API: American Petroleum Institute gravity, a measure of how heavy or light the oil is compared to water.  If API degree is greater than 10, the oil is lighter and floats on water; if less than 10, it is heavier and sinks

Appraisal well: A well drilled as a part of an appraisal drilling programme to determine the physical extent, reserves and likely production rate of a discovery/field

bbl:  Barrels of oil

Also referred to as Concession(s) or Licence(s)

boe: Barrels of oil equivalent

bopd: Barrels of oil per day

Brent: A reference oil for the various types of oil in the North Sea, used as a basis for pricing

Concession: Also referred to as Block(s) or Licence(s)

DOC: Declaration of commerciality

EPSA: Exploration and Production Sharing Agreement

Exploration well: A well drilled to determine whether hydrocarbons are present in a particular area or structure

Farm out / farm in: The holder of shares in an oil licence may transfer shares (“farm out”) to another company in exchange for this company taking over (“farm-in”) some of the work commitments in the licence, such as paying for a drilling or a seismic investigation within a certain period

HSE: Health, Safety and Environment

Injection well: A well that is used for injection of fluids into the reservoir to enhance hydrocarbon recovery

Licence: Also referred to as Block or Concession

Onshore: Designation for operations on land

Offshore: Designation for operations at sea

Operator: The member that is leading the work on the block or field

Porosity: The porosity of a rock is determined by measuring the amount of cavities inside, and determining what percentage of the total volume that consists of cavities

Prospect: A geographical area which exploration has shown contains sedimentary rocks and structures that may be favourable for the presence of oil or gas

Reserves: Quantities of oil that may be commercially recoverable in future

Reservoir: An accumulation of oil or gas in a porous type of rock with good porosity, such as sandstone or limestone

Resources: Hydrocarbons that are viewed as potentially recoverable depending on either technical developments or a more favourable position

Seismic data:
Seismic investigations are made to be able to describe geological structures in the bedrock. Such data is collected by shooting acoustic energy – sound pulses –into the ground and listening to the responding sounds

Spud: To start drilling

Stb/d: Stock tank barrels per day