A DETERMINATION OF THE CH4, NOX AND CO2 EMISSIONS FROM THE PRUDHOE BAY, ALASKA OIL DEVELOPMENT

In this paper we quantify the CH4, CO2 and NOx emissions during routin e operations at a major oil and gas production facility, Prudhoe Bay, Alaska, using the concentrations of combustion by products measured at the NOAA-CMDL observatory at Barrow, Alaska and fuel consumption data from Prudhoe Bay. During the 1989 and 1990 measurement campaigns, 10 periods (called 'events') were unambiguously identified where surface winds carry the Prudhoe Bay emissions to Barrow (approximately 300 km) . The events ranged in duration from 8-48 h and bring ambient air mass es containing substantially elevated concentrations of CH4, CO2 and NO x to Barrow. Using the slope of the observed CH4 vs CO2 concentrations during the events and the CO2 emissions based on reported fuel consum ption data, we calculate annual CH4 emissions of (24 +/- 8) x 10(3) me tric tons from the facility. In a similar manner, the annual NOx emiss ions are calculated to be (12 +/- 4) x 10(3) metric tons, which is in agreement with an independently determined value. The calculated CH4 e missions represent the amount released during routine operations inclu ding leakage. However this quantity would not include CH4 released dur ing non-routine operations, such as from venting or gas flaring.