For securing oil from "restricted locations", the second oil recovery solution is called "Extended Reach". Typically, this approach is used when the surface area above a reservoir is restricted, perhaps because of conditions that can include urban development, a pristine environment, a park, or a location offshore. With this concept, the underground access site is located outside of the restricted area. Horizontal drifts (which can be miles long) are used to get to the area above the reservoir. Underground galleries are excavated and the drill rig operates in this gallery to drill down (typically) to the reservoir. Projects that include installing an Extended Reach Underground Platform are likely to target and ultimately recover millions of barrels of oil, so the extra costs of the underground construction would be acceptable when calculated on a per barrel basis.