Mitigating oil and gas production with chemical inhibitors is challenging when high temperature (>120°C) and H2S is present. The high temperatures associated with deep wells and thermal recovery methods demand an advancement in conventional inhibitor technologies. Traditional organic inhibitors struggle to protect carbon steel assets lending them susceptible to localized corrosion in sour environments. These environments require inhibitors with a combined thermal stability and persistency to provide uniform filming and corrosion protection.
For high temperature corrosion applications imidazoline chemistry ranks highly as a chemistry likely to be able to mitigate corrosion at elevated temperatures. However, at temperatures between 120 and 150°C performance is very system specific while over 150°C performance can be severely limited. An extensive in-house screening program was undertaken which identified a generic chemistry (pyrimidine) that exhibited the required performance characteristics up to 175°C for a variety of field applications. Based on this work, several other materials exhibited performance benefits for alternate applications, for instance high temperature, deep water applications. Laboratory testing of the novel corrosion inhibitors at high temperatures, also highlighted the limitations of corrosion test methodologies for evaluating inhibitors under extreme conditions.