OilSim can be run either in an offshore or an onshore setting.

When setting up an OilSim session, one of the key points to decide is whether the simulation will take place at sea or on land. Offshore or onshore. Below you can see two sample OilSim maps; one for offshore and one for onshore.

In the offshore map above, deeper blue indicates deeper water, and in the onshore map yellow and brown indicate mountains. In the offshore map shown above you can see islands in the south west, and in the onshore map you can see cities as yellow dots, roads as red lines, and rivers as blue lines.

The maps are divided into license areas known as "blocks", and the numbering of blocks normally starts with 501 for offshore and 1001 for onshore. Each location on the maps is identified by a column and a row, numbered from (C1, R1) in the top left hand corner to for example (C112, R144) in the lower right hand corner.

The main difference between offshore and onshore is that most services are much more expensive offshore. Although seismic surveys and some infrastructure can be more expensive onshore, drilling is much more expensive offshore, and field development projects are normally very costly too.

It is possible to import your own map - e.g. of a real world area - into OilSim, and it is also possible to have a combined offshore and onshore session.