1 Relinquishment Report for Licence P1755 Estimates, statistics, opinions and forecasts contained in this document are based on TOTAL’s own information and knowledge. They are provided in good faith, but, by their nature, are based on a number of assumptions and are subjective. Readers should therefore carry out appropriate reviews and due diligence to satisfy themselves as to all information contained in this document including, without limitation, TOTAL’s opinions, prospect evaluations, reserve figures, production and cost forecasts and all technical aspects of production, transmission and other facilities. While this information was prepared in good faith, no representation or warranty, expressed or implied, is or will be made, and no responsibility or liability is or will be accepted by TOTAL or any of their respective affiliates or subsidiaries, employees, officers, directors and agents as to, or in relation to, the accuracy or completeness of this document and any liability thereof is hereby expressly disclaimed. In furnishing this Relinquishment Report to DECC, TOTAL undertakes no obligation to provide any Third party recipient with access to any additional information.
14
Embed
Relinquishment Report - Oil and Gas Authority Relinquishment Report for Licence P1755 Estimates, statistics, opinions and forecasts contained in this document are based on TOTAL’s
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
Relinquishment Report for
Licence P1755
Estimates, statistics, opinions and forecasts contained in this document are based on
TOTAL’s own information and knowledge. They are provided in good faith, but, by their nature,
are based on a number of assumptions and are subjective. Readers should therefore carry out
appropriate reviews and due diligence to satisfy themselves as to all information contained in
this document including, without limitation, TOTAL’s opinions, prospect evaluations, reserve
figures, production and cost forecasts and all technical aspects of production, transmission
and other facilities.
While this information was prepared in good faith, no representation or warranty, expressed or
implied, is or will be made, and no responsibility or liability is or will be accepted by TOTAL or
any of their respective affiliates or subsidiaries, employees, officers, directors and agents as
to, or in relation to, the accuracy or completeness of this document and any liability thereof is
hereby expressly disclaimed.
In furnishing this Relinquishment Report to DECC, TOTAL undertakes no obligation to provide
any Third party recipient with access to any additional information.
2
Contents 1. Licence Information ........................................................................................................................ 3
(Figure 2). N11 and the other Nuggets leads were identified as 4-way dip closures of
the Eocene Frigg turbiditic sands. The Ardincaple prospect was identified at Base
Cretaceous level as NNE-SSW trending dip closure of Upper Volgian sands.
Raemoir prospect was identified as consisting of Oxfordian sands in a large N-S
trending faulted anticline, with the N-S trending normal fault separating the prospect
into Raemoir East and Raemoir West. Sween prospect included the 4/26-1A
Oxfordian gas discovery, for which two possible geological models involving either
shallow or deep marine sands were proposed. The Skibo lead included the 3/30-2A
Callovian deep marine turbidite sands gas discovery. Lochindorb lead was based on
the concept of equivalents of Rhum sands being deposited east of the Rhum
Terrace.
Figure 2 P1755 Prospect Summary Map at the 26th Licence Round
5
This 26th Round Licence was awarded on 10th January 2011 as a Traditional
Seaward Production Licence (4 years). The commitments were:
To acquire 1036 km2 new PGS 3D spec. data,
To reprocess 490 km2 of anisotropic 3D PSDM (Kirchhoff and Beam),
To reprocess 100 km2 of PSTM for long offset 3D data, and
To drill a contingent well on N11 prospect.
The only commitment not fulfilled in the licence is drilling the contingent well on the
N11 prospect which lies within Block 3/25b. DECC agreed to waive the contingent
well element of the Firm Licence work programme due to the uneconomic potential
of the N11 prospect (unrisked Mean resource of 2.8Mboe).
TEPUK and Maersk relinquished the P1755 licence on January 13th 2014.
3. WORK PROGRAMME SUMMARY
The exact Work Programme agreed has been discussed in the licence synopsis
above.
4. DATABASE
TEPUK has full 3D seismic coverage across the P1755 licence. Figure 3 shows the
seismic and well database used in the P1755 licence.
In 2012, as a commitment for the P1755 license, the NVG05, NVG10 and NVG11
were reprocessed to Pre Stack Depth Migration (PSDM) using both Kirchhoff and
BEAM algorithms with the aim of improving the seismic imaging quality and the
structural interpretation (Figure 4):
The Beam PSDM main focus was to assist the structural interpretation and to
suppress maximum seismic artefact, such as multiples,
The Kirchhoff PSDM main objective was to provide an overall good seismic
image quality and at the same time better preserve the seismic amplitude
response and optimal vertical seismic resolution.
6
Figure 3 Seismic and well database for P1755 blocks
7
Figure 4 Seismic database comparison- PGS2012 Merged NVG11 data vs reprocessed Beam and Kirchhoff
PSDM data
0km 5km 5km0km 0km 5km
A A’ A A’ A A’PGS2012_NVG11_Merged
P1755PGS2012_NVG11_Merged
P1755_Beam PSDMPGS2012_NVG11_Merged
P1755_Kirchhoff PSDM
A
A’
8
The well results on the P1755 licence and on previous licences are summarised in
the Table 1.
Table 1 P1755 Well database
5. PROSPECTIVITY UPDATE
5.1 Nuggets 11 to 15 Prospect (26th Round Application)
The Nuggets prospects had been identified from their positive AVO response as gas
accumulation in simple four-way dip closures. Reservoir thickness and quality
parameters were adopted from nearby Nugget wells. Source and charging for the
existing Nuggets field was already proven. Expected hydrocarbon was dry gas, with
no CO2. Due to limitation of seismic resolution, top of the reservoir was difficult to
resolve, thus the net pay within the closure was the main uncertainty. High resolution
reprocessing of the PGS NVG05-06 survey and subsequent computation of a new
AVO cube was planned to de-risk the prospects.
Nuggets 11 to 15 Prospect (2013 Update)
Following the 26th Round, additional seismic data (PGS-NVG05 long offset 2005 &
2006, reprocessed 2007 and PSDM data) were available and used for the
interpretation of the N11 prospect. The most recent Kirchhoff data has been
analysed through the AVO sismofacies sequence and has confirmed the presence of
the anomaly identified previously (Figure 5). GRV was calculated using two
methodologies: AVO wedge and Gradient stack. To account for the uncertainties
associated with the GOC depth estimation and structural picking, three possible
GOC’s were considered, 1785 msec, 1790msec and 1795msec. These contacts
and petrophysical parameters from local wells and nearby Frigg gas accumulations
were used to calculate the In Place and Resources figures. The fluid properties were
based on data from the Nuggets Frigg sand gas fields in the area which are a direct
analogue. The recovery factors are based on data from the Nuggets development.
Well OperatorYear of
drillingStatus Comments
4/26-1A Ranger Oil 1985 Gas discovery, P&A Gas discovery in 7m Oxfordian sands3/30-2A BP 1978 Gas shows, P&A Good gas shows in Callovian sands, no logs/cores
3/25-1 Total 1971 Gas shows, P&A Well kick in Kimmeridgian sands
3/25a-3 Total 1976 Dry, P&ANo UJ reservoir, high trip and connection gas in
Kimmeridgian shales
3/25a-4 Sovereign Oil and Gas 1985 Gas shows, P&A High pressure gas encountered in Jurassic
3/25b-5 Elf 1995 Dry, P&ANon reservoir quality Volgian and Kimmeridgian,
minor shows
3/30-1 Ranger Oil 1975 Dry, P&A Dry well
3/30b-6 Elf 1998 Dry, P&A No UJ reservoir
3/30a-5 Ranger Oil 1987 Dry, P&A Water in Eocene Frigg sands
9
Figure 5 N11 Depth Structure and AVO maps
Resource and Risk Summary
Resources Mboe
Min Mode Max Mean POS
Risked Mean
Resources
N11 1.5 2.6 4.4 2.8 64% 1.8
The overall POS of N11 has been calculated at 64% with Mean Unrisked
Resources of 2.8 Mboe. The primary uncertainty is associated with the fluid contact
estimation, structural picking (trap geometry) and quality of reservoir. All other
Nuggets prospects identified at the time of application are smaller than N11, so no
further analysis has been performed on these.
5.2 Raemoir Prospect (26th Round Application)
Raemoir prospect was identified by mapping a strong seismic marker, thought to be
of Oxfordian age, defining a large N-S trending faulted anticline. The strong
amplitude Oxfordian marker was modelled as deep water turbidite sandstone
forming the main reservoir. Heather Shale and Brent Coals were considered as the
main source rocks. The main risk involved was the presence and quality of reservoir.
It was planned to undertake Beam Migration to improve data quality and use it
further for rock physics and fluid substitution studies to de-risk the prospect.
1
TWTci:20msec
AVO
3/25b-4
3/25b-4
0km 1km0km 1km 0km 1km
10
Raemoir Prospect (2013 Update)
Reinterpretation of the Raemoir prospect was carried out in the new reprocessed 3D
seismic. It indicated two possible scenarios, a 4-way dip closure with crest at
5990mSS and 14 km2 areal extent, and a 3-way dip closure against the main N-S
trending Raemoir fault with crest at 6050mSS (Figure 6). Both the scenarios
indicated critical risk in reservoir presence and quality due to depths > 6000mSS
where the prospects had been identified. Thus further detailed study has not been