摘要 |
<p>Bitumen is recovered from an underground tar sands (oil sands) formation by an in-situ percolation process. After drilling a borehole to the bottom of the tar sand formation, the hole is enlarged by radially hydraulic jetting, with the resultant slurry being removed to the surface. Then, the main body of the formation immediately surrounding the borehole is fragmented and slurried, forming a cell or chamber for in-situ processing. system of small diameter, specially designed, flexible, perforated metal pipes is then introduced through the slurry mixture to the bottom of the chamber. As designed, the pipes flare radially outward as they descend, resulting in a set of pipes resting on or near the bottom of the chamber, pointing outwardly from the central pipe like wheel spokes. Processing material, such a hot alkaline water, is pressured through the pipe system and percolates upwardly through the slurry mixture, separating the bitumen from the sand matrix. The crude bitumen is collected at the top of the processed slurry and pumped to the surface, for further treatment.</p> |