License Relinquishment Report
P.1920: Block 12/30
December 2013
12/30 Relinquishment Report
UK Seaward Production License P.1920, Block 12/30
License Summary:
Block 12/30 was a 26th Round Promote License awarded 100% to Echo Exploration Limited on
August 2nd 2012, effective from 1st February 2012. The initial term expires 31st January 2014. Echo
Exploration Limited (Echo) was purchased by North Sea Energy Inc. (NSE) in March 2011 and is a
fully owned subsidiary of NSE. On October 4th 2012 Premier Oil (UK) Limited exercised its option
right to require transfer of a 50% interest in UKCS Block12/30 pursuant to an April 28, 2010
agreement between Encore Oil and Echo Exploration Limited. Premier Oil completed the acquisition
of Encore on January 16, 2012. The granting of this option set up the joint venture to explore the
prospectivity of the block.
Co-venture:
Echo Exploration Limited 50%: License Administrator
Premier Oil (UK) Limited 50%: Partner
Work Commitment:
The Licensee shall obtain 150km of seismic data.
Commit to drill or drop a 1525m well by January 2014.
The Licensee purchased 157km of the DG972D2001 survey over the block and has
completed the firm work commitment.
Synopsis:
This report covers the initial two year period of the Promote license. Regional work,
preliminary prospect mapping and audited prospective resource assessments were carried
out by Senergy UK on behalf of, and supervised by, the License Administrator. This work
programme was performed in the period February-May 2012 using the newly acquired
seismic data and nearby wells.
Key: Purchased lines
Fig1: Seismic and Well database
December 2013
2
12/30 Relinquishment Report
A promising stratigraphic prospect (Badger) was identified in the Lower Cretaceous Coracle
(referred to as ‘Upper Punt’ unit in Senergy CPR) and (Lower) Punt Sandstone units. The
seismic data base was deemed to be too widely spaced to confirm a drilling location.
Fig 2 Stratigraphic Column
As a result of the preliminary prospect mapping the License Administrator was keen to
pursue a closely spaced hi-resolution dip line 2-D seismic programme to reduce risk and firm
up a drilling location. This was proposed and agreed in the co-venture. Monarch
Geophysical was engaged to facilitate the survey. Seismic acquisition and processing
contractors were chosen but two weeks prior to signing the acquisition and processing
contracts the Partner could not get AFE approval so the survey was cancelled and the
decision made to relinquish the block. With the seismic database available the chance of
failure was considered to be too high to commit to a firm well and the license was
determined at the end of the Promote period on January 31st 2014.
Echo Exploration Limited still firmly believes the Badger prospect has merit and would
welcome an opportunity to acquire and interpret a more rigorous seismic programme in the
future.
Exploration Activities:
Senergy Inc. was retained to review the regional context and interpret the prospectivity of the
block and produce an audited estimate for the resource potential of any newly interpreted
prospects. Their work was strongly grounded on the regional work used to underpin the
December 2013
3
12/30 Relinquishment Report
license application plus the 157 km of newly purchased seismic data which fulfilled the
required seismic obligation.
Prospectivity:
Introduction: Block 12/30 is located in the Inner Moray Firth at the eastern end of the West
Bank high straddling the Buckie Ridge. The block is located in 210 ft of water and a
prospective fairway was identified in early Cretaceous Coracle (the principle prospect
reservoir) and Punt sands. These sands are interpreted as channelized deepwater (Coracle)
and mass flow sheet (Punt) sands, which have a probable provenance from the north and
west. They are deposited in the South Halibut Basin / West Bank Graben where they are
partially controlled by the basin morphology and the plunging northern and eastern margins
of the West Bank High and the Buckie Ridge. Subsequent faulting has perched sections of
the sand fairway on structural highs with potential trapping configurations. The South Halibut
basinal area is also identified as the Kimmeridge Clay Formation oil source kitchen. The
newly interpreted prospect identified in this fairway was named ‘Badger’
Regional mapping at base Cretaceous level in Fig 3 depicts the main structural features
which set up the Badger prospect on the first fault block out of the southern boundary of the
West Bank Graben/South Halibut Basin. The prospect reservoirs are identified in well 12/301 which is just north of the prospect in a downthrown basinal setting.
Fig 3 Base Cretaceous Regional Structure map
West Bank Graben
12/30
-01
Buckie Ridge
12/30
Ross Boundary
Fault (down to
south)
South
Halibut
Basin
13/28
-04
13/26
b-03
13/28
b-08
Banff
Basin
13/28
-01
Badger Prospect
The Badger Prospect is a west-east oriented stratigraphic /structural trap at Coracle and
Punt Sandstone level. Structural dip closure is recognised to the east and downthrown fault
closure to the north. The principle Coracle reservoir relies on up-thrown fault closure against
the Buckie Ridge to the south and stratigraphic closure to the west where the Coracle
(Upper Punt) channel sands thin and appear to pinchout. A refined definition of the sand
pinchout, which was the major risk for the prospect, was not possible with the current
seismic coverage.
Closure: The Badger structure in the centre of the block lies 420 ft above the Coracle
section intersected by the 12/30-1 well. It dips down to the east by 500 ft across Block 12/30
December 2013
4
12/30 Relinquishment Report
giving dip closure. To the north it is bounded by an east to west downthrown fault that
bisects the Coracle channel. Smaller faults can be seen cutting the channel in 13/26. In the
south, the sand fairway appears to be limited by an up-thrown W-E fault that bounds the
main West Bank High. The channel system continues to the west and north such that the
channel margin forms the stratigraphic trapping limit just to the west of the block boundary.
The crest of the structure is at 3,400 ft tvdss and the hydrocarbon column is limited by the
WUT of -4,372fttvdss in 12/30-1 giving an area of ca. 6,500 acres in the Coracle Sandstone.
Reservoir: Lower Cretaceous sandstone has been encountered in four key wells: 12/30-1,
13/26b-3, 13/27-2 and 13/28-8 where significant net sand is present. Of these 12/30-1 and
13/28-8 have identified a Coracle aged channel sand system. In all cases the reservoir is of
high quality with porosities from 25% to 30% and the net Coracle sand in 12/30-1 is 78 feet.
The Punt sand is more widely spread and is 300 feet thick and more in these key wells.
Permeability in both reservoirs is typically hundreds of millidarcies to darcies.
Seal: The top seal for the Lower Cretaceous Sandstones are the thick mudstones of the
overlying Valhall Formation. Laterally, the Coracle and Punt turbidite sands are replaced by
claystones of equivalent age. The principle risk on Badger is the up dip seal which requires a
stratigraphic pinch out of the sand. It is interpreted that the Coracle channel sand flows
eastwards and southwards, crossing the main basin bounding fault into 12/30 and following
the axis of subsidence along the north side into 13/26 where an accumulative facies is
apparent on the seismic. The channel margin therefore forms the up dip seal to the west. Up
thrown fault seal is required to the south and there is some risk here of breach against late
Jurassic sands.
Hydrocarbon type, Source maturity and migration: The source rock is the Kimmeridge
Clay Formation that is mature on the south side of the Ross fault. Migration to the west is
focused upon the West Bank High through Late Jurassic Burns sands and the Punt system
itself. The expected hydrocarbon type is not certain; in the 13/26a-2 Dee discovery the Punt
contains gas that was tested at 22.3mmcfpd but there is oil in the Punt system at Hobby
Field further to the west. Because Badger is located on the northern side of the West Bank
High an oil case is proposed since dry gas in the Lower Cretaceous is not the norm in this
area.
Audited Resource Analysis:
Fig 4: Combined Coracle (Upper Punt) and (Lower) Punt Sandstone Oil resources
Maps and Representative Seismic:
December 2013
5
12/30 Relinquishment Report
Fig 5: Top Coracle (Upper Punt) Depth Map
(Coracle)
(Coracle)
Fig 6: Representative E-W Seismic Line across prospect
Clearance:
Echo Exploration confirm that DECC is free to publish information in this document and that
3rd party ownership rights have been considered and appropriately cleared for publication
purposes.
December 2013
6