Treatment Performance in Barriers <br />as Substrate is Consumed
Treatment efficiency
maximum when excess <br />substrate is present
will drop as substrate <br />is consumed
Substrate Scaling Factor (SFS)
SFS = fraction of substrate <br /> consumed when <br /> treatment < acceptable
SFS ? time to reinject
SFS typically varies from 0.3 to 0.6
Field monitoring results from emulsified oil barriers indicates that treatment efficiency is fairly constant when excess oil is present.
However as the oil begins to be depleted, treatment efficiency will gradually decline.
In the design tool, we account for this decline in treatment efficiency using a substrate scaling factor.
The substrate scaling factor is equal to the fraction of oil consumed when treatment declines below acceptable levels.
At this point, you would typically inject more oil to rejuvenate the barrier.
Past experience suggests that treatment efficiency will drop significantly once 30 to 60% of the injected oil has been consumed.