S.bull@gns.cri.nz

The Southern TaranakiBasin is currently beingm a p p e d o n s e i s m i creflection profiles as part ofthe GNS Science “4DTaranaki Project’. Thisproject aims to produce adigital atlas of the seismicstratigraphy and structurewithin the basin, includingderivative products such as4D petroleum generationand migration models. Thebasin has been divided intoseveral regions, withmapping now complete inthe pilot Kupe area (Fig. 1),and nearing completion int h e We s t e r n S t a b l ePlatform and Centralareas.

1. Introduction

GNS Science

Refined Geological Constraints for the Southern Taranaki Basin as part of thethe 4D Taranaki Project

Suzanne Bull , Miko Fohrmann , Hai Zhu , Matt Hill , Karsten Kroeger , Cathal Reilly1 1 1 1 12

1GNS Science, 1 Fairway Drive, Avalon, Lower Hutt 5011

OMV New Zealand Ltd, 10 Brandon Street, Wellington 60152

Figure 1. Map showing division of Taranaki Basin into working areas for the 4D Taranaki Project.KUP – Kupe (pilot study area; highlighted); CEN – Central; WPL – Western Stable Platform; SIV –Southern Inversion Zone; WAN – Wanganui Basin; ONS – Onshore Taranaki Peninsula; NGR –Northern Graben; NWP – North West Platform.

2. Seismic Mapping

Up to seventeen surfaces have been identified based on an allostratigraphic approach whereby horizons arepicked to define regionally extensive, time-equivalent depositional sequences (Fig. 2). Interpreted horizonsare then gridded to produce time-structure surfaces and depth converted to produce depth surfaces andisopach maps (Fig. 3).In the Kupe area, this approach has led to improved understanding of the timing of movement on the ManaiaFault and establishment of depocentres throughout Eocene and Miocene times (Fohrmann et al., 2012a).

Figure 2..

Interpreted west-east seismic section through Toru-1 well. Seismic surfaces for the base of each allostratigraphic sequence are shown alongwith the structural interpretation Location shown in Fig. 1.

Gridded time-structure and fault surfaces have been used to construct a working 3D static geological modelfor the Kupe and Central areas (Fig. 4). The model has been built using an iterative approach which hasallowed it to act as a QC tool for the seismic interpretation, and has been used for input into depthconversion (Hill & Milner, 2012; and Hill et al., this session), and petroleum systems modelling (see Kroegeret al., this session).

Figure 4. 3D perspective view of the GNS Science in-house static 3D geological model for the Kupe and Central areas

l

l

l

New seismic and structural interpretations across the Kupe and Central regions of the Taranaki Basin have been used to construct 3D geological models for input into petroleum systemsmodelling.

GNS Science Data Series 12a now available consisting of PDF maps and digital products for the Kupe area, along with GNS Science Report 2012/36 & 37

Mapping nearing completion in the Western Stable Platform and Central areas, and underway in Southern Inversion Zone with a view to producing a static 3D geological model of thesouthern Taranaki Basin

l

l

l

Fohrmann, M., Reid, E., Hill, M,G., King, P.R., Zhu, H., Bland, K.J., Strogen, D.P., Roncaglia, L., Scott, G.P.L., 2012b, Seismic reflection character, mapping and tectono-stratigraphichistory of the Kupe area (4D Taranaki Project), south-eastern Taranaki Basin. Lower Hutt: GNS Science. GNS Science Report 2012/36. 62 p.

Hill, M., and Milner, M., 2012, The Kupe Velocity Model – 4D Taranaki Project, GNS Science Report 2012/37

Fohrmann, M., Hill, M G., Reid, E., and Keats, B., 2012a, Time-structure, depth-structure, and isopach maps from the Kupe mapping area (4D Taranaki Project), south-eastern TaranakiBasin, GNS Data Series 12a, p. 13 + 1 DVD

This research is being undertaken with crown funding through the New Zealand Ministry of Business, Innovation and Employment (MBIE). All members of the 4D Taranaki team arethanked, along with Paradigm Ltd for use of their SeisEarth and SKUA software within which all interpretation and modelling is carried out.

The complete series of time-structure, depth-structure and isopachmaps for the Kupe area (Fig. 3), along with a digital data pack, havebeen released as GNS Science Data Series 12a (Fohrmann et al.,2012b). Maps are available as PDFs, along with digital grids and t-surfaces of all horizons and faults.

Figure 3. Example of time-structure map from Kupe area now available as part of GNS ScienceData Series 12a.

3. Data Series 4. Static Modeling

5. Outlook

References

Acknowledgements

Fig. 2

NWP

NGR

WPL CEN

WAN

SIV

KUP

ONS