posted on 2021-02-12, 10:13authored byFelipe
J. Cardoso-Saldaña, Kelly Pierce, Qining Chen, Yosuke Kimura, David T. Allen
Atmospheric emissions
from oil and gas production operations are
composed of multiple hydrocarbons and can have large variations in
composition. Accurate estimates of emission compositions are needed
to estimate the fate and impacts of emissions and to attribute emissions
to sources. This work presents a database, constructed with empirical
data and thermodynamic models, that can be queried to estimate hydrocarbon
compositions from emission sources present at oil and gas production
sites. The database can be searched for matches using between two
and seven well parameters as query inputs (gas-to-oil ratio, API gravity,
separator pressure, separator temperature, methane molar fraction
in produced gas, ethane molar fraction of produced gas, and propane
molar fraction in produced gas). Database query performance was characterized
by comparing returns from database queries to a test data set. Application
of the database to well parameters for tens of thousands of wells
in the Barnett, Eagle Ford, and Fayetteville production regions demonstrates
variations in emission compositions. Ethane to methane ratio varies
by more than an order of magnitude from well to well and source to
source. VOC to methane ratios are comparable in variability to ethane
to methane ratios for most emission sources, but have a higher variability
for emissions from flashing of liquid hydrocarbon tanks.