Hydrogen sulfide alarm methods

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.

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.

DETAILED DESCRIPTION

FIGS. 1 and 2show an example H2S alarm method10for a remote worksite16where a group of workers might experience an alarm event34(e.g., high concentration of H2S). In response to sensing H2S gas12at a concentration exceeding a predetermined threshold, an H2S monitor14at worksite16sends an alarm signal26to a computer system22and multiple potential responders, e.g., a person-A18and a person-B20. To acknowledge having received alarm signal26and to accept responsibility for dealing with alarm event34, person-A18and/or person-B20responds by sending a response signal27to computer system22. Computer system22then documents alarm event34by creating a report32that, in some examples, includes an alarm title35and a response time28. Alarm title35is any identifier providing some information related to alarm event34, e.g., worksite location, worksite name, type or nature of the alarm event, etc.

In some examples, response time28, as recorded in report32, pertains to which of person-A18or person-B20was a first-to-respond person30, i.e., the first to send response signal27. Report32records first-to-respond person30by way of a person identifier30′ (name, code, etc.), which in the illustrated example happens to correspond to person-B20. A slower-to-respond person (person-A18in this particular example) would be the one that failed to respond or responded later than the first-to-respond person.

Report32can document response time28in various ways. In some examples, for instance, response time28is documented in report32as a combination28bof an alarm timestamp24and a response timestamp25. Alarm timestamp24is the approximate time that alarm event34started. In some examples, alarm timestamp24is the time H2S monitor14sent out alarm signal26. In some examples, alarm timestamp24is the time computer system22received alarm signal26. Response timestamp25is the approximate time that the first-to-respond person30(person-A or person-B) sent out response signal27. In some examples, response timestamp25is the time computer system22received response signal27. In some examples, response time28is documented in report32as a difference28abetween alarm timestamp24and response timestamp25. In the illustrated example, difference28aequals ten minutes.

Report32can be in various formats including, but not limited to, a single screen shot displayed on a computer screen of computer system22, multi-page screen shots displayed on a computer screen of computer system22, a single page printed document, a multi-page printed document, etc. In some examples, computer system22comprises 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 monitor14at worksite16, a computer of computer system22, person-A18and person-B20are all remote relative to each other. In some examples, a wireless communication system29(satellite, radio waves, cell towers, antennas, etc.) provides wireless communication links between two or more remote elements14,18,20and22. The term, “wireless” means at least some portion of a communication link conveys a signal (e.g., signals26and27) without wires through air.

In some examples, H2S alarm method10is carried out as shown inFIG. 2, wherein block37illustrates H2S monitor14sensing the alarming level of H2S12at worksite16. Block39illustrates assigning alarm timestamp24to alarm event34. Block41illustrates assigning alarm title35to alarm event34. Block43illustrates H2S monitor14generating alarm signal26as a consequence of sensing the alarming level of H2S at worksite16. Block45illustrates wirelessly transmitting alarm signal26to person-A and to person-B, wherein one of them is the first-to-respond person30. Block47illustrates the first-to-respond person30responding to alarm signal26. Block49illustrates assigning response timestamp25to the first-to-respond person30, wherein, in some examples, timestamp25identifies a time-of-day at which the first-to-respond person30responded to alarm signal26. Block51illustrates computer system22generating report32documenting alarm event34, alarm title35, response time28, and person-identifier30′ identifying first-to-respond person30, wherein response time28is the difference28abetween alarm timestamp24and response timestamp25and/or a display of both alarm timestamp24and response timestamp25.

FIGS. 3 and 4illustrate an example H2S alarm method36for a group of workers38at risk for exposure to hazardous concentrations of H2S gas. To prepare workers38for various emergencies, method36provides means for periodically initiating various emergency response drills, and automatically generating a report60that documents the drills and when they were run. Examples of such drills include, but are not limited to, a shut-in drill48, a man-down drill50, and an evacuation drill52.

In some examples of shut-in drill48, a designated person65(e.g., some chosen member of workers38) lies down pretending to be in distress and needing help, and other members of workers38respond accordingly. In some examples of shut-in drill48, workers38close a plurality of fluid valves associated with worksite16, wherein worksite16in this example is a well site. In some examples of evacuation drill52, workers38begin leaving worksite16.

In some examples, a coordinator40(e.g., supervisor, manager, or a member of workers38) initiates a desired drill using a control system42, which is in communication with an annunciator46(audible alarm) that is in the vicinity of workers38. In some but not all examples, control system42and annunciator46are remote relative to each other, and a wireless communication link44connects the two. In some examples, control system42comprises a computer that enables coordinator40to select and initiate a desired drill

To run man-down drill50, for instance, coordinator40uses a mouse-click (or some other known input means) to select man-down drill50. Control system42records the coordinator's chosen drill and the input's time of entry (drill initiation timestamp56) and sends a chosen drill signal54(e.g., man-down drill50) to annunciator46. Annunciator46then emits an audible alarm48′,50′ or52′, i.e., the one corresponding to man-down drill50. Audible alarms48′,50′ and52′ 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 alarm48′ is one beep, second alarm50′ is two beeps and third alarm52′ is three beeps. The number of beeps, in this example, tells the group of workers38which drill to perform. When coordinator40observes or otherwise becomes aware that workers38have completed the chosen drill, coordinator40uses control system42to record a drill completion timestamp58. Control system42then generates report60documenting the chosen drill, initiation timestamp56and completion timestamp58.

In some examples, H2S alarm method36is carried out as shown inFIG. 4, wherein block67illustrates coordinator40using control system42for selecting one of three safety drills comprising a shut-in drill, a man-down drill and an evacuation drill. Block69illustrates transmitting a chosen drill signal from control system42to annunciator46, wherein the chosen drill signal identifies which of the three safety drills coordinator40selected. Block71illustrates in response to the chosen drill signal, annunciator46emitting first audible alarm48′ if coordinator40selected the shut-in drill. Block73illustrates in response to the chosen drill signal, annunciator46emitting second audible alarm50′ if coordinator40selected the man-down drill. Block75illustrates in response to the chosen drill signal, annunciator46emitting third audible alarm52′ if coordinator40selected the evacuation drill, wherein the first audible alarm, the second audible alarm and the third audible alarm are distinguishable from each other. Block77illustrates in response to annunciator46emitting at least one of the first audible alarm, the second audible alarm and the third audible alarm, the group of workers38performing and completing a chosen drill associated with the chosen drill signal54. Block79illustrates assigning drill initiation timestamp56to the chosen drill. Block81illustrates assigning drill completion timestamp58to the chosen drill. Block83illustrates control system42generating report60documenting the chosen drill and further documenting drill initiation timestamp56and/or drill completion timestamp58.

FIGS. 5 and 6illustrate an example H2S alarm method62for automatically distinguishing and documenting various H2S related tests, such as a calibration test85and a bump test87. In some examples, calibration test85involves using a pressurized canister89of H2S gas to expose H2S monitor14with a predetermined first concentration of H2S gas66, such as a concentration of 20 ppm, and at another time exposing H2S monitor14to a second concentration of H2S gas68of substantially zero ppm. The resulting response of H2S monitor14is then noted or adjusted accordingly.

Bump test87, in some examples, involves using a canister89′ to expose H2S monitor14with a third concentration of H2S gas70that is appreciably greater in concentration than the predetermined first concentration66. In the illustrated example, the third concentration of H2S gas70is 57 ppm. Calibration test85is used for establishing the accuracy of H2S monitor14, and bump test87provides a simple means for determining whether H2S monitor14is even functional.

In some examples, method62ensures that calibration test85is performed and documented during an equipment setup period88, prior to an operational period90of well bore equipment86. Well bore equipment86is machinery used in the drilling or servicing of a well bore. Examples of well bore equipment86include, but are not limited to, a derrick, drilling rig, workover rig, etc.

One example operational sequence of H2S alarm method62is as follows. A work crew during setup period88sets up equipment86at worksite16(e.g., a well bore). Prior to fully operating equipment86during operational period90, calibration test85is run. H2S monitor14is exposed sequentially to H2S gas concentrations66and68(or in reverse order), and the monitor's resulting first and second readings66′ and68′, respectively, are wirelessly transmitted to a computer system78at a remote home base64. Computer system78generates a report84documenting readings66′ and68′ and assigns them a calibration timestamp82. If readings66′ and68′ indicate that H2S monitor14is properly calibrated and functional, equipment86is cleared for use during operational period90.

To ensure H2S monitor14remains functional, bump test87is performed periodically during operational period90. In the illustrated example, H2S monitor14is exposed to H2S gas concentration70, and the monitor's resulting third reading70′ is wirelessly transmitted to computer system78. Through report84, computer system78documents reading70′ and assigns it a bump test timestamp80.

Based on the values of readings66′,68′ and70′, computer system78determines whether a particular reading is from calibration test85or from bump test87. In some examples, computer system78determines a reading is from calibration test85if the reading is within a first predetermined range (e.g., within 5 ppm, or between 0 and 25 ppm, etc.) of the monitor'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 monitor14emits an alarm. In some examples, computer system78determines a reading is from calibration test85if 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 readings66′ and68′. In some examples, computer system78determines a reading is from bump test87if 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 method62is carried out as shown inFIG. 6, wherein block91illustrates performing a calibration test on H2S monitor14, wherein the calibration test involves during a first period exposing H2S monitor14to 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 monitor14to a second concentration of H2S that is within a second predetermined range of zero. Block93illustrates performing a bump test on H2S monitor14, wherein the bump test involves during a third period exposing H2S monitor14to a third concentration of H2S gas that exceeds the predetermined threshold by at least a predetermined amount. Block95illustrates H2S monitor14generating first reading66′, second reading68′ and third reading70′ corresponding respectively to the first concentration of H2S gas66, the second concentration of H2S gas68, and the third concentration of H2S gas70. Block97illustrates transmitting first reading66′, second reading68′ and third reading70′ from H2S monitor14to home base64. Block99illustrates based on readings66′,68′ and/or70′, determining whether a performed test was calibration test85or the bump test87. Block101illustrates computer system78assigning bump test timestamp80to the bump test. Block103illustrates computer system78assigning calibration timestamp82to the calibration test. Block105illustrates computer system78generating report84documenting bump test timestamp80and/or calibration timestamp82. Block107illustrates computer system78documenting via report84at least one of readings66′,68′ and70′. Block109illustrates computer system78displaying report84at home base64. Block111illustrates based on at least one of readings66′,68′ and70′; report84providing 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: