Marriott and the key personnel within the Marriott Group have been involved in geothermal exploration and development for over 40 years. Projects carried out include high temperature hydrothermal wells and hot aquifer wells as well as for Engineered Geothermal Systems in basement rocks.

The Marriott rig inventory includes rigs with high substructures to accommodate the large diameter blow out preventers necessary for geothermal exploration and development.

Projects have been undertaken in Europe, Central America and East Africa.