Calcite Inhibition System: Lihir Experience

Abstract

Calcite Inhibition has been an integral part of maintaining geothermal power generation at the Lihir Geothermal Field, Lihir Island, Papua New Guinea. Due to the unique composition of the field’s brine chemistry, conventional simulation software is not compatible for easy evaluation of a geothermal well’s scaling potential. Thus, a strategy of using antiscalant systems on all the wells with considerable brine contribution was adopted.

Since 2003, only one chemical, a polyacrylate based inhibitor, was proven to be effective for the Lihir chemistry. With the increasing cost associated with the inhibitor, it was deemed necessary to find an alternative product that is more economical.

In 2010, laboratory and field trials of new, antiscalant chemicals were conducted to determine their inhibition efficiencies and relative effectivity to Lihir geothermal fluids. Based on the results of these tests, one of the new anti-scalant chemicals was chosen to replace the current inhibitor and its optimum dosing rates was determined. The utilization of this new chemical equates to a 73% reduction in the antiscalant system’s operational costs.