I think what you are getting at is that there are fixed costs and variable costs associated with oil production. We know the total of these costs and we know the variable costs (lifting cost per barrel) is around $6 per barrel. With increased production, the fixed costs naturally stay the same.
From this we can work out a rough figure for fixed costs and extrapolate these calculations to get a rough estimate of costs for 220bopd.
Also, as production increases, the proportion of costs attributed to fixed out of the total cost is reduced, so that profits increase more exponentially than linearly. We will see this especially at this early stage of moving into first profit.