Petroleum Exploration and Geosciences Initiative

Announced in May 2010 by New Zealand Petroleum & Minerals, the two-year PEGI programme was aimed at improving knowledge and access to information on New Zealand’s oil and gas resources.

The initiative was completed by GNS Science by April 2012.

PEGI comprises a suite of 14 inter-related projects, and the provision of eight existing GNS Science data products. In summary, the PEGI projects are a range of evaluations and upgrades of knowledge on Taranaki and other key basins along with specialist studies of the geochemistry of oils and gases and their source rocks, detailed palaeontology control of wells, and screening of frontier basins.

New Zealand Petroleum & Minerals contributed $4 million to the programme, and GNS Science $3.8 million from programme grants.

In May 2012 the PEGI project won Discovering Gold at the Wellington Gold Awards.

The projects undertaken were:

1. Petroleum Basin Explorer: An interactive web-based tool that allows discoverability and access to a wide range of geoscience data from across the New Zealand sub-continent. Petroleum Basin Explorer is the single interface for oil and gas explorers to freely access PEGI outputs. Go to http://data.gns.cri.nz/pbe

2. Enhanced Frontier Basin Screening: Compilation, integration and digital delivery of metadata on Google Earth of all publicly available swath bathymetry and seismic data that assist in defining the presence of active petroleum systems between the extended continental shelf boundary and the New Zealand coastline. Includes a report on Direct Hydrocarbon Indicators in a selected area of the Canterbury Basin – Tools for Frontier Basin Screening.

3. Seismic Legacy Data QC: A two-year assisted programme to sort, organise, catalogue and upload seismic data and all related metadata into the New Zealand Petroleum & Minerals’ Data Management System, which can be accessed through NZP&M’s Online Exploration Database. Go to https://data.nzpam.govt.nz/GOLD/system/mainframe.asp

4. NZ Stratlink Project: A suite of interactive digital chronostratigraphic transects from four major exploration regions of New Zealand, referencing New Zealand strata (layers of sedimentary rock) to assist familiarisation and comparison of petroleum exploration basins using Timescale Creator. Containing selected exploration well and outcrop data.

5. Offshore Prospectivity Atlas: A New Zealand wide compilation of geophysical data. Systematic evaluation of the basin fill and a basin-by-basin assessment of the potential for undiscovered oil and gas resources, initially for the East Coast and Pegasus Basins.

6. CONOP Correlation Taranaki: A quantitative stratigraphic analysis of 20 hydrocarbon exploration and appraisal wells distributed through the offshore Taranaki Basin using the method of constrained optimization (CONOP). This study also included some examples of application of the CONOP results to four Taranaki wells.

7. Offshore Taranaki Seismic Sequence Stratigraphy: A set of five regional reference transects to appraise exploration opportunities across the Taranaki Basin, including seismic base images, stratigraphic unit interpretations and seismic facies and sequence stratigraphy interpretations.

8. Well Depth-Two-Way-Time (TWT) Calibration: A reference dataset from a range of 10 onshore and 42 offshore Taranaki wells comprising standardised and quality-controlled checkshot and other velocity information, and derivative conversions of well depth to TWT (two-way travel time).

9. Taranaki Reservoir Quality Database – Analytical Supplement: Enhancement of an existing digital reservoir quality database for Taranaki through compilation and collection of additional data such as core plug descriptions and Special Core Analysis (SCAL) from open-file petroleum reports. A new mineralogical database is included.

10. Digital Well Log Evaluation Database and Petrophysical Atlas: Wireline log evaluation of 20 wells over Taranaki and Canterbury Basins in New Zealand to develop a consistent methodology for determining basic petrophysical parameters that can be used to determine rock properties for assessment of reservoir and seal quality.

11. NZ Petroleum PVT Database: An Excel database of all open-file PVT (pressure-volume-temperature) data contained in New Zealand Petroleum & Minerals’ Petroleum Report archive. This provides data on 500+ petroleum fluid samples that can be used to model oil, gas and condensate volumes and compositions over the expected production history of a field, and can also be used in exploration to model whether a particular prospect is likely to contain oil or gas. The database is accompanied by a pdf compilation of openfile PVT reports to March 2011.

12. NZ Oils Geochemistry Database: An Excel database of biomarker, other hydrocarbon, and stable carbon isotope analytical data and derived parameters for 139 New Zealand oils and gas condensates, together with their assigned oil families and calibrated maturities. The sample set is mostly from Taranaki Basin, but also includes samples from the East Coast, Canterbury, Great South and several other basins. The database is accompanied by an interpretative report.

13. NZ Oil Shows Database: A new Excel database of biomarker, other hydrocarbon, and stable carbon isotope analytical data and derived parameters for 100 Taranaki oil show samples, together with their assigned oil families and calibrated maturities. The database is accompanied by an interpretative report.

14. NZ Petroleum Isotope Database: A new Excel database of compound-specific carbon and hydrogen isotope data for 113 New Zealand petroleum samples (oils, gas condensates and gases) and 66 source rock extracts (carbon data only). The data are for both normal alkanes (n-alkanes) and selected acyclic isoprenoids. The sample set is weighted towards Taranaki Basin, but petroleum and source rock samples from the East Coast, Canterbury, Great South and several other basins are also included. The database is accompanied by an interpretative report.

15. Existing Products: A suite of eight existing GNS Science data products have been made freely available to the industry to aid understanding of the petroleum geology of Taranaki region. These products have been incorporated into Petroleum Basin Explorer and can be accessed through the Science Outputs menu option:

  • Taranaki Basin Petroleum Atlas digitally remastered – regional compilation of the petroleum geology of the entire Taranaki basin.
  • Offshore Taranaki phase matched seismic database. Integrated dataset from offshore northern Taranaki
  • Reservoir quality in the Taranaki basin. A core based study of petrology and poroperm
  • Mudstone database in eastern margin Taranaki. A seal properties database of lithology along the eastern margin
  • Mangahewa project. Delineating geometrical reservoir distribution through the middle to late Eocene succession with the Taranaki Basin
  • Biostratigraphic review of offshore Taranaki. Review of the tie well biostratigraphy to complement seismic data for deepwater Taranaki.
  • Taranaki digital well summary sheets. A collection of standardised composite logs.
  • Cretaceous-Cenozoic geology and petroleum systems of the Taranaki basin. Interpretations of the geological origins and development of the Taranaki basin and resultant petroleum accumulations

To access all of these products please register for free access through Petroleum Basin Explorer (http://data.gns.cri.nz/pbe)

New Zealand Petroleum & Minerals Website

Press Release by Phil Heatley

Further New Zealand data products are available through GNS Science.