Abstract Shell runs a Steam Assisted Gravity Drainage (SAGD) operation at the Orion field in Alberta, Canada. Pressure drops during bitumen and water recovery can lead to precipitation and buildup of scales which can plug up well equipment and lead to an increase in differential pressure and lower production. Early attempts to remove such blockages with high pressure steam or salinity-altering brine injections resulted in transient returns to normal operations but with diminishing returns. Acid treatments to dissolve the scale encountered problems with corrosion and an inability to handle the discovery of the presence of acid insoluble scales. Alterations to the operating conditions such as pH along with the addition of a chelating agent, EDTA, were successful in treating both types of scales. As a result, differential pressures and steam to oil ratios decreased while oil production grew. This treatment was extremely cost-effective and payout was on the order of a few days.