Steam drive is an enhanced oil recovery method which reduces crude oil viscosity and cleans
the near-wellbore area. However, high temperature and high pressure steam injection creates
challenging scale problems.
Heavy scale was reported in high temperature wells for a steam drive reservoir in western US.
The incumbent phosphonate scale inhibitor, which worked very well in relatively low
temperature wells, was suspected to fail at high temperatures. Therefore, a group of polymeric
scale inhibitors with various chemistries were investigated to replace the incumbent chemical
for high temperature wells. They were evaluated in dynamic scale loop equipment at 350°F
(177°C).
Sulphonated carboxylic acid copolymer was determined to be the best candidate for calcite
scale control at high temperatures. The polymer was recommended to be continuously
deployed downhole to prevent calcite scale formation.
Keywords: polymeric scale inhibitor, high temperature, steam drive, dynamic scale loop