Reserve Status Categories

Reserve status categories define the development and producing status of wells and
reservoirs.
Developed Reserves
Developed reserves are expected to be recovered from existing wells including reserves
behind pipe. Improved recovery reserves are considered developed only after the
necessary equipment has been installed, or when the costs to do so are relatively minor.
Developed reserves may be sub-categorized as producing or non-producing.
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Producing Reserves
Reserves subcategorized as producing are expected to be recovered from completion
intervals which are open and producing at the time of the estimate. Improved recovery
reserves are considered producing only after the improved recovery project is in
operation.
Non-producing Reserves
Reserves subcategorized as non-producing include shut-in and behind-pipe reserves.
Shut-in reserves are expected to be recovered from (1) completion intervals which are
open at the time of the estimate but which have not started producing, (2) wells which
were shut-in for market conditions or pipeline connections, or (3) wells not capable of
production for mechanical reasons. Behind-pipe reserves are expected to be recovered
from zones in existing wells, which will require additional completion work or future
recompletion prior to the start of production.
Undeveloped Reserves
Undeveloped reserves are expected to be recovered: (1) from new wells on undrilled
acreage, (2) from deepening existing wells to a different reservoir, or (3) where a
relatively large expenditure is required to (a) recomplete an existing well or (b) install
production or transportation facilities for primary or improved recovery projects.