| A | B |
|---|
| Natural gas | Gas, occurring naturally, and often found in association with crude petroleum |
| Reservoir | The underground formation where oil and gas has accumulated. It consists of a porous rock to hold the oil or gas, and a cap rock that prevents its escape. |
| Well log | A record of geological formation penetrated during drilling, including technical details of the operation. |
| Petroleum | Hydrocarbons, including crude oil, natural gas liquids, natural gas and their products. |
| Porosity | The percentage of void in a porous rock compared to the solid formation |
| Hydrocarbon | A compound containing only the elements hydrogen and carbon. May exist as a solid, a liquid or a gas. The term is mainly used in a catch-all sense for oil, gas and condensate. |
| Christmas tree | The assembly of fittings and valves on the top of the casing which control the production rate of oil. |
| Casing | Pipe cemented in the well to seal off formation fluids or keep the hole from caving in. |
| Oil | A mixture of liquid hydrocarbons of different molecular weights. |
| Well log | A record of geological formation penetrated during drilling, including technical details of the operation. |
| Geologist | a scientist who gathers and interprets data pertaining to the formations of the earth’s crust. |
| Rig | the derrick or mast, drawworks, and attendant surface equipment of a drilling or workover unit. |
