Percentage of recoverable hydrocarbon reserves recovered by a given time moment :

{\rm DF}(t) = \frac{{\rm V_{recovered \ reserves}}(t)}{{\rm V_{recoverable \ reserves}}}


It always ranges  and is related to Recovery Factor (RF) as:

{\rm DF}(t) = \frac{[\rm RF}(t)}{EUR}

where EUR is Estimated Ultimate Recovery.


The Depletion Factor concept splits naturally into two categories: 

Oil Recovery Factor (RFO)Gas Recovery Factor (RFG)


(3)

RFO=QOVSTOIIPRFO=QO↑VSTOIIP



(4)

RFG=QGVSTGIIPRFG=QG↑VSTGIIP


QOQO↑

cumulative oil production

QGQG↑

cumulative gas production

VSTOIIPVSTOIIP

STOIIP

VSTGIIPVSTGIIP

STGIIP


See Also


Petroleum Industry / Upstream /  Production / Subsurface Production / Field Study & Modelling / Production Analysis

Recovery Factor (RF) ]