Session 2Session 2

Stage in Field DevelopmentStage in Field Development

Hydrocarbon Classification and Oil Hydrocarbon Classification and Oil ReservesReserves

Hydrocarbon ClassificationHydrocarbon Classification

Liquid HydrocarbonsCrude Oil, NNatural Gas Liquids, NGL

Condensate, CLGasoline, CLgLiquefied Petroleum Gases, CLp

(LPG)

Hydrocarbon Classification and Oil Hydrocarbon Classification and Oil ReservesReserves

Natural GasNatural Gas

Nonassociated Gas, GNonassociated Gas, G

Associated Gas, GAssociated Gas, Gaa

Dissolved Gas, GDissolved Gas, Gdd

Injected Gas, GInjected Gas, Gii

Hydrocarbon Classification and Oil Hydrocarbon Classification and Oil ReservesReserves

Fig. 1 - Fluid Hydrocarbon Classification

Hydrocarbon Classification and Oil Hydrocarbon Classification and Oil ReservesReserves

Oil Reserves ClassificationOil Reserves Classification

finalRreserves = ΔN = N×E

Recovery possibilitiesDegree of proof

Development and producing statusEnergy source

Primary reservesSecondary reservesTertiary reserves

Hydrocarbon Classification and Oil Hydrocarbon Classification and Oil ReservesReserves

Fig. 2 - Oil Reserves Classification and EOR Target and Path

Producing ReservesProducing Reserves

Oil Recovery MethodsOil Recovery Methods• Primary Recovery MethodsPrimary Recovery Methods• Improved Recovery MethodsImproved Recovery Methods

Conventional methods (secondary methods)Conventional methods (secondary methods) Enhanced oil recovery methods (tertiary methods)Enhanced oil recovery methods (tertiary methods)

from research and lab experiment, which can improve the possible reserves,

through field pilot tests, which can increase the probable reserves,

to proved and producing reserves when the commercial development of the reservoir under one of the EOR methods is in place.

Fig. 3 - Primary and Improved Recovery Methods

oil

water

Water Drive

Well Head

RESERVOIR

RF mencapai 50%

Primary Recovery FactorPrimary Recovery Factor

oil

Solution Gas Drive

Well Head

RESERVOIR

RF mencapai 15%-25%

Gas terlarut

Gas terlarut

Gas terlarutGas terlarut

Gas terlarut

Gas terlarutGas terlarut Gas terlarut

Free Gas

oil

Gas Cap Drive

Well Head

RESERVOIR

RF mencapai ……. %

Producing ReservesProducing Reserves

Enhanced Oil Recovery MethodsEnhanced Oil Recovery Methods

improve sweep efficiency by reducing the mobility ratio between injected and in-place fluids,

eliminate or reduce the capillary and interfacial forces and thus improve displacement efficiency, and

act on both phenomenon simultaneously.

• Chemical Methods

• Miscible Methods

• Thermal Methods

Table 1 – Methods and Enhanced Recovery

Producing ReservesProducing Reserves

Oil Recovery FactorOil Recovery Factor

finalRE5-10%5-10% Tight oil reservoirs, slightly fractured or Tight oil reservoirs, slightly fractured or

heavy oil reservoirsheavy oil reservoirs

10-25%10-25% Oil reservoirs produced mainly by solution Oil reservoirs produced mainly by solution gas drivegas drive

25-40%25-40% Oil reservoirs producing under partial water Oil reservoirs producing under partial water drive, gas injection, or gravity drainagedrive, gas injection, or gravity drainage

40-55%40-55% Oil reservoirs produced by conventional Oil reservoirs produced by conventional waterfloodwaterflood

Producing ReservesProducing Reserves

Table 2 – Conventional and EOR Methods Efficiency (ER)