Geothermal Development at Lihir - An Overview

Abstract

Gold bearing ore is mined from an open-pit mine within an active geothermal system at Lihir. The geothermal system consists of a deep liquid dominated reservoir overlaid by shallow steam zone located within close proximity to the ore bodies.
The mine pit floor will ultimately reach the shallow steam zone in some parts of the mine. Steam relief wells are drilled into this shallow steam zone to depressurize and cool the formation ahead of mining operation while dewatering wells are used to pump out water from depths below the mine pit floor for safe mining and pit wall stability.
A 6MW geothermal power plant was commissioned in 2003 and a further 30MW plant is under construction and due to be commissioned in mid 2005. Studies are underway to prove up an additional 20MW expansion. The mining environment limits access to the production wells and the steamfield. A number of considerations are incorporated into the steam supply strategy to enable geothermal power generation and safe mining operation concurrently.