A Rapid Approach for Probabilistic Prospect Charge Assessment - With Examples from Taranaki Basin, NZ

R.H. Funnell, M. Geddes, and P.G. Scadden
GNS Science Ltd, New Zealand

While multi-1D, or pseudo-3D, basin models allow basin evolution, thermal history and expelled petroleum volumes to be rapidly quantified for input to flowpath or full 3D basin simulators, many inputs to such a model are poorly constrained. PC clusters or supercomputers permit stochastic modelling with Monte Carlo methods for probabilistic assessment of petroleum prospects. Such an approach allows the sensitivity of model inputs on likely oil volumes to be assessed and for realistic assessments of prospect charge for given uncertainties in the input data sets.

The BM1D code developed by GNS Science requires a large number of maps or grids, with isopachs, lithologic composition, depositional ages, and paleo-bathymetric data all input as grids, but the approach provides a detailed basin evolution model accurately accounting for the effects of time-transgressive deposition, volcanic intrusions and erosional unconformities. Parallel processing power has allowed this modelling tool to be adapted for assessing the uncertainties in the inputs.

New Zealand’s Taranaki Basin has a complex history, including components of rift, passive, foreland, and back-arc basins. The modelling of petroleum systems within such complex polyphase basins therefore requires the full capabilities of BM1D. Within this setting, model sensitivities to various input uncertainties are presented and the use of Monte Carlo methods for characterising the probable volumes of petroleum expulsion is illustrated.

 

AAPG Search and Discover Article #90066©2007 AAPG Hedberg Conference, The Hague, The Netherlands

 

AAPG Search and Discover Article #90066©2007 AAPG Hedberg Conference, The Hague, The Netherlands