Abstract:
H2S (hydrogen sulfide) alarm methods include automated systems for creating reports, initiating different safety drills and/or recording certain calibration and bump tests. The methods being automated reduces the chance of human error and falsified records. The H2S alarm methods are particularly useful for ensuring the safety of workers at remote worksites.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of provisional patent application Ser. No. 61/624,903 filed on Apr. 16, 2012 by the present inventor. 
    
    
     FIELD OF THE DISCLOSURE 
     The subject invention generally pertains to H2S gas alarm methods and more specifically to performing drills, tests and recording emergency responses. 
     BACKGROUND 
     In some locations, it may be important to monitor the concentration H2S (hydrogen sulfide) to alert people of hazardous levels of the gas. When the monitored area is a remote worksite, sometimes others beyond the worksite are also notified. The term, “remote,” means a separation distance of at least ten miles. Examples of H2S monitoring systems are disclosed in U.S. Pat. Nos. 6,954,143; RE40,238 and 7,463,160; all of which are specifically incorporated by reference herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of one example H2S alarm method. 
         FIG. 2  is a block diagram further illustrating the H2S alarm method shown in  FIG. 1 . 
         FIG. 3  is a schematic diagram of another example H2S alarm method. 
         FIG. 4  is a block diagram further illustrating the H2S alarm method shown in  FIG. 3 . 
         FIG. 5  is a schematic diagram of another example H2S alarm method. 
         FIG. 6  is a block diagram further illustrating the H2S alarm method shown in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  show an example H2S alarm method  10  for a remote worksite  16  where a group of workers might experience an alarm event  34  (e.g., high concentration of H2S). In response to sensing H2S gas  12  at a concentration exceeding a predetermined threshold, an H2S monitor  14  at worksite  16  sends an alarm signal  26  to a computer system  22  and multiple potential responders, e.g., a person-A  18  and a person-B  20 . To acknowledge having received alarm signal  26  and to accept responsibility for dealing with alarm event  34 , person-A  18  and/or person-B  20  responds by sending a response signal  27  to computer system  22 . Computer system  22  then documents alarm event  34  by creating a report  32  that, in some examples, includes an alarm title  35  and a response time  28 . Alarm title  35  is any identifier providing some information related to alarm event  34 , e.g., worksite location, worksite name, type or nature of the alarm event, etc. 
     In some examples, response time  28 , as recorded in report  32 , pertains to which of person-A  18  or person-B  20  was a first-to-respond person  30 , i.e., the first to send response signal  27 . Report  32  records first-to-respond person  30  by way of a person identifier  30 ′ (name, code, etc.), which in the illustrated example happens to correspond to person-B  20 . A slower-to-respond person (person-A  18  in this particular example) would be the one that failed to respond or responded later than the first-to-respond person. 
     Report  32  can document response time  28  in various ways. In some examples, for instance, response time  28  is documented in report  32  as a combination  28   b  of an alarm timestamp  24  and a response timestamp  25 . Alarm timestamp  24  is the approximate time that alarm event  34  started. In some examples, alarm timestamp  24  is the time H2S monitor  14  sent out alarm signal  26 . In some examples, alarm timestamp  24  is the time computer system  22  received alarm signal  26 . Response timestamp  25  is the approximate time that the first-to-respond person  30  (person-A or person-B) sent out response signal  27 . In some examples, response timestamp  25  is the time computer system  22  received response signal  27 . In some examples, response time  28  is documented in report  32  as a difference  28   a  between alarm timestamp  24  and response timestamp  25 . In the illustrated example, difference  28   a  equals ten minutes. 
     Report  32  can be in various formats including, but not limited to, a single screen shot displayed on a computer screen of computer system  22 , multi-page screen shots displayed on a computer screen of computer system  22 , a single page printed document, a multi-page printed document, etc. In some examples, computer system  22  comprises one or more computers examples of which include, but are not limited to, a desktop computer, a laptop computer, a server, a smartphone, tablet, etc. 
     In some examples, H2S monitor  14  at worksite  16 , a computer of computer system  22 , person-A  18  and person-B  20  are all remote relative to each other. In some examples, a wireless communication system  29  (satellite, radio waves, cell towers, antennas, etc.) provides wireless communication links between two or more remote elements  14 ,  18 ,  20  and  22 . The term, “wireless” means at least some portion of a communication link conveys a signal (e.g., signals  26  and  27 ) without wires through air. 
     In some examples, H2S alarm method  10  is carried out as shown in  FIG. 2 , wherein block  37  illustrates H2S monitor  14  sensing the alarming level of H2S  12  at worksite  16 . Block  39  illustrates assigning alarm timestamp  24  to alarm event  34 . Block  41  illustrates assigning alarm title  35  to alarm event  34 . Block  43  illustrates H2S monitor  14  generating alarm signal  26  as a consequence of sensing the alarming level of H2S at worksite  16 . Block  45  illustrates wirelessly transmitting alarm signal  26  to person-A and to person-B, wherein one of them is the first-to-respond person  30 . Block  47  illustrates the first-to-respond person  30  responding to alarm signal  26 . Block  49  illustrates assigning response timestamp  25  to the first-to-respond person  30 , wherein, in some examples, timestamp  25  identifies a time-of-day at which the first-to-respond person  30  responded to alarm signal  26 . Block  51  illustrates computer system  22  generating report  32  documenting alarm event  34 , alarm title  35 , response time  28 , and person-identifier  30 ′ identifying first-to-respond person  30 , wherein response time  28  is the difference  28   a  between alarm timestamp  24  and response timestamp  25  and/or a display of both alarm timestamp  24  and response timestamp  25 . 
       FIGS. 3 and 4  illustrate an example H2S alarm method  36  for a group of workers  38  at risk for exposure to hazardous concentrations of H2S gas. To prepare workers  38  for various emergencies, method  36  provides means for periodically initiating various emergency response drills, and automatically generating a report  60  that documents the drills and when they were run. Examples of such drills include, but are not limited to, a shut-in drill  48 , a man-down drill  50 , and an evacuation drill  52 . 
     In some examples of shut-in drill  48 , a designated person  65  (e.g., some chosen member of workers  38 ) lies down pretending to be in distress and needing help, and other members of workers  38  respond accordingly. In some examples of shut-in drill  48 , workers  38  close a plurality of fluid valves associated with worksite  16 , wherein worksite  16  in this example is a well site. In some examples of evacuation drill  52 , workers  38  begin leaving worksite  16 . 
     In some examples, a coordinator  40  (e.g., supervisor, manager, or a member of workers  38 ) initiates a desired drill using a control system  42 , which is in communication with an annunciator  46  (audible alarm) that is in the vicinity of workers  38 . In some but not all examples, control system  42  and annunciator  46  are remote relative to each other, and a wireless communication link  44  connects the two. In some examples, control system  42  comprises a computer that enables coordinator  40  to select and initiate a desired drill 
     To run man-down drill  50 , for instance, coordinator  40  uses a mouse-click (or some other known input means) to select man-down drill  50 . Control system  42  records the coordinator&#39;s chosen drill and the input&#39;s time of entry (drill initiation timestamp  56 ) and sends a chosen drill signal  54  (e.g., man-down drill  50 ) to annunciator  46 . Annunciator  46  then emits an audible alarm  48 ′,  50 ′ or  52 ′, i.e., the one corresponding to man-down drill  50 . Audible alarms  48 ′,  50 ′ and  52 ′ are distinguishable from each other in some way, e.g., by pitch, tone, number of beeps, duration of beep, etc. In some examples, for instance, first alarm  48 ′ is one beep, second alarm  50 ′ is two beeps and third alarm  52 ′ is three beeps. The number of beeps, in this example, tells the group of workers  38  which drill to perform. When coordinator  40  observes or otherwise becomes aware that workers  38  have completed the chosen drill, coordinator  40  uses control system  42  to record a drill completion timestamp  58 . Control system  42  then generates report  60  documenting the chosen drill, initiation timestamp  56  and completion timestamp  58 . 
     In some examples, H2S alarm method  36  is carried out as shown in  FIG. 4 , wherein block  67  illustrates coordinator  40  using control system  42  for selecting one of three safety drills comprising a shut-in drill, a man-down drill and an evacuation drill. Block  69  illustrates transmitting a chosen drill signal from control system  42  to annunciator  46 , wherein the chosen drill signal identifies which of the three safety drills coordinator  40  selected. Block  71  illustrates in response to the chosen drill signal, annunciator  46  emitting first audible alarm  48 ′ if coordinator  40  selected the shut-in drill. Block  73  illustrates in response to the chosen drill signal, annunciator  46  emitting second audible alarm  50 ′ if coordinator  40  selected the man-down drill. Block  75  illustrates in response to the chosen drill signal, annunciator  46  emitting third audible alarm  52 ′ if coordinator  40  selected the evacuation drill, wherein the first audible alarm, the second audible alarm and the third audible alarm are distinguishable from each other. Block  77  illustrates in response to annunciator  46  emitting at least one of the first audible alarm, the second audible alarm and the third audible alarm, the group of workers  38  performing and completing a chosen drill associated with the chosen drill signal  54 . Block  79  illustrates assigning drill initiation timestamp  56  to the chosen drill. Block  81  illustrates assigning drill completion timestamp  58  to the chosen drill. Block  83  illustrates control system  42  generating report  60  documenting the chosen drill and further documenting drill initiation timestamp  56  and/or drill completion timestamp  58 . 
       FIGS. 5 and 6  illustrate an example H2S alarm method  62  for automatically distinguishing and documenting various H2S related tests, such as a calibration test  85  and a bump test  87 . In some examples, calibration test  85  involves using a pressurized canister  89  of H2S gas to expose H2S monitor  14  with a predetermined first concentration of H2S gas  66 , such as a concentration of 20 ppm, and at another time exposing H2S monitor  14  to a second concentration of H2S gas  68  of substantially zero ppm. The resulting response of H2S monitor  14  is then noted or adjusted accordingly. 
     Bump test  87 , in some examples, involves using a canister  89 ′ to expose H2S monitor  14  with a third concentration of H2S gas  70  that is appreciably greater in concentration than the predetermined first concentration  66 . In the illustrated example, the third concentration of H2S gas  70  is 57 ppm. Calibration test  85  is used for establishing the accuracy of H2S monitor  14 , and bump test  87  provides a simple means for determining whether H2S monitor  14  is even functional. 
     In some examples, method  62  ensures that calibration test  85  is performed and documented during an equipment setup period  88 , prior to an operational period  90  of well bore equipment  86 . Well bore equipment  86  is machinery used in the drilling or servicing of a well bore. Examples of well bore equipment  86  include, but are not limited to, a derrick, drilling rig, workover rig, etc. 
     One example operational sequence of H2S alarm method  62  is as follows. A work crew during setup period  88  sets up equipment  86  at worksite  16  (e.g., a well bore). Prior to fully operating equipment  86  during operational period  90 , calibration test  85  is run. H2S monitor  14  is exposed sequentially to H2S gas concentrations  66  and  68  (or in reverse order), and the monitor&#39;s resulting first and second readings  66 ′ and  68 ′, respectively, are wirelessly transmitted to a computer system  78  at a remote home base  64 . Computer system  78  generates a report  84  documenting readings  66 ′ and  68 ′ and assigns them a calibration timestamp  82 . If readings  66 ′ and  68 ′ indicate that H2S monitor  14  is properly calibrated and functional, equipment  86  is cleared for use during operational period  90 . 
     To ensure H2S monitor  14  remains functional, bump test  87  is performed periodically during operational period  90 . In the illustrated example, H2S monitor  14  is exposed to H2S gas concentration  70 , and the monitor&#39;s resulting third reading  70 ′ is wirelessly transmitted to computer system  78 . Through report  84 , computer system  78  documents reading  70 ′ and assigns it a bump test timestamp  80 . 
     Based on the values of readings  66 ′,  68 ′ and  70 ′, computer system  78  determines whether a particular reading is from calibration test  85  or from bump test  87 . In some examples, computer system  78  determines a reading is from calibration test  85  if the reading is within a first predetermined range (e.g., within 5 ppm, or between 0 and 25 ppm, etc.) of the monitor&#39;s predetermined threshold (e.g., 20 ppm). Examples of said first predetermined range include, but are not limited to, within 5 ppm of 20 ppm, within 0 to 25 ppm, etc. The predetermined threshold is the chosen value at which H2S monitor  14  emits an alarm. In some examples, computer system  78  determines a reading is from calibration test  85  if the reading is within a second predetermined range of zero (e.g., within 5 ppm of zero ppm) and/or has a timestamp indicating a predetermined time span between readings  66 ′ and  68 ′. In some examples, computer system  78  determines a reading is from bump test  87  if the reading is of a predetermined limited duration and exceeds the predetermined threshold (e.g., 20 ppm) by at least a predetermined amount (e.g., by at least 15 ppm more than the predetermined threshold). 
     In some examples, H2S alarm method  62  is carried out as shown in  FIG. 6 , wherein block  91  illustrates performing a calibration test on H2S monitor  14 , wherein the calibration test involves during a first period exposing H2S monitor  14  to a first concentration of H2S that is within a first predetermined range of a predetermined threshold of the H2S monitor, the calibration test also involves during a second period exposing H2S monitor  14  to a second concentration of H2S that is within a second predetermined range of zero. Block  93  illustrates performing a bump test on H2S monitor  14 , wherein the bump test involves during a third period exposing H2S monitor  14  to a third concentration of H2S gas that exceeds the predetermined threshold by at least a predetermined amount. Block  95  illustrates H2S monitor  14  generating first reading  66 ′, second reading  68 ′ and third reading  70 ′ corresponding respectively to the first concentration of H2S gas  66 , the second concentration of H2S gas  68 , and the third concentration of H2S gas  70 . Block  97  illustrates transmitting first reading  66 ′, second reading  68 ′ and third reading  70 ′ from H2S monitor  14  to home base  64 . Block  99  illustrates based on readings  66 ′,  68 ′ and/or  70 ′, determining whether a performed test was calibration test  85  or the bump test  87 . Block  101  illustrates computer system  78  assigning bump test timestamp  80  to the bump test. Block  103  illustrates computer system  78  assigning calibration timestamp  82  to the calibration test. Block  105  illustrates computer system  78  generating report  84  documenting bump test timestamp  80  and/or calibration timestamp  82 . Block  107  illustrates computer system  78  documenting via report  84  at least one of readings  66 ′,  68 ′ and  70 ′. Block  109  illustrates computer system  78  displaying report  84  at home base  64 . Block  111  illustrates based on at least one of readings  66 ′,  68 ′ and  70 ′; report  84  providing evidence indicating whether the bump test or the calibration test was performed. 
     Additional points worth noting include the following: A group of workers is any group of people. In some examples, a group of workers includes the coordinator. In some examples, a timestamp includes the time of day and the date. In some examples, an H2S monitor includes an H2S sensor. A single page means a single sheet or a single screenshot on a computer. The term, “significantly exceeds” means at least 50% greater than a certain value or threshold. The term, “substantially equal to the threshold” means a value or reading that is within 20% of the threshold. A report can be a single page, a single screenshot, multiple pages, or multiple screenshots. 
     Although the invention is described with respect to a preferred embodiment, modifications thereto will be apparent to those of ordinary skill in the art. The scope of the invention, therefore, is to be determined by reference to the following claims: