| 摘要 |
<p>A method of extracting oil from an underground bed of an oil bearing mineral. The method comprises introducing a plurality of conduits into a first, lower part of the bed. Each conduit is spaced from its neighbours and includes a relatively course filter at its lower end and contains a relatively fine filter and a lift pump. A first conduit of the plurality of conduits extends to a depth less than the depth of its neighbours. The pressure in the first conduit is reduced. A solvent for the oil is introduced into those conduits at ambient pressure so that the solvent is drawn towards the first conduit and forms a flow path in the bed as it is drawn to the first conduit. The oil-solvent solution is pumped from the first conduit and the space left in the first area after extraction of the oil is filled with water. The conduits are raised to a second, higher part of the bed when all oil has been extracted from the first lower part and the flow direction is recovered by having the first conduit extend to a depth greater than the depth of its neighbours and reducing the vacuum in the neighbours. Oil and solvent are pumped from the neighbours. The conduits are successively raised and the flow direction changed for successive, higher parts of the bed.</p> |
