Pursuant to 30 CFR 250.215, 30 CFR 250.245, and 30 CFR 250.490(c), the operator of a lease must request that BOEMRE make a determination about and classify the presence of hydrogen sulfide (H2S) gas. The BOEMRE classifies an area of proposed operations as
(1) a zone known to contain H2S,
(2) a zone where the presence of H2S is unknown, or
(3) a zone where the absence of H2S has been confirmed.
If the H2S classification meets the criteria of either (1) or (2), before operations are conducted on a lease, the operator must submit an H2S Contingency Plan for approval. Some of the required elements of a Contingency Plan are safety procedures and rules for training, simultaneous drilling, well-completion, well-workover, and production operations (see 30 CFR 250.490).
Each Exploration Plan (EP) and Development Operations Coordination Document (DOCD) must include a request for a determination for one of the three classifications, pursuant to the NTL 98-16, dated August 10, 1998. The lessee must take all necessary and practicable precautions to protect personnel from the toxic effects of H2S and to mitigate the adverse effects of H2S on property and the environment.