Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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WIRELESS NETWORK SYSTEM
The present application claims priority on co-pending United States
provisional
patent application serial number 60/131,300 filed on April 27, 1999. The
entire text and
all contents of the above referenced disclosure is specifically incorporated
herein by
reference without disclaimer.
BACKGROUND
1. Field of the Invention
This invention relates generally to wireless local area networks, and in one
example, to mobile wireless local area networks used to interrelate individual
mobile
nodes. In one embodiment, this invention relates to wireless local area
networks having
the capability of automatically establishing and/or modifying fimctionality of
a network
in response to the characteristics and/or identity of the nodes connected to
the network at
a given time.
1 S 2. Description of the Related Art
Local area networks ("LANs") allow a group of devices (e.g., computers,
workstations, printers, file storage devices, and other devices) to
communicate and
exchange information and share resources over a limited area using a pre-
determined
software protocol. Each device connected to the LAN may be referred to as a
"node."
The nodes communicate using a software protocol, which is an electronic method
of
communicating using a formal set of conventions governing the format and
relative
timing of electronic messages exchanged between nodes in the LAN.
In the past, LANs have utilized hardwire connections with hardware interfaces
that allow individual devices or nodes to access the network. Within each
node, an
executable software program interprets the signals transmitted on the network
between
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the nodes. Individual nodes of a hardwired LAN may be moved and connected to a
new
wired network of a like kind, thus becoming part of a new LAN. However,
disconnecting
and reconnecting hardware components of a LAN is often inconvenient and time
consuming.
Just one example of an application for a LAN is for interrelating sensor
and/or
control devices employed when performing well treatments, such as well
stimulations.
Such well treatments are typically performed in the field using mobile vehicle
mounted
equipment, including pumps, vessels, mixing equipment, etc. The number and
characteristics of individual components of such equipment is typically
dependent on
factors such as the size and type of the well treatment job to be performed.
Individual
components of the mobile equipment are typically assembled and connected with
flowlines at the wellsite. Hardwire communication and data lines are typically
employed
to transmit voice and data (e.g., sensor readings and control signals) between
individual
nodes. In this capacity, treatment conditions (e.g., pumping pressures,
volumes pumped,
and temperatures) may be monitored and/or recorded, while treatment control
parameters
(e.g., pumping rate and mixing volumes) may be automatically and/or remotely
controlled in response to measured treatment conditions. In one example,
treatment
conditions may be monitored for safety concerns (such as over pressure
conditions) and
the necessary control steps may be automatically taken to address the safety
concerns
(such as pump shut-down).
Although LANs may be used to provide increased control and efficiency to well
treatment operations, a large number of wires or cables are typically required
to be
brought to the wellsite and strung between individual pieces of vehicle-
mounted
equipment prior to a job, and removed thereafter. This is typically a time
consuming and
manpower-intensive process. Reliability of such hardwired connections may also
be less
than desired. Furthermore, each well treatment may be unique, requiring
different types
of nodes, equipment, and combinations thereof, to communicate and exchange
data. As a
result, individual nodes of a LAN must typically be reconfigured, modified,
and/or
replaced according to the characteristics of the equipment combination
employed for a
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given job. This is also typically a time-consuming and manpower intensive
process. For
example, well servicing equipment nodes in a LAN at a wellsite location often
require
changes in the system configuration when reconfiguring the equipment or adding
nodes
to the LAN. Once again, this may also require time-consuming intervention on
the part
of a service engineer (e.g., field technician, network administrator, etc.).
Hardware and software has now evolved so that network communication between
two or more devices in a LAN may now be by wireless communication, such as
using
optical transmission or radio frequency (RF) broadcast. The use of wireless
communications simplifies movement and connection of such devices. A wireless
LAN
may be established when two or more devices with compatible wireless
communication
hardware and software are within communication range. In a typical wireless
LAN, a
"master" or "base" node is used to orchestrate communication between
individual nodes.
Individual nodes may be moved while maintaining contact with the network, or
nodes
may re-establish contact with the network when contact between nodes is lost.
Wireless LANs solve some of the problems encountered with traditional LANs
because hardwired connections are not required. However, existing wireless
networks
typically operate with strict limitations as to the communication protocol and
network
functionality. Because devices communicating in a wireless LAN have set and
defined
fimctionality, changes to network set-up and modifications or substitutions of
devices are
often required when configuring a wireless LAN at a new location.
SZIwIMARY OF THE INVENTION
Disclosed herein are methods and systems for providing wireless networks that
have communication functions of standard wireless networks, such as standard
wireless
LANs, but that offer increased flexibility and ease in changing system
configuration
when adding nodes to a network, and/or establishing or modifying fimctionality
of a
network as nodes become connected. Advantageously, embodiments of the
disclosed
wireless networks may be dynamic in nature, i.e., characteristics of network
functionality
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may change with time, and in embodiments employing one or more mobile nodes
may be
further characterized as mobile wireless networks.
As used herein, "node functionality" means functions, characteristics and/or
parameters associated with an individual piece of equipment associated with a
given
node, e.g., equipment type (e.g., pump truck, blender, delivery truck, master
control van),
equipment characteristic (e.g., engine model, pump capacity, horsepower,
carrying
capacity), etc. "Network functionality" means one or more selected or inherent
characteristics possessed or performed by a given network, including network
algorithms,
checklists or other routines. One example of network functionality includes
well
treatment simulation routines performed by an optional computer (e.g., "job
control PC")
or other processor (e.g., systems available from UNIX, IBM, SUN MICROSYSTEMS;
systems running MICROSOFT WINDOWS NT, etc.) attached to a master node during a
well treatment to accept and monitor acquired data from the master node,
verify presence
of necessary nodes or associated equipment, monitor conformance with safety
parameters, identify and/or request needed equipment, identify and/or release
excess
equipment, combinations of these functions, etc. Network algorithms,
checklists or other
routines may be present, for example, as software code in a processor or
computer
connected to one or more nodes of a network (e.g., master or base node, etc.),
in a
processor or computer present at or connected to a remote location (e.g.,
field or district
office, etc.), or present in any other form and/or location suitable for
interfacing with a
wireless network disclosed herein. Such network algorithms or other routines
may
operate or function automatically or autonomously, may function in conjunction
with
manual (human) input and/or decision-making, or with any combination thereof.
For example, different types and sizes of well treatments (e.g., hydraulic
fracture
stimulations, acid stimulations, cementing operations, coiled tubing
operations, sand
control operations such as gravel packing or frac packs, etc.) may require
distinct types
and/or numbers of individual well treating equipment (e.g., pump trucks,
blenders,
storage tanks, tank trucks, frac tanks, etc.). Based on the type and/or size
of well
treatment being performed, network algorithms or other routines may be
employed to
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verify that sufficient types and numbers of different equipment are present at
a wellsite to
adequately and safely perform a particular type and/or size of well treatment.
For
example, should a particular type of required equipment be missing (e.g.,
blender
required for a frac job, etc.); a particular type of required equipment be
deficient in
S quantity, type and/or size (e.g., insufficient total horsepower or number of
pump trucks to
obtain sufficient pump rate based on anticipated treatment conditions, etc. );
a particular
fluid or solid material be present in insufficient volume (e.g., water,
nitrogen, carbon
dioxide, polymer material, acid, cement, etc. ); or any other such parameter
be found
wanting or deficient, a network algorithm or other routine may inform or
otherwise alert a
field technician, remote location, etc. in any suitable manner (e.g., by
message on a CRT
screen, indicator light, etc. ). Furthermore, in one embodiment such a network
algorithm
or other routine may automatically and/or autonomously notify, request or
otherwise
direct that additional and/or replacement equipment, material, etc. as
appropriate report to
the wellsite. Conversely, surplus or unneeded equipment or material may be
similarly
1 S identified and personnel associated with such equipment directed to remove
the
equipment from the wellsite so that it may be employed elsewhere. This may be
done,
for example, by direct wireless communication with individual nodes present at
a wellsite
(or not present at the wellsite, but within reliable communication proximity),
by
communication with a remote location (district office, field office, etc.) or
other suitable
means.
Network algorithms or other routines may also monitor acquired data on a real
time basis (e.g., pressures, temperatures, viscosities, fluid or solid
material consumption
rates, remaining stored fluid or stored solid volumes, etc.) and use such data
to monitor
conformance of the job to safety parameters (e.g., maximum pressures, maximum
temperatures, evidence of leaks, etc.), monitor conformance of the job to
simulated well
treatment performance (e.g., anticipated successful well fracture performance
based on
pre job "mini frac" pressure fall-off simulation, well treatment
model/simulator such as
frac or acid model, etc.), etc. Well treatment model/simulators are known in
the art and
examples include, but are not limited to, "MACID" employed by "BJ SERVICES"
and
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available from Meyer and Associates of Natrona Heights, Pennsylvania;
"FRACPRO"
from Resources Engineering Services; "FRACPRO PT", available from Pinnacle
Technology or San Francisco, California, etc.
Well treating equipment may also be monitored in real time for mechanical
failure
or performance problems by network algorithms or other routines. Once again,
safety
problems, mechanical problems, emergency conditions, etc. may be detected by a
network algorithm or other routine and acted upon, by reporting to a local on-
site field
technician, reporting to a remote location, reporting to onsite or offsite
nodes, or
combinations thereof. In one embodiment, where mechanical problems are
detected with
a particular piece of equipment during a job, available information on the
problem (e.g.,
type, severity, etc.) may be noted in a job record file, reported to a remote
location, and/or
the node associated with the particular piece of equipment instructed to
report the
problem to its home office upon next contact with the same. Furthermore,
maintenance
personnel and/or supplies Fnay be requested to report to the jobsite, as
appropriate.
Furthermore, the node associated with the identified piece of equipment may
optionally
be instructed to report to a maintenance facility, immediately (and a
replacement
optionally ordered) or upon job completion.
Just a few examples of other network functionalities that may be performed by
an
network algorithm or other routine include, but are not limited to, reporting
of well
treatment data and node status/performance to a remote location (real time, or
delayed);
reporting of job initiation, termination, or delays to a remote location;
storage of the
foregoing information, commands to individual equipment directing certain
actions be
performed or modified (e.g., change in pump rate, open/close valve, shut down,
start up,
alarm, etc. ), etc.
In a given case, the particular type of well treatment being performed and/or
the
desired algorithm, checklist or other routine may be manually input into a
processor or
manually selected in a processor by a field technician, remote location, etc..
Alternatively, in another embodiment an algorithm or other routine may be
employed to
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automatically identify or characterize a particular type well treatment and/or
requirements
for such a treatment based on a "roll call" or inventory of nodes present at a
particular
location and/or the respective node functionalities associated with the same.
Based on
such an automatic identification or characterization, any one or more network
S functionalities appropriate for the particular type of job may be performed
(e.g., including
those described above).
Thus, it will be understood and appreciated with benefit of this disclosure
that
network functionality may be input and modified manually (by human operator
input)
and/or automatically (without human operator input), or a combination thereof.
It will
also be understood that network functionality may encompass a broad range of
functions,
e.g., from alerts to field technicians who may act on the alert, to automatic
messages to
one or more nodes or remote locations, to automatic commands to particular
equipment
to change operation or function. Furthermore, although network functionality
has been
described above in terms of well treating equipment, it will be understood
with benefit of
this disclosure by those of skill in the art that appropriate network
functionalities may
exist with other embodiments of the disclosed wireless networks employed in
other
industries, such as those listed or described elsewhere herein.
In one disclosed embodiment, the functionality of a LAN may be determined at
any particular time by the nature and number of nodes connected, the
particular attached
I/O devices, and/or the loaded functional and descriptor code in each node.
Such a
network may be assembled by bringing of least two nodes into reliable
communication
proximity, meaning signal communication is sufficiently reliable for the nodes
to
exchange data, commands and information, as described elsewhere herein. Each
node
includes core software code, which may be used to facilitate the exchange 'of
node
descriptor information, to determine if a master is needed, and/or to
determine the
network capability.
In another embodiment, one or more nodes of a mobile wireless LAN may be
provided with the capability of long range communication (e.g., via microwave,
satellite,
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or long range RF communication links). While the functionality and operation
of such a
wireless LAN may be related to its short range communication area, a node may
send and
receive its functional or descriptor code, or the functionality of the
network, to a remote
location via a long range communication link. Such a remote location may be
capable of
simultaneously monitoring the condition and modifying the characteristics of
multiple
LANs and/or internetworking such LANs. For example, the descriptor or
functional
information of a node, or the functionality of an entire LAN, may be modified
and/or
monitored from a remote location on a real-time basis.
Although any suitable communication mode may' be employed, one disclosed
embodiment utilizes nodes that communicate within a wireless LAN (also
referred to as a
"WLAN") using frequency-hopping spread spectrum communication technology.
However, regardless of communication type, wireless nodes of a WLAN may be
self
powered and have some amount of functionality useful within the network. Just
a few
examples of devices that may be connected at a node are devices having
input/output
capability including, but not limited to, devices such as sensors, recorders,
actuators,
solenoids, audio microphones, speakers, display screens, processors, or the
like. Other
examples include, but are not limited to, devices such as controllable valves,
engine
throttle actuators, measurement instruments, sensors (e.g., density, flow
rate, pressure,
temperature, viscometers, and pH sensors), or any other control or condition-
sensing
device known in the art for use in control and sensor equipment, for example,
employed
in well service applications at a well site.
In the disclosed embodiments, a node may have a unique address, processing
capability, memory for program and data, and/or software code. In this regard,
the
software code may function to interpret data and instructions, to modify how
the node
functions, and/or to store descriptor information about the status and
capabilities of a
node. Processing capability may be provided by any suitable data processing
element
including, but not limited to, a microprocessor, digital signal processor,
microcomputer,
micro controller, laptop computer, or larger computer system. Software code
incorporated in a node may be categorized as fixed "core" code that determines
how each
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node interprets information, "functional" code that defines or alters how a
node functions,
and "descriptor" code that defines the capabilities and status of a node. In
one
embodiment, the descriptor information includes an LD. code embedded with a
description of the equipment at a node.
With benefit of this disclosure, it will be understood that embodiments of the
disclosed wireless LAN systems may be assembled in a variety of ways and for
use in a
variety of applications or operational tasks known in the art for which LANs,
wireless
LANs or other wireless networks may be employed. Such applications may have
one or
more mobile nodes, and may include both mobile and fixed nodes. A mobile node
may
include any type of node that has some amount of mobility, for example nodes
and
associated equipment that are attached or connected to trucks, trailers,
skids, boats,
aircraft, human beings, etc. Examples of such applications include, but are
not limited to,
the maintenance, construction, event observation, and/or reporting associated
with well
servicing equipment and remote control stations. Other potential applications
include
coiled tubing, pigging, measurement while drilling ("MWD'~, refinery high
pressure
washing, recreational vehicle use, and nuclear waste pumping.
In one exemplary embodiment of the disclosed wireless network systems, oil
well stimulation equipment may be transported by vehicle to random job sites.
Each
vehicle has a roaming transceiver that announces it presence to a master
control (e.g.,
treater's computer) at the job site. Each vehicle has a unique identification
number (serial
number, alpha and/or numeric designation, etc. ) and a self description or
node
functionality, e.g., equipment type, equipment characteristic (pump capacity,
horsepower), etc.. Job data is transmitted real-time to the master control.
In one respect disclosed is a wireless network, including at least two nodes
in
wireless communication with each other, each of the nodes having at least one
of an
individual node functionality characteristic or an individual node identity
characteristic;
wherein at least a first node of the two or more nodes is capable of
transmitting at least
one of its individual node functionality characteristic or its individual node
identity
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characteristic to at least a second node of the two or more nodes; and wherein
the second
node is capable of establishing or modifying a network functionality of the
wireless
network based on respective node functionality characteristics of the first
and second
nodes, respective node identity characteristics of the first and second nodes,
or a
combination thereof.
In another respect, disclosed is a wireless network for conducting well
treatment
operations, including at least two nodes in wireless communication with each
other, each
of the nodes having at least one of an individual node functionality
characteristic or an
individual node identity characteristic; wherein at least a first node of the
two or more
nodes is capable of transmitting at least one of its individual node
functionality
characteristic or its individual node identity characteristic to at least a
second node of the
two or more nodes; wherein the second node is capable of establishing or
modifying a
network functionality of the wireless network based on respective node
functionality
characteristics of the first and second nodes, respective node identity
characteristics of the
first and second nodes, or a combination thereof; wherein each of the nodes
are mobile
nodes coupled to well treating equipment capable of assembling at a wellsite
to perform a
well treatment; and wherein each of the nodes are mobile nodes, and wherein
the wireless
network is a mobile wireless network; wherein each of the nodes includes a
radio
transceiver, and wherein the nodes are in communication via spread spectrum
radio
frequency.
In another respect, disclosed is a mobile wireless network, including a
plurality of
mobile secondary nodes in wireless communication with each other and a mobile
master
node, each of the secondary nodes having at least one of an individual node
functionality
characteristic or an individual node identity characteristic; wherein each of
the secondary
nodes is capable of transmitting at least one of its individual node
functionality
characteristic or its individual node identity characteristic to the master
node; wherein the
master node is capable of establishing a network functionality of the wireless
network
based on at least one of the respective secondary node functionality
characteristics, the
respective secondary node identity~characteristics, and the number of the
secondary nodes
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communicating in the wireless network; and wherein the master node is capable
of
accepting additional secondary nodes into the wireless network as the
additional nodes
enter into communication with the master node, and wherein the master node is
capable
of releasing existing nodes that terminate communication with the master node,
wherein
the accepting includes modifying the established network functionality of the
wireless
network based on the addition of at least one of respective node functionality
characteristics, respective node identity characteristics of each additional
node, and
revised number of secondary nodes communicating in the wireless network, and
wherein
the releasing includes modifying the established functionality based the
deletion of at
least one of respective node functionality characteristics, respective node
identity
characteristics of the exiting node and revised number of secondary nodes
communicating in the wireless network.
In another respect, disclosed is a method of performing an operational task
with at
least two mobile units, including assembling the at least two mobile units at
a task
location; and performing the operational task; wherein the at least two mobile
units
operate as nodes in a mobile wireless network; and wherein the at least two
nodes are in
wireless communication with each other, each of the nodes having at least one
of an
individual node functionality characteristic or an individual node identity
characteristic;
wherein at least a first node of the two or more nodes is capable of
transmitting at least
one of its individual node functionality characteristic or its individual node
identity
characteristic to at least a second node of the two or more nodes; and wherein
the second
node is capable of establishing or modifying a network functionality of the
wireless
network based on respective node functionality characteristics of the first
and second
nodes, respective node identity characteristics of the first and second nodes,
or a
combination thereof. An operational task may include any task for which the at
least two
mobile units are capable of, including any types of mobile units as described
elsewhere
herein. Examples of operational tasks include, but are not limited to, a well
treatment
operation (e.g., well stimulation, well drilling, well cementing, etc.);
delivery operation
(e.g., passenger, mail or freight delivery via water, ground or air vehicles;
etc.);
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maintenance operations (ground vehicle, ship, or aircraft maintenance
operations, etc. ), or
any other type of application or operational task described elsewhere herein.
Examples of
mobile units include mobile nodes and associated equipment as described
elsewhere
herein.
DESCRIPTION OF DRAWINGS
Fig. 1 is an illustrative embodiment having two interconnected mobile,
wireless
networks communicating to a remote site according to one embodiment of the
disclosed
wireless network systems.
Fig. 2 illustrates an exemplary node with illustrative devices connected to
the
node according to one embodiment of the disclosed wireless network systems.
Fig. 3 is a detailed block diagram of an exemplary radio module according to
one
embodiment of the disclosed wireless network systemls.
Fig. 4 shows a diagram of the software code and internal data structures of a
radio
module within a node according to one embodiment of the disclosed wireless
network
systems.
Fig. 5 is a flow chart that illustrates the ~ synchronization and registration
process
of a mobile, wireless LAN according to one embodiment of the disclosed
wireless
network systems.
Fig. 6 is a supervisory processor block diagram corresponding to the exemplary
embodiment of Example 1.
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DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS
As used herein, the indefinite articles "a" and "an" connote "one or more."
Furthermore, although some exemplary embodiments herein refer to WLAN
equipment,
it will be understood with benefit of this disclosure that benefits of the
disclosed methods
and apparatus may also be practiced in other wireless network configurations,
for
example non-local wireless environments where long range communication is
employed
and/or required.
By "in signal communication" it is meant that components may be electrically
connected, coupled, or otherwise configured to directly or indirectly send and
receive
signals including, but not limited to, electrical signals, radio signals,
microwave signals,
optical signals, ultrasonic signals, etc. By "in wireless communication" it is
meant that
components are in signal communication via any type of wireless signals known
in the
art suitable for sending and/or receiving communication signals. "Acquired
data"
includes any information gathered from one or more sources (e.g., sensing
devices,
keypads, audio microphone, etc.) including, but not limited to, well treatment
condition
information, vehicle operating condition information, operator input
information, etc.
"Network information" means any information or data concerning the status of
individual
nodes or the network as a whole including, but not limited to, information on
node
identity, node input/output devices, node fimctionality, network
fimctionality, etc.
"Network instructions" means any instructions or commands directed to
individual nodes,
groups of nodes, or a network as a whole, including, but not limited to,
commands related
to changes in node functionality, changes in node identity, redeployment of
one or more
nodes or entire network, etc.
Fig. 1 shows one embodiment of the disclosed wireless LAN systems having two
mobile, wireless LANs ("WLANs"). Both WLANs operate in a master-slave (e.g.,
"star," "token ring," etc. ) topology in that one node operates as the "base"
and controls
the operation of the WLAN and its distributed "remote" or "secondary" nodes.
In the
illustrated embodiment, one of the WLANs 100 is remote from the other WLAN
200. In
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this embodiment, both WLAN 100 and WLAN 200 have optional long range
communication via links 110 and 308 between communication devices 109 and 207,
and
a receiving and transmitting device 301 at a remote office location 300.
Communication
between receiving and transmitting device 301 and WLANs 100 and 200 may occur
using microwave, satellite, long range RF, cellular, or other suitable
wireless
transmission, although communication between receiving and transmitting device
301
and WLANs 100 and 200 may alternatively occur over wired conductor (e.g.,
phone line)
as well. It should also be understood that the WLANs may operate in the same
area by
communicating on different channels, hop patterns, or frequency ranges.
WLAN 100 has illustrative nodes 101, 102, 103, 104, and 105 and a master node
106. Node 101 is shown as a vehicle or truck to illustrate a complex node with
the ability
to transport all its multiple elements within the WLAN. Such a truck may be,
for
example, a service truck used in the well servicing industry, delivery or
maintenance
trucks, railroad service vehicles, aircraft, or off shore service vehicles.
Nodes 101-105 communicate with master node 106 via wireless communication
links (illustrated as 107). In one embodiment of the disclosed systems, the
links 107
utilize frequency hopping spread-spectrum RF communications to transmit voice
and
data between the remote nodes 101-105 and the base node 106. The "hop" pattern
is
predetermined and known by the base and remote nodes. A number of "hop"
patterns or
"channels" may be provided in an area over which one or more WLANs may
operate. In
alternate embodiments, nodes communicate using direct sequence spread spectrum
RF
communications. The use of spread spectrum techniques reduces the
vulnerability of a
radio system to both interference from jammers and multipath fading by
distributing the
transmitted signal over a larger region of the frequency band than would
otherwise be
necessary to send the information.
In one embodiment of the disclosed WLAN systems, nodes communicate using a
communication band set-aside at 2.4 GHz. In most countries (including the
U.S.), a
portion of the RF spectrum has been set aside at 2.4 GHz for the purpose of
allowing
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compliant spread spectrum systems to operate freely without the requirement of
a site
license. Because site licenses are not required, the presently disclosed
wireless LANs
have greater mobility in that the base and remote nodes may be relocated
without any
regulatory inconvenience.
It should be understood, however, that any suitable wireless communication
scheme in an appropriate communication band may be used with the presently
disclosed
wireless LAN systems. For example, nodes may communicate using a Time Division
Multiple Access ("TDMA") scheme, Frequency Division Multiple Access ("FDMA")
scheme, or any other known communications scheme.
In addition to mobility within a WLAN, node 101 may also travel from one
WLAN to another WLAN. For example, Fig. 1 illustrates a node 108, which may
also be
a service or maintenance truck used in the well service industry, traveling
between
WLAN 100 and WLAN Z00. Although the illustrated embodiment employs a service
or
maintenance truck as a node, the nodes of the disclosed WLAN systems may be
any
device normally associated with or connected to a LAN. Further, although
illustrated
embodiments relate to the well service industry, the disclosed methods and
apparatus may
be useful for any industry requiring dynamic updating and configuring of a
WLAN.
Fig. 1 also shows a node 206 arriving at WLAN 200 and establishing a wireless
communication link 203 with a master 202. As illustrated, WLAN 200 includes a
master
node 202, which is communicating with several other nodes (201, 204, and 205).
When
node 206 enters the area covered by the WLAN 200, it initiates a registration
procedure
with a "master" or a "base" 202. Each node in the illustrated WLANs may have
varying
functional capability. Further, each node may be mobile within a WLAN, or to
another
WLAN. The master nodes 106 and 202 are illustrative of nodes that may serve to
direct
or coordinate communication between several other nodes, remote stations, or
WLANs.
In operation, a WLAN may be assembled or modified based on the arrival of
mobile nodes. For example, in ode embodiment the first node to arrive has the
ability to
establish communications with another node when it arrives. One of the nodes
becomes
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the master node. A master node is defined as the node that directs the
communication
between two or more nodes. The master node determines if an arriving node
belongs to
its WLAN. In addition, the master node receives and shares communications from
a
remote office location 300. In the illustrated embodiment, any node may
optionally have
the elements to enable it to become a master node, or alternatively the node
may be
directed or designated to become the master by the loading of appropriate
software code.
Thus the presently disclosed WLANs are dynamic entities made up of a number of
nodes,
the characteristics of which may change with time. Further, the number and
characteristics of the nodes comprising a WLAN at any particular time may
determine the
tasks performed by the WLAN. For example, as described elsewhere herein,
additional
equipment may be required to meet particular job specifications and a system
operator
(e.g., field technician) or remote location informed of such requirement by
the network,
and/or the network may automatically call out or request directly for required
new units
to report to the jobsite. Alternatively, a network may revise the tasks to be
performed by
one or more individual units, and/or the nature of the entire job, based on
the number and
characteristics of the nodes comprising a WLAN.
It will also be understood with benefit of this disclosure that in one
embodiment
of the disclosed wireless network systems, two or more networks may be in
signal
communication (e.g., by wireless and/or hardwire communiciation) to
cooperatively
accomplish one or more operational tasks, such as a well treatment operation,
and/or to
perform two or more separate operational tasks simultaneously (related or
unrelated).
Examples of information that may be exchanged between two such networks
include, but
are not limited to, network information, network instructions, acquired data,
etc. The
relationship between any two or more networks may be defined, for example, as
any of
the master/slave node relationships described elsewhere herein for single
network
operations, with one network taking on the role of a master node, and one or
more other
networks taking on the role of slave nodes (or sub-networks).
The node targets communicate using a communication protocol that includes a
number of commands, including a "Dump Data," a "Write to LAN," and a "Read
from
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LAN' command. Under normal operation, communication is initiated by the base
or
master node. Depending upon the desired command, the base sends between three
and
eight bytes of data in succession for all of the nodes to hear. In an
exemplary
implementation of the communication protocol, the first byte is always an
ASCII
"ESCAPE" character (OxlBh), which is transmitted to 'wake up" the nodes and
prepare
them for additional bytes , of data. The second byte of data is the unique LAN
identification number ("ID") associated with the particular remote node with
which the
base desires to communicate. Under normal conditions, the ID for each remote
node is
unique so that only one node will respond to any base command. The third byte
of data
transmitted by the base represents the "command."
Specifically, the "Dump Data" command is represented by the ASCII "D"
(Ox44.h). Therefore, an exemplary command from a node will be as follows: 0001
1011
(ESC), 0000 1100 (Remote LAN LD.), 0100 0100 ("Dump Data" command). This
command indicates to a remote node that it should send a predefined data
string to the
base. The length of the response data string is dependent upon the type of
device that is
addressed.
Similarly, a "Write to LAN' command is represented by the ASCII "R" (Ox52h),
which tells the remote node to write the value of a specific parameter address
to the LAN
(i.e., the base wants to READ data from the LAN). The byte following the
"Write to
LAN' command provides an address location of a predefined area of memory that
holds
parameters specific to that device. In this example, the address byte may
address up to
256 parameters. The node responds by initially sending a four byte cluster
signifying the
start of data (e.g., 0, 0, 0, 1), followed by as many clusters as required for
the response.
Because the base requested the information, it should know the number and
content of the
data that it is attempting to read from the LAN.
In addition, the "Read from LAN' command is represented by the ASCII "W
(Ox57h), which tells the addressed remote node to read a specified parameter
from the
LAN (i. e., the base wants to WRITE data to the LAN). The byte following the
"Read
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from LAN" command provides an address location of a predefined area of memory
that
holds parameters specific to that node. The remaining bytes (bytes 5-8) will
be four data
bytes representing a floating point number (in binary) that the base device
writes into a
remote node's memory. For example, this command may be used to pass global
information or node specific information to a remote node.
In an exemplary embodiment, the WLAN 100 may be configured with nodes that
are operable to perform a well-fracturing fimction. In this application, the
base 106 is a
treating van, which is the van from which the job is monitored and controlled.
The
treating van communicates with "nodes," which would likely include pump trucks
and
other vehicles required for this particular fimction. For example, other nodes
may include
a "liquid additive module," "blender modules," or "gel pumps." When operating
at a job
site, a truck (or node), would register with the treating van when entering
the coverage
area of the WLAN.
In a well fracturing operation, pump trucks utilized typically have 1000 to
3000
horsepower for pumping gel fluid down a well at high flow rates and pressures.
For
particular applications, a number of pumping trucks may be piped together with
other
equipment to provide a gelled fluid that is displaced into a well at a rate
and pressure
sufficient to create a hydraulic fracture in a subterranean formation. Types
and functions
of such well servicing equipment are known to those of skill in the well
servicing art.
Once pumped into a well, the gel fluid breaks down, providing a path for the
oil to be
returned. As gel is being pumped into the well, proppant (e.g., sand) may be
gradually
added to the gel fluid to for placement in the hydraulic fracture. Sand is
added using a
sand blender truck, which is a truck that precisely controls the amount of
sand blended
with the gel fluid. Other trucks provide sand to the blender truck by conveyer
belt. Each
truck, or node, includes equipment for controlling and monitoring the process.
For
example, the blender truck must accurately monitor and control the amount of
sand to be
added to the gel fluid. These monitoring and control devices may be networked
to the
treating van via the presently disclosed WLAN systems. Other nodes may include
individual sensor and control devices. For example, the WLAN may include
individual
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sensors at the well head for monitoring the density or pressure of the gel
fluid entering the
well.
Further, the treating van (acting as the base 106) may relay data back to a
remote
office location 300. In that manner, the remote office location 300 may
monitor multiple
sites and reallocate resources based on need at the various WLANs. For
example, the
remote location may determine that an additional pumping truck is located at a
first node
and could be reallocated to a second node. The remote location may then
command the
additional pumping truck to register at a second WLAN (as illustrated by node
108). In
addition, the remote data transmission capabilities allows engineers or other
personnel to
monitor and control a job from a remote location. For example, job sites may
be located
off shore or thousands of miles away. The remote data transmission
capabilities of the
disclosed WLANs eliminate the need for engineers or other specialists to
travel to these
remote sites.
Although one exemplary embodiment related to hydraulic fracturing has been
described above, it will be understood with benefit of this disclosure that
other well
treatments and well services employing equipment known in the well servicing
art may
also be performed using embodiments of the disclosed WLAN. Such well
treatments and
services include, but are not limited to, treatment or services related to
acidizing,
condensate treatments, injectivity testing, gravel packing, frac packing,
introduction of
drilling fluids into a wellbore, etc. Other examples of well service
operations (and/or
related equipment) which may be advantageously performed and/or equipped using
embodiments of the disclosed WLAN system include, but are not limited to,
perforating
operations, coiled tubing operations, drilling and workover rig operations, as
well as any
other type of well service operation employing one or more pieces of mobile
equipment
(including, but not limited to, equipment that is truck-mounted, trailer-
mounted, skid-
mounted, barge-mounted, etc.).
As previously described, trucks (or nodes) may "roam" from one WLAN to
another WLAN. In one embodiment, trucks may leave a job site and return to a
home
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base operation. For example, the home base may be located at a district
office,
maintenance yard, or field office. When a truck returns to its home base, the
truck will
register with the home base and "wake up" any equipment attached to the truck.
The
equipment may then provide information obtained from the sensors and control
devices
S attached to the truck. In one embodiment, the information provided to the
master at the
home base may include material usage information (such as gas or gel fluid
usage), truck
maintenance reports (e.g., need for oil or gas in the truck), or other
relevant information.
Once the information has been dumped to the home base, the truck may be stored
and any
attached equipment may be placed in a "sleep" mode.
Fig. 2 illustrates an exemplary embodiment of a node 500. As previously
discussed, node 500 may be, for example, contained within a service or
maintenance
truck used in well-site operations. Node 500 includes two primary modules, a
processor
module 510 and a radio module 520. The radio module 520 includes a processor
for
executing a software protoeol and controlling radio transmission among nodes.
The
processor module 510 controls operation of peripheral devices 511 and sensors
504
within a node. For example, peripheral devices 511 and sensors 504 may measure
parameters, control valves, control a motor, or perform other functions
required by the
particular WLAN. Device 505 shows a manual input device that may be, for
example, a
keyboard, a keypad, or a voice recognition device that enables an operator to
access a
node. Device 506 illustrates a display that may provide visual feedback to an
operator.
For example, device 506 may display the output of a remote camera, a computer
screen,
or other such device. Device 502 illustrates a microphone for audio input, and
device 501
shows a speaker for audio output. These devices may be used for voice
communications
between operators at various nodes or at a remote office location.
The processor module 510 may be, for example, a personal computer, a laptop
computer, or any other processor-based computer equipment. The processor
module
interfaces to the radio module through interface 407. This interface may be an
RS-232
interface, an RS-422 interface, or,other suitable interface for connecting the
processor
module with the radio module. Although one processor module is illustrated
connected
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to the radio module, it should be understood that additional processor modules
may be
connected to the radio module.
The radio module 520 includes a communication antenna 400 for communications
between nodes. In one embodiment, one or more sensors 503 (e.g., density, flow
rate,
etc.) may be configured to operate directly with the radio module 520.
Just a few examples of devices that may be connected at a node are devices
having input/output capability including, but not limited to, devices such as
sensors,
recorders, actuators, solenoids, audio microphones, speakers, display screens,
processors,
or the like. Other examples include, but are not limited to, devices such as
controllable
valves, pump controls, engine throttle actuators, measurement instruments,
sensors (e.g.,
density, flow rate, pressure, temperature, viscometers, and pH sensors), or
any other
control or condition-sensing device known in the art for use in equipment, for
example,
employed in well servicing operations.
The node 500 may be powered by a power supply (not shown), which may be
batteries, a generator, or other suitable device for powering node 500. For
example, if
node 500 were integrated as part of a service vehicle, node 500 may be powered
from the
vehicle's battery.
Fig. 3 is a detailed block diagram of one embodiment of a radio module of the
disclosed methods and apparatus. The illustrated embodiment includes an
embedded
supervisory processor 402, a transceiver 401 with an antenna 400, external
memory 404,
flash ROM 406, and UART 408. The radio module may interface to external
devices
through a variety of interfaces, including an RS-422 interface 412, RS-232
interface 414,
or a standard I/O buffer 416.
Still referring to FIG. 3, transceiver module 401 may be a WIT2410 RF module,
available from Digital Wireless Corp. The WIT2410 uses frequency-hopping
spread-
spectrum communication technology or TDMA technology to allow communication
with
other nodes. The WIT2410 operates in the 2400 to 2483 MHz frequency band and
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provides up to 75 frequency channels operating at channel data rates of 460
kbps. The
WIT2410 module may operate as either a "remote" node or "base" node. In this
exemplary embodiment, the transceiver 401 is connected to an antenna 400,
which may
be a fiberglass radome enclosed omni-directional antenna with a minimum 2 db
gain over
unity when operating as a remote or slave node, or an optional minimum 6 db or
9 db
gain over unity when operating as a base node or master station. In one
embodiment, the
node is typically operable to communicate at least 1250 feet under all
conditions.
The embedded processor 402 provides the primary function and control of the
node 500 by retrieving and executing program instructions from flash ROM 406.
In other
embodiments, the program instructions may be contained in a ROM, EPROM, or
other
suitable storage device designed to store instruction code. The embedded
processor 402
may be any suitable processing element, including, but not necessarily limited
to,
microprocessors or digital signal processors. In one embodiment, the processor
402 may
be a Motorola MC68332-25 processor.
Node 500 may also include external memory 404. This memory may be
connected to processor 402 and may store additional data or other program code
for
supervisory processor 402. In one embodiment, this memory is a RAM or SRAM,
which
permits the processor 402 to read and write to the memory.
Referring still to Fig. 3, blocks 412, 414, and 416 illustrate exemplary
interfaces
for other equipment (e.g., a processor module) to interface to the radio
module. For
example, interface 412 may be an interface to an existing hardwired LAN
connector. For
example, the interface may be a standard RS-422 transceiver. In this manner,
the present
radio module may be readily used with equipment presently interfaced with
hardwired
LANs without changing the hardware interface. Interface 414 may be an RS-232
interface for interfacing the radio module to external devices, such as lap-
tops or desk-top
computers, that use an RS-232 interface. The radio module may also include an
I/O
buffer interface 416 for interfacing to external devices. The I/O buffer
interface 416 may
be used, for example, to read external switch settings. Other applications
that may be
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implemented using the I/O buffer interface include 'raking-up" or "placing to
sleep"
external devices as previously described. Although illustrative and exemplary
interfaces
have been described, it will be understood with benefit of this disclosure
that other
interfaces known in the industry may be provided to interface the radio module
to
S external equipment, and as many or as few of such interfaces as desired may
be present.
In one embodiment, processor 402 of the radio module may perform the following
fimctions within a node: process transceiver module network commands, format
and
buffer packets from the transceiver, perform handshaking, configure the mode
of
operation of the node within the network, control external peripherals and
devices, and
control LED status.
The processor 402 communicates with the transceiver 401 using packet
communications with the following message types:
TYPE USED BY FUNCTION
DATA base/remote Carries user data
COMMAND base/remote Queries and commands to the radio
ACK base/remote Indicates success or failure transmitting a packet
CONNECT base Notification that a remote has joined the network
DISCONNECT base Notification that a remote has left the network
In one embodiment, none of these packet types except the data packet are
required
for operation; command and framing packets are optional, and sequence numbers
and
ACK and CONNECT packets may be enabled or disabled through the Set Packet Mode
configuration command. Some packet types may not be applicable for both base
and
remote radios. The following table illustrates the various packet modes
available
according to one embodiment of the presently disclosed wireless LAN systems.
Set Packet Mode (sp- ) command settings:
00 - transparent mode
O1 - MRP mode 1, basic command and data only,
- no ACK or CONNECT/DISCONNECT packets, no sequence numbers
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02 - MRP mode 2, with connection notification,
- adds CONNECT/DISCONNECT packets
03 - MRP mode 3, with connection notification and acknowledgment reports,
S - adds CONNECT/DISCONNECT packets, sequence numbers and ACK
packets
04 - WIT2400 protocol mode (for backwards compatibility with earlier
versions of the RF module from Digital Wireless Corp.)
The byte formats for each packet type are shown in the tables below. Packet
fields are organized to fall on byte boundaries. In the case of bit-level
fields,
most-significant bits are on the left.
WIT2400 packet type (packet mode 04)
DATA 0000 0010 OOHH HI~iH ALLL LLLL <0-127 bytes data> 0000 0011
WIT2410 packet tyt~es:
DATA (modes 1 and 2) OOHH HI~iH ALLL LLLL <0-127 bytes data>
DATA (mode 3) " OOHH ~ 0000 SSSS ALLL LLLL <0-127 bytes data>
COMMAND 0101 1100 <4 byte command or 2 byte reply>
ACK OOHH ~ OO1X SSSS
CONNECT(base) lOHH HI~~Fi RRRR TTTT OONN NNNN <3 byte remote ID>
CONNECT(remote) l OHH HI-~~H RRRR TTTT OONN NNNN <3 byte base ID>
DISCONNECT lOHH HI~ 0111 1111
where:
H : handle number (0-63)
S : sequence number (0-63)
A : 0 = ARQ requested, 1 = no ARQ
requested
L : length (0-127)
X : 0 = ACK, 1 = NAK
N : network number
R : receive sequence number (from
previous LAN)
T : transmit sequence number (from
previous LAN)
P : handle of destination remote
Data Packet Format
Modes O1 and 02: OOHH HI-~H ALLL LLLL <0-127 bytes data>
Mode 03: OOHH ~ 0000 SSSS ALLL LLLL <0-127 bytes data>
Mode 04 (WIT2400): 0000 0010 XXI~H ~ ALLL LLLL <0-127 bytes data>
0000 0011
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where:
H : handle number (0-63)
S : sequence number (0-63)
S A : 0 = ARQ requested, 1 = no ARQ requested
L : length (0-127)
X : don't care (bits are ignored)
The data packet carries user data. The handle number is the handle of the
sending
or receiving remote, depending on whether the data is going to or coming from
the base.
Up to 127 bytes of user data may be carried per data packet. For example, the
data packet
may be used to send the previously described LAN protocol used to communicate
between various nodes.
The second byte of the data packet contains a sequence number and appears only
if ACK/NAK reporting is enabled with the Set Protocol command. If enabled,
this 4-bit
sequence number is incremented each time a new packet is sent or received for
the
purpose of distinguishing between possible duplicate packets and also to
identify which
message an ACK is associated with. Duplicate packets are a rare circumstance
and
generally do not need to be checked for since they can only occur in networks
with more
than one base when a remote roams to a new LAN. Note that separate sequence
numbers
are maintained for incoming and outgoing data streams.
Handle 63 is reserved for broadcast packets from the base to all remotes.
Acknowledgment requests are not supported for broadcasts. For this reason, it
is a good
idea to send broadcast messages several times to increase the odds of reaching
all
remotes.
Command Packet Format
Transmit: 0101 1100 <4 byte command>
Receive: 0101 1100 <2 byte result>
Command packets are intended to provide a means of accessing and configuring
the radio command processor while still remaining "online." Command packets to
the
radio always contain four characters. If a given command has less than four
characters,
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spaces should be used to pad the length to 4 characters. Replies from the
radio are always
two characters. Due to the way command packets are buffered, the user
application must
wait until the previous command has been replied to before sending a new one.
The radio can be configured to report several status events in the form of
command packets. The formats for these are given below:
Carrier Detected
B1N: 0101 1100 0010 1101 0010 1101 HEX: SC 2D 2D ASCII: \--
Carrier Lost
BIN: 0101 1100 0010 1011 0010 1011 HEX: SC 2B 2B ASCII: \++
Signal Strength
BIN: 0101 1100 xxxx xxxx xxxx xxxx HEX: SC xx xx ASCII: \xx
(where x = 8-bit signal strength reading given as two ASCII hex digits)
The Carrier Detected and Carrier Lost status events apply to remotes only, and
reflect the current state of-the DCD signal. Signal Strength is a periodic
report of
received signal power, averaged over the last 10 hops.
ACK/NACK Packet Format (receive only)
OOHH HI~I OO1X SSSS (ACK: x=0 NAK: x=1)
H : handle number (0-62)
S : sequence number (0-63)
X : 0 = ACK, 1 = NAK
An ACK report is issued to the user application upon confirmation from the
receiving radio that the message was successfully delivered. If the number of
attempts by
the radio to send the message exceeds the limit programmed by the Set Transmit
Attempts
Limit command, a NAK will be issued. Since multiple packets may be buffered in
the
radio at a time, the transmit sequence number is used to identify the packet
in question.
Connect Packet Format
l OHH I~i RRRR TTTT OONN NNNN <3-byte remote ID>
(base, receive only)
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H : handle number (0-62)
R : receive sequence number (from previous LAN)
T : transmit sequence number (from previous LAN)
N : network number of the previous base
l OHH ~ RRRR TTTT OONN NNNN <3-byte base ID>
(remote, receive only)
H : handle number (0-62)
R : receive sequence number
T : transmit sequence number
N : network number of base
Remotes must go through an automatic registration process when roaming from
one base to another, after loss of contact, or when acquiring a base signal
for the first time
after power up. See Fig. 5. The base then assigns the remote a handle value,
may or may
not assign it a dedicated channel depending on the user settings, and notifies
the user
application of the new remote with a connect packet.
The network number of the last base the remote was connected to is given to
aid
user software in resending orphan packets that may have been improperly sent.
If the
remote has been powered up for the first time and this is the first base
contacted, the last
base ID will be reported as OxFFh.
Disconnect Packet Format (base only, receive only)
lOHH ~ 0111 .1111
H : handle number (1-62)
When a remote goes out of range or roams to another LAN, the base issues a
disconnect packet to indicate that the remote is no longer available.
Fig. 4 provides a high-level block diagram of one embodiment of the software
components 808 that may be contained in a node. Firmware 803 is stored in
flash
memory 406 and performs the fimction of the operating system of the node--that
is, it
interprets the information coming into the node, loads and modifies functional
software
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code 801, and stores descriptor data 802 for the node. In this embodiment, the
fimctional
code 801 establishes a node's present configuration. For example, once a
module is
registered at a site, the node will use a short address or "handle." The
descriptor data 802
is a data structure within the node that describes the node's capabilities.
When a node
registers, the descriptor data 802 is communicated to the master or base to
describe the
functionality of the equipment at the remote node (e.g., the horsepower of a
pump at the
node, pump sizes, etc.). By providing separate functional code 801 and
descriptor data
802, a node can be dynamically configured within a WLAN. In addition, this
structure
permits an entire network to be reconfigured without operator intervention
when new
devices are connected to the network.
FIG. 5 illustrates the synchronization and registration process for one
embodiment of the disclosed WLAN systems. In this exemplary embodiment, the
nodes
may be, for example, frequency hopping nodes that periodically change the
frequency at
which they transmit. Because the frequencies over which transmission occurs is
changing, each node must be synchronized and set to the same hopping pattern.
As
previously discussed, one node in the WLAN may be designated or otherwise
selected as
the "master" or "base" station. All other nodes may be designated or otherwise
selected
as remotes. At block 900, the WLAN is operating in its normal network I/O
function
Each time the base station hops to a different frequency at the end of a hop
period at
block 902, the base immediately transmits a synchronizing signal to the remote
nodes.
Similarly, when a remote is powered on or enters a new WLAN at block 904, the
remote
rapidly scans the frequency band for the synchronizing signal from the base.
Upon synchronization, the remote must request registration from the base
station.
The registration process in block 906 involves the identification of the
remote to the base
by sending a node's descriptor data to the base. At block 908, the WLAN also
tracks the
remote nodes leaving the network. When a remote node leaves the network, the
base de-
registers the node at block 910. The base tracks remote nodes by building a
table of serial
numbers of registered remotes. As previously discussed, the WLAN may use
"handles"
to improve transmission efficiency. For example, a 24-bit remote serial number
may be
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assigned a 6-bit handle. With 6-bit handles, each base may register up to 62
separate
remotes (2 remotes are reserved for system use).
At the end of a task, a WLAN may execute a number of different options. For
example, the WLAN may receive data from a master node that instructs it to
reconfigure
S the network or to re-deploy nodes to another WLAN. In addition, the WLAN may
send
status or data to a remote location. In other applications, the entire WLAN
may be
requested to re-deploy to a new site, and re-establish wireless connection
with existing or
other nodes to begin another task.
In summary, the disclosed WLANs are dynamic, changing entities that are bound
only by a commonality in communication method, ID structure, and software
code.
Nodes may be configured in an number of different ways for the disclosed WLAN.
The
communication method is wireless and one embodiment uses spread spectrum
technology. Other communication technologies may be used within a WLAN that
operates at the desired bandwidth and with the desired reliability. The
instructions or
data that makes up the microcode, fimctional software code, and the descriptor
data may
be the result of an application program operating on a computer system like a
personal
computer, a laptop computer, computer workstation, or other computer system.
The
WLANs in this disclosure are also envisioned to incorporate nodes constructed
from, for
example, single chip computers and single chip radio communication modules.
These
single chip computers and radio communication modules may be used to make
nodes that
are quite small and as such may have unique applications. Also envisioned in
this
disclosure are WLANs that are collections of maintenance, distribution,
service or other
vehicles in a given communication area assembled as nodes to do a task where,
for
example, that task may change or need to be modified based on downloaded data,
acquired data, or operator entered information.
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F.Y A MDT .F C
The following example is illustrative and should not be construed as limiting
the
scope of the invention or claims thereof.
Example l: Spread Spectrum Wireless Network for Well Treating Application
This example describes a possible exemplary embodiment of the disclosed
wireless network systems as it might be configured for well treating
applications, and
consisting of a supervisory embedded processor, an OEM RF module, harsh
environment
packaging and appropriate communications protocol.
A. System
In this exemplary embodiment, the network is considered a master-slave
topology, rather than a peer to peer statistical collision based scheme.
Specifically, one
device is the system master and all other distributed points are a slave. The
software of
the system is designed to operate in a transparent mode, that is the target
data passes
through without characters added or dropped. Timing should be unaltered within
the
limitations of spread spectrum technology.
B. Job site operation
As vehicles arrive at a job site (radio power always on) the master and slave
exchange information and declare each other's presence. At this point normal
LAN
operations may commence. Several masters may operate in the same area but on
different hop patterns (channels).
Manual Network Input Embodiment: Master Control has a database that
associates individual slave node identity characteristics (node identity code)
with node
functionality of the equipment associated with each node. Human operator
present at
each slave node enters node identity code on a key pad and the code is
transmitted from
the individual slave node to the Master Control node, where it is associated
with node
functionality using the database. Field technician or network supervisor sets
a network
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computer connected to the master to monitor each identified node in the
network as
appropnate.
Automatic Network Input Embodiment: Individual slave nodes automatically
transmit identification codes to Master Control without manual input.
Transmission may
automatically initiated by Master Control node or alternatively automatically
initiated by
individual slave nodes. Alternatively, node fimctionality information may be
transmitted
by individual slave nodes to Master Control node in addition to, or as an
alternative to,
slave node identification codes.
C. Roaming
When a well treatment vehicle is out of the radio area it is in the roam mode.
Vehicles may move from one district (e.g., selected geographical area) to
another in the
roam mode. The hop pattern is constantly rotating through numerous pre-
assigned
"channels" of interest.
D. Home base operation
The well treatment vehicle may roam into any operational network. This
includes
a WLAN that is operational at a central office, maintenance yard or field
office. The
WLAN will "wake up" its attached host if not currently energized and initiate
special
home base functions. Such fimctions may include retrieval of acquired data
(e.g., well
treatment information, vehicle engine operation data, well treatment material
or fuel
usage, or vehicle/equipment maintenance information, etc.). The WLAN may then
put
the host system back to "sleep" as the vehicle is stored.
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E. RF Module Specifications
11
GENERAL SPECIFICATIONS
RF FREQUENCY 2400 to 2483 MHz
Radio CertificationFCC Part 15.247, ETS 300-328 and RSS210
rules, license free
Operating Range Indoor: 450 to 900 Outdoor: 3000 with dipole
antenna, >20 miles with
ain antenna
Network Topolog Star network
Network Protocol CSMA/CA or TDMA
Error Detection 24 bit CRC and ARC
and
Correction
Serial Data InterfaceAs nchronous (RS-232) CMOS si nals, 3.3v;
5v tolerant
IIO Data Rate Up to 115.2 Kb s, software selectable
Channel Data Rate 460 Kbps
# of Frequenc Channels75
RF Bandwidth 750 KHz
Transmit Power 10 mW or 100 mW, software selectable
Output
Receiver Sensitivity-93 dBm
Suppl voltage 3.3 v to 10 v, 5 v nominal
Current ConsumptionRemote Sleep <50mA Base Typical 120mA
(100 mW Transmit Operation Stby l2mA Operation Peak (Tx)
Power, 200mA
115.2Kbps I/O Typical 50mA
Peak (Tx) 200mA
Size 88mm x 47mm x 9mm
Weight 43
Operating Temperature-40C to 70C
Humidi 20% to 90% (non-condensing)
S
F. Other Node Equipment Specifications:
Node equipment designed to operate in extremely harsh environments with
immunity
from interference and may be configured in the field as a RS232 direct link or
as a
distributed base/remote LAN device. A unified connector routes power, data and
one
output driver. The antenna support mast is solid fiberglass and can adapt to
several
configurations.
Serial Channels: 1 General purpose RS232 2400,9600,19200,38400 baud
1 BJ LAN RS422(base or remote) 38400 baud
Power: 9-32 Vdc 3 Watts maximum input power. LED mufti-state
indicator
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Temperature: -40C to 70C operating, -SOC to 85C storage
Software: Compatible with JobMaster, Isoplex36 and 3600 etc.
Configuration: Self-contained configuration program. Operates with any
terminal.
RF: Transmitter 100mw ERP, Frequency hopping Spread Spectrum
2.4-2.5 GHz, Rx -93dBm, Range 1000'. [300 meters]
Certified license free FCC Part 15.247 and ETSI. FCC ID HSW
2410M
G. Antenna
In this exemplary embodiment, an antenna may be employed having a minimum
2dbi gain over unity for slave nodes and optionally 6db or 9db if a master
station. Wind
loading without damage is 120mph minimum. The radiation pattern is omni-
directional
and a ground plane is enclosed within the package.
H. Range Requirement and Interference
A minimum outdoors line-of sight operation is 1000' (304m) under all
conditions.
This includes operating in or near rain, lightening, adjacent UHF'/VHF radios,
microwave
ovens and direct sequence modulation Ethernet PC networks. Maximum data
throughput
degradation for this embodiment is 20% under any conditions.
The module may operate in 100mw or 10 mw power level by either software
command or auxiliary discrete input signal. This allows operation in
environments that
are sensitive to RF energy. Section 3.3 range requirements do not apply in low
power
mode. The FCC Identifier is HSW-WIT2410M.
I. Supervisory embedded processor
The RF module communicates with a local supervisor embedded processor that
performs the following functions.
~ RF module commands
~ Software and hardware handshaking/buffering
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~ Mode configuration, point to point and special applications
~ External auxiliary control, external device "wake-up"
~ LED status indicator
J. RF Module control syntax
The base application (JobMaster or 3600) transmits to all remote nodes
simultaneously and receives from a single responding remote. (Le. MCM1000).
K. Buffering
The supervisory processor buffers and formats communications strings as
required by the RF module. Each circular input and output buffer is minimum
256 bytes.
L. Handshaking
System components support both legacy systems with no handshake whatsoever
and newer systems that have allowed XON/XOFF.
M. Data Rates -
Wireless network communications channel operates at 38.4kbps and the RF
module operates at 38.4k bps. The DB9/RS-232 channel is programmable to
operate from
2400 bps to 38.4k bps and may use hardware or software handshaking.
N. Operating modes
Node system component may be used in special applications such as a single
point to point link when not in the standard LAN mode. Configuration is made
through
the DB-9/RS-232 port using a resident configurator program "Congo".
O. Production programming
Production and field updates to software can be made through the DB-91RS232
port. Software is also serviceable via the BDM connector located on the
processor PCB.
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P. Power supply
DC Input power voltage is 9-36vdc with 15% ripple maximum. Node component
driver and RS-232 port have an isolated supply. Total power dissipation is 3
watts
maximum.
Q. Packaging and environmental
The packaging is NEMA 4X sealed and all components are capable of operating
at ~0°C to +70°C. Storage is -50°C to 85°C.
R. CPU and Communication interfaces
The module has a minimum of 256k 16 bit Flash ROM and 64k byte static ram.
The CPU is a Motorola MC68332-25. The processor has a Vcc/watchdog reset and
ram
battery controller. One output for the control of an external device is
included. Output
current is 750ma continuous. A four channel buffered UART serves the node, RF
module
and RS-232 port.
S. Status display
A mufti-mode blink rate ultra-bright LED indicates operating status.
T. Supervisory processor block diagram
A supervisory processor block diagram for this example is shown in FIG. 6.
Fig.
6 shows an embedded Motorola MC68332-25 supervisory processor 602, a WIT2410
RF
module transceiver 601 with an antenna 600, external memory 604, flash ROM
606, and
UART 608. A watchdog timer 620, oscillator 622, and crystal oscillator 624 are
also
shown. The radio module may interface to external devices through a variety of
interfaces, including an RS-422 interface 612, RS-232 interface 614, or a
standard I/O
buffer 616. FIG. 6 shows connection to BJ LAN 626, DB9 connector 628, and
auxiliary
control 630. Also shown in FIG. 6 are power supply protect 632, power control
signals
638, unused LAN connectors 640, SV power supply for CPU and radio module 634,
and
SV power supply for the LAN and serial port transceivers 636.
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Example 2: Wireless Network Used in Fracture Stimulation Mode
This example describes a possible exemplary embodiment of wireless network as
it might be configured and uses for a fracture stimulation well treatment.
Such an
embodiment might also be employed for other stimulation treatments, such as
acid
treatments.
A. Topology and operation:
A central control vehicle contains several monitoring/control computers. Two
separate wireless networks are operating on different hop patterns (channels).
Wireless
network I consists of a central control computer, a hydration unit, and a
chemical additive
unit, a wellhead monitor unit, a blending unit and a laboratory van. A central
control
computer may be, for example, imbedded processor-based "ISOPLEX" system
operated
by BJ Services or alternatively a PC-based system. Wireless network II
consists of a
pump control computer (e.g., computer terminal denoted as "FracMan" where
operator
may control all pumps) and a various number of high pressure pumping units as
required
for an individual well treatment. The FracMan computer monitors telemetry from
the
pumping equipment, e.g., pressures, pump rate displacement, etc. Engine
control
circuitry may be optionally connected via wire with the pump control computer
(e.g.,
FracMan).
The network I and network II central control computers are each capable of
operating in a stand-alone mode. They may or may not pass data between each
other, as
desired for a given well treatment operation. In one configuration, Network I
treats
Network II as a slave node. All units/nodes have a spread spectrum wireless
system
attached, for example as described in Example 1. In the case of required radio
silence
(i. e., during wellsite operations with explosives), a conventional wired LAN
may be
substituted for the radio sets. In this regard, some operations merely shut
down and
observe radio silence only during a brief time while explosives are processed.
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A well treating specialist or petroleum engineer may supervise job operation.
Job
design changes (i.e., pressure, density, volumes and flow rates, leak-off
information, etc.)
may dynamically be altered from the original intended fracturing plan based on
discovered well characteristics during the treatment (e.g., flow rates and
treating
pressures, inj ectivity, etc. ).
B. Network I operation:
The Network I central computer first verifies that all anticipated slave units
are
available and working. The input flow rate is acquired from a blending unit
node and
rebroadcast to all slave nodes. The chemical additive and hydration unit node
uses this
data to adjust injected chemical rates. The blending unit node may optionally
use this
rebroadcast flow rate to use as its base to adjust proppant ratios. The
central computer
acquires from all units a full complement of operating real time data (e.g.,
fluid viscosity,
chemical flow rates, low pressure density, high-pressure density, fluid
temperature, input
and discharge flow rates and cumulative totals). The central control computer
may also
change the flow meter pulse constant (or "K factor") of any slave node.
C. Network II operation:
Network II is connected to all high-pressure pumps and optionally to network I
central computer. The engine throttle and transmission gear of an individual
pump unit
may be controlled in real time by a skilled operator, or optionally by
computer control
such as using FracMan to monitor actual treatment conformance with job plan
(e.g., rates,
number of working pump units, pressures, etc.) and to adjust pumping
conditions
accordingly. All parameters are monitored including estimated flow rate based
on pump
speed, engine diagnostic data, drive train vibration and discharge pressure.
The network II
central computer may declare an overpressure emergency shutdown at which time
an
emergency stop command ("E-STOP") is broadcast to all units.
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D. Post Job Operations:
Upon returning to the field district's office, job data may be automatically
(without
operator intervention) downloaded to, for example, a Company Intranet (e.g.,
TCPIP,
Windows based intranet, etc.) via a wireless node in the motor yard. This
information is
used for post job engineering analysis (e.g., job or treatment reports, etc.),
accountinglbilling purposes (e.g., chemical and material inventory control,
billing for
chemicals and materials, off road fuel consumption calculations, invoicing,
etc.), and
preventive maintenance.
Example 3: Wireless Network Used in Coiled Tubing Operation Mode
This example describes a possible exemplary embodiment of wireless network as
it might be configured and uses for coiled tubing operations.
Telemetry from a coiled tubing unit (e.g., tubing depth, tubing movement
direction, draw weight, pressure, etc.) may be monitored from a remote point,
for
example, located on a control barge in a coastal marsh canal or in offshore
waters.
Monitoring functions may be provided by the disclosed wireless network systems
utilizing slave nodes on the coiled tubing unit and a master node on the
control barge,
with a human operator or otherwise in a fashion described elsewhere herein. In
this
exemplary embodiment, the CTU (coiled .tubing unit) is advantageously on a
different
non-adjacent barge from the control barge. As shown by this example, this
embodiment
of the disclosed wireless network system allows grouped vessels to communicate
reliability, allows supervisory personnel to monitor/control equipment from a
location
remote to the well (e.g., enhancing safety, convenience, and/or barge space
optimization),
and under conditions where using hardwired connections is extremely difficult
(or
impossible) due to moving or floating platforms.
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Example 4: Wireless Network Used in Cementing Operation Mode
This example describes a possible exemplary embodiment of wireless network as
it might be configured and uses for cementing operations.
In one embodiment, a cement skid is used to perform cementing operations which
are required to be monitored in real time by, for example, a customer
representative of a
well treating service company's customer. This person may not be essential to
the job
operations, but nonetheless needs to monitor cementing conditions (e.g., fluid
density,
flow rates, pressures, etc.) and/or provide input on the performance of the
treatment.
Advantageously, use of the disclosed wireless network systems allows remote
data
acquisition by such a person from a safe area (e.g., 1000' away), for example,
in a pickup
truck, van, etc. with a laptop computer that operates as a node to the
disclosed wireless
network system.
As may be seen from the preceding examples, the disclosed wireless network
systems may be advantageously employed for remote monitoring/control, under
conditions where running hardwire cabling over long distances to remove
monitoring/control personnel from the wellsite is not practical and/or
economical.
Telemetry from a coiled tubing unit (e.g., tubing depth, tubing movement
direction, draw weight, pressure, etc.) may be monitored from a remote point,
for
example, located on a control barge in a coastal marsh canal or in offshore
waters.
Monitoring functions may be provided by the disclosed wireless network systems
utilizing slave nodes on the coiled tubing unit and a master node on the
control barge,
with a human operator or otherwise in a fashion described elsewhere herein. In
this
exemplary embodiment, the CTU (coiled tubing unit) is advantageously on a
different
non-adjacent barge from the control barge. As shown by this example, this
embodiment
of the disclosed wireless network system allows grouped vessels to communicate
reliability, allows supervisory personnel to monitor/control equipment from a
location
remote to the well (e.g., enhancing safety, convenience, and/or barge space
optimization),
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and under conditions where using hardwired connections is extremely difficult
(or
impossible) due to moving or floating platforms.
While the invention may be adaptable to various modifications and alternative
forms, specific embodiments have been shown by way of example and described
herein.
However, it should be understood that the invention is not intended to be
limited to the
particular forms disclosed. Rather, the invention is to cover all
modifications,
equivalents, and alternatives falling within the spirit and scope of the
invention as defined
by the appended claims. Moreover, the different aspects of the apparatus may
be utilized
in various combinations and/or independently. Thus the invention is not
limited to only
those combinations shown herein, but rather may include other combinations.
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