Washingtons International was engaged in provision of slim-hole coring services for Lihir Gold Limited in their geothermal exploration programme at Lihir Island, Papua New Guinea. 

This programme has greatly enhanced the stratigraphic, thermal and fluid information for defining the resource through a series of 60º continuous coring wells, meeting the targets for depth, deviation and core recovery. These wells were completed with perforated liners in the production zones, allowing for ongoing pressure, temperature and spinner testing following heat-up of the resource.

Washingtons International utilised its UDR KL1500 Slim-hole Rig for these operations, equipped with sufficient well control and pumping systems to be able to manage the issues presented with drilling and coring in temperatures which have ranged up to 250 ºC. The wells cored for Lihir Gold Limited have had 1,500m target depths, with extensive zones of total loss of circulation. Pullback loading at this depth has indicated that, in conducive formations and with suitable drill-strings, the Rig may be capable of coring to 1,800—2,000m. 

One of the advantages of the operation is its mobility and small environmental footprint. The Rig has accessed high altitude sites, and has operated in confined spaces. The standard Rig and ancillary connected equipment footprint is 40m x 20m, with a site access footprint of 50m x 30m, although both of these have been successfully reduced for specific sites. The Rig itself is mounted on an all-terrain crawler excavator base, and all ancillary equipment is moveable through use of trucking or sledding.