The Canterbury Great South Basin covers about 160,000 km2 off the southeast coast of the South Island of New Zealand. It formed during the Cretaceous as a rift basin and has experienced only very minor deformation (along its northwest margin) since then. The total sediment thickness is greater than eight km in the Central Sub-basin. Water depths range from 50 to 1600 metres.

Only 14 wells have been drilled in the basin, including in deep-water locations, but only one on 3D seismic. Despite being a frontier basin, 11 wells have encountered hydrocarbons in various syn- and post rift play intervals, and four technical successes have been made, proving a working petroleum system.

The eastern deep-water area of the basin, including acreage held by OMV New Zealand, is undrilled and the details of its history remain largely unknown. OMV has carried out a rigorous play-based exploration workflow that shows the main critical risks for the basin and the key syn- and post rift plays. It also offers the possibility to integrate dynamic well data and well failure mechanisms, so that early exploration activities can be focussed on the important aspects of the most valuable plays. This basin-focused approach and the in-depth petroleum system understanding forms the basis for OMVs subsequent play focused approach, which quantifies the various aspects of the system within each play and uses tools such as common risk segment mapping to highlight sweet spots within each play.

This approach has highlighted significant opportunities within the Cretaceous post-rift play, consisting of net transgressive shallow marine stacked sandstones that are compactionally draped over large basement highs. It also quantifies the exploration upside in OMVs operated PEP 50119, where we show that a proper basin and play focused workflow, coupled with an innovative pre-stack seismic interpretation workflow has added a material exploration opportunity for OMV with tremendous follow-up potential.