Recovery of bitumen by hydraulic excavation

Abstract

In one embodiment, a method of hydraulically mining of oil sands from a well pair drilled into an oil sands deposit is disclosed. The wells are preferably installed from a protected underground workspace in or near the producing zone. The method of hydraulic mining disclosed herein includes: means of drilling production and tailings injection wells; means of augmenting hydraulic excavation for example by inducing block caving and/or wormholing; means of isolating the underground personnel areas from formation gases and fluids; and means of backfilling the excavated volumes with tailings. In one configuration, production wells are formed and lined with a frangible material, for example, a weak concrete or an inflatable epoxy-impregnated felt tube. Hydraulic mining of the full deposit thickness using a directional water jet bit begins at the far end of the drill hole and continues back in stages toward the well-head. When each stage is complete, the water jet can be used to disintegrate sections of liner to allow mining to proceed back towards the well-head. An aspect of the present invention is that it provides for backfilling of the mined volume in stages so that subsidence of the ground is avoided. Possible advantages of the hydraulic excavation method disclosed herein are the low amount of energy and water required, the high production rates possible and the tolerance to difficult geologies, to recover bitumen from oil sands as compared to thermal recovery methods such as SAGD and HAGD.