingly when
installing or removing different
pipes or rods in the well. Changing the blowout preventer ram based on the
type of well rod being deployed
is both time consuming and impractical if used as the primary blowout
preventer system. Moreover, as a
result of the change, the wellbore is exposed without a control device for
brief periods of time. These devices
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may further require manual application to close off the annulus, whereby rig
operators manually actuate the
rams toward the rod, thereby placing workers within the vicinity of the
release.
[0005] Rod annular blowout preventers enclose around a rod using
an elastomeric
diaphragm member, which is hydraulically activated and moved into a position
that fills the gaps between the
annulus and the rod cavity. The hydraulic pressure source generally employed
for a rod annular blowout
preventer includes hydraulic hand pumps, redirecting the hydraulic pressure
supply from the rig, or
redirecting pressure from a blowout preventer system. Rods include, but are
not limited to, sucker rods,
fiberglass rods, co-rod, sinker bars, cable, or polished rods.
[0006] These three solutions present significant safety
limitations. A hand pump takes
several minutes to deploy and to inflate the diaphragm, and subsequently
causing loss of fluid from the well
and a dangerous environment for nearby personnel. The operators are requiring
to manually pump the
diaphragm, placing them closer to danger for longer periods. The second
alternative employs hydraulic
pressure from the rig. The pressure of the rig, however, operates at extremely
high levels. By contrast, the
necessary closing pressure for an annular diaphragm significant less than the
rig pressure. The excessive
force applied by the rig hydraulic pressure therefore results in damage and
premature failure of rod annular
elements as a result of overpressurization. This causes failure of seals and
rings, or splitting of the diaphragm
upon inflation. The same issue is present when drawing hydraulic pressure from
the accumulator.
[0007] The present invention contemplates a new system of
deploying a rod annular
blowout preventer, whereby hydraulic pressure is used from the blowout
preventer system. The system
employs a series of safety devices and a pressure regulator to ensure the
pressure being applied to the annular
diaphragm is suitable for its design. This effectively removes rig operators
from dangerous situations when
the blowout preventer needs to be deployed, and furthermore prevents
unpredictable overpressurization of
the diaphragm that may otherwise result. The system incorporates the rig
manifold, allowing rig operators to
operate the blowout preventer from a safe standoff distance. During normal
operation, and during well
servicing operations, overall safety is improved and efficiency is maximized.
DESCRIPTION OF THE PRIOR ART
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[0008] Devices have been disclosed in the prior art that relate to
hydraulic pumping systems
for oil wells, as well as blowout preventers that can close in a well in the
event of an emergency or during
maintenance. These include devices that have been patented and published in
patent application publications.
These devices generally relate to improved blowout mechanisms or improved
components of the overall
system. The present invention contemplates an intermediate system that
regulates hydraulic pressure from an
existing hydraulic reservoir blowout preventer system, and operably diverts
the pressure to the annual
blowout preventer to rapidly deploy the same when required to do so. The
present invention improves
existing hydraulic application while servicing an oil well by providing an
improved means of deploying a rod
annular blowout preventer.
[0009] Blowout preventer systems utilize hydraulic pressure and a
pump to move
incompressible hydraulic fluid from a reservoir. These systems generally
employ an incompressible fluid
storage, such as a hydraulic fluid or the like, a prime mover (e.g. a pump) to
apply pressure to the fluid, one
or more accumulators, and a control station. To operate the blowout preventer
device, high pressure
hydraulic fluid is generated by the pump and supplemented by the accumulator
of the blowout preventer
system. The hydraulic fluid is retained within the one or more accumulators
and routed to the blowout
preventer device using a manifold system, which is a controlled series of
pipes and valves that direct the fluid
to the blowout preventer device during operation of the well.
[0010] During maintenance procedures and during emergency events, the
blowout
preventer is deployed to close the wellbore around the rod string in the well.
This prevents oil leaks and
surges of pressurized fluid from the well escaping through the wellhead. The
present invention contemplates
a system that employs a manifold control, a pressure regulator, and a series
of safety features that can divert
hydraulic pressure from the existing hydraulic reservoir to a rod annular
blowout preventer. The pressure is
regulated and thus appropriate for energizing the diaphragm of the blowout
preventer, and furthermore offers
rig operations with a standoff control means to initiate the blowout preventer
when needed. The hydraulic
pressure energizes the diaphragm into place in a matter of seconds, as opposed
to manual operations that take
minutes. Use of controlled pressure further ensures no failure of the blowout
preventer under pressure.
[0011] It is submitted that the present invention substantially diverges in
elements from the
prior art, and furthermore adds a new and novel system to existing hydraulic
oil well technologies that
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improves safety and effectiveness of rod annular blowout preventers. Lack of
adequate solutions in the art
make it clear that there is an unmet need. The present invention substantially
fulfills this need by providing a
hydraulically deployed rod annular blowout preventer without requiring
additional hydraulic storage tanks or
standalone systems. The present invention is one that can be installed on
existing rigs with minimal
interference to existing operations.
SUMMARY OF THE INVENTION
[0012] In view of the foregoing disadvantages inherent in the
known types of rod annular
blowout preventer systems now present in the prior art, the present invention
provides a new system in which
to deploy a rod annular blowout preventer using available hydraulic pressure
from the blowout preventer
system.
[0013] It is therefore an object of the present invention to
provide a new and improved rod
annular blowout preventer system that has all of the advantages of the prior
art and none of the
disadvantages.
[0014] It is another object of the present invention to provide a
more efficient hydraulic
actuation for a rod annular blowout preventer device, whereby the hydraulic
pressure is drawn from the
existing blowout preventer system and tailored to the specifications of the
rod annular blowout preventer
device deployed.
[0015] Another object of the present invention is to provide a rod
annular blowout preventer
system that eliminates hand pumping a rod annular blowout preventer, and
furthermore prevents failure of
rod annular blowout preventers as a result of overpressurization.
[0016] Yet another object of the present invention is to provide a
rod annular blowout
preventer system that can be deployed from a control unit on the rig or a
distance therefrom, allowing rig
operators to initiate the rod annular blowout preventer from a distance if
required.
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[0017] Another object of the present invention is to provide a rod
annular blowout preventer
system that includes safety valve systems to prevent well fluid from exiting
the wellhead in the event the
regulator fails.
[0018] Another object of the present invention is to provide a rod annular
blowout preventer
system that does not require an additional hydraulic reservoir or prime mover
to operate, but rather
capitalizes upon existing equipment and ties into the system to divert
hydraulic fluid to the blowout
preventer.
[0019] Other objects, features and advantages of the present invention will
become apparent
from the following detailed description taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0020] Although the characteristic features of this invention will
be particularly pointed out
in the claims, the invention itself and manner in which it may be made and
used may be better understood
after a review of the following description, taken in connection with the
accompanying drawings wherein
like numeral annotations are provided throughout.
[0021] FIG. 1 shows a system diagram of the system of the present
invention in connection
with a hydraulic blowout preventer system.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Reference is made herein to the attached drawings. Like
reference numerals are used
throughout the drawings to depict like or similar elements of the rod annular
blowout preventer system of the
present invention. For the purposes of presenting a brief and clear
description of the present invention, the
preferred embodiment will be discussed as used for deploying the diaphragm of
a rod annular blowout
preventer system using hydraulic power from the existing hydraulic blowout
preventer system. The figures
are intended for representative purposes only and should not be considered to
be limiting in any respect.
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[0023] The present invention comprises a manifold control unit
that is hydraulically
connected to the blowout preventer system. The hydraulic fluid in the
reservoir is under pressure and is
controllably diverted to the rod annular blowout preventer at the wellhead
using the system of the present
invention. During prescribed maintenance or in the event of an emergency, rig
operators can deploy the
blowout preventer using the pressurized hydraulic fluid through the present
system, whereby the blowout
preventer is deployed in a matter of seconds, and from a distance from the
wellhead itself. The present
invention increases safety and all but eliminates escaping well fluid into the
environment.
[0024] Referring now to FIG. 1, there is shown a system view of
the present invention. The
present invention comprises a manifold 11 that comprises one or more valves
and hydraulic lines in
connection with user controls, whereby the well hydraulic system is connected
to the regulator system of the
present invention. The hydraulic blowout preventer system comprises an
accumulator 15, a prime mover in
the form of a pump 13, and a reservoir 12 of incompressible hydraulic fluid. A
nitrogen reserve 16 provides
backup to the accumulator 15, whereby the accumulator provides a pressurized
hydraulic fluid backup for the
pump during periods of peak demand on the system. A one-way valve 14 prevents
reverse flow of fluid,
whereby fluid cannot enter the hydraulic pump or reservoir when the
accumulator 15 and nitrogen reserve 16
are pressurized.
[0025] The hydraulic pressure of the blowout preventer system is
controlled by a manifold
system 11. The manifold system is a hydraulic manifold that regulators the
flow of hydraulic fluid between
the hydraulic inputs (e.g. the pump 13, accumulator 15, and the nitrogen
reserve tanks 16) and the output of
the system (namely, the blowout preventer device installed on the well). The
blowout preventer device is
installed on the well 24, implementing a control measure thereon while
services the well or when closing the
well during an emergency. The manifold system is controlled by rig operators.
[0026] The present invention contemplates integrating the
hydraulic inputs of an existing
blowout preventer system into a system that diverts hydraulic pressure to the
wellhead blowout preventer
device. To replace existing manual operations, and further to prevent
overpressurization as a result of
uncontrolled hydraulic actuation of the rod annular blowout preventer system,
the present invention
contemplates a system that can hydraulically close a blowout preventer device
using a rod annular blowout
preventer system with a controlled application of hydraulic pressure thereto.
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[0027] Specifically, the present invention contemplates
incorporation into the manifold
system 11 of the existing rig, or optionally a new manifold system, that
diverts hydraulic fluid pumped from
the reservoir or from the accumulator 15 to the blowout preventer. A pressure
regulator 17 monitors the
pressure of the hydraulic fluid from the manifold 11 and prevents overly high
pressure fluid from entering
the blowout preventer on the wellhead 24. Fluid at a controlled pressure is
directed through hydraulic lines to
the blowout preventer to inflate the diaphragm 25 within the wellhead 24.
[0028] Between the pressure regulator 17 and the wellhead 24 is a
series of valves for safety
purposes. Fluid is forced through a one-way valve 20 and an isolation valve 21
before reaching the wellhead.
The one-way valve 20 prevents backflow and the isolation valve 21 is an
optional safety valve in the event
the one-way valve 20 fails and backflow is being received from the wellhead
24. A pressure relief line is
installed in parallel to the one-way valve 20 and the isolation valve 21. The
relief line includes another
isolation valve 22, which is used to release applied pressure against the rod
annular blowout preventer in the
well head.
[0029] Under normal conditions, pressurized hydraulic fluid from
the reservoir 12 is
released through the manifold system 11 and into the pressure regulator. The
regulated hydraulic pressure is
then routed to the rod annular blowout preventer in the wellhead, which is
used to inflate or expand a
diaphragm 25 therein to enclose the well around a rod string therein. Pressure
can be deposited back into the
reservoir 12 through a return line having a one-way valve 19 therealong, which
fluidly connects the regulator
17 to the manifold when the diaphragm is expanded. Pressure in the system is
monitored by pressure gauges
23, 18 along the hydraulic lines.
[0030] Overall, the present invention provides a system for closing the rod
blowout
preventer device. This system allows an operator to use the hydraulic pressure
pumped from in the reservoir
and from an accumulator to close the rod annular blowout preventer device on
the wellhead. The present
invention provides an efficient way to close the annular in the event of a
blowout, enables an operator to
safely shut in the rod annular from a remote location, and reduces the risk of
blowout related risks from any
exposure to wellbore fluids or gases.
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[0030] It is therefore submitted that the instant invention has
been shown and described in
what is considered to be the most practical and preferred embodiments. It is
recognized, however, that
departures may be made within the scope of the invention and that obvious
modifications will occur to a
person skilled in the art. With respect to the above description then, it is
to be realized that the optimum
dimensional relationships for the parts of the invention, to include
variations in size, materials, shape, form,
function and manner of operation, assembly and use, are deemed readily
apparent and obvious to one skilled
in the art, and all equivalent relationships to those illustrated in the
drawings and described in the
specification are intended to be encompassed by the present invention.
[0027] Therefore, the foregoing is considered as illustrative only of the
principles of the
invention. Further, since numerous modifications and changes will readily
occur to those skilled in the art, it
is not desired to limit the invention to the exact construction and operation
shown and described, and
accordingly, all suitable modifications and equivalents may be resorted to,
falling within the scope of the
invention.
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