Note: Descriptions are shown in the official language in which they were submitted.
i ~i~,l, ~ I~ "i,i I ~ ,
CA 02263486 2004-09-17
VARIABLE ORIFICE GAS LIFT VALVE FOR HIGH FLOW RATES
WITH DETACHABLE POWER SOURCE AND METHOD OF USING
BACKGROUND OF THE INVENTION
S 1. Fig~d Of a Invention
The present invention relates to subsurface well completion equipment and,
more
particularly, to an apparatus for lifting hydrocarbons from subterranean
formations with gas at high
production rates. Additionally, embodiments of independent and detachable
actuators are disclosed.
2. Description Of The Related Art
I 0 Artificial lift systems, long known by those skilled in the art of oil
well production, are used
to assist in the extraction of fluids from subterranean geological formations.
The most ideal well
for a company concerned with the production of oil, is one that flows
naturally and without
assistance. Often wells drilled in new fields have this advantage. In this
ideal case, the pressure of
the producing formation is greater than the hydrostatic pressure of the fluid
in the wellbore, allowing
1 S the well to flow without artificial lift. However, as an oil bearing
formation matures, and some
significant percentage of the product is recovered, a reduction in the
formation pressure occurs.
With this reduction in formation pressure, the hydrocarbon issuance therefrom
is likewise reduced
to a point where the well no longer flows without assistance, despite the
presence of significant
volumes of valuable product still in place in the oil bearing stratum. In
wells where this type of
20 production decrease occurs, or if the formation pressure is low from the
outset, artificial lift is
commonly employed to enhance the recovery of oil from the formation. This
disclosure is primarily
concerned with one type of artificial lift called "Gas Lift."
Gas lift has long been known to those skilled in the art, as shown in U.S.
Patent No.
2,137,441 filed in November 1938. Other patents of some historic significance
are U.S. Patent Nos.
2S 2,672,827, 2,679,827, 2,679,903, and 2,824,525, all commonly assigned
hereto. Other, more recent
developments in this field include U.S. Patent Nos. 4,239,082, 4,360,064 of
common assignment,
as well as 4,295,796, 4,625,941, and 5,176,164. While these patents all
contributed to furthering the
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
art of gas lift valves in wells, recent trends in dulling and completion
techniques expose and
highlight long felt limitations with this matured technology.
The economic climate in the oil industry of the 1990's demands that oil
producing companies
produce more oil, that is now exponentially more difficult to exploit, in less
time, and without
increasing prices to the consumer. One successful technique that is currently
being employed is
deviated and horizontal drilling, which more efficiently drains hydrocarbon
bearing formations. This
increase in production makes it necessary to use much larger production tubing
sizes. For example,
in years past, 2-3/8 inch production tubing was most common. Today, tubing
sizes of offshore wells
range from 4-1/2 to 7 inches. While much more oil can be produced from tubing
this large,
conventional gas lift techniques have reached or exceeded their operational
limit as a result.
In order for oil to be produced utilizing gas lift, a precise volume and
velocity of the gas
flowing upward through the tubing must be maintained. Gas injected into the
hydrostatic column
of fluid decreases the column's total density and pressure gradient, allowing
the well to flow. As
the tubing size increases, the volume of eas required to maintain the well in
a flowing condition
increases as the square of the increase in tubing diameter. If the volume of
the gas lifting the oil is
not maintained, the produced oil falls back down the tubing. and the well
suffers a condition
commonly known as "loading up." If the volume of gas is too great, the cost of
compression and
recovery of the lift gas becomes a significant percentage of the production
cost. As a result, the size
of a gas injection orifice in the gas lift valve is of crucial importance to
the stable operation of the
well. Prior art gas lift valves employ fixed diameter orifices in a range up
to 3/4 inch, which may
be inadequate for optimal production in large diameter tubing. This size
limitation is geometrically
limited by the gas lift valve's requisite small size, and the position of its
operating mechanism,
which prevents a full bore through the valve for maximum flow.
Because well conditions and gas lift requirements change over time, those
skilled in the art
of well operations are also constantly aware of the compromise of well
efficiency that must be
balanced versus the cost of intervention to install the most optimal gas lift
valves therein as well
conditions change over time. Well intervention is expensive, most especially
on prolific offshore
or subsea wells, so a valve that can be utilized over the entire life of the
well, and whose orifice size
and subsequent flow rate can be adjusted to changing downhole conditions, is a
long felt and
unresolved need in the oil industry. There is also a need for a novel gas lift
valve that has a gas
injection orifice that is large enough to inject a volume of gas adequate to
lift oil in large diameter
2
CA 02263486 1999-02-15
WO 98/06928 PCTIUS97/14431
production tubing. There is also a need for differing and novel operating
mechanisms for gas lift
valves that will not impede the flow of injection gas therethrough.
SUMMARY OF THE INVENTION
The present invention has been contemplated to overcome the foregoing
deficiencies and
meet the above described needs. In one aspect, the present invention is a gas
lift valve for use in a
subterranean well, comprising: a valve body with a longitudinal bore
therethrough for sealable
insertion in a mandrel; a variable orifice valve in the body for controlling
fluid flow into the body;
and, an actuating means connected to the variable orifice valve. Another
feature of this aspect of
the present invention is that the actuating means may be electro-hydraulically
operated, and may
further include: a hydraulic pump located in a downhole housing; an electric
motor connected to
and driving the hydraulic pump upon receipt of a signal from a control panel;
hydraulic circuitry
connected to and responding to the action of the pump; and, a moveable
hydraulic piston responding
to the hydraulic circuitry and operatively connected to the variable orifice
valve, controlling
movement thereof. Another feature of this aspect of the present invention is
that the actuating
means may further include a position sensor to report relative location of the
moveable hydraulic
piston to the control panel. Another feature of this aspect of the present
invention is that the
actuating means may be selectively installed and retrievably detached from the
gas lift valve.
Another feature of this aspect of the present invention is that the actuating
means may further
include at least one pressure transducer communicating with the hydraulic
circuitry, and transmitting
collected data to the control panel. Another feature of this aspect of the
present invention is that the
actuating means may further include a mechanical position holder. Another
feature of this aspect
of the present invention is that the actuating means may be selectively
installed and retrievably
detached from the gas lift valve.
Another feature of this aspect of the present invention is that the actuating
means may be
hydraulically operated, and may further include: a hydraulic actuating piston
located in a downhole
housing and operatively connected to the variable orifice valve; a spring,
biasing the variable
orifice valve in a full closed position; and. at least one control line
connected to the hydraulic
actuating piston and extending to a hydraulic pressure source. Another feature
of this aspect of the
present invention is that the actuating means may further include a position
sensor to report relative
location of the moveable hydraulic piston to a control panel. Another feature
of this aspect of the
present invention is that the actuating means may further include at least one
pressure transducer
communicating with the hydraulic actuating piston, and transmitting collected
data to a control
3
CA 02263486 1999-02-15
WO 98/06928 PCT/L1S97/14431
panel. Another feature of this aspect of the present invention is that the
actuating means may be
selectively installed and retrievably detached from the gas lift valve.
Another feature of this aspect of the present invention is that the actuating
means may be
electro-hydraulic. and may further include: at least one electrically piloted
hydraulic solenoid valve
located in a downhole housing; at least one hydraulic control line connected
to the solenoid valve
and extending to a hydraulic pressure source; hydraulic circuity connected to
and responding to the
action of the solenoid valve; and, a moveable hydraulic piston responding to
the hydraulic circuitry
and operatively connected to the variable orifice valve, controlling movement
thereof. Another
feature of this aspect of the present invention is that the actuating means
may further include a
position sensor to report relative location of the moveable hydraulic piston
to a control panel.
Another feature of this aspect of the present invention is that the actuating
means may further include
at least one pressure transducer communicating with the hydraulic circuitry,
and transmitting
collected data to a control panel. Another feature of this aspect of the
present invention is that the
actuating means may be selectively installed and retrievably detached from the
gas lift valve.
Another feature of this aspect of the present invention is that the actuating
means may be
pneumo-hydraulically actuated. and may further include: a moveable hydraulic
piston having a first
and second end, operatively connected to the variable orifice valve,
controlling movement thereof;
at least one hydraulic control line connected to a hydraulic pressure source
and communicating with
the first end of the hydraulic piston; and, a gas chamber connected to and
communicating with the
second end of the hydraulic piston. Another feature of this aspect of the
present invention is that the
gas lift valve may be retrievably locatable within a side pocket mandrel by
wireline and coiled tubing
intervention tools. Another feature of this aspect of the present invention is
that the gas lift valve
may be selectively installed and retrievably detached from the actuating
means. Another feature of
this aspect of the present invention is that the actuating means may be
selectively installed and
retrievably detached from the gas lift valve.
In another aspect. the present invention may be a method of using a gas lift
valve in a
subterranean well. comprising: installing a first mandrel and a second mandrel
in a well production
string that are in operational communication; retrievably installing a
variable orifice gas lift valve
in a first mandrel; installing a controllable actuating means in a second
mandrel; and, controlling
the variable orifice gas lift valve by surface manipulation of a control panel
that communicates with
the actuating means. Another feature of this aspect of the present invention
is that the method of
installing the variable orifice gas lift valve and the actuating means may be
by wireline intervention.
4
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
Another feature of this aspect of the present invention is that the method of
installing the variable
orifice gas lift valve and the actuating means may be by coiled tubing
intervention.
In another aspect, the present invention may be a gas lift valve for variably
introducing
injection gas into a subterranean well, comprising: a valve body with a
longitudinal bore
therethrough for sealable insertion in a mandrel; a variable orifice valve in
the body for controlling
flow of injection gas into the body; and. a moveable hydraulic piston
connected to the variable
orifice valve and in communication with a source of pressurized fluid; whereby
the amount of
injection gas introduced into the well through the variable orifice valve is
controlled by varying the
amount of pressurized fluid being applied to the moveable hydraulic piston.
Another feature of this
aspect of the present invention is that the source of pressurized fluid may be
external to the gas lift
valve and may be transmitted to the gas lift valve through a control line
connected between the gas
lift valve and the external source of pressurized fluid. Another feature of
this aspect of the present
invention is that the external source of pressurized fluid may be located at
the earth's surface.
Another feature of this aspect of the present invention is that the source of
pressurized fluid may be
I S an on-board hydraulic system including: a hydraulic pump located in a
downhole housing and in
fluid communication with a fluid reservoir; an electric motor connected to and
driving the hydraulic
pump upon receipt of a signal from a control panel; and, hydraulic circuitry
in fluid communication
with the hydraulic pump and the hydraulic piston. Another feature of this
aspect of the present
invention is that the gas lift valve may further include an electrical conduit
connecting the control
panel to the gas lift valve for providing a signal to the electric motor.
Another feature of this aspect
of the present invention is that the hydraulic system may further include a
solenoid valve located in
the downhole housing and connected to the electrical conduit, the solenoid
valve directing the
pressurized fluid from the hydraulic system through the hydraulic circuitry to
the hydraulic piston.
Another feature of this aspect of the present invention is that the gas lift
valve may further include
at least one pressure transducer in fluid communication with the hydraulic
circuitry and connected
to the electrical conduit for providing a pressure reading to the control
panel. Another feature of this
aspect of the present invention is that the gas lift valve may further include
an upstream pressure
transducer connected to the electrical conduit and a downstream pressure
transducer connected to
the electrical conduit, the upstream and downstream pressure transducers being
located within the
gas lift valve to measure a pressure drop across the variable orifice valve,
the pressure drop
measurement being reported to the control panel through the electrical
conduit. Another feature of
this aspect of the present invention is that the gas lift valve may further
include a position sensor to
5
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
report relative location of the moveable hydraulic piston to the control
panel. Another feature of this
aspect of the present invention is that the gas lift valve may further include
a mechanical position
holder to mechanically assure that the variable orifice valve remains in its
desired position if
conditions in the hydraulic system change during use. Another feature of this
aspect of the present
invention is that the variable orifice valve may be stopped at intermediate
positions between a full
open and a full closed position to adjust the flow of injection gas
therethrough, the variable orifice
valve being held in the intermediate positions by the position holder. Another
feature of this aspect
of the present invention is that the hydraulic system may further include a
movable volume
compensator piston for displacing a volume of fluid that is utilized as the
hydraulic system operates.
Another feature of this aspect of the present invention is that the variable
orifice valve may further
include a carbide stem and seat. Another feature of this aspect of the present
invention is that the
mandrel may be provided with at least one injection gas port through which
injection gas flows when
the variable orifice valve is open. Another feature of this aspect of the
present invention is that the
gas lift valve may further include an upper and lower one-way check valve
located on opposite sides
of the variable orifice valve to prevent any fluid flow from the well into the
gas lift valve. Another
feature of this aspect of the present invention is that the gas lift valve may
further inciude latch
means for adapting the variable orifice valve to be remotely deployed and
retrieved. Another feature
of this aspect of the present invention i:> that the variable orifice valve
may be remotely deployed and
retrieved by utilization of coiled tubing. Another feature of this aspect of
the present invention is
that the variable orifice valve may be remotely deployed and retrieved by
utilization of wireline.
Another feature of this aspect of the present invention is that the gas lift
valve may further include
a valve connection collet.
In another aspect, the present invention may be a gas lift valve for variably
introducing
injection gas into a subterranean well, comprising: a valve body with a
longitudinal bore
therethrough for sealable insertion in a mandrel; a hydraulic control line
connected to the gas lift
valve for providing a supply of pressurized fluid thereto; a variable orifice
valve in the body for
controlling flow of injection gas into the body; a spring biasing the variable
orifice valve in a full
closed position; a moveable hydraulic piston connected to the variable orifice
valve; and, an
actuating piston located in a downhole housing, connected to the moveable
hydraulic piston and in
communication with the control line; whereby the amount of injection gas
introduced into the well
through the variable orifice valve is controlled by varying the amount of
pressurized fluid being
applied to the actuating piston. Another feature of this aspect of the present
invention is that the
6
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
control line may be connected to a source of pressurized fluid located at the
earth's surface. Another
feature of this aspect of the present invention is that the gas lift valve may
further include a
mechanical position holder to mechanically assure that the variable orifice
valve remains in its
desired position if conditions in the gas lift valve change during use.
Another feature of this aspect
of the present invention is that the variable orifice valve may be stopped at
intermediate positions
between a full open and a full closed position to adjust the flow of injection
gas therethrough, the
variable orifice valve being held in the intermediate positions by the
position holder. Another
feature of this aspect of the present invention is that the variable orifice
valve may further include
a carbide stem and seat. Another feature of this aspect of the present
invention is that the mandrel
may be provided with at least one injection gas port through which injection
gas flows when the
variable orifice valve is open. Another feature of this aspect of the present
invention is that the gas
lift valve may further include an upper and lower one-way check valve located
on opposite sides of
the variable orifice valve to prevent any fluid flow from the well into the
gas lift valve. Another
feature of this aspect of the present invention is that the gas lift valve may
further include latch
means for adapting the variable orifice valve to be remotely deployed and
retrieved. Another feature
of this aspect of the present invention is that the variable orifice valve may
be remotely deployed and
retrieved by utilization of coiled tubing. Another feature of this aspect of
the present invention is
that the variable orifice valve may be remotely deployed and retrieved by
utilization of wireline.
Another feature of this aspect of the present invention is that the gas lift
valve may further include
a valve connection collet.
In another aspect. the present invention may be a gas lift valve for variably
introducing
injection gas into a subterranean well, comprising: a valve body with a
longitudinal bore
therethrough for sealable insertion in a mandrel; a valve-open and a valve-
closed hydraulic control
line connected to the gas lift valve for providing dual supplies of
pressurized fluid thereto; a variable
orifice valve in the body for controlling flow of injection gas into the body;
and, a moveable
hydraulic piston connected to the variable orifice valve and in fluid
communication with the valve-
open and valve-closed hydraulic control lines; whereby the variable orifice
valve is opened by
applying pressure to the hydraulic piston through the valve-open control Iine
and bleeding off
pressure from the valve-closed control line; the variable orifice valve is
closed by applying pressure
- 30 to the hydraulic piston through the valve-closed control line and
bleeding off pressure from the
valve-open control line; and, the amount of injection gas introduced into the
well through the
variable orifice valve is controlled by varying the amount of pressurized
fluid being applied to and
7
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
bled off from the hydraulic piston through the control lines. Another feature
of this aspect of the
present invention is that the control lines may be connected to a source of
pressurized fluid located
at the earth's surface. Another feature of this aspect of the present
invention is that the gas lift valve
may further include a mechanical position holder to mechanically assure that
the variable orifice
valve remains in its desired position if conditions in the gas lift valve
change during use. Another
feature of this aspect of the present invention is that the variable orifice
valve may be stopped at
intermediate positions between a full open and a full closed position to
adjust the flow of injection
gas therethrough, the variable orifice valve being held in the intermediate
positions by the position
holder. Another feature of this aspect of the present invention is that the
variable orifice valve may
further include a carbide stem and seat. Another feature of this aspect of the
present invention is that
the mandrel may be provided with at least one injection gas port through which
injection gas flows
when the variable orifice valve is open. Another feature of this aspect of the
present invention is that
the gas lift valve may further include an upper and lower one-way check valve
located on opposite
sides of the variable orifice valve to prevent any fluid flow from the well
into the gas lift valve.
Another feature of this aspect of the present invention is that the gas lift
valve may further include
latch means for adapting the variable orifice valve to be remotely deployed
and retrieved. Another
feature of this aspect of the present invention is that the variable orifice
valve may be remotely
deployed and retrieved by utilization of coiled tubing. Another feature of
this aspect of the present
invention is that the variable orifice valve may be remotely deployed and
retrieved by utilization of
wireline. Another feature of this aspect of the present invention is that the
gas lift valve may farther
including a valve connection collet. Another feature of this aspect of the
present invention is that
the gas lift valve may further include a fluid displacement port for use
during the bleeding off of
pressurized fluid from the hydraulic piston. Another feature of this aspect of
the present invention
is that the gas lift valve may further include a valve-open and a valve-closed
conduit for routing
pressurized fluid from the valve-open and valve-closed control lines to the
hydraulic piston.
Another feature of this aspect of the present invention is that the gas lift
valve may further
include an electrical conduit connecting a control panel at the earth's
surface to the gas lift valve for
communicating collected data to the control panel. Another feature of this
aspect of the present
invention is that the gas lift valve may further include a valve-open pressure
transducer and to a
valve-closed pressure transducer, the valve-open pressure transducer being
connected to the
electrical conduit and in fluid communication wit the valve-open conduit, the
valve-closed pressure
transducer being connected to the electrical conduit and in fluid
communication with the valve-
CA 02263486 1999-02-15
WO 98/06928 PCT/IJS97/14431
closed conduit, the pressure transducers providing pressure readings to the
control panel via the
electrical conduit. Another feature of this aspect of the present invention is
that the gas lift valve
may further include an upstream pressure transducer connected to the
electrical conduit and a
downstream pressure transducer connected to the electrical conduit, the
upstream and downstream
S pressure transducers being located within the gas lift valve to measure a
pressure drop across the
variable orifice valve, the pressure drop measurement being reported to the
control panel through
the electrical conduit.
In another aspect, the present invention may be a gas lift valve for variably
introducing
injection gas into a subterranean well, comprising: a valve body with a
longitudinal bore
therethrough for sealable insertion in a mandrel; a hydraulic control line
connected to the gas lift
valve for providing a supply of pressurized fluid thereto; a variable orifice
valve in the body for
controlling flow of injection gas into the body; a nitrogen coil chamber
providing a pressurized
nitrogen charge through a pneumatic conduit for biasing the variable orifice
valve in a full closed
position; and, a moveable hydraulic piston connected to the variable orifice
valve and in fluid
communication with the hydraulic control line and the pneumatic conduit;
whereby the variable
orifice valve is opened by applying hydraulic pressure to the hydraulic piston
through the hydraulic
control line to overcome the pneumatic pressure in the pneumatic conduit; the
variable orifice valve
is closed by bleeding off pressure from the hydraulic control line to enable
the pneumatic pressure
in the nitrogen coil chamber to closed the variable orifice valve; and, the
amount of injection gas
introduced into the well through the variable orifice valve is controlled by
varying the amount of
hydraulic fluid being bled off from the hydraulic piston through the hydraulic
control line. Another
feature of this aspect of the present invention is that the hydraulic control
line may be connected to
a source of pressurized fluid located at the earth's surface. Another feature
of this aspect of the
present invention is that the gas lift valve may further include a mechanical
position holder to
mechanically assure that the variable orifice valve remains in its desired
position if conditions in the
gas lift valve change during use. Another feature of this aspect of the
present invention is that the
variable orifice valve may be stopped at intermediate positions between a full
open and a full closed
position to adjust the flow of injection gas therethrough, the variable
orifice valve being held in the
intermediate positions by the position holder. Another feature of this aspect
of the present invention
is that the variable orifice valve may further include a carbide stem and
seat. Another feature of this
aspect of the present invention is that the mandrel may be provided with at
least one injection gas
port through which injection gas flows when the variable orifice valve is
open. Another feature of
9
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
this aspect of the present invention is that the gas lift valve may further
include an upper and lower
one-way check valve located on opposite sides of the variable orifice valve to
prevent any fluid flow
from the well into the gas lift valve. Another feature of this aspect of the
present invention is that
the gas lift valve may further include latch means for adapting the variable
orifice valve to be
remotely deployed and retrieved. Another feature of this aspect of the present
invention is that the
variable orifice valve may be remotely deployed and retrieved by utilization
of coiled tubing.
Another feature of this aspect of the present invention is that the variable
orifice valve may be
remotely deployed and retrieved by utilization of wireline. Another feature of
this aspect of the
present invention is that the gas lift valve may further include a valve
connection collet.
In another aspect, the present invention may be a gas lift valve for variably
introducing
injection gas into a subterranean well, comprising: a first mandrel connected
to a second mandrel,
the first and second mandrel being installed in a well production string; a
valve means having a
variable orifice for controlling flow of injection gas into the well. the
valve means being installed
in the first mandrel; an actuating means for controlling the valve means, the
actuating means being
installed in the second mandrel, in communication with and controllable from a
control panel, and
connected to the valve means by a first and second hydraulic control line.
Another feature of this
aspect of the present invention is that the valve means and the actuating
means may be remotely
deployed within and retrieved from their respective mandrels. Another feature
of this aspect of the
present invention is that the valve means and actuating means may be remotely
deployed and
retrieved by utilization of coiled tubing. Another feature of this aspect of
the present invention is
that the valve means and actuating means may be remotely deployed and
retrieved by utilization of
wireline.
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
BRIEF DESCRIPTION OF THE DRAWINGS
Figures lA-1C are elevation views which together illustrate an electro-
hydraulically operated
embodiment of the apparatus of the present invention having an on-board
hydraulic system and
connected to an electrical conduit running from the earth's surface; the power
unit is shown rotated
ninety degrees for clarity.
Figures 2A-2C are elevation views which together illustrate a hydraulically
operated
embodiment of the apparatus of the present invention connected to a single
hydraulic control line
running from the earth's surface; the power unit is shown rotated ninety
degrees for clarity.
Figures 3A-3C are elevation views which together illustrate another
hydraulically operated
embodiment of the apparatus of the present invention connected to dual
hydraulic control lines
running from the earth's surface; the power unit is shown rotated ninety
degrees for clarity.
Figures 4A-4C are elevation views which together illustrate another
hydraulically operated
embodiment of the apparatus of the present invention connected to dual
hydraulic control lines
running from the earth's surface; the power unit is shown rotated ninety
degrees for clarity.
Figures SA-SC are elevation views which together illustrate a pneumatic-
hydraulically
operated embodiment of the apparatus of the present invention connected to a
single hydraulic
control line running from the earth's surface; the power unit is shown rotated
ninety degrees for
clarity.
Figure 6 is a cross-sectional view taken along line 6-6 of Figure 1B.
Figure 7 is a cross-sectional view taken along line 7-7 of Figure 1B.
Figure 8 is a cross-sectional view taken along line 8-8 of Figure 2B.
Figure 9 is a cross-sectional view taken along line 9-9 of Figure 2B.
Figure 10 is a cross-sectional view taken along line 10-10 of Figure 3B.
Figure 11 is a cross-sectional view taken along line 11-11 of Figure 3B.
Figure 12 is a cross-sectional view taken along line 12-12 of Figure 4B.
Figure 13 is a cross-sectional view taken along line 13-13 of Figure 4B.
Figure 14 is a cross-sectional view taken along line 14-14 of Figure 5B.
Figure 15 is a cross-sectional view taken along line 15-15 of Figure SB.
Figure 16 is a schematic representation of another embodiment of the present
invention with
a retrievable actuator positioned in an upper mandrel and a retrievable
variable orifice gas lift valve
positioned in a lowermost mandrel.
Figure 17 is a cross-sectional view taken along line 17-17 of Figure 16.
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
Figure 18 is a cross-sectional view taken along line 18-18 of Figure 16.
While the invention will be described in connection with the preferred
embodiments, it will
be understood that it is not intended to limit the invention to those
embodiments. On the contrary,
it is intended to cover all alternatives, modifications, and equivalents as
may be included within the
spirit and scope of the invention as defined by the appended claims.
12
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the description that follows, like parts are marked through the
specification and drawings
with the same reference numerals, respectively. The figures are not
necessarily drawn to scale, and
in some instances, have been exaggerated or simplified to clarify certain
features of the invention.
One skilled in the art will appreciate many differing applications of the
described apparatus.
For the purposes of this discussion, the terms ''upper" and "lower," "up hole"
and
"downhole," and "upwardly" and "downwardly" are relative terms to indicate
position and direction
of movement in easily recognized terms. Usually, these terms are relative to a
line drawn from an
upmost position at the surface to a point at the center of the earth, and
would be appropriate for use
in relatively straight, vertical wellbores. However, when the wellbore is
highly deviated, such as
from about 60 degrees from vertical, or horizontal, these terms do not make
sense and therefore
should not be taken as limitations. These terms are only used for ease of
understanding as an
indication of what the position or movement would be if taken within a
vertical wellbore.
Figures 1 A-1 C together show a semidiagrammatic cross section of a gas lift
valve 8 shown
in the closed position, used in a subterranean well (not shown), illustrating:
a valve body 10 with
a longitudinal bore 12 for sealable insertion in a side pocket mandrel 14, a
variable orifice valve 16
in the body 10 which alternately permits, prohibits, or throttles fluid flow
(represented by item 18
- see Figure 7) into said body through injection gas pons 13 in the mandrel
14, and an actuating
means, shown generally by numeral 20 which is electro-hydraulically operated
using a hydraulic
pump 22 located in a downhole housing 24, an electric motor 26 connected to
and driving the
hydraulic pump 22 upon receipt of a signal through an electrical conduit 23
connected to a control
panel (not shown) located at the earth's surface. Also shown is a moveable
temperature/volume
compensator piston 15 for displacing a volume of fluid that is utilized as the
actuating means 20
operates and for compensating for pressure changes caused by temperature
fluctuations. A solenoid
valve 28 controls the movement of pressurized fluid pumped from a control
fluid reservoir 25
through a pump suction port 21 and in a hydraulic circuitry 30, and the
direction of the fluid flowing
therethrough, which is connected to and responding to the action of the pump
22. A moveable
hydraulic piston 32 responding to the pressure signal from the hydraulic
circuitry 30 opens and
controls the movement of the variable orifice valve 16. The actuator has a
position sensor 34 which
- 30 reports the relative location of the moveable hydraulic piston 32 to the
control panel (not shown),
and a position holder 33 which is configured to mechanically assure that the
actuating means 20
remains in the desired position by the operator if conditions in the hydraulic
system change slightly
13
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
in use. Also shown is a pressure transducer 35 communicating with the
hydraulic circuitry 30, and
transmitting collected data to the control panel (not shown) via the
electrical conduit 23. As shown
in Figure 1 C, a downstream pressure transducer 19 may be provided to
cooperate with the pressure
transducer 35 for measuring and reporting to the control panel any pressure
drop across the variable
orifice valve 16. It will be obvious to one skilled in the art that the
electric motor 26 and downhole
pump 22 have been used to eliminate the cost of running a control line from a
surface pressure
source. This representation should not be taken as a limitation. Obviously, a
control line could be
run from the surface to replace the electric motor 26 and downhoIe pump 22,
and would be
controlled in the same manner without altering the scope or spirit of this
invention. When it is
operationally desirable to open the variable orifice valve 16, an electric
signal from the surface
activates the electric motor 26 and the hydraulic pump 22, which routes
pressure to the solenoid
valve 28. The solenoid valve 28 also responding to stimulus from the control
panel, shifts to a
position to route hydraulic pressure to the moveable hydraulic piston 32 that
opens the variable
orifice valve 16. The variable orifice valve 16 may be stopped at intermediate
positions between
open and closed to adjust the flow of lift or injection gas 31 therethrough,
and is held in place by the
position holder 33. To close the valve, the solenoid valve 28 merely has to be
moved to the opposite
position rerouting hydraulic fluid to the opposite side of the moveable
hydraulic piston 32, which
then translates back to the closed position.
As shown in Figure 1 B, the variable orifice valve 16 may include a carbide
stem and seat 17.
The gas lift valve 8 may also be provided with one-way check valves 29 to
prevent any fluid flow
from the well conduit into the gas lift valve 8. The gas lift valve 8 may also
be provided with a latch
27 so the valve may be remotely installed and/or retrieved by well known
wireline or coiled tubing
intervention methods. As shown in Figure 6, this embodiment of the present
invention may also be
provided with a valve connection collet 11, the structure and operation of
which are well known to
those of ordinary skill in the art.
Figures 2A-2C together depict a semidiagrammatic cross section of a gas lift
valve 8 shown
in the closed position, used in a subterranean well (not shown), illustrating:
a valve body 10 with
a longitudinal bore 12 for sealable insertion in a side pocket mandrel 14, a
variable orifice valve 16
in the body 10 which alternately permits, prohibits, or throttles fluid flow
(represented by item 18
- see Figure 9) into said body through injection gas ports 13 in the mandrel
14, and an actuating
means shown generally by numeral 36 that is hydraulically operated. Further
illustrated is: a
hydraulic actuating piston 38 located in a downhole housing 40 and
op.;ratively connected to a
14
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
moveable piston 42, which is operatively connected to the variable orifice
valve 16. A spring 44,
biases said variable orifice valve 16 in either the full open or full closed
position, and a control line
46 communicates with the hydraulic actuating piston 38 and extends to a
hydraulic pressure source
(not shown). When it is operationally desirable to open the variable orifice
valve 16, hydraulic
pressure is applied from the hydraulic pressure source (not shown), which
communicates down the
hydraulic control line 46 to the hydraulic actuating piston 38, which moves
the moveable piston 42,
which opens the variable orifice valve 16. The variable orifice valve 16 may
be stopped at
intermediate positions between open and closed to adjust the flow of lift or
injection gas 31
therethrough, and is held in place by a position holder 33 which is configured
to mechanically assure
that the actuating means 36 remains in the position where set by the operator
if conditions in the
hydraulic system change slightly in use. The valve is closed by releasing the
pressure on the control
line 46, allowing the spring 44 to translate the moveable piston 42, and the
variable orifice valve 16
back to the closed position.
As shown in Figure 2B, the variable orifice valve 16 may include a carbide
stem and seat 17.
I S The gas lift valve 8 may also be provided with one-way check valves 29 to
prevent any fluid flow
from the well conduit into the gas lift valve 8. The gas lift valve 8 may also
be provided with a latch
27 so the valve may be remotely installed and/or retrieved by well known
wireline or coiled tubing
intervention methods. As shown in Figure 8, this embodiment of the present
invention may also be
provided with a valve connection collet 11, the structure and operation of
which are well known to
those of ordinary skill in the art.
Figures 3A-3C together disclose another embodiment of~ a semidiagrammatic
cross section
of a gas lift valve 8 shown in the closed position, used in a subterranean
well (not shown),
illustrating: a valve body 10 with a longitudinal bore 12 for sealable
insertion in a side pocket
mandrel 14, a variable orifice valve 16 in the body 10 which alternately
permits, prohibits, or
throttles fluid flow (represented by item 18 - see Figure 11 ) into said body
through injection gas
ports 13 in the mandrel 14, and an actuating means shown generally by numeral
48 that is
hydraulically operated. Further illustrated: hydraulic conduits 50 and 51 that
route pressurized
hydraulic fluid directly to a moveable piston 32, which is operatively
connected to the variable
orifice valve 16. Two control lines 46 extend to a hydraulic pressure source
(not shown). The
moveable hydraulic piston 32 responding to the pressure signal from the "valve
open" hydraulic
conduit 50 which opens and controls the movement of the variable orifice valve
16 while the "valve
closed" hydraulic conduit S 1 is bled off. The variable orifice valve 16 may
be stopped at
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
intermediate positions between open and closed to adjust the flow of lift or
injection gas 31
therethrough, and is held in place by a position holder 33 which is configured
to mechanically assure
that the actuating means 48 remains in the position where set by the operator
if conditions in the
hydraulic system change slightly in use. Closure of the variable orifice valve
16 is accomplished
by sending a pressure signal down the "valve closed" hydraulic conduit 51, and
simultaneously
bleeding pressure from the "valve open" hydraulic conduit 50.
A fluid displacement control port 49 may also be provided for use during the
bleeding off
of the conduits 50 and 51, in a manner well known to those of ordinary skill
in the art. As shown
in Figure 3B, the variable orifice valve 16 may include a carbide stem and
seat 17. The gas lift valve
8 may also be provided with one-way check valves 29 to prevent any fluid flow
from the well
conduit into the gas lift valve 8. The gas lift valve 8 may also be provided
with a latch 27 so the
valve may be remotely installed and/or retrieved by well known wireline or
coiled tubing
intervention methods. As shown in Figure 10, this embodiment of the present
invention may also
be provided with a valve connection collet 11, the structure and operation of
which are well known
to those of ordinary skill in the arc.
Figures 4A-4C together depict a semidiagrammatic cross section of a gas lift
valve 8 shown
in the closed position, used in a subterranean well (not shown), illustrating:
a valve body 10 with
a longitudinal bore 12 for sealable insertion in a side pocket mandrel 14, a
variable orifice valve 16
in the body I 0 which alternately permits, prohibits, or throttles fluid flow
(represented by item 18
- see Figure 13) into said body through injection gas pons 13 in the mandrel
14, and an actuating
means shown generally by numeral 48 that is hydraulically operated. Further
illustrated: hydraulic
conduits 50 and 51 that route pressurized hydraulic fluid directly to a
moveable piston 32, which is
operatively connected to the variable orifice valve 16, and two control lines
46 extending to a
hydraulic pressure source (not shown). The movable hydraulic piston 32
responding to the pressure
signal from the "valve open" hydraulic conduit 50 which opens and controls the
movement of the
variable orifice valve 16 while the "valve closed" hydraulic conduit 51 is
bled off. The variable
orifice valve 16 may be stopped at intermediate positions between open and
closed to adjust the flow
of lift or injection gas 31 therethrough, and is held in place by a position
holder 33 which is
configured to mechanically assure that the actuating means 20 remains in the
position where set by
the operator if conditions in the hydraulic system change slightly in use.
Closure of the variable
orifice valve 16 is accomplished by sending a pressure signal down the "valve
closed" hydraulic
conduit 51, and simultaneously bleeding pressure from the "valve open''
hydraulic conduit 50. The
16
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
actuator has a position sensor 34 which reports the relative location of the
moveable hydraulic piston
32 to the control panel (not shown) via an electrical conduit 23. Also shown
are pressure transducers
35 communicating with the hydraulic conduits 50 and 51 through hydraulic
pressure sensor
chambers (e.g., conduit 51 communicates with chamber 9), and transmitting
collected data to the
control panel (not shown) via the electrical conduit 23.
As shown in Figure 4C, a downstream pressure transducer 19 may be provided to
cooperate
with the pressure transducer 35 for measuring and reporting to the control
panel any pressure drop
across the variable orifice valve 16. As shown in Figure 4B, a fluid
displacement control port 49
may also be provided for use during the bleeding off of the conduits SO and S
1, in a manner well
known to those of ordinary skill in the art. As also shown in Figure 4B, the
variable orifice valve 16
may include a carbide stem and seat i 7. The gas lift valve 8 may also be
provided with one-way
check valves 29 to prevent any fluid flow from the well conduit into the gas
lift valve 8. The gas
lift valve 8 may also be provided with a latch 27 so the valve may be remotely
installed and/or
retrieved by well known wireline or coiled tubing intervention methods. As
shown in Figure 12, this
embodiment of the present invention may also be provided with a valve
connection collet 11, the
structure and operation of which are well known to those of ordinary skill in
the art.
Figures SA-SC together depict a semidiagrammatic cross section of a gas lift
valve 8 shown
in the closed position, used in a subterranean well (not show), illustrating:
a valve body 10 with
a longitudinal bore 12 for sealable insertion in a side pocket mandrel 14, a
variable orifice valve 16
in the body I 0 which alternately permits, prohibits, or throttles fluid flow
(represented by item 18
- see Figure 15) into said body through injection gas ports 13 in the mandrel
14, and an actuating
means shown generally by numeral 52 that is hydraulically operated. Further
illustrated: a hydraulic
conduit 54 that routes pressurized hydraulic fluid directly to a moveable
piston 32, which is
operatively connected to the variable orifice valve I6. Hydraulic pressure is
opposed by a
pressurized nitrogen charge inside of a nitrogen coil chamber 56, the pressure
of which is routed
through a pneumatic conduit 58, which acts on an opposite end of the moveable
hydraulic piston 32,
biasing the variable orifice valve 16 in the closed position. The nitrogen
coil chamber 56 is charged
with nitrogen through a nitrogen charging port 57. When it is operationally
desirable to open the
variable orifice valve 16, hydraulic pressure is added to the control line 54,
which overcomes
pneumatic pressure in the pneumatic conduit 58 and nitrogen coil chamber 56,
and translates the
moveable piston 32 upward to open the variable orifice valve 16. As before,
the variable orifice
valve 16 may be stopped at intermediate positions between open and closed to
adjust the flow of lift
I7
CA 02263486 1999-02-15
WO 98/06928 PCT/US97/14431
or injection gas 31 therethrough, and is held in place by a position holder 33
which is configured to
mechanically assure that the actuating means 52 remains in the position where
set by the operator
if conditions in the hydraulic system change slightly in use. Closing the
variable orifice valve 16
is accomplished by bleeding off the pressure from the control line 54, which
causes the pneumatic
pressure in the nitrogen coil chamber 56 to close the valve because it is
higher than the hydraulic
pressure in the hydraulic conduit 54. An annulus port 53 may also be provided
through the wall of
the mandrel 14 through which pressure may be discharged to the annulus during
operation.
As shown in Figure ~B, the variable orifice valve 16 may include a carbide
stem and seat 17.
The gas lift valve 8 may also be provided with one-way check valves 29 to
prevent any fluid flow
from the well conduit into the gas lift valve 8. The gas lift valve 8 may also
be provided with a latch
27 so the valve may be remotely installed and/or retrieved by well known
wireline or coiled tubing
intervention methods. As shown in Figure 14. this embodiment of the present
invention may also
be provided with a valve connection collet 11, the structure and operation of
which are well known
to those of ordinary skill in the art.
F figure 16 is a schematic representation of one preferred embodiment of the
present invention.
Disclosed are uppermost and lowermost side pocket mandrels 60 and 61 sealably
connected by a
well coupling 62. A coiled tubing or wireline retrievable actuator 64 is
positioned in the uppermost
mandrel 60, and a variable orifice gas lift valve 66 is positioned in the
lowermost mandrel 61, and
are operatively connected by hydraulic control lines 68. In previous figures,
the variable orifice
valve 16 and the actuating mechanisms described in Figures 1-5 are shown
located in the same
mandrel. making retrieval of both mechanisms difficult. if not impossible. In
this embodiment, the
variable orifice gas lift valve 66, and the electro-hydraulic wireline or
coiled tubing retrievable
actuator 64 of the present invention are located, installed and retrieved
separately, but are operatively
connected one to another by hydraulic control lines 68. This allows retrieval
of each mechanism
separately, using either wireline or coiled tubing intervention methods which
are well known in the
art. As shown in Figure 18, which is a cross-sectional view taken along line i
8-18 of Figure 16, an
operating piston 72 is disposed adjacent the variable orifice valve 66 in the
lowermost mandrel 61.
In every other aspect, however, the m;,chanisms operate as heretofore
described.
It should be noted that the preferred embodiments described herein employ a
well known
valve mechanism generically known as a poppet valve to those skilled in the
art of valve mechanics.
It can, however, be appreciated that several well known valve mechanisms may
obviously be
employed and still be within the scope and spirit of the present invention.
Rotating balls or plugs,
18
CA 02263486 1999-02-15
WO 98/06928 PCT/US97114431
butterfly valves, rising stem gates, and flappers are several other generic
valve mechanisms which
may obviously be employed to accomplish the same function in the same manner.
Whereas the present invention has been described in particular relation to the
drawings
attached hereto, it should be understood that other and further modifications,
apart from those shown
or suggested herein, may be made within the scope and spirit of the present
invention. Accordingly,
the invention is therefore to be limited only by the scope of the appended
claims.
19
