CONDUCTION HEATING AIDED DRAINAGE PROCESS FOR THE RECOVERY OF HEAVY OIL AND BITUMEN

摘要

A process for the recovery of viscous hydrocarbons from a subterranean hydrocarbon bearing reservoir or formation includes the step of transmitting heat into the reservoir by closed loop circulation of a hot fluid heat transfer medium through slanted wells (up-dip or down-dip) placed inside the reservoir, thus indirectly heating the reservoir matrix and thereby causing a significant viscosity reduction in the reservoir fluids viz. heavy oil and bitumen, which drain by gravity to the flow conduit in the slanted well. This oil and bitumen flows through and along the slanted well to the heel (for the up- dip well) or to the toe (for the down-dip well) or to a vertical or horizontal producer hole drilled near the toe of the down-dip slanted well. As the heavy oil and bitumen comes in contact with the high temperature closed loop heating in the slanted well, lighter components of the heavy oil and bitumen are vaporized. These vaporised lighter components move into the colder section of the reservoir and are capable of causing viscosity reduction when redissolved in the heavy oil and bitumen. This provides an additional benefit of solvent dilution effect in the drainage process. Vaporized lighter components (as described above) and vaporized connate water create a convection current in the reservoir matrix and increase the heat transfer which in turn enhances the extraction rate. The accumulated oil at the heel or toe of the slanted well or at the vertical or horizontal producer well is produced to the surface using either natural or artificial lifts.