Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
Field of the Invention
The subject invention pertains to the hazards of hydrogen
sulfide and more specifically to a personal system for responding to
an excessive amount of hydrogen sulfide.
Description of Related Art
Hydrogen sulfide, H2S, is a toxic gas that often accompanies
the production of gas, oil and water. H2S can usually be contained,
but if it escapes, an H2S monitor can be used for alerting personnel
in the area. In response to sensing about 10 to 20 ppm of H2S,
typical H2S monitors will sound an alarm that warns of the danger.
Once the alarm sounds, personnel often have sufficient time to vacate
the area. In some cases, however, someone or everyone in the area
may be overcome by the gas and fall to the ground. Since H2S is
heavier than air, an unconscious person lying on the ground may
continue breathing the toxic gas. If outside help is not quickly
summoned to the area, eventually those continuing to breath the gas
may die.
U. S. Patent 6,252,510 discloses an H2S system that calls
for outside help upon sensing an excessive amount of H2S at a distant
location. The system appears to be designed for an established
chemical plant where the H2S monitor is at a fixed, known location.
Such a system may be fine for monitoring hydrogen sulfide gas at a
particular location, but it may be inadequate for protecting an
individual moving from one location to another.
In the case of an outdoor well site that includes a
stationary H2S monitor, an undetected problem may occur if a hydrogen
sulfide leak is downwind of the H2S monitor, and an oilfield worker
is downwind of the leak. The worker may be exposed to the hydrogen
sulfide gas, but the monitor may fail to detect the leak.
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Today, H2S monitors, various fault monitoring systems, and
wireless communications are used for monitoring conditions at a well site.
SCADA (Supervisory Control And Data Acquisition) is perhaps the most
common system for monitoring the pumping conditions at a well site and for
communicating pumping-related faults to another location. Various
transducers that sense a pumping condition (i.e., fluid pressure, fluid level,
power failure, etc.) are hardwired to the hardware portion of the SCADA
system. Hardwiring a person-carried H2S monitor to a SCADA system,
unfortunately, would drastically limit the portability of the H2S monitor.
Thus, person-carried H2S monitors are generally stand-alone devices that
simply sound an alarm upon sensing a certain concentration of hydrogen
sulfide gas. Such an alarm, however, may not necessarily alert outside help.
Consequently, a need exists for a completely portable,
person-carried H2S monitor that can summon help from a remote location.
It may be beneficial to have such a system where an existing conventional
H2S monitor can be incorporated into a conventional SCADA system,
thereby avoiding the cost of an entirely new monitor and communication
system.
Summary of the Invention
Accordingly, the invention seeks in some embodiments to
provide a person-carried H2S monitor that communicates with a stationary
fault monitoring system, which in turn communicates with a distant host
computer.
Further, the invention in some embodiments seeks to provide
a personal alarm system where an existing conventional H2S monitor can be
incorporated into a conventional SCADA system, thereby avoiding the cost
of an entirely new monitor and communication system.
Still further, the invention in some embodiments seeks to use
a microphone to help communicate an H2S fault to a fault monitoring system
such s a SCADA system.
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-4-
Yet further, the invention in some embodiments seeks to
provide a signal relay unit with a learning mode so that the unit can adapt
itself to different types of H2S monitors.
Moreover, the invention in some embodiments seeks to
provide a signal relay unit with a leaning mode for learning and storing
multiple audible alarm patterns so that the unit can respond to a variety of
H2S monitors.
Further still, in some embodiments the invention seeks to
store the occurrence of an H2S fault event until a host computer pings the
fault monitoring system.
Still further, in some embodiments the invention seeks to send
an inquiry signal or ping a fault monitoring system to establish the location
of where an H2S fault may have occurred.
In some embodiments, the invention seeks to use a SCADA
or other type of fault monitoring system to monitor pumping-related faults at
fixed locations within a well site and to monitor H2S-related faults at
indeterminate locations within the well site.
Further still, in some embodiments the invention seeks to
provide a personal alarm system for responding to hydrogen sulfide gas at a
well site that is at a remote location relative to a host computer, comprising
a person-carried alarm instrument providing a trigger signal in response to
a concentration of hydrogen sulfide gas reaching a predetermined limit, and
a fault monitoring system set up at a generally fixed location at the well
site,
wherein the person-carried alarm instrument is movable relative to the fault
monitoring system. A first wireless communication link has a limited
distance range between the person-carried alarm instrument and the fault
monitoring system, wherein the first wireless communication link conveys the
trigger signal from the person-carried alarm instrument to the fault
monitoring system, and an alarm status signal is created by the fault moni-
toring system in response to receiving the trigger signal from the person-
carried alarm instrument. A second wireless communication link has a
greater distance range between the fault monitoring system and the host
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4a
computer, wherein the greater distance range is greater than the limited
distance range, and wherein the second wireless communication link conveys
the alarm status signal from the fault monitoring system to the host computer,
whereby the host computer is notified that the concentration of hydrogen
sulfide gas reached the predetermined limit at the well site.
Still further, in some embodiments the invention provides a
personal alarm system for responding to hydrogen sulfide gas at a known
well site that is at a remote location relative to a host computer, wherein a
well-related operation may occur at the known well site. The personal alarm
system comprises a person-carried alarm instrument providing a trigger signal
in response to a concentration of hydrogen sulfide gas reaching a
predetermined limit. A fault monitoring system is set up at a generally fixed
location at the known well site to monitor the well-related operation, wherein
the person-carried alarm instrument is movable relative to the fault moni-
toring system. A first wireless communication link has a limited distance
range between the person-carried alarm instrument and the fault monitoring
system, wherein the first wireless communication link conveys the trigger
signal from the person-carried alarm instrument to the fault monitoring
system, and a memory included with the fault monitoring system, wherein the
fault monitoring system remembers receiving the trigger signal even after the
trigger signal is discontinued. An alarm status signal is created by the fault
monitoring system in response to receiving the trigger signal from the person-
carried alarm instrument, an inquiry signal is periodically conveyed from the
host computer to the fault monitoring system, and a second wireless com-
munication link has a greater distance range between the fault monitoring
system and the host computer, wherein the greater distance range is greater
than the limited distance range, and wherein the second wireless
communication link conveys the alarm status signal from the fault monitoring
system to the host computer in response to the fault monitoring system re-
ceiving the inquiry signal from the host computer, and whereby the host
computer is notified that the concentration of hydrogen sulfide gas reached
the predetermined limit at the known well site.
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4b
Yet further, in some embodiments the invention provides a method for
responding to hydrogen sulfide gas at a well site that is at a remote location
relative to a host computer, the method comprising, placing a fault
monitoring system at a generally fixed location at the well site, performing
a well-related operation at the well site, generating a fault signal in
response
to an operational fault occurring with the well-related operation,
communicating the fault signal to the fault monitoring system, and providing
a person-carried alarm instrument at the well site, wherein the person-carried
alarm instrument provides a trigger signal in response to sensing a con-
centration of hydrogen sulfide gas has reached a predetermined limit. There
is provided a method for carrying the person-carried alarm instrument at the
well site, whereby the person-carried alarm instrument travels relative to the
fault monitoring system, communicating via a first wireless communication
link the trigger signal from the person-carried alarm instrument to the fault
monitoring system, and communicating via a second wireless communication
link a first alarm status signal and a second alarm status signal from the
fault
monitoring system to the host computer, wherein the first alarm status signal
corresponds to the fault signal of the well-related operation and the second
alarm status signal corresponds to the trigger signal of the person-carried
alarm instrument.
Further still, in some embodiments the invention provides a method
for responding to hydrogen sulfide gas at a well site that is at a remote
location relative to a host computer, wherein a service vehicle facilitates
performing a service operation at the well side, the method comprising using
the service vehicle to transport a fault monitoring system to the well site,
parking the service vehicle at the well site, thereby placing the fault
monitoring system at a generally fixed location at the well site, performing
the service operation at the well site, providing a person-carried alarm
instrument at the well site, wherein the person-carried alarm instrument pro-
vides a trigger signal in response to sensing a concentration of hydrogen
sulfide gas has reached a predetermined limit, and carrying the person-carried
alarm instrument at the well site, whereby the person-carried alarm
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instrument travels relative to the fault monitoring system which is at the
generally fixed location. The method comprises communicating via a first
wireless communication link the trigger signal from the person-carried alarm
instrument to the fault monitoring system, communicating via a second
wireless communication link an alarm status signal from the fault monitoring
system to the host computer, wherein the alarm status signal corresponds to
the trigger signal of the person-carried alarm instrument, and communicating
via the second wireless communication link a well location signal from the
fault monitoring system to the host computer, wherein the well location signal
identifies the remote location of the well site, whereby the host computer is
notified that the concentration of hydrogen sulfide gas reached the
predetermined limit at the remote location of the well site.
Brief Description of the Drawing
Figure 1 is a schematic diagram showing a personal alarm
system for responding to hydrogen sulfide gas at a well site.
Description of the Preferred Embodiment
Figure 1 is a schematic diagram illustrating a personal alarm
system 10 for detecting hydrogen sulfide gas 12 at a well site 14, which is
at a remote location relative to a host computer 16. The term, "remote"
refers to a distance of at least ten miles.
Alarm system 10 comprises a person-carried alarm instrument
18 and a fault monitoring system 20, wherein fault monitoring system 20 is
placed (e.g., mounted, parked, installed, set up, etc.) at a generally fixed
location at well site 14. System 20 can be any
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electrical system for receiving, storing and transmitting electrical
signals. In some embodiments, fault monitoring system 20 is a
conventional SCADA (Supervisory Control And Data Acquisition) system
for monitoring and recording the conditions of a well-related
5 operation 22 at well site 14 and making the stored monitored
information, particularly well-related faults, available to host
computer 16. A pressure sensor 24, for example, may send an
operational fault signal 26 when the pumping pressure (or other
operational characteristic, such as flow rate, temperature, liquid
level, strain, load, etc.) at well site 14 is abnormal. Well-related
operation 22 is schematically illustrated to represent operations
that include, but are not necessarily limited to, producing gas,
water or petroleum; repairing a well; servicing a well; inspecting a
well; etc. In some cases, a service vehicle 23 can be used to help
facilitate performing well-related operation 22 and can be used to
transport system 20 to well site 14.
In cases where conventional SCADA software is used, host
computer 16 accesses the stored monitored information by pinging
system 20, whereby an alarm status signal 28 corresponding to fault
signal 26 is conveyed to host computer 16 via a wireless
communication link 30. Computer 16 can ping fault monitoring system
20 by sending an inquiry signal 32 to system 20 via wireless
communication link 30. Inquiry signal 32 and the pinging process
enables computer 16 to access well-related data of a particular well
site that is at a location known to computer 16.
In other cases, however, fault monitoring system 20 provides
alarm signal 28 over wireless communication link 30 without having to
first be pinged. In such cases, system 20 may also provide a well
location signal 35 that indicates the location of well site 14. Well
location signal 35 can be in the form of an address, APIN or well
number, or a gps reading (coordinates of a conventional global
positioning system). Host computer 16 is thus informed of the H2S
fault and its location.
Another wireless communication link 34 places fault
monitoring system 20 in communication with person-carried alarm
instrument 18. The term, "person-carried" refers to an item having
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one or more features that makes the item readily carried by a person.
Such person-carried features include, but are not limited to, a belt
clip, pocket clip, strap, compact size, lightweight, etc. Alarm
instrument 18 is shown being carried by an oilfield worker 36, so
instrument 18 actually travels or moves relative to fault monitoring
system 20.
Upon sensing that a concentration of hydrogen sulfide gas 12
has reached a predetermined limit (e.g., 10 ppm), person-carried
alarm instrument 18 provides a trigger signal 38. Wireless
communication link 34 conveys trigger signal 38 to fault monitoring
system 20, and fault monitoring system 20, in turn, provides an alarm
status signal 40. The other wireless communication link 30 then
conveys alarm status signal 40, and in some cases well location
signal 35 and well-related operation data such as alarm status signal
28, to one or more designated host computers 16. In some
embodiments, alarm status signals 28 and 40 are both communicated to
computer 16 upon computer 16 pinging fault monitoring system 20.
Alarm status 40 corresponds to trigger signal 38, so host computer 16
is notified that a hydrogen sulfide gas problem has occurred at well
site 14. Thus, host computer 16 can be used for dispatching
assistance to well site 14.
Wireless communication link 34 can be of various forms
including, but not limited to, radio waves, infrared, spread
spectrum, etc. Communication link 34 can have a range of a few
hundred feet, which is appreciably less than that of communication
link 30. Communication link 30 has a range of several miles, which
can be achieved using technology such as satellite communications,
radio waves, cell phone technology, etc. In some embodiments,
communication with one or more host computers 16 involves the use of
the Internet.
Alarm instrument 18 can be a single unit or may comprise two
separate units. With two separate units, alarm instrument 18 may
comprise a conventional H2S monitor 42 and a signal relay unit 44.
Signal relay unit 44 provides a way for a conventional H2S monitor to
communicate with a conventional SCADA system, such as fault
monitoring system 20. The functional relationships of fault
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monitoring system 20, H2S monitor 42, and signal relay unit 44 can be
further understood with a description of their operation.
When H2S monitor 42 senses that the concentration of
hydrogen sulfide gas 12 exceeds a predetermined allowable limit,
monitor 42, being a conventional H2S monitor, sounds an audible alarm
signal 46. Signal relay unit 44 includes a microphone 48 that
detects alarm signal 46, and signal relay unit 44 responds by
generating trigger signal 38. A receiver 50 associated with fault
monitoring system 20 receives trigger signal 38 and responds by
recording the event on fault monitoring system 20. The H2S fault is
recorded or stored to ensure that the awareness of the event is not
lost before computer 16 pings fault monitoring system 20 or before
alarm status signal 40 is communicated to computer 16. For instance,
if computer 16 only pings fault monitoring system 20 once every ten
minutes, computer 16 should receive alarm status signal 40 even if
alarm signal 46 were cleared prior to system 20 being pinged. The
step of recording the event can be carried out by tripping a
conventional latch relay or storing the event on some other type of a
memory (e.g., integrated circuit) of system 20. Such a memory or
latch relay is schematically illustrated by numeral 52.
Since existing conventional H2S monitors may provide
different sounding alarm signals, signal relay unit 44 includes a
learning mode 54 for teaching unit 44 to recognize the sound of a
particular alarm signal and to distinguish that sound from other
extraneous or background sounds. When operating in learning mode 54,
signal relay unit 44 listens to alarm signal 46 and stores its
various attributes, which may include, but are not limited to, pitch,
volume, waveform, tone, pulsating pattern, etc. Afterwards, signal
relay unit 44 is returned to its normal operating mode where unit 44
listens for the alarm signal it just learned to recognize while in
its learning mode. Such a learning process is based on common voice
recognition technology, which is practiced by Sensory, Inc. of Santa
Clara, California.
In some cases, signal relay unit 44 can be taught to
recognize several different audible alarm patterns. This allows unit
44 to be paired up with different models of H2S monitors without
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having to repeat the learning process for each individual H2S
monitor. Signal relay unit 44 would then emit trigger signal 38 if
any one of several known alarm patterns were detected.
- Although the invention is described with reference to a
preferred embodiment, it should be appreciated by those skilled in
the art that other variations are well within the scope of the
invention. Also, it should be noted that the various elements, such
as those represented by numerals 16, 20, 22, 23, and 36 are drawn out
of scale to show more or less detail depending on the need.
Therefore, the scope of the invention is to be determined by
reference to the claims, which follow.
