According to current estimates, oil production will peak worldwide somewhere between 2010 and 2020 neverto rise again. The oil industry is therefore having to search further afield to satisfy our demand for crude oil. Quentin Cooper speaks to geologists about the possibilities of exploiting the riches of the very deep sea. How do you drill for oil two miles beneath the ocean, and where are these ultradeep reserves? Producer Jonathan Fildes E-MAIL: material.world@bbc.co.uk