Anglo Coal – Grasstree - Case Study

Client Background

Anglo Coal is a wholly owned division of Anglo American plcs, which is one of the largest private sector coal producers in the world. They have significant coal operations in Australia, as well as South Africa and South America.

Anglo Coal Australia is one of the nation's largest coal producers and has extensive coal mining interests and development prospects in Queensland and New South Wales, with a total workforce of approximately 2600 located at mine sites and in the Brisbane based head office.

Project Overview

Grasstree is located 200 kilometres west north-west of Rockhampton in Queensland. It is being developed as a significant coal mine by Anglo Coal.

Mitchell Drilling were contracted to undertake a full turnkey project at the site. Traditionally in that region, coal mines have simply de-gassed their coal seams prior to coal mining operations. In the case of Grasstree, Anglo Coal recognised a potential for the coal seam gas to be harvested and utilised as an energy resource.

Mitchell Drilling's Dymaxion® technique was identified as ideal for this purpose. In Anglo Coal recognising that their business and strengths were coal mining, and not gas field operation, they called on the skills of Mitchell Integrated Services to form a complete turnkey project – from well modelling through to well completion, installation, and ongoing monitoring.

The drilling program called for eight surface-to-inseam holes to intersect eight vertical production wells. The in-seam sections were 750 metres to 1000 metres long.

The vertical production wells were then equipped with pumps, production tubing, casing, wellheads and associated infrastructure. The Mitchell team brought the wells online to production and then carried out monitoring of the wells.

The drilling program was to be approached in two stages. It was agreed that the second stage would only commence if the first stage proved successful. It was indeed successful and stage two was drilled immediately, delivering more success for the client and the project.