DRILLING GEOTHERMAL WELLS EFFICIENTLY, WITH REFERENCE TO THE MUTNOVSKY, MAK-BAN AND LIHIR GEOTHERMAL FIELDS

摘要

Drilling geothermal wells efficiently is dependent on a number of factors. Good forward planning is essential. The well design, contracts and site preparation are normally prepared well before resources are mobilised to drill a well. Well design is largely influenced by the subsurface constraints and the primary objective for drilling the well. However, there are some aspects of well design that ought to be considered in improving drilling efficiency. The contract and technical specifications are one of the key areas that can influence on whether or not a well can be drilled efficiently and cost effectively. Matching a drilling rig to the well design is critical. There are many devices and materials available on the international market that can enhance efficiency in making wells but some of these come at a price that can impact negatively on the cost of a well. This paper looks at examples of wells that have been drilled at the Mutnovsky Geothermal Project. Site isolation and the severe weather conditions have affected drilling efficiency at this project. Examples of drilling geothermal wells in Mak-Ban, Philippines and Lihir, Papua New Guinea, are used as benchmarks. It is concluded that drilling at Mutnovsky can be carried out efficiently and cost effectively, in spite of special conditions applying there compared with other drilling projects throughout the world.