Integrated Workflow for Modeling Basin-Scale Petroleum Systems: Applications to the Kupe Area, Taranaki, New Zealand

This paper describes a multidisciplinary integrated workflow for mapping Late Cretaceous to Recent subsurface structure and stratigraphy, and modeling petroleum systems of the Taranaki Basin (74,209 km²), New Zealand. The basin-scale assessment of geology and fluid flow is aimed to improve previous, mostly local, studies. The size of the study area and integration over a nine-year timeframe of large datasets, multiple software and disciplines present technical challenges.

The workflow consists of the following six main tasks: data compilation, quality assessment and integration; structural and stratigraphic interpretation of seismic reflection data over a regional framework and local grids including assessment of timing and volumetrics of erosion; validation of the geometric and geological integrity of the structural framework through structural restoration; seismic attribute analysis and facies mapping to constrain the sedimentary facies distribution and the paleogeographic evolution of the basin; construction of 3D static models of stratigraphy, lithology distribution and faulting, as determined from the seismic and well interpretations; development of 4D dynamic models of basin deformation and petroleum generation and migration through time, to improve prediction of where as-yet undiscovered petroleum accumulations may be preserved.

Representative examples of data applications and results are presented for the hydrocarbon-producing Kupe area (4,155 km²). In Kupe, more than 200 fault planes and 20 laterally-continuous stratigraphic horizons are mapped, constrained by well data, and included in structurally-validated 3D framework models, which are populated with seismic attribute properties. The 4D models are created by integrating the results of all the steps of the workflow with source rock geochemical properties, heat-flow data from crustal-scale modeling, and rock properties for reservoir fairways.

This integrated workflow and associated data management and interpretation protocols have proved effective for developing a holistic 4D depiction of Taranaki Basin tectono-stratigraphy and petroleum systems. It provides a co-ordinated approach to interrogating large amounts of independent data, and the derivative models are the base for detailed petroleum exploration. Lessons learned may serve as guidelines for projects of similar scale.