Q827. How do I determine the gas to oil ratio (GOR) for my oil well operations to decide whether I need to report emissions from completions and workovers of oil wells with hydraulic fracturing?

A827. As noted in 40 CFR 98.232(c)(4) and (6), an onshore petroleum and natural gas production facility should report emissions from well venting during well completions and workovers with hydraulic fracturing that have a GOR of 300 scf/STB or greater.

40 CFR Part 98, Subpart W does not prescribe a specific approach to calculate GOR. Onshore natural gas and petroleum facility operators may use the best approach for their facility for the completion and workover of oil wells with hydraulic fracturing, including direct measurement, calculation from other measured data, and standard estimation measures. We note that within the EPA’s 2016 updates to New Source Performance Standards for the oil and natural gas sector, GOR is defined as the ratio of the volume of gas at standard temperature and pressure that is produced from a volume of oil when depressurized to standard temperature and pressure. See 40 CFR 60.5430a. Those regulations also provide information on how to substantiate GOR values to assess whether a well is subject to reduced-emissions completion (REC) or combustion requirements using the same 300 scf/STB threshold (see 81 FR 35853, 40 CFR 60.5375a, and 40 CFR 60.5420a).