Note: Descriptions are shown in the official language in which they were submitted.
CA 02582744 2007-03-21
Wireless automation systems and processes for wells
BACKGROUND OF TH.E INVENTION
1. Field of the Invention
The present invention relates to a system in which one or more master remote
tenninal/telemetry unit (MRTU) is wirelessly connected to a central host
system, for
example a computing system, using wireless multi-cast networking communication
to
create a wide area network (WAN). The wireless multi-cast networking
communication
system allows an operator to monitor and control two or more automated wells
and/or
associated well facilities from virtually any location.
2. Backaound of the Related Art
State-of-the-art modern hydrocarbon (gas or oil) production wellheads are
automated using systems coinmonly referred to as supervisory control and data
acquisition
(SCADA) systems as taught by Ocondi, C. U.S. Patent No. 5,9$3,164 issued on
November 9, 1999. Such SCADA systems are each designed to calculate gas and
fluid
production from a production wellhead, as well as monitor production trends
and control
with passive and active end-devices. As is well known in the art, wellhead end-
devices
include tubing and casing pressure transducers to transmit their readings,
multi-variable
transducers, position switches, motorized choke valves, and so on at each
individual well
site. These wellhead end-devices are currently typically conneeted to a remote
terminal/telemetry unit (RTU) with underground wiring. It is also cotnmon
practice to
automate associated production facilities such as separator/dehydration units,
production
meter-runs, and tank batteries by connecting end devices at these facilities
to the wellhead
RTU with underground wiring. The wellhead and its associated facilities are
typically
separated by somc distance. It is not uncommon to find wellhead systems in
which tubing
and casing pressure transducers, choke controllers, plunger arrival switches,
and other
end-devices installed more than several hundred feet away from the
separation/dehydration equipment, the meter-run end-devices at which gas and
fluid
production are measured, and the tank battery end-devices. Hydrocarbon
measurement is
normally accontplished using electronic transducers that measure static and
differential
pressures and temperature across the orifice meter usually installed
downstream from the
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CA 02582744 2007-03-21
separatorldehydration facilities. Fluid flow results are most often calculated
by a
microprocessor associated with the RTU in accordance with the requirements of
AGA-3
(American Gas Association Report #3).
Typically separation/dehydration vessels and storage tanks are installed at
least
fifty feet away from a welihead in order to allow wire-line equipment and work-
over rigs
easy access to the wellhead. In addition, on occasion surface restrictions for
wells drilled
in farming or agricultural areas may require that separation/dehydration
facilities as well
as the tank batteries be located hundreds or even thousands of feet away from
a wellhead.
In addition, systems that allow well operators to monitor, control, and
optimize
production of oil or gas from wellh.eads from virtually anywhere using field
wireless local
area network (LAN) and wide area net%vork (WAN) communication systems or
multicast
wireless network systems are taught by Ocondi, M. U.S. Patent Application
Publication
No. 2007/0018851 published on January 25, 2007.
It is noted that conventional RTUs referred to above are designed to automate
only
one well or one associated well facility as there is no economical reason to
develop
conventional RTU sofhvare to handle multiple wells or multiple associated well
facilities
because the cost of installing underground wiring to connect multiple wells
and/or
associated well facilities is significantly greater than installing an
individual RTU at each
well site and at each associated well facility.
It is therefore seen that there is an economic justification to wirelessly
link two or
more wellheads and/or two or more associated well facilities by using a slave
remote
telemetry unit (SRTU) and/or a MRTU in lieu of wires or cables. The cost of
the SRTU
and the MRTU for communication using a field LAN system that wirelessly links
two or
more end-devices to the MRTU can easily off set the cost of a liardwire cable
installation
of say thirty feet or less. Also, ditcliing and trenching operations around
wellhead
facilities is hazardous. It has been generally recognized in the gas and oil
production
industry that cables that are cut as a result of facility repair is a major
cause of automation
systems downtime.
In addition it is seen that developing software to handle multiple wells and
end
devices at multiple associated well facilities would in fact be economically
advantageous.
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CA 02582744 2007-03-21
SUMMARY OF THE INVENTION
It is thus an object of the present invention to provide a system that is
specifically
designed to wire.lessly connect groups of end-devices at two or more oil or
gas production
wellheads or groups of end-devices at two or more associated well facilities,
and mixtures
tlicreof so that the associated end devices may be wirelessly monitored and
measured
during wellhead production, and then wirelessly controlled by one or more
master remote
terminal/telemetry unit MRTUs, and in turn wirelessly controlled by a master
host
computer systeni according to the teaching of the present invention. Such
measurement
and control is accomplished through slave remote telemetry units SRTUs
associated with
the end devices. This is accomplished by using, in lieu of hardwire or cable,
one or more
wireless sub-network LAN communication systems to connect the end devices of
two or
more well systems witlt the MRTU through the SRTUs.
That is, rather titan using one conventional RTU to monitor, measure, and
control
one well or end devices at one associated well facility, a MRTU in wireless
communication with multiple SRTUs that are operatively attached to end-devices
installed at two or more wells or two or more associated well facilities , or
mixture thereof,
is provided by the present invention to operate as multiple state-of-the-art
RTUs. Each
MRTU is configurable with two or more RTUs of the present invention. As taught
herein,
individual wells or associated well facilities are given unique memory
addresses and that
meniory is partitioned to recognize and store trending, measurement, and
control
algorithms from each end device group installed at each of t-vvo or more well
sites or at
each of two or more associated well facilities. The MRTU is programmed to
recognize
whether the end-devices are com,ected directly to its input/output (I/O)
through hard-wired
connection or whether they are connected wirelessly to a SRTU. The MRTU is
programmed to sort out the end-device or devices attached to a particular well
system of
the two or niore well systems or to a particular system of two or more
associated well
facilities . Each MRTU can be programmed to perform the task of multiple on-
site
electronic flow nieasurement EFM computers complete with high-resolution audit-
trail as
taught by Ocondi, C. U.S. Patent 5,983,164. Control algorithms of the MRTU are
customized to individual wells or to individual associated well facilities to
affect
production monitoring, control and optimization of each well system or
associated well
facility by wireless linkage. The communication program for the MRTU will
appear to
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CA 02582744 2007-03-21
the master host, for example, a personal computer, or other state-of-the-art
computing
system, as if there is an individual conventional RTU installed at each of the
multiple well
or associated well facility sites.
It is thus seen that in the present invention the long and costly cable or
hardwire
wire, along with the costly trenching to put it in place that traditionally
connects field end
devices are replaced with a field wireless LAN data radio and the SRTU
directly attached
to multiple end-devices at multiple wells and/or multiple associated well
facilities. This
not only solves the installation cost problems associated with the topology
and remoteness
of the wel lheads and end-devices installed at various parts of the wells
production facility,
it also adds or distributes the intelligence and the data of the systems to
the discrete
MRTUs and host device so that captured data integrity and functional
reliability of
automated well control and production optimization are significantly enhanced.
More
importantly, the present invention wirelessly expands the input/output (UO)
capability of
the MRTU significantly beyond its on-board I/O counts available from a single
well
automation system.
Taking advantage of the teaching of the present invention that a MRTU can be
used to wirelessly link SRTUs attached to end-devices associated with two or
more wells
and/or end devices attached to two or more associated well facilities, the
present invention
also teaches m.ethods and processes of configuring a MRTU to operate with
multiple
RTUs. The system of the present invention and the process of using it allow
the MRTU to
automate two or niore well systems and/or two or more associated well
facilities. The
MRTU in wireless connection through the field LAN with multiple SRTUs
installed at
two or more wellheads or two or more associated well facilities is able to
operate as if it
provided multiple on-site electronic flow measurements (EFMs) in compliance
with API
2l .1 and BLMs NTL 2004-01. The invention of the present invention also
operates as
multiple automated well or end device eontrol systems to affect production
optimization
and provides detailed historical data capturing and event logging of operating
alarm
conditions as taught by Ocondi, C. U.S. Patent 5,983,164.
Finally, the present invention also has the ability to retrofit state-of-the-
art existing
RTUs, Remote 1/0 units, EFMs, and programmable logic controllers (PLCs) to
economically affect wireless measurement and production optimization.
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The present invention can also be applied to retrofit with state-of-the-art,
or
conventional third-party supplied RTUs with EFM and control capability that
require
upgrade. A MRTU can be associated witli two or more wells and/or two or more
associated well facilities in which each well or associated well facility has
an existing
RTU, and each RTU is in turn equipped with a data radio to wirelessly connect
it to the
MRTU. In such a retrofit configuration each RTU is programmed to operate as a
passive
device or a wireless remote UO device. The retrofit system based on the master
remote
telemetry unit MRTU will provide high resolution trending data, an EFM system
with on-
site and off-site capability, and a controller with eustoniized control
algorith.ms.
As used herein, and as set forth in context in the attached figures and in the
detailed description below, the MRTU is a computcr with software and hardware
that
records and trends various analog data and controls remote electronic devices
measuring
and controlling the production of oil and gas fields. Such devices include,
for example,
those used for reading pressure and flow volumes in oil and gas wells and
fields. Other
electronic deviees are used to opeti and close valves in oil and gas wells and
fields_ The
MRTU, also records device information, which, in the practice of the present
invention,
are transmitted and received data to and from the SRTU, using wireless spread
spectrum,
(SS) data radio communication technology. The MRTU, with the ability to store
multiple
well and/or associated well facility data, is also equipped with another WAN
data radio
that is in communication with a master host and other remote hosts, for
example, a
personal coniputer, PC or other state-of-the-art computing system, systems
that allow the
users to control, nionitor and optimize production from virtually anywhere as
taught by
Ocondi, M. U.S. Patent Application Publication No. 2007/001885I, published on
January 25, 2007.
In addition to wireless SS data radios, it should be noted that for purposes
of the
present invention WAN communication among remote hosts and MRTUs may use other
state-of-the-art known conventional wireless technologies and future wireless
communication technologies. Such communication technologies include satellite
technology, cell phone technology, licensed radio technology and others.
However, it is
currently found that SS data radio is the preferred wireless communication
system since it
is most cost effective and provides better overall perfonnance in tenns of
reliability and
flexibility.
CA 02582744 2007-03-21
As also used herein and detailed below, SRTUs, are also computers with
software
and hardware capable of reading the end-devices, flow calculation and
controlting external
end-devices such as pressure transducers, plungcr arrival switches, motorized
choke
valves, tank level transducers, etc. The data stored in the SRTU, can be
uploaded and
downloaded from other SRTUs and MRTUs,. Data transferred wirelessly among the
MRTUs, and SRTUs is done througll a field LAN.
In addition, as used herein, the term "end device" includes well system
measuring
and controlling devices such as tubing pressure transducers, casing pressure
transducers,
control valve, valve position switches, and plunger arrival switches. The term
"end
device" also includes meter-rtin transducers and tank battery system
transducers, as well as
any current or future measuring and controlling devices used with wells or
associated well
facilities now or in the future. Such end devices and related groups of end
devices are all
included in the term "end device" as used herein.
As further detailed below, the data transferred wirelessly among the MRTUs and
the master host and the computer host is through a field WAN, or multicast
wireless
network system as taught by Ocondi, M. U.S. Patent Application Publication
No. 2007/0018851 publistied on January 25, 2007, or other state-of-the-art
computing
systems.
These and other teachings of the present invention will become apparent to
those
skilled in the art from the following detailed description, showing the
contemplated novel
construction, combination, and elements as herein described, and more
particularly
defined by the appended claims, it being understood that changes in the
precise
embodiments to the herein disclosed invention are meant to be included as
coming within
the scope of the claims, except insofar as they may be precluded by the prior
art.
BRIEF DESCRIPTION OF THE DRAWINGS:
The accompanying drawings illustrate complete preferred embodiments of the
present invention according to the best modes presently devised for the
practical
application of the principles thereof, and in which:
FIG. I illustrates two types of wireless networking systems, according to the
teaching of the present invention, that each serve to provide a user with a
field wireless
wide area network WAN and a field wireless local area network LAN to provide
system
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users access from multiple end devices and well systems or associated well
facilities to a
master remote terminal/telemetry unit MRTU to monitor operating data and allow
wireless
remote control of such end devices and well systems and associated well
facilities; and
FIGS. 2A and 2B show a flow-chart of the master remote terminal/telemetry unit
MRTU
sofhvare allowing wireless communication with the slave reinote telemetry unit
SRTU
and/or third party legacy RTUs and allows the slave remote telemetry unit SRTU
to
function as a state-of-the-art multiple reniote terminal/telemetry unit RTU.
DETAILED DESCRIPTION OF THE PREFFERED EMBODIMENTS
Referring to FIG. 1, a group of related end devices are shown on the right
side
illustrating a representative physical layout of various groups of end-devices
that are
commonly installed at gas or oil. wellliead. These include, for example
wellhead system
End Device A-1, meter-run End-Device B-1, and Tank Battery system End-Device C-
1.
Note, as explained below in view of the teaching of the present invention, the
physical
proximity of the three related groups of end devices is not critical.
Well head system End Device A includes state-of the-art nieasuring and
controlling devices such as tubing pressure transducer (11), casitig pressure
transducer
(12), control valve (13), valve position switch (14), and plunger arrival
switch (15). These
arc all hardwire connected in the vicinity of the wel lhead to slave remote
telemetry unit
SRTU (16). SRTU (16) is in turn hardwire connected to radio (17) including
antenna (18).
Referring again to FIG. 1, meter-n.tn End-Device B-I, multivariable transducer
(21) is hardwired to SRTU, B 1 (22). SRTU B 1 (22). SRTU B 1 (22) is in turn
liardwire
connected to data radio (23) and antenna (24). In this embodiment to FIG. 1,
tank level
transducer (31) is directly wired to SRTU, C-1 (32). SRTU C-1 (32) is in turn
hardwire
connected to data radio (33) and antenna (34).
In this modified system tank level tra.nsducer (71), tubing pressure
transducer (51),
casing pressure transducer (52), control valve (53), valve position switches
(54), and flow
transducer (61) of wellhead End device A-2 are all directly hardwire connected
to master
remote telenietry unit MRTU #2 (91). unit MRTU #2 (91) is directly connected
to data
radio (94) and antenna (95). MRTU #2 (91) is in wireless communication with
SRTU,
(81) via data radio (82) and antenna (83), which is part of the field wireless
LAN.
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Referring to FIG. 1, a group ofrelatcd end devices are shown on the left.
These include,
for exaniple wellhead system End Device A-l, meter-run End-Device B-1.
Thus, this group of related end devices shows connectivity of end-devices-
group A-
1, B-1, and C-1 of what is arbitrarily designated as well system #1 directly
wired to SRTUs
(16), (22) and (32) operatively attached to respective end-deviee groups A-1,
B-l, and C-1.
It also shows the three field wireless LAN data radios (1), (22) and (33) and
their respective
antennas of well system #I arrayed for wireless communication to MRTU #I and
the
wireless connection of MRTU #1 to the field wireless WAN with the master host
(101) for
example a personal computer, PC (101), or other state-of-the-art computing
systems such as
slave remote host system (201), all as set forth in greater detail below.
Note that MRTU #1 seen in the upper center of FIG. I is shown to be designed
to
receive data wireiessly from a group of SRTUs (16), (22) and (32) from well
system #1
only. It should be noted however that MRTU #1 is capable of receiving data
wirelessly
from SRTUs associated with two or more wells and/or associated well
facilities, as
illustrated and as set forth in greater detail below.
Referring once again to FIG. 1, a second group of related end devices are
shown on
the lower left. These include, for example, welihead system #2 including End
Device A-2,
meter-run End-Device system B-2, and Tank Battery system End-Device C-2. In
this
system #2 tank level transducer (71), tubing pressure transducer (51), casing
pressure
transducer (52), control valve (53), valve position switch (54), and flow
transducer (61) of
wellhead End device A-2 are all directly hardwire connected to MRTU #2 (91).
This
modified MRTU #2 (91) is directly connected to data radio (94) and associated
antenna
(95). However, in this embodiment MRTU #2 (91) is in wireless communication
with
SRTU, (81) via data radio (82) and antenna 83 which is part of the field
wireless LAN as
shown, and as set forth in greater detail below.
As further shown in FIG. I at the lower center, a group of related end devices
A-3,
B-3, C-3, for exam.ple associated with a third wellhead systeni, all aiot
shown, are
identified. A SRTU (81) is hardwire attached to end-devices A-3, B-3, C-3. In
practice,
and as illusti-ated by the system of well # 1, end devices A-3, B-3, and C-3
of well #2Are
operatively attached or hard wired to individual SRTUs. This portion of the
drawing has
been simplified to show a single SRTU and other end devices of well # 3 in
order to
illustrate that a single MRTU is capable of monitoring and controlling two or
more wells.
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CA 02582744 2007-03-21
In this embodiment SRTU (81) is in turn directly connected to data radio (82)
and antenna
(83) which is also part of the field wireless LAN, as shown, and as set forth
in greater
detail below.
It should be noted that additional wells and end-devices can also be
wirelessly
linked to MRTU #2 (91) via the SRTU not shown in the drawing so long as they
are
within radio range of a sliared field wireless LAN.
In the approximate center of FIG. 1, MRTU #1 (41) is connected to data radio
(44)
having antenna (45). To the left of that is illustrated MRTU#2 (91) wirelessly
connected
to data radio (94) having antetma (93).
Now at the left center of FIG. 1, there is illustrated a master host, for
example, a
personal computer, PC (101), or other current or future state-of-the-art
computing system.
Master host (101) is operatively connected to data radio (102), which is in
turn operatively
connected to radio tower (103) to the field wireless WAN, or a portion of a
field wireless
WAN,. Also at the left center of FIG. 1, there is illustrated a slave host,
for example, a
notebook computer (201), or other current or future state-of-the-art computing
system.
Slave host (201) is operatively connected to slave data radio (202) having an
antenna
(203) which forms a portion of a field wireless WAN,. radio tower (103) and
antenna
(202) are wirelessly linked through the field wireless WAN, to wirelessly
receive data
signals from multiple data radio systems from two or more end devices, in this
illustration
from LAN data radio (17) and antenna (18), LAN data radio (23) and antelula
(24), LAN
data radio (33) and antenna (34), LAN data radio (82) and antenna (83), and
LAN data
radio (94) and antenna (95), and also via WAN data radio (94) and antenna
(93). The
details and operations of such wireless LAN and WAN conurtunication systems
are taught
in greater detail by Ocondi, M. U.S. Patent Application Publication No.
2007/0018851
published on January 25, 2007.
For purposes of illustration, remote host computer (201) has been shown as a
notebook computer to illustrate a practical portable field host system.
Notebook host
computer (201) operates in all other ways in the same manner as host computer
(101).
Host computer (201) is not required for host computer (101) to operate, nor is
host
computer (101) required for host computer (201) to operate. Furthermore,
although not
shown, more than two host computers may be associated with the system of the
present
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CA 02582744 2007-03-21
invention, and so long as one host computer is wirelessly operationally
involved, the
system of the present invention can function.
Throughout the systenl shown, SRTUs in communication with the tank battery and
connected to end-devices will scan and store detailed raw data (configurable
down to one-
second or less) of tank level data of multiple tanks (in this case, condensate
and salt-water
tanks). It will calculate the amount of liquid produced through tank level
increment and
store the results. It will transmit alarm messages when a preset level is
detected to the
SRTU to control and prevent spillage and transmit to the host computer (101),
or other
state-of-the-art computing systems, via MRTU, to affect tank level manageznent
by
providing a timely liquid hauling schedule.
The MRTU, in wireless communication with the SRTU, s in the .f eld wireless
LANs, will store trending and event log data and organize the data on a per
well basis, in
order that host computer (101), or other state-of-the-art computing systems
can retrieve,
store, and display, the well data for analysis to affect production
optimization.
FIGS.. #2A and 2B represent a single flow-chart of the MRTU softrivare
allowing
and controlling wireless communication with the SRTU or third party legacy RTU
and
incorporates all IlOs of the SRTU or legacy RTU to function as its own built-
in UO. The
end result is that the MRTU's UO count can be expanded to the limit of the
MRTU
memory by simply adding SRTUs.
In the above preferred embodiment, the MRTU's UO is wirelessly connected to
end-devices of multiple wells, which requires software to monitor and control
the end-
devices installed at each well. At the same time it must be able to
communicate to the
master and the remote host systems to transfer trending data as well as
control and
calibration configurations among the host systems and the MRTU. To affect the
data
transfer, each MRTU must be able to sort out data associated to each well. The
following
describes the functionalities of the steps of FIGS. 2A and 2B flow-cliart
softvrare:
St ep 1: the processor in the MRTU starts execution of the
application software either when the power is turned "on" or it is
reset by software or the hardware.
Step 2:the processor reads the pre-configured data, defining the
nuniber of wells or end devices it is assigned to monitor, measttre,
and corttrol. It will be pronlpted with the WAN and LAN networks
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CA 02582744 2007-03-21
addressing communication scheme to affect communicatiori with
the host systenis as well as all, the SRTUs or the other legacy RTU s
connected to the end-devices installed at each well or well's
associated facility. It will be prompted to sort and recognize 1/0
devices designated to each well or end device.
Step 3: memory is allocated and assigned to each well or end device
to cover all the trending filcs for 35 days and event logs all the
configuration changes.
Sten 4: read all I/Os to build high-resolution trending files
configurable to oiie-second resolution.
tc 5: read in control configuration and strategy for all wells or
end devices assigned.
Step 6: activate control per the above Step 5 strategy sequentially.
St~: check WAN coinmunication port for host's data request or
eonfigui-ation changes of new control, and calibration, or additional
well I/O maps.
After responding to eitlier transmitting the requested data or storing the
downloaded
configuration data from the host the processor repeats the execution from
"Start" of Step 1.
It is therefore seen that a system for wirelessly linking end devices on two
or more
wellheads and/or two or more associated well facilities using a SRTLI and/or a
MRTU in
lieu of wires or cables has been taught, and that it can easily offset the
cost of a hardwire
cable installation, as well as the cost, complications and hazards of ditching
and trenching
operations around wellhead facilities. In addition the present invention
provides a system
and process that is specifically designed to wirelessly connect groups of end-
devices
associated with, two or more oil or gas production rvellheads so that the
associated end
devices may be wirelessly monitored and measured during wellhead production,
and then
wirelessly controlled by a single MRTU, and in turn wirelessly controlled by a
master host
computer system, according to the teaching of the present invention. It is
further taught how
such measurement and control is accomplished wirelessly through SRTUs
associated with
the end devices by using, in lieu of hardwire or cable, one or more wireless
sub-network
field wireless LAN comnwnication systems to connect the end devices of two or
more
wellheads and/or two or niore associated well facilities with a MRTU througll
SRTUs.
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CA 02582744 2007-03-21
Furthermore a software flow chart for handling end devices on multiple wells
and//or
multiple associated well facilities has been shown.
Wlule the invention has been particularly shotvn, described and illustrated in
detail
with reference to preferred embodiments and modifications thereof, it should
be understood
by those skilled in the art that the foregoing modifications are exemplary
only, and that
equivalent changes in form and detail may be made therein without departing
from the true
spirit and scope of the invention as claimed, except as precluded by the prior
art.
12
