Calibration of Fault Sealing Techniques as Part of a Resource Assessment of the Amadeus Basin Central Australia

Torey Marshall¹, Titus Murray², John Warburton³, Sebastian Gonzalez⁴, Bronwyn Camac⁴, Greg Christie⁴, and Ian Little⁴. (1) Petroleum Geology, Northern Territory Geological Survey, 3rd Floor CentrePoint Building, Darwin, 0801, Australia, phone: 61 8 8999-5307, fax: 61 08 8999-6824, torey.marshall@nt.gov.au, (2) FaultSeal Pty Ltd, 35 Market St, Randwick, Sydney, 2031, Australia, (3) Executive Insight Pty Ltd, 71 Stafford St, Paddington, Sydney, NSW 2021, Australia, (4) Faultseal Pty Ltd

The Amadeus Basin is a large (170 000 km2), arcuate, elongate, under explored Proterozoic basin in Central Australia. Structurally the Amadeus is an inverted extensional salt basin, currently exhibiting very strong compressional features (fold and thrust belt) and type 2 & 3 fractured reservoirs. It has two producing fields, Mereenie which is Australia's largest onshore oil field (200+MMSTB, OOIP), and Palm Valley field (600+ BCF OGIP).

The calibration of fault seal potential was conducted as an integral part of a resource assessment of the basin. This calibration was also used to constrain the potential for footwall plays in the basin, improve prospect risking pre-drill, and improve charge models. As the basin is immature in terms of both economics and exploration (One well per 10 000 km 2), it was important for stakeholders to be equipped with information to assist in development of exploration strategies. With so few wells, no footwall traps tested and old fractured rocks, scenarios involving fault seal supporting a hydrocarbon column, are narrow. To calibrate the conventional sealing processes 20 faults were analyzed over 16 structures. A broad cross section of types were used, including leads, relatively mature prospects, and producing field data, these correspond roughly to the relative size of faults and detail..

A conceptual fault seal model, based on calibration, for an immature hydrocarbon producing basin is presented. Calibration and a conceptual fault seal model will be presented in the presentation.

Faults: Cross-Migration Versus Seal
2005 AAPG Annual Convention (June 19-22, 2005) Technical Program