The formation of the scale (e.g. CaCO3, BaSO4) in the wells is undesired as scale deposition will increase the surface roughness of the pipe and decrease the flow area.This impacts the efficiency of the well. Moreover, the well integrity may be challenged due to scale precipitation across sub-surface safety valves (SSSV). Further, it is believed that the scale formation increases the risk for under-deposit corrosion and pitting, which may influence the well integrity.

DHRTC research

Depending on the physical properties of the scales (e.g. solubility, hardness), either chemical or mechanical methods can be used to remove them. However, such scale-removal techniques are costly and might contribute to increased corrosion rate and shorter lifetime of the wells, facilities and pipelines. Therefore, the focus of this area is to understand the mechanisms and kinetics of scale formation and predict the operating conditions that cause the various types of scales to be formed and where in the well the scales are located. It is believed that such information will help to predict and carefully plan appropriate treatments, which would be either used to mitigate scale formation or to remove already existing deposits. It will in turn result in reduced operating expenditures as well as increased oil recovery and extended lifetime of the wells, facilities and pipelines.
26 FEBRUARY 2020