Abstract
SAGD (Steam Assisted Gravity Drainage) thermal production of heavy oil in the area surrounding Lloydminster involves the
injection of steam and subsequent pressurization of the reservoir. As fluid enters the horizontal producer, the pressure drop
results in the deposition of calcium carbonate scale. Scale depo
sition eventually begins to have a detrimental effect on fluid
inflow into the wellbore. In addition to the calcium carbonate
scale, the high ashphaltene content of the oil results in a
hydrocarbon coating being deposited on the scale. Many options
exist to remove the scale/ashphaltene deposit and return the
well to prior oil production rates. This paper will review
the mechanism believed to cause scale deposition, available
chemical and mechanical methods to remo
ve the scale and Husky’s recent successe
s from treatment of SAGD wells in a
sandstone reservoir in the Lloydminster heavy oil area.
