Licence P1851
Relinquishment Report
Jan 2014
P1851 Relinquishment Report
Document last updated 21-01-2014 10:03 GMT
P1851 Relinquishment Report
1 Licence Data
1
2 Synopsis
3
3 Exploration Activities
5
4 Exploration Analysis
6
4.1 Play Elements
4.2 Prospectivity
4.2.1 Balblair Prospect
4.2.2 Dalwhinnie Lead
7
9
9
14
5 Conclusions
16
6 Clearance
17
List of figures
1.1
2.1
3.1
4.1
4.2
4.3
4.4
P1851 Summary Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Regional tectoinc map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Seismic Datbase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Base Basalt Depth Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Lava Escarpments - Seismic Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Seismic Line FSB99-214D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Geoseismic section through Balblair Prospect & Dalwhinnie lead. . . . . . . . . . . . . . . . 12
List of tables
1.1
4.1
4.2
4.3
4.4
4.5
Licence summary table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Risk & Resource summary table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Balblair Prospect Risk table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Balblair Prospect Resource table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Summary risk table for Dalwhinnie Lead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Dalwhinnie Lead volumetric parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1 Licence Data
Table 1.1
Table 1.1 Licence summary table.
Fig. 1.1
1 Licence Data
1
Fig. 1.1 P1851 Summary Map
1 Licence Data
2
2 Synopsis
Licence P1851 (blocks 223/26, 223/27, 219/2 & 219/3) was acquired in the 26th licence round, and
surrendered in November 2013 with the work programme being fully completed. The regional and
tectonic geology of the area is shown in Fig. 2.1 as well as the location of the P1851 licence The main
prospective focus, the "Balblair" prospect is a shallow 4-way dip structure at base basalt level, and
below a major basalt escarpment. The initial hope was that exploration success at Lagavulin to the
west (217/15-1Z) would have further opened up the sub-basalt play, with Balblair and the
neighbouring prospect, Ardbeg (P1852) holding valuable upside reserves. Unfortunately drilling
results at Lagavulin were not supportive, and along with other negative sub-basalt drilling results in
the Faroese sector (e.g. Brugden, Ann Marie and William) has now significantly downgraded this
deep, high risk play.
2 Synopsis
3
Fig. 2.1 Regional tectoinc map.. A map illustrating the structural framework of the Northern West of Shetland area,
including oceanic spreading centres, continental/ocean boundaries, continental crust with main sedimentary basins and
structural highs.
2 Synopsis
4
3 Exploration Activities
As part of the agreed firm work programme, Faroe Petroleum, and it partner E.ON E&P Ltd,
acquired 400km of long offset data, and licensed a further 200km of the same data from TGS Nopec.
The map in Fig. 3.1 shows the location of the 2D Seismic as depicted within the 26th round
application document.
X/Y:
Meters
480000
3°W
500000
520000
540000
2°W
560000
580000
1°W
600000
620000
640000
0°W
660000
N
680000
Faroe Non-Operated
7040000
7040000
Licenced Acreage
Acreage applied for
Study Area
7020000
7020000
Seismic Database
0
40 km
7000000
222
221
63°N
7000000
223
63°N
6980000
6980000
6960000
6960000
6940000
6940000
6920000
6920000
219/21-1
6900000
6880000
219
218
217
216
62°N
214/4-1
209/4-1A
219/28-1
214/9-1
2D Acquisition
208/15-1A
2D Acquisition /
Licence from Ardbeg
Application
208
214
6820000
480000
500000
3°W
520000
540000
6860000
209/9-1A
2D Licence
L
560000
2°W
209/6-1
209/12-1
208/15-2
L
580000
620000
210/13-1
6840000
LL
M
Seismic
210Database Map
209
600000
1°W
640000
6880000 62°N
210/4-1
209/3-1A
6860000
6840000
6900000
219/27-1 219/28-2Z
660000
0°W
680000
M
6820000
Fig. 3.1 Seismic Datbase
3 Exploration Activities
5
4 Exploration Analysis
4 Exploration Analysis
6
4.1 Play Elements
Source
The organic rich marine mudstones of the Late Jurassic Kimmeridge Clay formation are regarded as
the principal oil source rocks within the FSB region. In the area of interest, wells drilled have
encountered up to 295.5m of the Kimmeridge Clay formation. The more gas prone mudstones of the
Middle - Late Jurassic Heather formation (Bathonian and Oxfordian) locally underlie the Kimmeridge
Clay Formation in the FSB and have also been penetrated by wells. Proof that the Kimmeridge source
rock is widespread in the area of interest lies in the presence of a biomarker (28,30 Bisnorhopane) in a
wide range of relative concentrations in oils analysed from the Faroe - Shetland region. This
biomarker is known to occur only in the Kimmeridge Clay formation.
Burial history modelling of Late Jurassic source rocks indicate that most of the FSB area should be
either gas mature or at least post mature for oil. However, it is mostly oil that has been found so far. A
suitable explanation for this phenomenon could be that the rapid Palaeocene subsidence induced
over-pressure which inhibited further thermal maturation, causing subsequent oil generation from the
Jurassic source rocks.
Hydrocarbon Migration
Hydrocarbon migration has been predominantly vertical, the conduits being non sealing faults. Thus,
the producing oil/gas fields lay within the geographical boundary of the mature source rocks (DECC
2010). There is evidence of an active hydrocarbon migration system in the FSB. Gas accumulations in
the Eocene have been drilled into. Furthermore, the Middle to Late Miocene compression event
created an elongate ridge in the middle of the FSB which was a focus for migrating hydrocarbons. In
addition to this, many vertical disturbed zones (hydrothermal vents/gas escape conduits) have been
observed. These could very well be migration pathways from source rocks beneath the basalts.
Reservoir
Due to the lack of well control, there is a high amount of uncertainty regarding the presence and
extent of reservoirs. However, based on well penetrations elsewhere in the FSB there is potential for
reservoir development beneath the basalt cover;
Pre-rift strata: Middle Jurassic sandstones preserved on a fault terrace flanking the Rona ridge have
yielded oil and gas shows. Also, the Solan and Strathmore discoveries, southeast of the FSB contain
oil in Jurassic and Triassic reservoirs within the West of Shetland basin. the pre-rift prospects would
be effectively sealed by Upper Jurassic or Cretaceous mudstones. The Rona formation has been
proved within the Solan and West Shetland basins. They are Kimmeridgian to Tithonian in age (Late
Jurassic), resting on Lewisian basement, Middle Triassic and Lower Jurassic rocks. Core analysis
from well 205/22-1A indicates porosities less than 10% and permeability usually less than 10mD.
The Rona formation is overlain by the Kimmeridge Clay Formation which acts as an effective source
and seal. Devonian and even fractured basement rocks may provide additional reservoir targets.
Syn-rift strata: At least 12 wells have encountered oil/gas shows in Upper Jurassic or Lower
Cretaceous shallow marine sandstones in the FSB. Uneconomic gas discoveries in the basin have
Lower Cretaceous, syn-rift apron fan and basin floor sandstones as their reservoirs. Upper Cretaceous
mudstones exceeding 3800m in thickness provide excellent seals throughout most of the region.
4.1 Play Elements
7
Post-rift strata: Upper Cretaceous slope - apron sandstones (Cenomanian - Turonian) occur 327m
thick along the Eastern flank of the FSB, stacked against the Rona fault,with the possibility of
detached fan complexes down-dip. However, these sands thin westwards, where basalt thicknesses
are substantial.
Seal
The Upper Jurassic has proven thermally mature (source) and immature mudstones as effective seals.
The Cretaceous mudstones of the Shetland group also provide effective, laterally continuous seals. In
the Early Palaeocene, basinal mud, particularly regionally extensive Major Flooding Surfaces, are
believed to provide effective seals. (Ebdon et al. 1995) The extensive Palaeocene basalts in this region
also act as potential seals.
Traps
Structural, stratigraphic and combination traps have been found in the Faroe - Shetland Basin. The
rifting in the FSB during the Mesozoic which caused break up followed by post rift subsidence during
the Palaeocene resulted in basin floor bathymetric depressions above the hanging walls of Northeast Southwest trending extensional faults (Cartwright et al. 2004). Some Mesozoic accumulations are
therefore likely to be trapped structurally in rotated fault blocks, rollover anticlines, etc. The terminal
fans that filled these bathymetric depressions also have the potential to pinch out forming
stratigraphic traps as well. Compression during the Late Miocene caused contractional reactivation of
the Mesozoic extensional faults and folding of the overlying Palaeocene and Middle Miocene post rift
sediments into a series of Northeast - Southwest striking anticlinal domes. This switch from hanging
wall bathymetric depressions to anticlinal domes has led to present day effective traps. The anticlines
also acted as foci for gas migration. However, the time of compression and differential uplift may be a
negative factor by causing the hydrocarbon phase to spill during structural reorganization. The
hydrocarbon may have either escaped via seeps or migrated updip into shallower traps (Cartwright et
al. 2004).
4.1 Play Elements
8
4.2 Prospectivity
Table 4.1
Table 4.1 Risk & Resource summary table
4.2.1 Balblair Prospect
Description
The Balblair prospect is a 4-way dip closed structure at base basalt level. Mapping of of the top basalt
event is straightforward, however the base basalt event is more subjective. What it does clearly show
hoever is the presence of two lava escarpments which cross the acreage and the structural closures of
Balblair and Dalwhinnie are located directly beneath these escarpments (Fig. 4.1). The basalt layer
can be seen to become thinner over Balblair by onlap, suggesting that Balblair formed a structural
high prior to deposition of the basalt in the Early Eocene. The overlying escarpment (labelled
Escarpment 2) is observed on a parallel section (FSB2000-101) to have internal clinoform character
and to be related only to the youngest lava flow Fig. 4.2.
The Balblair structure is illustrated by seismic line FSB99-214D Fig. 4.3 and the geoseimic section
shown (Fig. 4.4). The primary reservoirs are assumed to be Palaeocene or Mesozoic in age, sitting
beneath the basalt closure.
4.2 Prospectivity
9
1ºW
0º48’W
0º36’W
0º24’W
0º12’W
0º
0º12’E
0º24’E
0º36’E
63º20’N
N
0º48’E
4D
21
9B9
FS
Acreage applied for
0
40 km
2
10
000
B2
FS
-2500
Balblair
63º10’N
63º10’N
Escarpment 2
-6500
63ºN
63ºN
223
222
Dalwhinnie
219
218
62º50’N
62º50’N
Escarpment 1
62º40’N
62º40’N
Base Basalt Depth Structure (m)
1ºW
0º48’W
0º36’W
0º24’W
0º12’W
0º
0º12’E
0º24’E
0º36’E
0º48’E
Fig. 4.1 Base Basalt Depth Structure.. Outline showing Balblair prospect & Dalwhinnie Lead.
4.2.1 Balblair Prospect
10
Fig. 4.2 Lava Escarpments - Seismic Detail. Illustrating the internal clinoform character of the lava escarpments.
Data from TGS.
4.2.1 Balblair Prospect
11
Fig. 4.3 Seismic Line FSB99-214D. This line illustrates the Balblair and Dalwhinnie structures. Data from TGS.
223/21
TWT NW
(ms)
223/26
223/27
223/28
219/3
SE
Blocks Applied For
1500
1500
2000
2000
e
Mid Pleistocen
Sea Bed
Escarpment 1
Escarpment 2
2500
2500
Mid Miocene
3000
3500
3000
Top Basalt
4000
3500
Basalt
Base
4000
4500
4500
5000
5000
5500
5500
Balblair Sub Basalt High
Dalwhinnie Sub Basalt High
6000
6000
0
6500
20 km
6500
Fig. 4.4 Geoseismic section through Balblair Prospect & Dalwhinnie lead.
Risking
Table 4.2
4.2.1 Balblair Prospect
12
Table 4.2 Balblair Prospect Risk table.
Resources
Table 4.3
Table 4.3 Balblair Prospect Resource table.
4.2.1 Balblair Prospect
13
4.2.2 Dalwhinnie Lead
Description
The Dalwhinnie Lead is a structural closure at the Base Basalt in the two way time domain but after
depth conversion it is much less secure (Fig. 4.1). This uncertainty is compounded by the lack of
seismic coverage in this area. The structure is tentatively mapped with the crest at 3000m and up to
250m of vertical relief. The overlying basalt section varies from 1000m to less than 200m in thickness
across the structure associated with the lava escarpment (Fig. 4.2).
The seismic (Fig. 4.3) and geoseismic (Fig. 4.4) sections illustrate the Dalwhinne lead.
Risking
Table 4.4
Table 4.4 Summary risk table for Dalwhinnie Lead.
Resources
Table 4.5
4.2.2 Dalwhinnie Lead
14
Table 4.5 Dalwhinnie Lead volumetric parameters.. The percentage of on block reserves refers to the blocks directly
applied for within this application.
4.2.2 Dalwhinnie Lead
15
5 Conclusions
The 2D seismic acquisition, whilst helping to provide more control on the mapping of the Balblair &
Dalwhinnie feature was not able to significantly de-risk the prospectivity. Major uncertainty still
exists with the identification of the base basalt seismic marker, and the interpretation of the
underlying Palaeocene and Mesozoic structures and with it the identification of potential reservoir
packages. The sub-basalt play has now been the target of a number of exploration wells such as
William (6005/13-1) and Brugden (6104/21-1), and more recently Ann Marie (6004/8a-1), Lagavulin
(217/15-1Z), and the Brugden re-drill (6104/21-2). The common theme from these results is that the
basaltic sequence (basalt and associated hyaloclastites etc) are far thicker than first anticipated, and
that any potential reservoirs are too deep to have a viable preserved porosity and for that reason, the
sub-basalt play is now effectively dead.
5 Conclusions
16
6 Clearance
Faroe Petroleum, as operator of License P1852 has approved this relinquishment report for
publication by the DECC. Permission to show the seismic lines contained within this report has also
been obtained from TGS.
6 Clearance
17