Glossary & Conversions

Oil & Gas Conversion Chart (2008)

m Thousand
mm Million
b Billion
t Trillion
k kilo - 103
M Mega = 106
G Giga = 109
T Tera = 1012
P Peta = 1015
bbl Barrel
bpd Barrels Per Day (Liquids)
bopd Barrels of Oil Per Day
m bbls Thousand Barrels
mm bbls Million Barrels
boe Barrel of Oil Equivalent
stb Stock Tank Barrel
KL Kilolitre
scf Standard Cubic Feet
mscf Thousand Standard Cubic Feet
mmscf Million Standard Cubic Feet (106)
mmscfd Million Standard Cubic Feet Per Day
mRT Metres below the rotary table of the drilling rig
bcf Billion Cubic Feet
bscf Billion Standard Cubic Feet (109)
tcf Trillion Cubic Feet
scm Standard Cubic Metre
Btu British Thermal Unit
J Joule
Gj Gigajoule 109
TJ Terajoule 1012
PJ Petajoule 1015
T Tonne
Kt Thousand Tonnes
Tpa Tonnes Per Annum
Toe Tonne of Oil Equivalent
Other terms
APPEA Australian Petroleum Production & Exploration Association
API American Petroleum Institute (oil gravity)
AVO Amplitude vs Offset (seismic analysis)
BOP Blow out preventer
DCQ Daily contract quantity
DHI Direct Hydrocarbon Indicator (on seismic)
DST Drill Stem Test
ESP Electrical submersible pump
Feed Front End Engineering and Design
FPSO Floating Production, Storage & Offloading Unit
GOR Gas oil ratio
GWC Gas Water Contact
LOGS Wireline logging tool (electronic, sonic, etc)
MDQ Minimum Daily Quantity
NWSGP North West Shelf Gas Project
OOIP Original Oil in Place
OWC Oil water contact
PRRT Petroleum Resource Rent Tax
PSC Production Sharing Contract
RFT Repeat Formation Test
TVD True Vertical Depth (of hole while drilling)
WTI West Texas Intermediate (US benchmark oil)
Industry standard boe
Barrels of oil equivalent
1 boe
1 Barrel of Oil = 158.987 Litres
170mm boe = 1 TCF
= 34.9726 Imperial gallons/42 US gallons
= 6,000 Cubic Feet Gas (Oil Search)
= 5,700 Cubic Feet Gas (Woodside)
= 0.1024 Tonnes LNG)
= 1.069 Barrels of Condensate
= 0.136 Tonnes of Condensate
= 1.3986 Barrels LPG
= 0.1182 Tonnes LPG (Cooper Basin)
= 0.1206 Tonnes of LPG (Bass Strait)
= 0.1134 Tonnes Propane
= 0.1293 Tonnes Butane
= 0.1908 Tonnes Coal
1 Kilolitre = 6.2898 Barrels
Rates of production/flow
1,000 bpd = 50,000 tonnes per year
100 mmcfd = 36.5 bcf per year
LNG (liquefied natural gas at - 161 degrees Celsius)
1 Tonne LNG
= 8.9055 boe (Woodside)
= 45.9 mcf
= 1,428 cm
= 51.7 Mbtu (Delivered)
1 Cargo LNG (WPL NWS ships) = 56,000 Tonnes Delivered - (9th ship 62,000)
1 million tonnes of LNG / year = 3.65 million cubic metres of natural gas per day
1mm scm of Domgas/LNG has a heating equivalent of approximately 6,000 bbls of oil
LPG (liquefied petroleum gas [propane & butane])
1 Tonne LPG = 8.1876 boe (Woodside)
1 Tonne LPG = 8.458 boe (Santos)
Natural gas (primarily methane) assumes heating value of 1000 BTU per cubic foot
= 172 boe
= 163.6 boe (Woodside)
= 847 mcf (North West Shelf)
= 943 mcf (Cooper Basin)
= 948 mcf (Surat Basin)
1 kilojoule = 0.9478 btu
1PJ = 171,937 boe (Santos)
1CF = 1,000 Btu
= 1.09 Pj
= 0.178428 mm boe
1BCF = 1.055 Petajoules (Santos& Oil Search)
1 BTU = 1.055 Kj
1 mm Btu
= 0.1724 boe (Gulf of Mexico gas)
= 1 mcf
1 cubic metres of gas = 35.315 cubic feet or 35,315 BTU
1 Tonne Ethane = 26,800 cubic feet (Bass Strait)
Condensate (from wet gas)
1 Tonne
= 8.3 bbls (Woodside)
= 7.35 bbls
1 BBL Condensate/Naphtha
= 0.935 boe (Santos)
= 1.0 boe (Woodside)

Oil & Gas Conversion Chart (2008)

SPE reserve definitions
Proved (1P) reserves:

Quantities of petroleum, which, by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be commercially recoverable, from a given date forward, from known reservoirs under defined economic conditions, operating methods and government regulations. Probabilistic – at least 90% probability. Deterministic – high degree of confidence.
Probable (2P) reserves:
Additional reserves which analysis of geoscience and engineering data indicate are less likely to be recovered than proved reserves, but more certain to be recovered than possible reserves. It is equally likely that actual remaining quantities recovered will be greater than or less than the sum of the estimated proved plus probable reserves (2P). Probabilistic – at least 50% probability that quantities recovered will equal or exceed the 2P estimate.
Possible (3P) reserves:
Additional reserves which analysis of geoscience and engineering data suggest are less likely to be recoverable than probable reserves. The total quantities ultimately recovered from a project have a low probability to exceed the sum of provided plus probable plus possible (3P) reserves. Probabilistic – at least 10% probability that quantities recovered will equal or exceed the 3P estimate.
Probabilistic reserve definitions
P90. A probability cut-off of 90% is often used to describe proved reserves. In this case, proved reserves are defined as having a better-than-90% chance of being produced over the life of the field.
P50. A probability cut-off of 50% is often used to describe probable reserves. Reserves that have a better-than-50% chance of being technically and economically producible. These are reserves that are often referred to as 'indicated'.
P10. A probability cut-off of 10% is often used to describe possible reserves. These are reserves that are often described as ‘inferred’. They have a less-than-50% chance of being technically and economically producible.
Proved reserves
The estimated quantities of crude oil, natural gas and natural gas liquids that geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Economic producibility must be supported by either actual production or conclusive formation test. The SEC allows 3Dseismic data to be used in the deep water Gulf of Mexico where high drilling costs prohibit full evaluation of a reservoir section.
Contingent reserve definition
Quantities of hydrocarbon estimated to be potentially recoverable from known accumulations, but are not currently considered to be commercially recoverable. Contingent resources may be of a significant size, but still have constraints to development. These constraints, preventing the booking of reserves, may relate to lack of gas marketing arrangements or to technical, environmental or political barriers that prevent current economic development.
Prospective resources
Those quantities of petroleum estimated, as of a given date, to be potentially recoverable from undiscovered accumulations by application of future development projects. This class represents a higher risk than contingent resources as the risk of discovery is also added.