U.S. patent application number 13/262189 was filed with the patent office on 2012-01-26 for wireless monitoring of pump jack sucker rod loading and position.
Invention is credited to Paul N. Katz, Rick A. Lawson.
Application Number | 20120020808 13/262189 |
Document ID | / |
Family ID | 42279345 |
Filed Date | 2012-01-26 |
United States Patent
Application |
20120020808 |
Kind Code |
A1 |
Lawson; Rick A. ; et
al. |
January 26, 2012 |
Wireless Monitoring of Pump Jack Sucker Rod Loading and
Position
Abstract
Forces on and respective positions of a pump jack sucker rod are
determined in real time by load cells attached to the sucker rod
and a position sensor, and are stored for further processing. A
wireless transmitter transmits stored load and position values,
calculated process parameters, and/or exception alerts to a
wireless spread spectrum receiver that can be coupled to a motor
speed controller used to set the rotational speed of the pump jack
motor, and/or to monitoring systems, such as a central controller
used to optimize total field production.
Inventors: |
Lawson; Rick A.; (Spring,
TX) ; Katz; Paul N.; (Bellaire, TX) |
Family ID: |
42279345 |
Appl. No.: |
13/262189 |
Filed: |
March 31, 2010 |
PCT Filed: |
March 31, 2010 |
PCT NO: |
PCT/US10/29453 |
371 Date: |
September 29, 2011 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61165628 |
Apr 1, 2009 |
|
|
|
Current U.S.
Class: |
417/18 ;
73/152.61 |
Current CPC
Class: |
F04B 51/00 20130101;
E21B 43/127 20130101; F04B 47/02 20130101; F04B 49/065
20130101 |
Class at
Publication: |
417/18 ;
73/152.61 |
International
Class: |
F04B 49/20 20060101
F04B049/20; E21B 47/00 20120101 E21B047/00 |
Claims
1. A pump jack adapted for monitoring sucker rod load and position,
comprising: a sucker rod string in a well bore pipe; a polished rod
coupled to the sucker rod string; a horsehead coupled to the
polished rod; a rocker beam coupled to the horsehead; a connecting
rod coupled to the rocker beam; a counter weight coupled to the
connecting rod; a pittman arm coupled to the connecting rod and
counter weight; a variable speed motor-gear drive assembly coupled
to the pittman arm for rotational movement thereof; a frame
pivotally coupled to the rocker beam; a base attached to the frame;
first and second force sensors attached to a proximate end of the
sucker rod string, wherein the first and second force sensors
measure elongation and compression stresses, respectively, of the
sucker rod string while the sucker rod string moves up and down in
the well bore pipe; a position sensor attached toward the proximate
end of the sucker rod string, wherein the position sensor
determines positions of the sucker rod string; a sensor interface
assembly having wireless transmitting capabilities, wherein the
sensor interface assembly is attached to the sucker rod string, and
is coupled to the first and second force measurement sensors and
the position sensor, whereby the sucker rod string forces and
position information are wirelessly transmitted therefrom; and a
wireless receiver coupled to the variable speed motor-gear drive
assembly, wherein the wireless receiver receives the force and
position information transmitted from the interface assembly for
determining control of rotational speed of the variable speed
motor-gear drive assembly.
2. The pump jack according to claim 1, wherein the position sensor
is a tri-axial accelerometer.
3. The pump jack according to claim 1, wherein the position sensor
is a distance measuring device for measuring distances between the
proximate end of the sucker rod string and a reference point.
4. The pump jack according to claim 3, wherein the distance
measuring device uses ultrasonic pulses for measuring the
distances.
5. The pump jack according to claim 3, wherein the distance
measuring device uses radio frequency pulses for measuring the
distances.
6. The pump jack according to claim 3, wherein the distance
measuring device uses infrared pulses for measuring the
distances.
7. The pump jack according to claim 3, wherein the distance
measuring device uses laser light pulses for measuring the
distances.
8. The pump jack according to claim 1, further comprising a well
bore pipe elongation distance sensor coupled to a proximate end of
the well bore pipe, and from which elongation length of the well
bore pipe is available as elongation data.
9. The pump jack according to claim 1, further comprising pressure
and flow rate sensors coupled to a flange/fluid takeoff assembly
that is coupled to the proximate end of the well bore pipe, and
from which pressure and flow rate at the flange/fluid takeoff
assembly are available as pressure and flow rate data,
respectively.
10. An apparatus for monitoring position and load of a sucker rod
in a pump jack, comprising: first and second force sensors attached
at a proximate end of a sucker rod string of a pump jack, wherein
the first and second force sensors measure elongation and
compression stresses, respectively, of the sucker rod string while
the sucker rod string moves up and down in a well bore pipe; a
position sensor attached toward the proximate end the sucker rod
string, wherein the position sensor determines positions of the
sucker rod string; and a sensor interface assembly having wireless
transmitting capabilities, wherein the sensor interface assembly is
attached to the sucker rod string, and is coupled to the first and
second force measurement sensors and the position sensor, whereby
the sucker rod string forces and position information are
wirelessly transmitted therefrom.
11. The apparatus according to claim 10, wherein the position
sensor is a distance measuring device for measuring distances
between the proximate end of the sucker rod string and a reference
point.
12. The apparatus according to claim 11, wherein the distance
measuring device uses ultrasonic pulses for measuring the
distances.
13. The apparatus according to claim 11, wherein the distance
measuring device uses radio frequency pulses for measuring the
distances.
14. The apparatus according to claim 11, wherein the distance
measuring device uses infrared pulses for measuring the
distances.
15. The apparatus according to claim 11, wherein the distance
measuring device uses laser light pulses for measuring the
distances.
16. A pump jack adapted for monitoring sucker rod load and
position, comprising: a sucker rod string in a well bore pipe; a
polished rod coupled to the sucker rod string; a horsehead coupled
to the polished rod; a rocker beam coupled to the horsehead; a
connecting rod coupled to the rocker beam; a counter weight coupled
to the connecting rod; a pittman arm coupled to the connecting rod
and counter weight; a variable speed motor-gear drive assembly
coupled to the pittman arm for rotational movement thereof; a frame
pivotally coupled to the rocker beam; a base attached to the frame;
first and second force sensors attached to a proximate end of the
sucker rod string, wherein the first and second force sensors
measure elongation and compression stresses, respectively, of the
sucker rod string while the sucker rod string moves up and down in
the well bore pipe; a sensor interface assembly having wireless
transmitting capabilities, wherein the sensor interface assembly is
attached to the sucker rod string, and is coupled to the first and
second force measurement sensors, whereby the sucker rod string
force information is wirelessly transmitted therefrom; a distance
measuring device attached on a plan of the base and under the
sensor interface assembly, wherein the position sensor determines
positions of the sucker rod string by measuring distances between
the distance measuring device and the sensor interface assembly;
and a wireless receiver coupled to the variable speed motor-gear
drive assembly, wherein the wireless receiver receives the force
information transmitted from the sensor interface assembly, and
wherein position information from the distance measuring device is
coupled to the variable speed motor-gear drive assembly, whereby
control of rotational speed of the variable speed motor-gear drive
assembly is determined from the force and position information.
17. The pump jack according to claim 16, wherein the distance
measuring device uses ultrasonic pulses for measuring the
distances.
18. The pump jack according to claim 16, wherein the distance
measuring device uses radio frequency pulses for measuring the
distances.
19. The pump jack according to claim 16, wherein the distance
measuring device uses infrared pulses for measuring the
distances.
20. The pump jack according to claim 16, wherein the distance
measuring device uses laser light pulses for measuring the
distances.
21. The pump jack according to claim 16, further comprising a well
bore pipe elongation distance sensor coupled to a proximate end of
the well bore pipe, and from which elongation length of the well
bore pipe is available as elongation data.
22. The pump jack according to claim 16, further comprising
pressure and flow rate sensors coupled to a flange/fluid takeoff
assembly that is coupled to the proximate end of the well bore
pipe, and from which pressure and flow rate at the flange/fluid
takeoff assembly are available as pressure and flow rate data,
respectively.
23. An apparatus for monitoring position and load of a sucker rod
in a pump jack, comprising: first and second force sensors attached
at a proximate end of a sucker rod string of a pump jack, wherein
the first and second force sensors measure elongation and
compression stresses, respectively, of the sucker rod string while
the sucker rod string moves up and down in a well bore pipe; a
sensor interface assembly having wireless transmitting
capabilities, wherein the sensor interface assembly is attached to
the sucker rod string, and is coupled to the first and second force
measurement sensors, whereby the sucker rod string force
information is wirelessly transmitted therefrom; a distance
measuring device attached on a plane of a base of the pump jack and
under the sensor interface assembly, wherein the distance measuring
device determines positions of the sucker rod string by measuring
distances between the distance measuring device and the sensor
interface assembly; and a wireless receiver coupled to the variable
speed motor-gear drive assembly, wherein the wireless receiver
receives the force information transmitted from the sensor
interface assembly, and wherein position information from the
distance measuring device is coupled to the variable speed
motor-gear drive assembly, whereby control of rotational speed of
the variable speed motor-gear drive assembly is determined from the
force and position information.
24. The apparatus according to claim 23, wherein the distance
measuring device uses ultrasonic pulses for measuring the
distances.
25. The apparatus according to claim 23, wherein the distance
measuring device uses radio frequency pulses for measuring the
distances.
26. The apparatus according to claim 23, wherein the distance
measuring device uses infrared pulses for measuring the
distances.
27. The apparatus according to claim 23, wherein the distance
measuring device uses laser light pulses for measuring the
distances.
Description
RELATED PATENT APPLICATION
[0001] This application claims priority to commonly owned U.S.
Provisional Patent Application Ser. No. 61/165,628; filed Apr. 1,
2009; entitled "Wireless Monitoring Of Pump Jack Sucker Rod Loading
And Position," by Rick A. Lawson and Doneil Dorado; and is hereby
incorporated by reference herein for all purposes.
TECHNICAL FIELD
[0002] The present disclosure relates to oil well pump jacks and,
more particularly, to monitoring and control of the pump jacks to
optimize pumping operation of the pump jacks in producing
production from the oil wells.
BACKGROUND
[0003] Historically, oil wells which must produce by artificial
lift have used horsehead-type pumping units such as those made by
Lufkin Industries and others. To counterbalance the weight of the
sucker rod string, counterweights are used, either mounted on the
walking beam or a rotary-type mounted on the gear box Pittman arm.
Another class of pumping unit (also made by Lufkin) uses an air
cylinder in place of the metal counterweights. The effect is
roughly the same. The sucker rod string reciprocates up and down in
a sine wave motion caused by rotation of the Pittman arm by an
electric motor.
[0004] The electric motor drives the pumping jack sucker rod string
on as to lift oil in discreet slugs or pulses from a pocket at the
bottom of the well bore to the surface. Such a pumping system
typically comprises a power driven jack or beam which reciprocates
on a pivot to reciprocate a string of well (sucker) rod up and down
in the well casing, and thereby provide a lifting or pumping action
that delivers the crude oil and brine from the well pocket to the
well head at the surface and thereafter storage.
[0005] The rate at which the crude oil in an oil well migrates to
the well bore and fills the well pocket may vary widely from one
well to another depending upon specific geologic conditions in the
oil bearing sands, and the age of the oil field in terms of the
proportion of recoverable crude oil which has been removed from the
geologic formations. In mature wells, commonly known as stripper
wells, the maximum attainable production rate will depend entirely
on how quickly the spontaneous migration of crude oil to the well
pocket can fill the pocket. Typically, in such wells the pumping
capacity of the pumping jack is far greater than the capacity of
the field to refill well pocket with crude oil from the oil bearing
formations. Even in newer, more productive wells the pumping
capacity of the pumping jack may far exceed spontaneous well pocket
refill rates.
[0006] To accommodate these well pocket refill rates and other
limitations of oil well production, the rotational speed of the
electric motor is controlled so as to optimize fluid pumping action
by the well sucker rod string of the pumping jack, so that pumping
action is not too fast or too slow.
[0007] A pump motor speed controller is used to control the pumping
action of the pump jack from various parameters of the pump jack.
For example, the well sucker rod string load (up and down) and
rotational speed of the pump motor may be used in determining
optimal pumping action, and/or to alert for undesirable conditions
in the well.
[0008] FIG. 1 illustrates a schematic elevational diagram of a
prior technology pump jack system having hardwired sucker rod load
and position sensors, and connected to a well sucker rod string.
The pump jack system, represented by the numeral 100, comprises a
sucker rod string 110, a polish rod 120, a horsehead 122, a rocker
beam 124, connecting rod 132, counter weight 134, Pittman arm 136,
motor/gear drive 138, frame 128 and base 146. As the motor/gear
drive 138 rotates, the Pittman arm 136 causes the connecting rod
132 to push up or pull down one end of the rocker beam 124. On the
other end of the rocker beam 124 is the horsehead 122 connected to
the polish rod 120. As the horsehead 122 moves up and down so does
the polish rod 120 which in turn moves the sucker rod string 110 in
and out of the well bore pipe 118. The well bore pipe 118 is
terminated at flange/fluid takeoff assembly 116 that is adapted to
allow fluid (or gas) being pumped out of the well bore pipe 118 to
flow to a storage tank/pipeline (not shown). The flange/fluid
takeoff assembly 116 also is used to seal around a portion of the
sucker rod string 110 so that well fluid does not spill onto the
ground.
[0009] Axial forces on the sucker rod string 110 may be measured by
a load cell 114 that determines the axial forces applied to the
sucker rod string 110 when being draw upwards and when being pushed
downward. The load cell 114 accomplishes these measurements by
being held in a fixed position on the sucker rod string 110 between
a top clamp collar 112a and a bottom clamp collar 112b.
[0010] The vertical position of the sucker rod string 110 relative
to the down hole well pocket may be determined by positional
information from a rotation position sensor 140, e.g., Hall effect
device, that indicates the rotational position of the Pittman arm
136. The vertical position of the sucker rod string 110 may then be
correlated with the rotational position of the Pittman arm 136.
Once the sucker rod string 110 axial forces and associated vertical
positions are available, a determination can be made for a desired
rotational speed(s) of the motor/gear drive 138 to optimize well
fluid pumping action. Note that the rotational speed can be varied
during a pumping cycle (360 degree rotation of the Pittman arm 136)
to further optimize the well fluid pumping action.
[0011] The load cell 114 may be electrically coupled to a motor
speed controller 144 through a flexible electrical cable 126 that
may be attached to the frame 128 with a junction/strain relief box
130. The rotation position sensor 140 may be electrically coupled
to the motor speed controller 144 through an electrical conduit or
cable 142. The electrical cable 126 may be routed over the
horsehead 122 and across the rocker beam 124.
[0012] Flexibility of the electrical cable 126 is very important in
that the load cell 114 is constantly moving up and down. However
this constant flexing of the electrical cable 126 causes failures
thereto that requires maintenance and replacement in the field.
Also the rotation position sensor 140 is subject to failure and
also requires periodic maintenance and/or replacement. Working in
close proximity to the Pittman arm 136 when servicing the rotation
position sensor 140 poses serious safety issues and careless field
service technicians have been injured, some severely, by coming in
contact with a Pittman arm 136 that accidentally starts to rotate
while service/replacement of the position sensor 140 is being
performed. Thus, service, reliability and safety problems exist in
present technology load and position measurement installations and
servicing of pump jack systems, specifically for fatigue of the
connecting electrical cables and the hazards of accidental rotation
of machinery while servicing sensors in close proximity
thereto.
SUMMARY
[0013] Therefore a need exists to overcome the above-identified
problems as well as other shortcomings and deficiencies of existing
technologies by providing wireless transmission of data from sucker
rod load and position sensors, and then using that data to control
the pump jack system operating parameters so as to optimize fluid
lift from the well pocket.
[0014] According to the teachings of this disclosure, a wireless
sensor package is mechanically and electrically attached to the
load cell 114, and moves therewith. The wireless sensor package
comprises an electrical interface for receiving electrical signals
from the load cell 114, and a position sensor, e.g., a tri-axial
accelerometer, or device for measuring distance from a fixed point,
e.g., ultrasonic, radio frequency, infrared, laser light, etc. In
addition, a downhole temperature gradient may be determined by
measurement of the elongation of the well bore pipe 118 projecting
out of the ground (e.g., distance from ground level to the top of
the well bore pipe 118). Well pressure and flow rate may also be
measured at the flange/fluid takeoff assembly 116.
[0015] The wireless sensor package is adapted to transmit the
sucker rod load and position information over a radio frequency
channel(s), e.g., short-range radio, for example but not limited
to, frequencies at about 315 MHz, 433 MHz, 868 MHz, 902 to 928 MHZ,
2.4 to 2.5 GHz, 5.7 to 5.8 GHz, etc. In addition, any form of
transmission and modulation techniques may be used, for example but
not limited to, spread spectrum to a compatible receive, e.g.,
spread spectrum receiver, coupled to a motor speed controller.
Computations for optimal motor speeds from the wireless load and
position data may be performed in the wireless sensor package
and/or the wireless motor speed controller. A central controller
receiving load and position information and/or motor speeds from
each of the plurality of pump jacks may further be used to control
pump speeds of the plurality of jump jacks so as to optimize oil
field production, e.g., flow rates of pumped product. The central
controller may also determine optimal pumping parameters of each of
the plurality of pump jacks so as to maximize oil field
production.
[0016] According to a specific example embodiment of this
disclosure, a pump jack adapted for monitoring sucker rod load and
position comprises: a sucker rod string in a well bore pipe; a
polished rod coupled to the sucker rod string; a horsehead coupled
to the polished rod; a rocker beam coupled to the horsehead; a
connecting rod coupled to the rocker beam; a counter weight coupled
to the connecting rod; a pittman arm coupled to the connecting rod
and counter weight; a variable speed motor-gear drive assembly
coupled to the pittman arm for rotational movement thereof; a frame
pivotally coupled to the rocker beam; a base attached to the frame;
first and second force sensors attached to a proximate end of the
sucker rod string, wherein the first and second force sensors
measure elongation and compression stresses, respectively, of the
sucker rod string while the sucker rod string moves up and down in
the well bore pipe; a position sensor attached toward the proximate
end of the sucker rod string, wherein the position sensor
determines positions of the sucker rod string; a sensor interface
assembly having wireless transmitting capabilities, wherein the
sensor interface assembly is attached to the sucker rod string, and
is coupled to the first and second force measurement sensors and
the position sensor, whereby the sucker rod string forces and
position information are wirelessly transmitted therefrom; and a
wireless receiver coupled to the variable speed motor-gear drive
assembly, wherein the wireless receiver receives the force and
position information transmitted from the interface assembly for
determining control of rotational speed of the variable speed
motor-gear drive assembly.
[0017] According to another specific example embodiment of this
disclosure, an apparatus for monitoring position and load of a
sucker rod in a pump jack, comprises: first and second force
sensors attached at a proximate end of a sucker rod string of a
pump jack, wherein the first and second force sensors measure
elongation and compression stresses, respectively, of the sucker
rod string while the sucker rod string moves up and down in a well
bore pipe; a position sensor attached toward the proximate end the
sucker rod string, wherein the position sensor determines positions
of the sucker rod string; and a sensor interface assembly having
wireless transmitting capabilities, wherein the sensor interface
assembly is attached to the sucker rod string, and is coupled to
the first and second force measurement sensors and the position
sensor, whereby the sucker rod string forces and position
information are wirelessly transmitted therefrom.
[0018] According to still another specific example embodiment of
this disclosure, a pump jack adapted for monitoring sucker rod load
and position comprises: a sucker rod string in a well bore pipe; a
polished rod coupled to the sucker rod string; a horsehead coupled
to the polished rod; a rocker beam coupled to the horsehead; a
connecting rod coupled to the rocker beam; a counter weight coupled
to the connecting rod; a pittman arm coupled to the connecting rod
and counter weight; a variable speed motor-gear drive assembly
coupled to the pittman arm for rotational movement thereof; a frame
pivotally coupled to the rocker beam; abuse attached to the frame;
first and second force sensors attached to a proximate end of the
sucker rod string, wherein the first and second force sensors
measure elongation and compression stresses, respectively, of the
sucker rod string while the sucker rod string moves up and down in
the well bore pipe; a sensor interface assembly having wireless
transmitting capabilities, wherein the sensor interface assembly is
attached to the sucker rod string, and is coupled to the first and
second force measurement sensors, whereby the sucker rod string
force information is wirelessly transmitted therefrom; a distance
measuring device attached on a plan of the base and under the
sensor interface assembly, wherein the position sensor determines
positions of the sucker rod string by measuring distances between
the distance measuring device and the sensor interface assembly;
and a wireless receiver coupled to the variable speed motor-gear
drive assembly, wherein the wireless receiver receives the force
information transmitted from the sensor interface assembly, and
wherein position information from the distance measuring device is
coupled to the variable speed motor-gear drive assembly, whereby
control of rotational speed of the variable speed motor-gear drive
assembly is determined from the force and position information.
[0019] According to yet another specific example embodiment of this
disclosure, an apparatus for monitoring position and load of a
sucker rod in a pump jack comprises: first and second force sensors
attached at a proximate end of a sucker rod string of a pump jack,
wherein the first and second force sensors measure elongation and
compression stresses, respectively, of the sucker rod string while
the sucker rod string moves up and down in a well bore pipe; a
sensor interface assembly having wireless transmitting
capabilities, wherein the sensor interface assembly is attached to
the sucker rod string, and is coupled to the first and second force
measurement sensors, whereby the sucker rod string force
information is wirelessly transmitted therefrom; a distance
measuring device attached on a plane of a base of the pump jack and
under the sensor interface assembly, wherein the distance measuring
device determines positions of the sucker rod string by measuring
distances between the distance measuring device and the sensor
interface assembly; and a wireless receiver coupled to the variable
speed motor-gear drive assembly, wherein the wireless receiver
receives the force information transmitted from the sensor
interface assembly, and wherein position information from the
distance measuring device is coupled to the variable speed
motor-gear drive assembly, whereby control of rotational speed of
the variable speed motor-gear drive assembly is determined from the
force and position information.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] A more complete understanding of the present disclosure
thereof may be acquired by referring to the following description
taken in conjunction with the accompanying drawings wherein:
[0021] FIG. 1 illustrates a schematic elevational diagram of a
prior technology pump jack system having hardwired sucker rod load
and position sensors, and connected to a well sucker rod
string;
[0022] FIG. 2 illustrates a schematic elevational diagram of a pump
jack system having wireless sucker rod load and position sensors
coupled to a well sucker rod string, a distance measuring device
for determining well bore pipe elongation, and a wireless data
input motor speed controller, according to a specific example
embodiment of this disclosure;
[0023] FIG. 3 illustrates a more detailed schematic block diagram
of the wireless sensor packages shown in FIG. 2;
[0024] FIG. 4 illustrates a schematic elevational diagram of a pump
jack system having wireless sucker rod load and distance
measurement sensors coupled to a well sucker rod string, a distance
measuring device for determining well bore pipe elongation, and a
wireless data input motor speed controller, according to another
specific example embodiment of this disclosure;
[0025] FIG. 5 illustrates a more detailed schematic block diagram
of the wireless sensor packages shown in FIG. 4;
[0026] FIG. 6 illustrates a schematic elevational diagram of a pump
jack system having wireless sucker rod load measurement sensors
coupled to a well sucker rod string, distance measuring devices for
determining well sucker rod string positions and well bore pipe
elongation, and a wireless data input motor speed controller,
according to still another specific example embodiment of this
disclosure;
[0027] FIG. 7 illustrates a more detailed schematic block diagram
of the wireless sensor packages shown in FIG. 6; and
[0028] FIG. 8 illustrates schematic diagrams of various power
sources available for powering the wireless sensor packages shown
in FIGS. 3, 5 and 7, according to specific example embodiments of
this disclosure.
[0029] While the present disclosure is susceptible to various
modifications and alternative forms, specific example embodiments
thereof have been shown in the drawings and are herein described in
detail. It should be understood, however, that the description
herein of specific example embodiments is not intended to limit the
disclosure to the particular forms disclosed herein, but on the
contrary, this disclosure is to cover all modifications and
equivalents as defined by the appended claims.
DETAILED DESCRIPTION
[0030] Referring now to the drawing, the details of specific
example embodiments are schematically illustrated. Like elements in
the drawings will be represented by like numbers, and similar
elements will be represented by like numbers with a different lower
case letter suffix.
[0031] Referring to FIG. 2, depicted is a schematic elevational
diagram of a pump jack system having wireless sucker rod load and
position sensors coupled to a well sucker rod string, a distance
measuring device for determining well bore pipe elongation, and a
wireless motor speed controller, according to a specific example
embodiment of this disclosure. The pump jack system, according to
the teachings of this disclosure and generally represented by the
numeral 200, comprises a sucker rod string 110, a polish rod 120, a
horsehead 122, a rocker beam 124, connecting rod 132, counter
weight 134. Pittman arm 136, motor/gear drive 138, frame 128 and
base 146. A wireless sensor package 250 is mechanically and
electrically attached to the load cell 114, and moves therewith. In
addition, another wireless sensor package 254 attached at about the
top of the well bore pipe 118, e.g., coupled to the flange/fluid
takeoff assembly 116. The wireless sensor package 254 comprises a
distance measurement device that accurately measures a distance, d,
from the wireless sensor package 254 to a reference point 256,
e.g., a target at ground level.
[0032] As the motor/gear drive 138 rotates, the Pittman arm 136
causes the connecting rod 132 to push up or pull down one end of
the rocker beam 124. On the other end of the rocker beam 124 is the
horsehead 122 connected to the polish rod 120. As the horsehead 122
moves up and down so does the polish rod 120 which in turn moves
the sucker rod string 110 in and out of the well bore pipe 118. The
well bore pipe 118 is terminated at the flange/fluid takeoff
assembly 116 that is adapted to allow fluid (or gas) being pumped
out of the well bore pipe 118 to flow to a storage tank/pipeline
(not shown). The flange/fluid takeoff assembly 116 also is used to
seal around a portion of the sucker rod string 110 so that well
fluid does not spill onto the ground. Pressure and flow rate
sensors may also be incorporated into the wireless sensor package
254. It is contemplated and within the scope of this disclosure
that the sensor package 254 may alternatively be hard wired to the
motor speed controller 258 since the sensor package 254 is
stationary with respect to the well bore pipe 118.
[0033] Axial forces on the sucker rod string 110 may be measured by
a load cell 114 that determines the axial forces applied to the
sucker rod string 110 when being draw upwards and when being pushed
downward. The load cell 114 accomplishes these measurements by
being held in a fixed position on the sucker rod string 110 between
a top clamp collar 112a and a bottom clamp collar 112b. The load
cell 114 may be, for example but is not limited to, a Lufkin
Industries model 1923.
[0034] The wireless sensor package 250 is mechanically and
electrically coupled to the load cell 114, and moves therewith. A
right angle coupling 252 may be used for mounting thereof. The
wireless sensor package 250 comprises an electrical interface for
receiving electrical signals from the load cell 114, and a position
sensor, e.g., a tri-axial accelerometer (see FIG. 3). The wireless
sensor package 250 is adapted to transmit the sucker rod load and
position information over a radio frequency channel(s), e.g.,
short-range radio, for example but not limited to, frequencies at
about 315 MHz, 433 MHz, 868 MHz, 902 to 928 MHZ, 2.4 to 2.5 GHz,
5.7 to 5.8 GHz, etc. In addition, any form of transmission and
modulation techniques may be used, for example but not limited to,
spread spectrum to a compatible receive, e.g., spread spectrum
receiver, coupled to a motor speed controller 258. Computations for
optimal motor speeds from the wireless load and position data may
be performed in the wireless sensor package 250 and/or the wireless
motor speed controller 258. A central controller receiving load and
position information and/or motor speeds from each of the plurality
of pump jacks may further be used to control pump speeds of the
plurality of jump jacks so as to optimize oil field production,
e.g., flow rates of pumped product. The central controller (not
shown) may also determine optimal pumping parameters of each of the
plurality of pump jacks so as to maximize oil field production.
[0035] Once the sucker rod string 110 axial forces and associated
vertical positions thereof are available, a determination(s) can be
made for a desired rotational speed(s) of the motor/gear drive 138
to optimize well fluid pumping action. Note that the rotational
speed can be varied during a pumping cycle (360 degree rotation of
the Pittman arm 136) to further optimize the well fluid pumping
action.
[0036] Referring to FIG. 3, depicted is a more detailed schematic
block diagram of the wireless sensor packages shown in FIG. 2. The
wireless sensor package 250 may comprise a position sensor 360, a
position sensor interface 362, top and bottom load cell interfaces
364, data processing logic and memory storage 368, a wireless
transmitter 370a, and a power source 366. The position sensor 360
may be a tri-axial accelerometer, for example but not limited to,
Analog Devices ADXL330.
[0037] As the sucker rod string 110 moves up and down, represented
schematically by the heavy line double arrow, the position sensor
360 determines at the movement distances from a reference point.
Thus real time position signals representative of the positions of
the sucker rod string 110 are available from the position sensor
360. The power source 366 supplies power to the position sensor
360, the data processing logic and memory storage 368, and the
wireless transmitter 370. The interfaces 362 and 364 may receive
power from the data processing logic and memory storage 368, and
the load cells 114 may receive power from their respective
interfaces 364.
[0038] The top and bottom load cells 114a and 114b also make
available real time signals representative of the up and down
forces, respectively, being applied to the sucker rod string 110.
These real time position and force signals are transferred by the
respective position sensor interface 362 and load cell interfaces
364 to the data processing logic and memory storage 368. The data
processing logic and memory storage 368 may comprise a digital
processor (not shown) and a memory (not shown). The data processing
logic and memory storage 368 may be used for processing the real
time position and force signals into optimal motor speed control
values to be transmitted to the wireless motor speed controller 258
through the wireless transmitter 370. Also values of the real time
position and force signals may be stored in the memory of the data
processing logic and memory storage 368 for historical and
exception reporting, e.g., real time position and/or force values
that are outside of the expected norm, and may be exception
reported through the wireless transmitter 370 to a control and
monitoring system (not shown) or as a shutdown and/or alarm signal
to the wireless motor speed controller 258.
[0039] The sensor package 254 may comprise a distance detector 372,
e.g., a distance determining device using, for example but not
limited to, ultrasonic, radio frequency (radar), infrared or laser
light timed pulse transmissions. Another wireless transmitter 370b
may be used to transmit the distance information from the distance
detector 372 and used for determining the elongation of the well
bore pipe 118 due to an increase of the downhole temperature. In
addition, pressure and/or flow rate sensors may be coupled at the
flange/fluid takeoff assembly 116. The sensor package 254 may be
powered through an internal power source (e.g., wireless sensor
package) or from the motor speed controller 258 (hardwired).
[0040] Referring to FIG. 4, depicted is a schematic elevational
diagram of a pump jack system having wireless sucker rod load and
distance measurement sensors coupled to a well sucker rod string, a
distance measuring device for determining well bore pipe
elongation, and a wireless motor, speed controller, according to
another specific example embodiment of this disclosure. The pump
jack system, according to the teachings of this disclosure and
generally represented by the numeral 400, comprises a sucker rod
string 110, a polish rod 120, a horsehead 122, a rocker beam 124,
connecting rod 132, counter weight 134, Pittman arm 136, motor/gear
drive 138, frame 128 and base 146. A wireless sensor package 450 is
mechanically and electrically coupled to the load cell 114, and
moves therewith. In addition, another wireless sensor package 254
may be attached at about the top of the well bore pipe 118, e.g.,
coupled to the flange/fluid takeoff assembly 116. The sensor
package 254 comprises a distance measurement device that accurately
measures a distance, d.sub.1, from the sensor package 254 to a
reference point 256a, e.g., a target at ground level. The sensor
package 254 may be wireless or hard wired to the motor speed
controller 258.
[0041] Axial forces on the sucker rod string 110 may be measured by
the load cell 114 as more fully described hereinabove. The wireless
sensor package 450 comprises an electrical interface for receiving
electrical signals from the load cell 114, and a distance
measurement sensor, e.g., ultrasonic, radio frequency, infrared,
laser light that measure a distance, d.sub.2, representing the
vertical distance of the load cell 114 from the reference point
256b, e.g., a target at ground level. The wireless sensor package
450 is adapted to transmit the sucker rod load and distance
information over a radio frequency channel(s) as described more
fully hereinabove.
[0042] It is contemplated and within the scope of this disclosure
that the distance measurement device that measures the distance
(position) of the load cell 114 may be located at the reference
point 256b at or about ground level. By locating this distance
measurement device at a fixed location (reference point 256b) it
can now be either wireless or wired to the motor controller 258. In
addition, the movable wireless sensor package 450 may be simplied
as it need only transmit load cell 114 information wirelessly, as
more fully described herein. Also any intellegent electronics may
now be located with the stationary (fixed) distance measurement
device, and a very low power and simple (e.g., Bluetooth) wireless
communications protocol may be utilized for the real time load cell
data.
[0043] Referring to FIG. 5, depicted is a more detailed schematic
block diagram of the wireless sensor packages shown in FIG. 4. The
wireless sensor package 450 may comprise a distance detector 560, a
distance detector interface 562, top and bottom load cell
interfaces 364, data processing logic and memory storage 368, a
wireless transmitter 370a, and a power source 366. The distance
detector 560 may be similar to the distance detector 372 as more
fully described hereinabove.
[0044] As the sucker rod string 110 moves up and down, represented
schematically by the heavy line double arrow, the distance detector
560 determines the distances, d.sub.2, from the reference point
256b. Thus real time positions derived from the measured distances,
d.sub.2, are representative of the positions of the sucker rod
string 110. The power source 366 supplies power to the distance
detector 560, the data processing logic and memory storage 368, and
the wireless transmitter 370a. The interfaces 362 and 364 may
receive power from the data processing logic and memory storage
368, and the load cells 114 may receive power from their respective
interfaces 364.
[0045] The top and bottom load cells 114a and 114b also make
available real time signals representative of the up and down
forces, respectively, being applied to the sucker rod string 110.
These real time position and force signals are transferred by the
respective distance detector interface 562 and load cell interfaces
364 to the data processing logic and memory storage 368. The data
processing logic and memory storage 368 may comprise a digital
processor (no(shown) and a memory (not shown). The data processing
logic and memory storage 368 may be used for processing the real
time position and force signals into optimal motor speed control
values to be transmitted to the wireless motor speed controller 258
through the wireless transmitter 370a. Also values of the real time
position and force signals may be stored in the memory of the data
processing logic and memory storage 368 for historical and
exception reporting, e.g., real time position and/or force values
that are outside of the expected norm, and may be exception
reported through the wireless transmitter 370a to a control and
monitoring system (not shown) or as a shutdown and/or alarm signal
to the wireless motor speed controller 258.
[0046] It is contemplated and within the scope of this disclosure
that the distance detector 560, the distance detector interface 562
and the data processing and storage 368 may be located at the fixed
location (reference point 256b) and the wireless sensor package 450
need only comprise the load cell interfaces 364, a power source
366a and a wireless transmitter 370a. The housing of the wireless
sensor package 450 could serve as a reflective target for the
distance detector 560 or a distance measuring signal reflective
plate can be attached thereto. See also FIG. 7 and the disclosure
therefor hereinbelow.
[0047] The sensor package 254 may comprise a distance detector 372,
e.g., a distance determining device using, for example but is not
limited to, ultrasonic, radio frequency (radar), infrared or laser
light timed pulse transmissions. Another wireless transmitter 370b
may be used to transmit the distance information from the distance
detector 372 and used for determining the elongation of the well
bore pipe 118 due to an increase of the downhole temperature. In
addition, pressure and/or flow rate sensors may be coupled at the
flange/fluid takeoff assembly 116.
[0048] Referring to FIG. 6, depicted is a schematic elevational
diagram of a pump jack system having wireless sucker rod load
measurement sensors coupled to a well sucker rod string, distance
measuring devices for determining well sucker rod string positions
and well bore pipe elongation, and a wireless motor speed
controller, according to still another specific example embodiment
of this disclosure. The pump jack system, according to the
teachings of this disclosure and generally represented by the
numeral 600, comprises a sucker rod string 110, a polish rod 120, a
horsehead 122, a rocker beam 124, connecting rod 132, counter
weight 134, Pittman arm 136, motor/gear drive 138, frame 128 and
base 146. A wireless sensor package 650 is mechanically and
electrically attached to the load cell 114, and moves therewith. In
addition, another wireless sensor package 654 attached at about the
top of the well bore pipe 118, e.g., coupled to the flange/fluid
takeoff assembly 116. The sensor package 654 comprises distance
measurement devices that accurately measure distance, d.sub.b, from
the sensor package 654 to a reference point 256, e.g., a target at
ground level, and distance, d.sub.a, from the sensor package 654 to
the sensor package 650 (also used as a target). The sensor package
654 may be wireless or hard wired to the motor speed controller 258
since it remains stationary. The sum of the measured distances,
d.sub.a and d.sub.b, plus the height of the sensor package 654 will
be representative of an accurate measured distance of the load cell
114 from the reference point 256. Both distances, d.sub.a and
d.sub.b, have to be taken into account since elongation of the well
bore pipe 118 vary depending upon the temperatures along the pipe
118. An alternative mounting of a distance measurement sensor (not
shown) at the fixed reference point 256 may be used and then the
distance from the ground mounted (or fixed pedistile mounted)
distance detector in the sensor package 654a would measure the
housing as a target of the sensor package 650. An advantage of
putting the distance measurement detectors in the fixed sensor
package 652 is that only the load cell sensors in the sensor
package 650 need be wireless, though preferably all sensor packages
650 and 652 may be wireless.
[0049] Axial forces on the sucker rod string 110 may be measured by
the load cell 114 as more fully described hereinabove. The wireless
sensor package 650 comprises an electrical interface for receiving
electrical signals from the load cell 114. The wireless sensor
package 650 is adapted to transmit the sucker rod load over a radio
frequency channel(s) as described more fully hereinabove.
[0050] Referring to FIG. 7, depicted is a more detailed schematic
block diagram of the wireless sensor packages shown in FIG. 6. The
wireless sensor package 650 may comprise top and bottom load cell
interfaces 364, data processing logic and memory storage 368, a
wireless transmitter 370a, and a power source 366. It is
contemplated and within the scope of this disclosure that the data
processing and storage 368 may be located in the sensor package 652
and that the wireless transmitter 370a may communicate directly
with a receiver (not shown) in the sensor package 652. This will
further reduce the power consumption used by the sensor package
650. The distance detector 760 may be similar to the distance
detector 560 as more fully described hereinabove.
[0051] As the sucker rod string 110 moves up and down, represented
schematically by the heavy line double arrow, the distance detector
760 determines the distance, d.sub.a, from the top of the sensor
package 654 housing, and the distance detector 762 determines the
distance, d.sub.b, from the top of the well bore pipe 118 to the
reference point 256 (e.g., ground reference). Thus real time
positions derived from the measured distances, d.sub.a plus d.sub.b
plus the height of the sensor package 654 housing, represent the
positions of the sucker rod string 110. Power sources supply power
to the distance detectors 760 and 762, the data processing logic
and memory storage 368, and the wireless transmitters 370. The
interfaces 362 and 364 may receive power from the data processing
logic and memory storage 368, and the load cells 114 may receive
power from their respective interfaces 364. The data processing
logic may also be located in the sensor package 654 and that the
sensor package 654 may be either wireless or hard wired to the
motor controller 258. Also the wireless transmitter 370a may send
the load cell information first to a receiver (not shown) in the
stationary sensor package 654 where all of the smart processing may
also be located.
[0052] The top and bottom load cells 114a and 114b also make
available real time signals representative of the up and down
forces, respectively, being applied to the sucker rod string 110.
These real time position and force signals are transferred by the
respective distance detector interface 562 and load cell interfaces
364 to the data processing logic and memory storage 368. The data
processing logic and memory storage 368 may comprise a digital
processor (not shown) and a memory (not shown). The data processing
logic and memory storage 368 may be used for processing the real
time position and force signals into optimal motor speed control
values to be transmitted to the wireless motor speed controller 258
through the wireless transmitter 370a. Also values of the real time
position and force signals may be stored in the memory of the data
processing logic and memory storage 368 for historical and
exception reporting, e.g., real time position and/or force values
that are outside of the expected norm, and may be exception
reported through the wireless transmitter 370a to a control and
monitoring system (not shown) or as a shutdown and/or alarm signal
to the wireless motor speed controller 258.
[0053] Referring to FIG. 8, depicted are schematic diagrams of
various power sources available for powering the wireless sensor
packages shown in FIGS. 3, 5 and 7, according to specific example
embodiments of this disclosure. A rechargeable battery 366a may be
used as the power source 366. A capacitor 366b may be charged as
described hereinafter and used as the power source 366. A battery
and solar cell charger 366c may be used as the power source 366. An
inductive pick-up charger coil 480 external to the wireless sensor
package 250, 450 or 650 may be used to inductively charge the
internal charging coil 482 coupled to the battery 478 through
rectifier 484. A motion charger and battery 366c may comprise a
charging pick-up coil in close proximity to a permanent magnet 488,
wherein the permanent magnet moves in an axial direction depending
upon the axial motion of the wireless sensor package 250. The
magnet 488 has mass and travels back and forth between the springs
490 when the wireless sensor package 250, 450 or 650 is moving up
and down, thus charging the battery 478 through the diode 484. The
battery 478 may be replaced with the capacitor 492 and be similarly
charged. It is contemplated and within the scope of this disclosure
that other sources of power 366 not disclosed herein may be also be
utilized to power the components of the wireless sensor package
250.
[0054] While embodiments of this disclosure have been depicted,
described, and are defined by reference to example embodiments of
the disclosure, such references do not imply a limitation on the
disclosure, and no such limitation is to be inferred. The subject
matter disclosed is capable of considerable modification,
alteration, and equivalents in form and function, as will occur to
those ordinarily skilled in the pertinent art and having the
benefit of this disclosure. The depicted and described embodiments
of this disclosure are examples only, and are not exhaustive of the
scope of the disclosure.
* * * * *