PROCEDURE FOR WITHDRAWAL OF HIGH VISCOUS OIL AND BITUMENT FROM BED Russian patent published in 2011 - IPC E21B43/24 

FIELD: gas and oil production.

SUBSTANCE: procedure for withdrawal of high viscous oil and bitumen from reservoir consists in construction of vertical pressure and producing wells with successive secondary reservoir opening, in pumping heat carrier through pressure wells and in recovery of reservoir fluids through producers. Pressure wells and producers are alternated. Depending of thickness of a reservoir wells at a section of the reservoir from a subsurface to a roof are broken down to similar number of intervals of 5-25 m. Secondary opening of the reservoir is carried out first in a lower interval. Process strings are lowered into wells before pumping heat carrier and recovery of reservoir fluids; annular space above opening is insulated. In case of reservoir fluids water encroachment in one of producers, withdrawal from it and heat carrier pumping into pressure wells around it are stopped. Backfilling solution is pumped into an opened interval of the producer. Upon process conditioning process pipes are lifted from stopped wells. The next interval of the reservoir above the opened interval is exposed. Before heat carrier pumping and reservoir fluids withdrawal process strings are lowered into wells and annular space is insulated above the next exposure. Upon reservoir fluid water-cut operations similar to the preceding interval are carried out at this interval successively up to top of the reservoir.

EFFECT: raised high viscous oil recovery factor with successive and complete development of whole reservoir composed of weak cemented oil containing rock; simplified development of high viscous oil reservoir at reduced cost consisting in stage-by-stage development of reservoir with its conditional breaking down to several intervals of withdrawal.

4 dwg