Intetech was asked to review the design of two offshore pipelines for Dolphin Energy’s Dolphin Project in Qatar and perform a cost-reduction study. The carbon-steel pipelines were to carry untreated sour gas to an onshore processing facility. The original design used pH-controlled glycol injection to manage corrosion.

Our review highlighted the risks associated with this approach. Specifically, the water breakthrough date could not be determined, and interaction between the pH control agent and the produced water would result in solids that could block the line.

We suggested alternative approaches. Inhibitor injection was selected, which considerably reduced the project’s capital costs. A USD54-million onshore glycol regeneration plant was no longer required, and two huge offshore free-water knockout vessels could be removed from the design. Space and weight were also saved on the platforms.

“Intetech’s recommendations removed the need for the glycol regeneration plant. Not only did this save us over USD54 million, but you provided us with a better and safer solution.”

Sea-lines engineering manager