Hydrogen Sulfide Gas (H2S) Low Hazard Area
Low hazard area – any well which will penetrate a formation containing H2S with a known .35 psi/ft B.H. pressure gradient or less and/or in which the H2S zone-has been
effectively sealed off by casing/ cementing and/or cementing method.
Source: State of Wyoming Occupational Safety and Health Rules and Regulations for Oil and Gas Well Drilling, Revised January 8, 2013. Regulations