DECC Relinquishment Report – April 2009

Licence Number: P1534 / Licence Round: 24th
Licence Type: Promote / Block Number: 47/6
Operator: GTO Limited – 50% / Partners: Venture North Sea Gas Exploration Ltd – 50%
Work Programme Summary:
The work programme for licence P1534 was as follows:
  • Obtain all existing 2D seismic in the blocks and reprocess if necessary and original field tapes are available
  • Interpret all data and update subsurface evaluation
  • Summarise prospectivity.

Licence Synopsis:
  • Licence P1534 was awarded to Wham Energy on 1st April 2007 as part of its 24th Round Application.
  • Wham Energy was purchased by Venture Production in October 2007.
  • Venture North Sea Gas Exploration Limited – transferred operatorship to GTO limited in November 2008.
The licence has been relinquished at the end of the initial two year period of the Promote Licence, effective 31st March 2009.
Exploration Activities:
GTO Limited on behalf the group carried out a full subsurface evaluation through 2008 using GeoMega Ltd – a company based in Budapest, Hungary. This study used all the available 2D seismic including that which had been reprocessed by Tullow Oil during the 23rd Promote Licence Round in 2004/5. The data base used for the study is shown in the map below.

The study was comprehensive G&G evaluation of the hydrocarbon potential in Block 47/6 and was supervised by GTO Limited and presented to partners in late 2008. The recommendation of the study was that new 3D seismic acquisition and processing will be required to firm up any drillable prospects. It concluded that the main target is the Rotliegendes Sandstone play, sealed by Zechstein salt and sourced with gas from the underlying Carboniferous. Three small leads were identified on the available 2D vintage seismic. The secondary potential of the Carboniferous, Bunter and Spilsby Sandstones were all reviewed but did not materialise into any leads on the existing data set.
This work is documented in electronic format and is available on request.
The group tried to seek in-coming partners to fund a 3D acquisition programme of 100 – 200km2, unfortunately no parties or funds were forthcoming and the block was recommended for relinquishment.
Prospectivity Analysis:
No drillable prospects are mapped in the block on current seismic data. The vintage 2D seismic data is of poor to moderate quality and density is sparse in places.
The following table summarises the plays evaluated leads identified and general risk assessment.
Target play / Play elements – Risk / Leads/Prospects
Reservoir / Source / Seal / Charge
Spilsby Sandstone / Mod / High / High / High / None
Bunter Sandstone / Low / High / High / High / None
Rotliegendes Sandstone / Low / Low / Good / Low / 3 leads
Intra Carboniferous Sandstone / Mod / Low / High / Low / None
From the evaluation three leads were identified at the Rotliegendes prime reservoir target interval. These leads are all poorly constrained with lack of 2D seismic data, and the quality of the data is generally poor. The leads are shown in the map below:

The three leads are summarised in the table below:
Lead / Play/Trap / Volumes
Unrisked GIIP / Comments/Risk
  1. Ararat
/
  • Rotliegendes sand, sealed by Zechstein salt, vertical gas charge from underlying Carboniferous coals/shales.
  • Tilted fault block in complex E-W trending regional fault trend.
/
  • P90 – 24bcf
  • P50 – 58bcf
  • P10 – 138bcf
/ This lead has been identified by all previous interpretations. However, it is high risk due to the poor seismic data quality. The potential gas volumes could be commercial due to the blocks proximity to infrastructure.
  1. Fuji
/
  • Rotliegendes sand, sealed by Zechstein salt, vertical gas charge from underlying Carboniferous coals/shales.
  • Tilted fault block/nose on regional fault trend. Limited throw on faults. No data to constrain the northern limit.
/
  • P90 – 101bcf
  • P50 – 120bcf
  • P10 – 139bcf
/ Very poorly constrained with data. Very high risk, but lies on trend to analogous fields.
Success should be commercial.
  1. Uluru
/
  • Rotliegendes sand, sealed by Zechstein salt, vertical gas charge from underlying Carboniferous coals/shales.
  • Tilted fault block/nose on regional fault trend. Limited throw on faults. Limited data to constrain bounding fault.
/
  • P90 – 234bcf
  • P50 – 275bcf
  • P10 – 322bcf
/ Very poorly constrained with data. Very high risk, but lies on trend to analogous fields.
Success would be commercial.
No leads or potential were mapped at any of the remaining identified plays – Intra-Carboniferous, Bunter and Spilsby Sandstone intervals. The identification of potential in these prospective horizons all suffer from the lack of seismic data and the poor quality of the existing data.
Block 47/6 has an attractive address in terms of proven play potential and proximity to infrastructure. However, its lack of current mapped potential and its proximity to the coastline, shallow water and cost to acquire new 3D seismic has resulted in an unsuccessful campaign to explore appropriately this acreage.
Reserves Summary:
No reserves are proven on this block.
Maps and Figures:
Location Map with Lead outlines

Ararat Lead: Time and Depth Structure maps with seismic sections.

Fuji Lead: Time and Depth Structure maps with seismic sections.

Uluru Lead: Time and Depth Structure maps with seismic sections.

Clearance:
GTO Limited and Venture North Sea Limited confirms that DECC is free to publish the above information and that all 3rd party ownership rights have been considered and appropriately cleared for publication purposes.