Thermal Water Classification of Morobe, Ferguson Is., West New Britain and Feni Is of Papua New Guinea Using Water Chemistry and Isotope Analysis

Abstract

The Morobe field is structurally controlled and shows no characteristics of volcanic influence. The elevated temperature of hot springs is observed to be due to downward percolating meteoric waters that heat up due to higher geothermal gradient and ascends to surface. The two distinct inferred temperature of Buluwat and Wandumi at ~80 °C and ~160°C respectively is directly associated with the geological structure. Thus, the Morobe field is considered a low to intermediate temperature field ( 250 °C and are therefore considered high enthalpy systems. The natural surface manifestation also shows signature features such as clear-bluish alkali chloride pools, active geysers, boiling pools and silica terraces. Rabili, Talase St., Balamuson and Waramong are observed to have sea water signatures and are likely hybrid heated waters. Further work including geophysical surveys and exploration drilling will be helpful to ascertain reservoir extent and further understanding of the reservoir.