Page 15 - Sphere No.31 (Jul 2012)

13
Sphere 31
Alberta, utilises an in situ technique that employs
steam-assisted gravity drainage techniques
(sAgd), coupled with horizontal drilling
methods, to extract the bitumen.
traditionally, oil wells have been drilled
vertically from the surface straight down
into oil reserves. however, as easy-to-access
resources diminish, this is not always the most
practicable method. In husky’s sunrise energy
Project, the wells are drilled at an angle from
the earth’s surface, typically 45 degrees, and
then deviated to the horizontal 90 degrees,
into the shallow target formation.
The concept of horizontal drilling was
first proposed in the 1980s and first used by
husky in the summer of 1989 in an oil-rich area
of Canada known as rainbow. A straightforward
concept, horizontal drilling involves drilling a
horizontal (as opposed to vertical) well in order
to access resources that could not ordinarily
be reached easily – or at all – with traditional
vertical wells.
This often allows more of the petroleum resources
to be accessed than via traditional techniques.
Importantly, horizontal drilling has also been shown
to increase recovery from older reservoirs under
certain circumstances, giving new life to resources