Emma Nelson

PhD student - Geo

Biography

Emma Nelson obtained her BSc (Hons) in Petroleum Geology and Geophysics from the Australian School of Petroleum in 2002. She began studying for her PhD at the ASP in 2003. Her project concentrates on determination of the in situ stress tensor from oilfield data, and the pre-drill prediction of local and near-wellbore in situ stresses using finite element modelling techniques. She is also interested in application of the in situ stress tensor to issues of wellbore stability, hydraulic fracturing and waterflooding. Member: ASEG, AAPG, SPE and PESA.

PhD/MEng Research Project

In Situ Stress of the Gippsland Basin

Supervisors: Prof Richard Hillis and Dr Scott Mildren

Scholarship support: The University of Adelaide

Technical support: ASEG RF grant

Project Description

The Gippsland Basin has produced over 3.5 billion barrels of oil and 5 trillion cubic feet of gas since production began in 1969. Most of this has been produced from shallow reservoirs within the Eocene structural closures of the top Latrobe Group. As the shallow reservoirs become increasingly exhausted, development focus is being directed towards extending the life of producing reservoirs and developing deeper less productive reservoirs for example those within the deep intra-Latrobe Group and Golden Beach Subgroup.

Accurate knowledge of the in situ stress tensor can be critical to the efficient development of mature petroleum provinces. The in situ stress tensor has applications to the design of deep and deviated wells including the prediction of optimum casing points, mudweights and tripping speeds, the assessment of wellbore stability and the planning of enhanced hydrocarbon recovery operations, particularly the design of fracture stimulation and waterflooding programs. The in situ stress tensor also influences the hydraulic conductivity of fracture networks that provide permeable pathways in poor permeability reservoirs.

Previous to this study little was known about the in situ stress field of the Gippsland Basin. Only stress orientations based on breakout interpretation of 4-arm dipmeter logs were previously available. This study will determine the full stress tensor (orientations and magnitudes) in as many fields as possible within the Gippsland Basin. The study will utilise image logs, wireline logs and pressure data to investigate both the far field and near-wellbore stress distribution. Finite element methods will also be employed to investigate the pre-drill prediction of local and near-wellbore in situ stresses. The determined in situ stress tensor will then be applied to a range of petroleum related issues including wellbore stability, water-flooding, and exploiting fracture enhanced permeability in the Gippsland Basin.