About the Montney Shale
Sasol Canada’s upstream natural gas assets are located in one of the most prolific shale gas plays in North America: the Montney shale basin located in northeast British Columbia.
The Montney Shale Gas Basin is found primarily in northeast British Columbia (B.C.). Development using horizontal wells began in 2005 and, with the advent of multi-stage fracture technology, the true potential of the Montney was realized.
Shale gas is natural gas found in fine-grained rock called shale, composed of clay-sized particles. Canada’s shale gas reservoirs are estimated to hold more than 1,000 trillion cubic feet of natural gas, although only 20 per cent of that can be recovered with current technologies. By comparison, in 2009 Canada produced 5.26 Tcf of natural gas.
Improvements in drilling technology have dramatically increased production of previously inaccessible shale gas resources. Shale gas development has added more than 70 years of resource life based on current North American production and is still increasing. The Montney shale formation is one of the most competitive plays on the continent.
Producing shale gas
Low permeability has made shale gas difficult and uneconomic to produce in the past, but by combining hydraulic fracturing and horizontal drilling, affordable, reliable production of natural gas from shale resources is now commonplace.
Horizontal drilling uses a flexible drilling pipe that starts vertically and is gradually angled so that it can run horizontally in parallel with the shale formation. Horizontal wells can extend more than two kilometres, exposing the wellbore to a larger part of the reservoir. In addition, multiple horizontal wells can be drilled from a single pad, which reduces the disturbance to land.
Hydraulic fracturing, also known as fracking, is a common method of improving oil and gas flow to the wellbore and is used when extracting shale gas from the basin. Typical fracture stimulations involve pumping fluids such as water or carbon dioxide into the reservoir under high pressure to cause the rock to crack or fracture. Once fractured, a proppant – a material such as sand or small ceramic beads – is pumped into the fractures to hold them open, enabling the gas to escape from the formation and flow more easily to the well.