Paul Lyon

PhD student - Geo

Biography

Paul commenced a PhD in 2002 investigating fault seal integrity in the onshore Otway Basin. His research interests include fault development, seal integrity and petrophysics. He has worked on projects with Schlumberger, University of Lisbon, British Geological Survey, Department of Water Land and Biodiversity, South Australia and Petratherm Ltd. He has recently presented his research to several national and international companies in Australia, the U.S.A. and Europe. He has recently accepted a position with Shell International Exploration and Production as an exploration geologist.. Member: AAPG, PESA, SPE, SEG, ASEG and EAGE.

Awards

• PSI International $20, 000 prize for best structural interpretation from seismic data
• Midland Valley Special Recognition Award for an international strucutural geology paper competition
• PESA certificate of high commendation
• 2002 recipient of International Post-Graduate Research Scholarship

PhD Research Project

Fault seal and breach mechanisms in the Penola Trough, Otway Basin

Supervisors: Prof Richard Hillis, Dr. Peter Boult (PIRSA)

Project support: Primary Industry Resources, South Australia; Origin Energy and University of Adelaide

Scholarship support: International post-graduate research scholarship (IPRS), University of Adelaide

Project Description

Aims:
To undertake a full and systematic assessment of the fault seal breach mechanisms in the Penola Trough. Firstly the structural history of the study area will be re-evaluated using seismic data. Fault juxtaposition, fault sealing processes and reactivation will be assessed over a series of selected traps to investigate which of these control the presence of a hydrocarbon column in the Otway Basin

Background:
Exploration interest in the Otway Basin has waned in recent years due to the frequent drilling of unsuccessful wells that have encountered only residual hydrocarbon columns (i.e. columns that have previously existed, but have since leaked away).

Structurally, the Penola Trough shows a complex interaction of younger Early Cretaceous and older Late Cretaceous faulting. The petroleum play type is thus one of fault bound traps.

In at least some cases, it has been demonstrated that the sealing capacity of the cap seal rocks are sufficient to hold back hydrocarbon columns, hence leakage appears to primarily be a fault seal problem. Furthermore, again in at least some cases, both juxtaposition of units across the faults and shale smear/damage on the fault plane itself indicate that the faults should be sealing. Hence reactivation of trap-bounding faults subsequent to accumulation of hydrocarbon columns may be the key cause of breaching.

Fault Analysis Seals Technology (FAST) is a technique that can be used to quantitatively define the propensity of a fault plane to reactivate under the contemporary stress tensor. This tool has been successfully calibrated in the Timor Sea, but has not yet been properly tested in the Otway Basin.

The thesis will implement the FAST technique in the evaluation of seal breach due to reactivation of faulting using revised structural interpretation of fault geometries. Other causal mechanisms of unsuccessful trap accumulation due to unfavourable juxtaposition of reservoir against permeable units, or lack of development of sealing rock on the fault plane itself will also be determined.

Publications

1. LYON, P.J., BOULT, P.J., MITCHELL, A. AND HILLIS, R.R., 2004-Improving fault geometry interpretation through 'pseudo-depth' conversion of seismic data in the Penola Trough, Otway Basin. In: Boult, P.J., Johns, D.R. and Lang, S.C. (eds) Eastern Australian Basins Symposium II, Petroleum Exploration Society of Australia, Special Publication, 695-706.
2. LYON, P.J, BOULT, P.J., HILLIS, R.R. AND MILDREN, S.D., (in press)-Sealing by shale gouge and subsequent seal breach by reactivation: A case study of the Zema Prospect, Otway Basin. AAPG Hedberg Volume 1.
3. LYON, P.J., BOULT, P.J., WATSON, M. AND HILLIS R.R., (in press)-A systematic fault seal evaluation of the Ladbroke Grove and Pyrus traps, the Penola Trough, Otway Basin. APPEA Journal, 45.
4. BOULT, P.J., LYON, P.J., CAMAC, B. AND McKIRDY, D., 2004-Subsurface plumbing of the Penola Trough, Otway Basin. In: Boult, P.J., Johns, D.R. and Lang, S.C. (eds) Eastern Australian Basins Symposium II, Petroleum Exploration Society of Australia, Special Publication, 483-498.
5. MILDREN, S.D., HILLIS, R.R., DEWHURST, D.N., LYON, P.J., MEYER, J.J. AND BOULT, P.J., (in press)-FAST (Fault Seal Analysis Technology): A new technique for geomechanical assessment of the risk of reactivation-related breach of fault seals. AAPG Hedberg Volume 1
6. Caption for .r3d file: First pass modelling of fault geometry and horizon data using 3D visualistaion.