relinquishment report licence p2016 block 205/4c · database is shown in figure 2. figure 2 p2016...
TRANSCRIPT
Relinquishment Report
Licence P2016
Block 205/4c
September 2016
JX Nippon Exploration and Production (U.K.) Limited
Idemitsu Petroleum UK Ltd.
Table of Contents
1. Licence Information ............................................................................................................................ 1
2. Licence Synopsis .................................................................................................................................. 2
3. Work Programme ................................................................................................................................ 3
3.1 Drill or Drop Well .......................................................................................................................... 3
3.2 Inversion and Rockphysics Modelling Study ................................................................................. 3
3.4 Core Study ..................................................................................................................................... 3
3.5 Fault Seal Analysis Study ............................................................................................................... 3
3.6 Bandwidth Extension Processing .................................................................................................. 4
4. Database ............................................................................................................................................. 4
5. Prospectivity........................................................................................................................................ 4
5.1 Source Rock ................................................................................................................................... 5
5.2 Migration ....................................................................................................................................... 5
5.3 Reservoir ....................................................................................................................................... 6
5.4 Trap ............................................................................................................................................... 7
5.5 Seal ................................................................................................................................................ 7
6. Additional Technical Work .................................................................................................................. 8
7. Resource and Risk Summary ............................................................................................................... 8
8. Conclusions ......................................................................................................................................... 8
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1. Licence Information Licence Number: P2016
Licence Round: 27th Round
Licence Type: Traditional seaward production licence
Licence award: 1st January 2013
Block Number: 205/4c
Operator: JX Nippon Exploration and Production (U.K.) Limited (55%)
Partner: Idemitsu Petroleum UK Ltd. (45%)
Block coordinates: 60° 54’00.000’’N 3°18’00.000’’W 60° 54’00.000’’N 3°15’30.000’’W 60° 52’00.000’’N 3°15’30.000’’W 60° 52’00.000’’N 3°12’00.000’’W 60° 50’00.000’’N 3°12’00.000’’W 60° 50’00.000’’N 3°18’00.000’’W 60° 54’00.000’’N 3°18’00.000’’W
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Figure 1 P2016 (Block 205/4c) license location map
2. Licence Synopsis Licence P2016 is located 90 km northwest of the Shetland Islands in water depths of c.a. 675m. The
block is adjacent to the Total operated Tormore field and lies to the SW of JX Nippon’s operated
P1850 and P2024 licences. The P2016 licence was awarded to JX Nippon and Idemitsu on the 1st
January 2013 as a Traditional Licence and expires on 31st December 2016.
The evaluation of the P2016 licence at the time of application identified two Vaila Formation aged
prospects in the T35 sequence. The prospects are stratigraphically trapped and identified on the
basis of seismic amplitude anomalies with moderate-good structural conformance.
The licensees have elected not to drill a well on the licence and not to continue the Licence into the
second term.
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3. Work Programme The licence commitments consist of the following work programme,
Full Bandwidth Pre-stack AVO Inversion of 200 km2 of the 2009 Laggan 3D survey, including
Baysian Lithology and Fluid Prediction utilising the Seismic Inversion Attributes.
1 drill or drop well, to be drilled to a depth of 4000 m, or 50 m below the base of the T35.3
sandstone, whichever is the shallower.
In addition to completing the firm work programme, the licensees carried out the following
studies:
Biostratigraphic and sedimentological studies on offset wells to constrain reservoir
stratigraphy, facies models and predictive reservoir quality models for the T35 sequence in
the vicinity of Block 205/4c.
Rock physics modelling to calibrate seismic attributes from the Laggan 3D seismic data to
well control and derive predictive models for reservoir quality and fluid content.
1D fault seal study of the main prospect and bandwidth extension seismic processing (BE®)
on a subset of the 3D data to de-risk the trap element of the petroleum system.
3.1 Drill or Drop Well
The licensees have elected not to drill a well on the licence acreage and to relinquish the licence.
3.2 Inversion and Rockphysics Modelling Study
The licensees purchased the PGS MegSurveyPlus data which includes the reprocessed 2009 Laggan
3D survey. These data were used for Pre-stack AVO inversion. An area of 225km2 was inverted and
includes the entire licence area and the adjacent Tormore field. The 205/5a-1, 205/9-1 and 205/9-2
wells were used for calibration and rock physics modelling.
3.4 Core Study
A core study on well 205/9-1 focused on understanding the sedimentological and paragenetic
aspects of both the Kettla Tuff Member and Vaila Sandstone. A full core and petrographic
description was undertaken and integrated into the regional depositional model.
3.5 Fault Seal Analysis Study
1D fault seal analysis was carried out using a pseudo log located adjacent to the southern trap
defining fault and was evaluated using Shale Gouge Ratio triangle diagrams.
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3.6 Bandwidth Extension Processing
Bandwidth extension processing was applied to the full stack seismic data, using 225 km2 of PGS
MegaSurveyPlus data.
4. Database The Laggan 3D seismic volume was acquired by Total in 2009. The reprocessed MegaSurveyPlus
data by PGS contains this volume and was used for seismic interpretation, pre-stack AVO inversion
and bandwidth extension processing. The 205/5a-1, 205/9-1 and 205/9-2 wells were used for well
correlation, core study, sequence stratigraphy, biostratigraphy and petrophysics analysis. The
database is shown in Figure 2.
Figure 2 P2016 (Block 205/4c) license location and database map
5. Prospectivity Two T35 aged sandstone prospects were identified in the licence application — Upper Barr and
Lower Barr. The work programme confirmed the validity of both prospects and an additional deeper
prospect (Deep Barr) was identified. The Lower Barr prospect contributed most of the resource in
the licence area. Figure 3 is a full stack amplitude map extracted over the Lower Barr horizon
(T35.4A).
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Figure 3 Full stack amplitude map with depth structure contours seismic amplitude map of the T35.4 A horizon defining the Lower Barr prospect
5.1 Source Rock
The most significant and widespread source rock within the Flett sub-basin is believed to be the
Kimmeridge Clay Formation (KCF), which typically has moderate-high TOC and consists
predominantly of type II/III marine kerogen. HC generation is modelled as beginning in the Late
Cretaceous with main gas generation in the early Tertiary. The presence of oil beneath the gas leg in
the Tormore field requires either “motel” models or an evaporative fractionation process.
5.2 Migration
In the Laggan and Tormore fields, it is the licensees view that significant discontinuities along
intrusive sills beneath the reservoir horizons provide favourable migration paths from source to
reservoir. The proximity of the Barr prospects to the Tormore and Laggan Fields, together with their
location updip of a significant fault linking an underlying igneous sill with the target horizons, de-risk
the charging component of the petroleum system.
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5.3 Reservoir
The 205/9-1 well encountered a thick T35.4 sandstone* consisting of a 370m thick sequence of basin
floor fan sandstones with good reservoir quality. Based on seismic well tie, three distinct sand
packages have been identified — the A, B and C sands (Figure 4). On the basis of seismic
interpretation, there is high confidence in correlating sand packages between the prospects and the
205/9-1 and 205/5a-1 wells (Figure 5).
Figure 4 Petrophysical analysis of well 205/9-1 CPI and CCA – T35.3 and T35.4 section
* The sandstone dominated sequence sitting immediately below the Kettla Tuff Member, corresponding to the upper part
of the Vaila Formation (V4 unit), is defined by JX Nippon as a new T35.4 sequence, whose base is bounded by the T35.3
sequence boundary.
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Figure 5 Seismic section between 205/9-1, the Lower Barr prospect and 205/5a-1 Data: MegaSurveyPlus data courtesy of PGS MultiClient
5.4 Trap
The quality of seismic data is good and depth conversion uncertainty was considered small due to
close well control. All the prospects are stratigraphic traps relying on sand pinchout to the east
(confirmed by the absence of T35.4 sands in the Tormore field). The quality of the seismic data
confirms that the fault defining the southern boundary of the prospects has sufficient throw to allow
separation of the prospects from the water wet 205/9-1 well.
5.5 Seal
The T35 basin floor fan sandstones, which form the primary reservoir objective in the Flett Sub-basin,
are overlain by a regionally extensive highstand system mudstone sequence (T35.4 mudstone or V4
Upper Vaila Fm. mudstone) which forms an effective regional pressure seal separating normally
pressured Lamba Formation from over-pressured Vaila sandstones below.
Base seal is provided by intraformational mudstones within the individual fan sequences.
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6. Additional Technical Work In addition to the petroleum system evaluation, the licensees have undertaken rock physics studies
using inversion attributes, core study, fault seal analysis study and bandwidth extension processing
(BE®).
As a result of these studies, the charge risk has been reduced and there is greater confidence in fault
and trap definition.
7. Resource and Risk Summary Based on the prospect evaluation, resources and risk are summarized as below (Table 1 and 2).
ON LICENCE (P2016) Total Rec. Resource
MMboe
ENTIRE PROSPECT Total Rec. Resource
MMboe
P90 P50 P10 Pmean P90 P50 P10 Pmean
Upper Barr 0.6 2.3 6.2 2.9 0.8 3.5 9.4 4.5
Lower Barr 8 26 73 34 12 42 106 52
Deep Barr 4 11 23 12 4 12 28 15
Table 1 Summary table of prospect reserves evaluated using a gas case scenario
Trap Seal Reservoir Source Migration GPOS Key risk
Upper Barr 0.63 0.56 0.81 1 0.85 0.24 Seal
Lower Barr 0.81 0.56 0.81 1 0.85 0.31 Seal
Deep Barr 0.52 0.56 0.81 1 0.85 0.20 Trap
Table 2 Risking Table
8. Conclusions The work programme has assessed the Upper and Lower Barr prospects identified in the 27th Round
Application and identified a further prospect (Deep Barr), with the bulk of the resource in the lower
Barr prospect.
Both reserves and GPOS have been downgraded compared to the pre-award evaluation. As a result,
with current economic assumptions, the prospects are considered commercially unattractive. The
licensees have therefore decided to relinquish the P2016 licence.