New Zealand – 2016 Taranaki MegaSurvey The Taranaki MegaSurvey is a partnered project between PGS and GNS Science. The MegaSurvey contains 11 360 sq. km of 3D seismic data matched and merged with 5 140 km of 2D data converted into depth from a seismic horizon constrained velocity model covering the New In partnership with: Zealand Taranaki Basin.
The region’s major prospective fairways lie within the Late Mesozoic extensional phase and inversion phase of the Neogene, with accelerated inversion during the Mid-Miocene supplying vast amounts of sediment to the basin.
The project area includes the Maui gas condensate field (4 TCF) and Maari-Manaia oil field (48.8 MMB).
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INTRODUCTION
The Taranaki MegaSurvey provides volume linking to 31 wells via 2D Inversion and uplift in the Late Miocene an excellent opportunity for both structural framework in the Taranaki complicates the charge model, which new entrant companies and existing Basin, which is the only producing makes the extensive footprint of the stakeholders to obtain a fully integrated petroleum basin in New Zealand. Taranaki MegaSurvey an excellent regional overview through a cost The key exploration challenge stems tool for placing field-scale geological effective seismic package. We have built from the poor understanding of the interpretation into a basin-wide context the first regionally contiguous amplitude- charge model due to the lack of regional - a major step forward in de-risking and phase-matched 3D seismic depth seismic coverage. prospectivity.
Inline through unmerged surveys - Tui 3D, Maui 3D and Opunake 3D
Inline through merged MegaSurvey volume with amplitude- and phase-matching to produce a balanced dataset PGS DataLibrary New Zealand
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SEISMIC DATA MERGING
Input Data High-grading Matching and Merging of Data 24 3D surveys ■■ Applied to stack data prior to ■■ Referenced to Kokako 3D; a modern ■■ Total 3D area 11 360 sq. km matching/merging 3D dataset central to the Taranaki ■■ Zero-phasing MegaSurvey 16 2D surveys, 45 lines ■■ Bandwidth optimisation ■■ Matching applied from the central ■■ Total 2D length 5 140 km survey outwards ■■ Footprint attenuation ■■ Initial bulk adjustments for amplitude, ■ Interpolation and re-binning ■ phase and time shifts applied (12.5m x 12.5m) ■■ Final matching filters calculated and applied over multiple time windows ■■ Time variant scaling and filtering across all surveys
STRUCTURAL SETTING
The Taranaki MegaSurvey extends from ■■ Northern Graben models to help unlock additional play between the North and South Islands of ■■ Central Graben types. New Zealand, out into the Taranaki Basin. ■■ Taranaki Fault Zone The region is a proven hydrocarbon The Taranaki Basin is bounded to the ■■ Western Stable Platform province with oil, gas and condensate north by the Reinga Basin & West ■■ Taranaki Delta and delta-front discoveries generated from Cretaceous to Norfolk Ridge, to the southwest by the Miocene-aged rocks with potential in the ■■ Southern Inversion Zone Challenger Plateau, the west by the Lord Jurassic: Sands within the Taranaki Basin range Howe Rise and the east by the Taranaki ■■ Significant asg resource that includes from Upper Cretaceous to Pliocene-aged Fault and is a predominantly offshore the Maui field adjacent to the Cape sequences present in both structural and extensional depocentre which has Egmont Fault Zone undergone recent episodes of inversion. stratigraphic trap styles. ■■ Significant oil resource that includes It covers an area of approximately The majority of exploration has the Maari-Manaia field within the 330 000 sq. km with sediment historically been focused on structural Southern Inversion Zone of the thicknesses up to 9 km and its key highs, although the MegaSurvey enables Eastern Mobile Belt regional features include: large-scale evaluation of depositional
Taranaki MegaSurvey data coverage PGS DataLibrary New Zealand
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VELOCITY MODEL FOR DEPTH CONVERSION
The velocity model used for seismic depth conversion forms an integral part of the Taranaki MegaSurvey. This regional velocity model was generated from well data, regional interpretations and a local knowledge of the geology. ■■ Wells were carefully selected based on well log completeness, reliability and distribution ■■ Velocity functions extracted from well data ■■ Horizon based interpolation and extrapolation of velocity functions ■■ Large scale structure incorporated into the velocity model ■■ Final velocity model calibrated to well markers
Sonic Log QC for building Vo-K functions 3D TWT map of an Early Miocene horizon used to constrain the velocity model
Geologically-conformable VINT model across the Taranaki Basin generated from seismic horizons and well velocities
For all enquires please contact Tel: +61 8 9320 9000 | Email: [email protected] March 2017