Sets out the requirements of design and work practices necessary to ensure the safe drilling and operation of wells that penetrate hot subsurface conditions, particularly in volcanic regions, by the geothermal industry of New Zealand. It promotes best practice in the management of deep geothermal wells throughout their lifetime from drilling through to abandonment of wells. It provides guidance and encourages operators, drilling contractors, service companies, regulators, and other stakeholders to improve the overall management of wells, including safety and environmental management.