Hydraulic Underground Mining of Oil Sands – The Next Big Step?
CIM MineSpace 2001
Derek Martin, Bruce Regensburg,
Oil sands mining must compete with conventional oil and gas production at the global scale. Ten years ago, the transition from dragline and bucket-wheel reclaimer to large truck and shovel mining methods in Alberta’s oil sand industry was a key step in reaching that competitive edge. The current technological leap forward to reduce costs further is the introduction of slurry transportation and cooler, more energy efficient bitumen separation from the oil sand. What will be the next quantum jump ten years from now that will enable Canada to continue to recovery oil from oil sands economically? We suggest that it will be hydraulic underground mining of oil sands.
The area suitable to surface mining techniques, where the oil sands lie within roughly 100m of the surface, is only a 10% of the area of Alberta’s oil sands deposits. Steam assisted gravity drainage (SAGD) is moving from pilot stage to full-scale operation in areas where the depth of overburden is sufficient to contain the steam injection pressures (depths below about 200 to 300m). However, there are vast areas where SAGD and conventional surface mining are technologically unsuitable or uneconomical. This paper introduces a hydraulic underground mining method that can be used at virtual any depth, and has the potential to provide much better recovery of bitumen than SAGD.
Hydraulic underground mining of oil sands (HUMOS) combines several different technologies that are either proven or at an advanced stage of research.
· Directional drilling
· Water jet cutting of oil sand
· Block caving
· Cold water extraction of bitumen
· Slurry transportation
· Thickened tailings
HUMOS also offers numerous environmental benefits. For example, a significant portion of the bitumen separation from the oil sands occurs insitu in agitation chambers created within the oil sands thus reducing the size of surface processing facilities compared to conventional surface mining. Tailing disposal underground would substantially reduce surface disturbance and the size of surface disposal facilities.
This paper will examine the components needed to create a large-scale underground hydraulic mining/ore processing/tailings disposal mining method. The technologies that exist today and those that need to be developed in the future to enable this mining method and how these technologies combine to form an efficient mining method will be reviewed.
Directional drilling, Bitumen separation, water jet, Block caving, Hydraulic mining, Slurry transportation, Oil sands