Glossary
Accumulation
Concentration of hydrocarbons within a trap or geological unit bounded by stratigraphic or structural rock boundaries.
ABEX (Abandonment Expenditures)
Expenditures associated with well, facility, and field abandonment operations.
AFREC (African Energy Commission)
Specialised agency of the African Union (AU), under the infrastructure and energy department, responsible for coordinating, harmonising, protecting, conserving, developing, efficiently exploiting, commercialising, and integrating energy resources across the African continent.
APPO (African Petroleum Producers Organisation)
African institution mandated to promote cooperation in hydrocarbons among member countries and global institutions, fostering collaboration and partnerships, and using petroleum as a catalyst for energy security, sustainable development, and economic diversification in Africa.
AVO (Amplitude Variation with Offset)
Variation in seismic reflection amplitude with increasing source-receiver distance, indicating lithological and fluid property variations above and below the reflector. AVO analysis is used to determine thickness, porosity, density, velocity, lithology, and fluid content of subsurface rocks.
Sedimentary Basin
A structural depression in which sediments accumulate. It is a portion of the Earth’s crust that has undergone long-term subsidence, often with intermittent uplift and faulting (horsts and grabens). Sediment thickness generally increases towards the basin centre.
Barrel
Standard unit of volume in the petroleum industry used to measure crude oil and refined products. One barrel equals 42 US gallons (approximately 159 litres).
Bitumen
Residue of heavy hydrocarbons used in road construction and roofing waterproofing applications.
Block
Geographical area defined by a State and granted for petroleum exploration, appraisal, or production rights.
Bright Spot (or Dim Spot)
Seismic amplitude anomaly appearing as high (or low) amplitude reflections caused by lithological contrasts or fluid content. Often associated with hydrocarbon presence but may also result from non-hydrocarbon-related lithological changes.
Brent
Benchmark crude oil used as a pricing reference for crude oil produced in Europe, Africa, and the Middle East.
CAPEX (Capital Expenditure)
Investment expenditure used by oil and gas companies for exploration and development activities.
Catalyst
Substance that accelerates a chemical reaction without being consumed in the reaction.
ECOWAS
Economic Community of West African States, an intergovernmental organisation promoting regional cooperation and integration to improve living standards, economic stability, and development in West Africa.
Field / Oil Field (Champ pétrolier)
Geological unit or set of structures containing producible hydrocarbons, forming a single petroleum accumulation or multiple connected accumulations.
Gas Chimney
Seismic anomaly indicating vertical gas migration through subsurface formations, often associated with Direct Hydrocarbon Indicators (DHI).
Oil Shock
Sudden and significant increase in crude oil prices caused by geopolitical events, supply disruptions, wars, policy decisions, or natural events.
Condensate
Heavy hydrocarbon fractions that condense from natural gas at surface conditions.
Conversion (Refining)
Processes including cracking, catalytic reforming, hydroconversion, and coking used to transform heavy hydrocarbons into higher-value lighter products.
API Gravity
Scale developed by the American Petroleum Institute measuring crude oil density relative to water.
- Light oil: >30° API
- Medium oil: 20-30° API
- Heavy oil: 10-20° API
- Extra-heavy oil: <10° API
Well Logs (Diagraphies de puits)
Continuous records obtained from instruments lowered into wells measuring physical rock properties.
Drill Stem Test (DST)
Downhole well test used to evaluate reservoir pressure, permeability, and fluid characteristics in exploration wells.
Recovery Factor
Proportion of hydrocarbons that can be technically and economically recovered from a reservoir compared to original in-place volumes.
R-Factor
Ratio of cumulative revenues to cumulative costs used in PSCs to determine profit oil sharing levels.
Flat Spot
Seismic reflection anomaly representing a fluid contact (oil-water, gas-oil, or gas-water contact).
Associated Gas
Natural gas in contact with crude oil, either dissolved or as a gas cap.
Pipeline-Quality Gas
Processed natural gas meeting commercial specifications (typically 900-1,200 BTU/scf).
Natural Gas
Hydrocarbons in gaseous state under atmospheric conditions, including dry, wet, and associated gas.
Non-Associated Gas
Free gas not in contact with oil in a reservoir.
Dry Gas
Natural gas composed almost entirely of methane.
Pipeline
Infrastructure used to transport oil or gas over long distances.
Discovery / Field
Hydrocarbon accumulation confirmed by drilling and considered potentially commercial.
GIIP (Gas Initially In Place)
Total volume of gas originally contained in a reservoir under standard conditions.
LNG (Liquefied Natural Gas)
Natural gas liquefied at cryogenic temperatures for transport and storage.
LPG (Liquefied Petroleum Gas)
Mixture of propane and butane liquefied under moderate pressure.
Gravity Survey
Geophysical method measuring variations in Earth’s gravitational field to identify subsurface structures.
Lead
Subsurface feature with potential to contain hydrocarbons but not yet fully mapped.
Magnetometry
Geophysical method measuring variations in the Earth’s magnetic field to identify subsurface structures.
Migration
Movement of hydrocarbons from source rock to reservoir rock:
- Primary migration: expulsion from source rock
- Secondary migration: movement through carrier beds to traps
- Tertiary migration: remigration or leakage
Naphtha
Light petroleum fraction used in refining and petrochemical feedstock.
Pipeline (Oil Pipeline)
System transporting crude oil or petroleum products over long distances.
OPEX (Operating Expenditure)
Costs associated with daily petroleum production operations.
Petroleum
Natural hydrocarbons in liquid, gaseous, or solid state, including crude oil, condensates, and natural gas liquids.
Permeability
Ability of rock to transmit fluids through interconnected pore spaces.
Trap
Geological structure that prevents hydrocarbon migration, allowing accumulation.
Play
Geological area where conditions for hydrocarbon accumulation are present.
Reservoir Rock
Porous and permeable rock capable of storing and transmitting hydrocarbons.
Source Rock
Organic-rich rock that generates hydrocarbons under heat and pressure.
Seal (Cap Rock)
Impermeable rock preventing upward migration of hydrocarbons.
Seismic Survey
Geophysical method using acoustic waves to image subsurface structures.
STOOIP
Stock Tank Oil Originally In Place — total recoverable oil volume in surface conditions.
VSP (Vertical Seismic Profile)
Downhole seismic measurement using receivers placed in a borehole for high-resolution subsurface imaging.
ZLECAf
African Continental Free Trade Area (AfCFTA) — continental agreement to promote intra-African trade.
End of Glossary