Oil Imperium (Black Gold in the US) is a business sim created and published in 1989 by reLINE Software for Atari ST, Commodore 64, DOS, and Amiga.
The game was designed by a group of people that include P. Börner, Thomas Kruza, Tobias Richter and A. Graf von der Schulenburg. In this original simulation, you will have to manage your oil company, competing with up to 3 other players (controlled by humans or the computer). You can choose the mission at the beginning of the game, for example, reaching 80% of the market share, becoming the best in 3 years, or ruining all other players.
Your company will have to purchase new lands, drill boreholes, and protect the wells from sabotages. Of course, you will have to sell oil when the demand is high. You can also try to sabotage your adversaries, but if you get caught, you will have to pay the consequences (for example, losing a well).
Several mini-games add some arcade actions and make the game more interesting (or more boring, depending on the point of view). Overall, Oil Imperium is a fantastic game, pretty unique in its genre, and it received very positive reviews.