The WRCs of crude oil, condensate, natural gas, coal, and
lignite are based on the water consumed during production [9].
Crude oil (E1) production was divided into seven processes:
onshore oil exploration, onshore oil extraction and production,
enhanced oil recovery, water flooding, thermal steam injection,
oil refining, and other plant operations, and has a total water
consumption of 0.92e1.10 m3 water/GJ; we have used the
average value. Natural gas (E3) consumes 0.11 m3 water/GJ for
the processes of onshore gas exploration, onshore gas extraction,
natural gas processing, gas pipeline operation, and other plant
operations. Coal (E4) requires water at the rate of 0.14e0.20 m3
water/GJ for surface or underground mining, beneficiation, slurry
pipelines, and other plant operations; again, we have used the
average value. We also assumed that the WRCs of condensate
(E2) and lignite (E5) were the same as those of crude oil and coal,
respectively, due to lack of specific data and because their characteristics
are similar.