Part of current Drainable Oil which is going to be recovered with positive profitability:
Drainable Oil = Profitable Oil Recovery + Non-profitable Oil Recovery
The Non-drainable Oil is a result of deviation from the current Field Development Plan (FDP) or mistakes in FDP itself, for example, the overestimation of OR.
The Drainable Oil is often split into Profitable Oil Recovery and non-profitable oil recovery.
See Also
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petroleum Geology / Oil In Place (OIP)/ Oil Reserves (OR) / Drainable Oil
[ Hydrocarbon Reserves ] [ Gas reserves ]