Fig 1.
System diagram with flow labels as used in equations. Consistent assumptions about type of energy across fields allows easier characterization of upstream emissions.
Table 1.
Calculation methods for flows used in ERRs.
Table 2.
Sensitivity case definitions.
Fig 2.
Total net energy ratio NERtot and oil-specific net energy ratio NERoil for studied global oil fields.
NERtot is always greater than or equal to NERoil. NERtot, flare adds in energy content of flared gases as consumed energy (see discussion in main text).
Table 3.
Groups of fields and resulting NERtot measures.
Fig 3.
Total external energy ratio EERtot and oil-specific external energy ratio EERoil for studied global oil fields.
Note logarithmic scale due to very wide variation in EER values.
Fig 4.
Sensitivity of all studied fields to two varied parameters.
(a) drilling energy sensitivity case and (b) processing configuration sensitivity cases (see case definitions in text).
Fig 5.
Sensitivity of low-NER thermal oil recovery fields to assumptions about steam generation efficiencies and configurations.