Gas Detection (H2S and Methane)

Drilling Equipment Inspections

How often

Calibrate and test when the BOP stack is first installed after rig-up, at every AOGCC-witnessed BOP test, and at least every 30 days. A system that self-checks continuously is function-tested at those times and at least every 6 months. PM Plan: H2S and methane detectors Category II weekly (Electrician); portable monitors monthly.

Source: 20 AAC 25.066(b); Nordic PM Plan 9.0 Table 2 and Table 5; Nordic PM Plan 5.0 Table 2

📋 Inspection Information

Inspector Name *

Date *

Rig *

Tour *

Well Name/Number

📏 Readings

H2S low alarm set point (ppm) *

H2S high alarm set point (ppm) *

Methane low alarm set point (% LEL) *

Methane high alarm set point (% LEL) *

Date of the last fixed-system calibration and test *

✅ Checklist

Answer every line. N/A means it does not apply today. Every Fail needs a note saying what is wrong.

Sensor locations (AOGCC minimum)

Methane: under the substructure near the cellar, over the shaker, and above the floor near the driller; also over the pits if they are remote from the shaker and enclosed

Source: 20 AAC 25.066(a)(1)

Methane sensors placed to catch a lighter-than-air gas (high)

Source: 20 AAC 25.066(a)(2)

H2S: under the substructure near the cellar, near the shaker, and above the floor near the driller

Source: 20 AAC 25.066(a)(3)

H2S sensors placed to catch a heavier-than-air gas (low)

Source: 20 AAC 25.066(a)(4)

All Rig 4 sensor heads in service (Start-Up lists 6)

Source: Nordic R4 Rig Start-Up 14.0 step 6

Alarms

Sensors automatic, working independently and in parallel, sampling at least every minute

Source: 20 AAC 25.066(a)(5)

Separate alarms: visual for the low level, audible for the high level

Source: 20 AAC 25.066(a)(6)

Alarms seen and heard at the driller's station

Source: 20 AAC 25.066(a)(9)

H2S alarm heard throughout the location, including camp buildings

Source: 20 AAC 25.066(a)(9)

Methane low alarm set at no more than 20% LEL; high at no more than 40% LEL

Source: 20 AAC 25.066(a)(7)

H2S low alarm set at 10 ppm; high at no more than 20 ppm

Source: 20 AAC 25.066(a)(8)

Testing and records

Calibrated and tested within the required interval; record kept at the rig

Source: 20 AAC 25.066(b)

Gas alarms tested before the first BOP test after start-up

Source: Nordic R4 Rig Start-Up 26.0 item 21

Any gas detection failure reported to AOGCC within 24 hours

Source: 20 AAC 25.066(c)

Portable gas monitors: monthly check done; bump test and calibration per the manufacturer

Source: Nordic PM Plan 9.0 Table 5; manufacturer instructions

Personal H2S monitors in service less than 2 years

Source: Nordic PM Plan 9.0 Table 5

📝 Findings & Actions

Other findings

Corrective Actions

Signature (type your full name) *

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