Albian A geologic period, the uppermost sub-division of the early or lower Cretaceous period, that extends from about c.112 Mya (million years ago) to 100 Mya
Aptian A geologic period, a sub-division of the early or lower Cretaceous period, that extends from about c.125 Mya (million years ago) to 112 Mya
Appraisal well An appraisal well is drilled to assess the characteristics (e.g. flow rate, areal extent) of a discovered oil or gas accumulation
bbl Barrel of oil; equivalent to 42 US gallons
bcf Billion cubic feet of gas
boe Barrels of oil equivalent where the gas component is converted into an equivalent amount of oil using a conversion rate of approximately 6mcf to one barrel of oil
boepd Barrels of oil equivalent per day
bopd Barrels of oil per day
Carbonate Rocks Rocks made of particles (composed >50% carbonate minerals - limestones (CaCO3) and dolomites (CaMg(CO3)2)) embedded in a cement. They make up 10 - 15% of sedimentary rocks and dissolve in dilute acidic groundwater.  Most carbonate rocks result from the accumulation of bioclasts created by calcareous organisms and therefore originate in areas favouring biological activity i.e. in shallow and warm seas in areas with little to no clastic input.  In present day Earth conditions these would be primarily areas limited to ±40 latitude  
Cretaceous A geologic period that extends from about c.145 Mya (million years ago) to 65 Mya   
CSR Corporate Social Responsibility   
Development well A development well is drilled within the proved area of an oil or gas reservoir for the purpose of producing hydrocarbons
E&P Exploration and production
Exploration well An exploration well is drilled to find and test potential oil or gas accumulations in an unproved area
Formation Used to describe a particular sequence of rocks of similar character recognizable over distance. Also an oil industry term used to describe a particular layer being tested for oil and gas
Fracture A break in the rock that can serve as both a migration pathway and a reservoir for gas, oil and water
Graben A fault bonded structural feature in the sub-surface resulting from extension. It may serve as a site for thick accumulation of hydrocarbon prospective rocks
HSE Health, Safety and Environment
Hydrocarbon Any liquid or gas made up of an appreciable volume of combustible organic compounds of hydrogen and carbon, such as any of those that are the chief components of petroleum and natural gas.
Karst The topography that describes the erosion surfaces and caves that typically develop due to the solubility of carbonate rocks in dilute acidic groundwater
km2 Square kilometres
Jurassic A geologic period that extends from about c.200 Mya (million years ago) to 145 Mya
mcf Thousand cubic feet of gas    
mcf/d Thousand cubic feet of gas per day
mmbbl Millions of barrels of oil
mmboe Millions of barrels of oil equivalent
mmcf/d Millions of cubic feet of gas per day
mmstb Millions of stock tank barrels
NGLs Natural Gas Liquids
NGO Non-governmental organisation
Operator Runs the day to day hydrocarbon exploration and production programme on behalf of the working interest holders in the project
Permeable A rock that allows fluid to pass through it easily is said to be permeable
Petroleum A flammable mixture of gaseous, liquid, and solid hydrocarbons that occurs naturally beneath the Earth's surface capable of being separated into various fractions
Platform A continental area covered by relatively flat or gently tilted, sedimentary strata
Prospective Resources An estimate of the potential oil and gas volumes thought to be present in an undrilled area.
PSC Production Sharing Contract    
psi Pounds per square inch (pressure)
Reef A build-up of carbonate rocks in tropical waters developed through biotic processes dominated by corals and calcareous algae
Reservoir A rock formation with sufficient holes (porosity) to hold and store oil until it is discovered and sufficient permeability to allow the oil to be produced economically. A reservoir rock hosts the hydrocarbon accumulation in the subsurface and may consist of any number of rock types (although it is often sandstone). Also includes permeable and porous fractured rock and coal seams
Section A stratigraphic sequence encountered in a well
Seismic The seismic process records the time taken for a sound wave to travel from the surface of the earth to a sub-surface rock layer and then back again. The data collected can be processed to provide a pictorial representation of the sub-surface rock layers and is used extensively in hydrocarbon exploration and production. In a 2D seismic survey, several seismic lines are recorded to yield individual cross-sections. In a 3D seismic survey, multiple closely spaced seismic lines are recorded and the high density of cross sections are interpolated to yield detailed subsurface maps on which exploration prospects can be delineated.
Stock tank barrel A barrel of oil measured at standard temperature (60o F) and pressure (14.7 psi)
STOIIP Stock tank oil initially-in-place
Tertiary A geologic period that extends from about c.65 Mya (million years ago) to beginning of the last ice age.
WI Working interest