Abstract
It is well known that about half parts are remained as unrecovered in oil reservoirs, when oil fields haye been treated by so-called primary oil recovery methods or secondary ones.
In Japan, some oil fields seem to have vast quantities of oil unrecovered as they are so viscous and so heavy.
We have studied on recovering methods of this remained oil, resulting successfully by thermal methods. Some parts of residual oil are burned by injecting necessary air from a well. By those energies caused by the in-situ combustion, residual oil are to be moved to another wells from which we can get large quantities oil of which have not yet been recovered.
