4D Taranaki in New Zealand: Understanding a Petroleum System from Regional to Prospect Scale
Karsten F. Kroeger and Rob Funnell
Institute of Geological and Nuclear Sciences, Lower Hutt, New Zealand
A working petroleum system and the entrapment of commercially significant amounts of oil and gas depend on a large number of factors. A complete assessment is often beyond the scope of many E&P workflows; however, and dependent on the geology of the prospect, some factors (for example, crustal composition and structural evolution, climatic and sea-level changes, fluid flow along faults) that could significantly impact on prospectivity are commonly overlooked. We demonstrate a workflow ranging from regional basin screening and derivation of general properties of the petroleum basin to high resolution facies analysis, structural analysis and migration modeling, using data from Taranaki Basin in western New Zealand. The 4D Taranaki project is a multi-year programme to map and model the large (330,000 km2) and productive petroleum basin at high resolution (100x100 m cell size and 18 mapped horizons). This case study is used to identify basin-specific controls on petroleum systems and to illustrate how such controls might be included within exploration workflows.
The regional to prospect-specific workflow presented here highlights a series of factors that significantly affect maturity of source rocks, expelled petroleum volumes, timing and gas:oil ratio of charge and preservation of accumulations. Despite the fact that some of the data necessary to predict factors such as composition of the crust, structural evolution and climate are not always available we suggest they should be included as part of the required sensitivity analysis in early stage basin screening and prospectivity assessment. These factors, or at least their impact on regional model results, should be included in the boundary conditions of high-resolution models used to investigate petroleum charge of individual prospects.
AAPG Search and Discovery Article #120098©2013 AAPG Hedberg Conference Petroleum Systems: Modeling the Past, Planning the Future, Nice, France, October 1-5, 2012