Offshore manned facilities also present logistics and human resources challenges. An offshore oil platform is a small community in itself with cafeteria, sleeping quarters, management and other support functions. In the North Sea, staff members are transported by helicopter for a two-week shift. They usually receive higher salary than onshore workers do. Supplies and waste are transported by ship, and the supply deliveries need to be carefully planned because storage space on the platform is limited. Today, much effort goes into relocating as many of the personnel as possible onshore, where management and technical experts are in touch with the platform by video conferencing. An onshore job is also more attractive for the aging workforce in the petroleum industry , at least in the western world. These efforts among others are contained in the established term integrated operations . The increased use of subsea facilities helps achieve the objective of keeping more workers onshore. Subsea facilities are also easier to expand, with new separators or different modules for different oil types, and are not limited by the fixed floor space of an above-water installation.
Before drilling an exploratory well, an operator will conduct geologic surveys of an area to determine the potential for oil or gas deposits and to identify specific targets. The operator then hires a drilling contractor like Diamond Offshore to drill exploratory ("wildcat") wells offshore. The oil company chooses the location and supervises the operation, which may take as little as 15 days or as long as 12 months, of round-the-clock, seven-days-per-week operation to drill a single well depending on the complexity of the project.