faroe islands-licence 005 · 2019. 8. 5. · the 23rd july 2010 and reached the commitment td of...

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ECMS Doc No: 318905

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Faroe Islands-Licence 005

Well 6004/8a-1 Results and

Remaining Prospectivity Date: 11 October 2011

ENIUK_n318905_v1_Faroe-Lic_005_Remaining_Licence_Prospectivity.doc

This document is CONFIDENTIAL and it is the property of Eni Denmark B.V.

It shall not be shown to third parties nor shall be used for reasons different from which it is issued.

1



Remaining Prospectivity

Final Evaluation

Rev Date Description Originator Reviewed Checked Approved

0 Sept. 2011 First Issue EA/GB/SB/MR/PM EA/GB EA

1 Oct. 2011 Final Issue EA/GB/SB/MR/PM EA/GB EA MS

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DISTRIBUTION:

Copy No. Name Department Company

Paper Copies

1 E. Antonielli EXP Eni Denmark B.V.

1 Anne Stewart Library Eni U.K.

1 Carlo Zollino Archivio SEBU-ARMA Eni S.p.A. E & P Division

2 Heri Ziska Geology Jardfeingi (Faroe Directorate)

Electronic Copies

1 ECMS 318905 ENI Denmark B.V.

2 Heri Ziska Geology Jardfeingi (Faroe Directorate)

Original Archive Document Control ENI Denmark B.V.

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CONTENT:

1. EXECUTIVE SUMMARY ........................................................................................4

2. GEOLOGICAL SUMMARY ....................................................................................7

2.1 Geological Setting and prognosis .......................................................................7

2.2 Well Objectives.......................................................................................................8

2.3 Target Definition ....................................................................................................8

2.4 TD Criteria ...............................................................................................................8

2.5 Summary of the well results ...............................................................................9

3. POST DRILLING SEISMIC INTERPRETATION ..........................................15

3.1 Seismic Data Volume ..........................................................................................15

3.2 Stratigraphic and sequences calibration .........................................................20

3.3 Anne-Marie structure regional interpretation ................................................23

4. LICENCE 005 RESIDUAL POTENTIAL ..........................................................27

4.1 T50/T45 (post-Basalt) section ..........................................................................27

4.2 The T45/T36 section ...........................................................................................29

4.3 The T35 and older section .................................................................................31

4.4 Final conclusions ..................................................................................................34

5. ANNEX 1: REPORTS DELIVERED TO JARDFEINGI AND JV PARTNERS ........35

5.1 ENI IN HOUSE REPORTS:.................................................................................................35

5.2 OUTSOURCED CONTRACTORS REPORTS: ....................................................................35

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1. EXECUTIVE SUMMARY

The Licence 005 is located in the Faroese sector of the Faroe-Shetland Basin and it

has been operated by Eni Denmark B.V. with a 25% interest, along with the co-

venturers Dana Petroleum (25%), OMV (20%), Cieco E&P (12.5%), Faroe Petroleum

(12.5%) and First Oil Expro (5%).

The Anne-Marie Prospect was drilled by the 6004/8a-1 vertical exploration well,

located in 1106m of Water Depth, about 100 nautical miles from the nearest marine

base (Runavik).

The original targets were the clastic terms of the Palaeocene, T50/T45, T40/T38,

T36/T31 (and additionally T10 and Mesozoic) in a low relief, four-way, structural closure.

The drilling programme included coring and a comprehensive wire-line formation

evaluation programme.

The Seadrill West Phoenix deepwater semi-submersible rig spudded the well on

the 23rd July 2010 and reached the commitment TD of 3941m MDRT (-3901m TVDSS, as

per the licence obligations) on 23rd October 2010.

Upon completion of the logging program the 6004/8a-1 well was safely plugged

and abandoned: the West Phoenix Rig was then released from contract at 00:15 hrs of

11th November 2010.

Three significant gas shows intervals were crossed in the Palaeocene Sequence,

from 2854.5m to 2965m (Flett Volcanic Series), from 3392m to 3440m (Lamba 1) and,

finally, from 3734m to virtually TD (Lamba 2, Kettla Tuff Member and Vaila Volcanic).

A considerable amount of high quality data have been acquired in Anne Marie

well; however, due to the peculiar “unconventional” geological setting, their

interpretation was not straightforward and it took a significant amount of time to be

completed. A reconstruction of the geological setting by means of calibrated regional

seismic interpretation and multidisciplinary analysis, matching all independent

observations (GWD, core, log, MDTs,), finally produced a satisfactory integrated

interpretation.

The analysis highlighted the absence, or minimal quality, of any effective

reservoir in the gas shows intervals. Even with an optimistic approach, the Anne Marie

well data clearly demonstrate the absence of any accumulation of potentially commercial

size: a GOIP of 177Gft3 is estimated.

No remaining Prospectivity worth of consideration is recognised within Licence

005. No further technical work could be carried out, that could significantly change the

above perceptions.

Remark: For detailed description of the Drilling and Subsurface Operations, please refer to the ANNE-MARIE

6004/8a-1 EXPLORATION WELL END OF WELL DRILLING REPORT (issued April 2011) and the FINAL WELL GEOLOGICAL

REPORT (issued October 2011)

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Fig. 1: Location Map

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Licence 005 Jv : Eni Denmark Bv Oprt. 25%

DANA 25%

OMV 20%

CIECO 12.5%

Faroe Petroleum 12.5%

First Oil Expro 5%

GEOG. SYSTEM/GRID:

Spheroid WGS84, Datum ETRF89 / UTM Zone 30, CM 3° West

SURFACE LOCATION LAT/LONG : 60° 49' 14.667" North 04° 33' 55.327" West

SURFACE LOCATION UTM : 6 743 836.40m North 414 864.60m East

BOTTOM HOLE LOC. LAT/LONG :60° 49' 13.934" North 04° 33' 52.947" West

BOTTOM HOLE UTM :6 743 812.87m North 414 900.01m East

DISPLACEMENT AT TD : 51.95m

WATER DEPTH : 1106.35m

RIG/TYPE : West Phoenix / Deepwater Semi submersible

REFERENCE DATUM (RTE) : 38.65m

PERMANENT DATUM : Mean Sea level

RIG ON CONTRACT : 12/07/2010

SPUD DATE : 23/07/2010

DATE WELL AT FINAL TD : 23/10/2010

RIG OFF CONTRACT : 11/11/2010

TOTAL DAYS : 118

TOTAL DEPTH (DRILLERS): 3941m MD 3902.35m TVDSS

TOTAL DEPTH (LOGGERS): 3943m MD 3904.35m TVDSS

BHF :Vaila Eq., Palaeocene - T35

RESULT :GAS (three intervals w/ shows)

Reservoir :Tuffs, weathered volcanic, silty-sst

GOIP estimated : combined mean 177Gft3

STATUS : P&A

Final classification : Gas discovery

CONTRACTORS:

DRILLING: Seadrill

DRILLING FLUIDS: Baker Hughes

MWD/LWD: Pathfinder

WIRELINE LOGGING: Schlumberger

MUDLOGGING: Geoservices

CORING: Halliburton

BIOSTRATIGRAPHY: Ichron

Fig. 2: Well 6004/8a-1 (Anne-Marie) basic data summary

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2. GEOLOGICAL SUMMARY

2.1 Geological Setting and prognosis

Licence 005 is located in the lightly explored Faroese sector of the Faroe-Shetland

Basin and covers an east-west trending splay off the Westray-Corona Ridge that

separates the Faroe sub-basin to the north from the Judd sub-basin to the south.

The licence lies within the larger area covered by a thick extrusive Palaeogene

basalt sheet that extends over much of the Faroese sector of the basin.

The presence of this Basalt cover is the major controlling factor for assessing the

Prospectivity of the Basin, as it impacts the seismic data quality at the extent of limiting

the reliability of the interpretation and mapping of all the key elements of the Petroleum

System.

Within the Licence 005, the Anne-Marie Prospect, a structural trap with four-way

dip closure located over an old Mesozoic high, was recognised as valid target for an

exploration well after a lengthy process of seismic reprocessing, interpretation and basin

modelling,.

The Well 6004/8a-1 was therefore aimed at two primary and up to four secondary

reservoir targets, as originally identified:

The primary targets comprised:

Early Eocene T50-T45 fluvial and shallow marine sandstones (the reservoir for

the 204/10-1 Cambo oil discovery to the east of the licence).

Late Palaeocene T36-T31 deep marine sandstones (the reservoir for several large

oil discoveries in the Judd sub-basin to the south of the licence).

Secondary targets comprised:

Sandstones in the late Palaeocene T40 and T38 sections,

The early Palaeocene T10 section

The Mesozoic section

Seal was assumed to be provided by the regionally extensive early Eocene and late

Palaeocene shales or tuffs.

Two main source rock intervals were supposed capable of providing a hydrocarbon

charge to the Anne-Marie prospect: oil-prone lacustrine shales of the middle Jurassic

section and oil-prone marine shales in the late Jurassic section (the Kimmeridge Clay

Formation equivalent).

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2.2 Well Objectives

The original well objectives were as follows:

□ Drill a vertical exploration well on the defined target of the Anne-Marie

Prospect and to the licence commitment depth of -3900m TVDSS, or 50m into

the Mesozoic, whichever recorded first.

□ Drill the Primary target reservoirs (T50/T45 and T36/T31 levels) and the

secondary target reservoirs (T40/T38, T10 and possibly, Mesozoic) in a

complete / un-faulted section and in a structurally valid position in order to

test the hydrocarbon column.

□ Acquire representative bottom-hole core sample.

□ Obtain sufficient information on the hydrocarbon bearing reservoirs

encountered in order to evaluate the commercial potential of the discovery,

i.e. estimations of hydrocarbons in place volumes, potential reserves and well

productivity. Therefore the following requirements were essential:

□ Obtain representative core in hydrocarbon bearing sections.

□ Acquire a full set of Petrophysical logs through the reservoir in order to assess

reservoir characterisation.

□ Obtain down-hole pressure measurements and temperatures.

□ Establish fluid contacts, if any.

□ Acquire fluid samples (gas, oil, water) in order to obtain fluid properties (API,

composition, dew point).

□ Perform a rig sourced VSP survey in order to establish a seismic to well tie.

All of the objectives given above would have been pursued within Eni Denmark

B.V. commitment to safe operations with minimal impact on the environment and cost-

effective drilling operations.

2.3 Target Definition

The proposed surface well location was defined as 60°49’14.51’’N and

004°33’56.17’’W (Datum ETRF89, Spheroid GRS 1980), 6,743,832.1m Northing and

414,851.7m Easting (Zone 30N; Central Meridian 3° W), with a 150m circle radius at

each of the target levels from the surface location.

2.4 TD Criteria

The licence commitment well TD of -3900m TVDSS was of reference.

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However, should have occurred a scenario of oil shows recorded down to -3900m

TVDSS, there was a contingency to deepen the well to a maximum TD at -4500m

TVDSS.

2.5 Summary of the well results

A tailored set of studies were started during the drilling of the well and concluded

through the 3rd quarter of 2011 to clarify the Petrophysical, Mineralogical and

structural/stratigraphic characteristics of the drilled sequence.

A seismic interpretation on semi-regional scale was carried out and the estimate of

the possible range of Gas In Place was also completed.

The analysis of the Anne-Marie well data was performed with a truly integrated

approach by a multidisciplinary team, composed of Professionals of Eni Denmark, Eni

Head Quarters and Contractors.

Such an approach allowed to obtain a satisfactory interpretation of the vast

amount of data acquired and to achieve a “fit for purpose” evaluation of Anne Marie.

While detailed and specific analyses and inference of the data are contained in the

dedicated reports, the fundamental conclusions are here summarised.

The major outcomes of the well were finally presented and fully discussed at the

30th March 2011 Workshop held at Eni Denmark Office in London and presented to

Jardfeingi on a dedicated Meeting held in Torshavn on the 12th April 2011.

The Operator reported the essential elements and results as follows:

√ A very substantial Geological, Geophysical and Drilling dataset was

positively acquired, satisfying the work obligations:

o LWD: Gamma Ray, Resistivity, Sonic, Density and Neutron:

DIR / GR (36"/42 hole)

DIR / GR / RES (26“ hole)

DIR / GR / RES / SONIC / PWD (17 ½” hole)

DIR / GR / RES / DENS / POR / SONIC / PWD

DIR / GR / RES / SONIC / PWD

o WIRE LINE: FMI: both in 12 1/4”and 81.2” holes

o SWC: Recovered 21 out of 23 (12 ¼” hole)

Recovered 20 out of 20 (8 ½” hole)

o CORE: one 11m (recovered 98%) at 3412mMD

o MDT:

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22 pre-tests, 10 good, 7 tight, 5 lost seals.1 fluid sample.(12 ¼”

hole)

11 pre-tests, 1 good attempt, 3 tight, 7 lost seals. (8 ½” hole)

√ A working Petroleum System with the presence of a charged trap has been

proved

√ Well 6004/8a-1 result departed from prognosis as lithology and HC type.

√ The Well drilled a valid 4 way closure for all the original targets: o The T50 shallow target has good reservoir characteristics, but was clearly

water bearing

o The Section of T45 to T36 age (Flett and Lamba equivalent) is made up by

three distinct, unconformity-bounded, sequences of Basalt, Volcanic and

Tuffs deposited along a volcanic dominated ridge

o The T35 age (Vaila Fm) shows the onset of clastic input in a distally sourced

and/or shallow intra-basinal ridge, affected by volcanic sill intrusion.

√ 5 main lithofacies associations have been recognised using core data,

conventional logs and formation image logs: o Basalts, basaltic lava flows, sub-volcanic dolerite sills and dykes

o Coarse-grained volcaniclastic, reworked/altered basalts, breccias,

conglomerates, Hyaloclastite and minor tuffs

o Stratified tuffs, stratified and laminated tuffs

o Structure less tuffs, homogeneous, amalgamated tuffs

o Mixed deposits, lithic-arenites and volcaniclastic-siliciclastic alternations

√ The Gas shows recorded as “Flett 1”, “Lamba 1” and “Lamba 2” intervals,

proved the presence of an active charge, but: o Gas is not related to viable reservoir facies and the net pay is negligible, as

per the CPI-Petrophysical Study conclusions

o Pay sensitivity has been run using 25% porosity cut-off (0.1 mD

permeability cut-off as conventional gas reservoir) and 30% porosity cut-off

(0.3 mD) considering MDT results

o Best case pay: 5m of net pay thickness with 27% of porosity.

o Worst case pay: thickness lower than 1m

o Intervals with high porosity values are related to micro-porosities

o Fractures contribution is difficult to be estimated

o MDT were attempted in correspondence to all major Gas Shows interval

which resulted in negligible, if any, permeability

o GOIP, Gas Original in Place volume is very modest.

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Fig. 3 Well 6004/8a-1 (Anne-Marie) Prognosis Vs. Actual

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Anne-Marie GWD

2800

2900

3000

3100

3200

3300

3400

3500

3600

3700

3800

3900

4000

0 25 50 75 100 125 150 175 20 0 225 250 275 300 325 350 375 40 0

(C1+C2 )/(C3+C4+C5)

DE

PT

H m

/RT

2800

2900

3000

3100

3200

3300

3400

3500

3600

3700

3800

3900

4000

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20

(C3+C4+C5)/(C1 +C2+C4)

C12 sur C345

C345 sur C124

C ut offs:C 1 < 5000 ppmT G/Sum C cor < 0.7T G/Sum C cor > 1.7N C1*CD PC < 10R OP < 2 m /h

Flett 1

Lamba 1

Lamba 2

Vaila

Gas While Drilling – Gas ratios (after cut offs)Anne-Marie GWD

2800

2900

3000

3100

3200

3300

3400

3500

3600

3700

3800

3900

4000

0 25 50 75 100 125 150 175 20 0 225 250 275 300 325 350 375 40 0

(C1+C2 )/(C3+C4+C5)

DE

PT

H m

/RT

2800

2900

3000

3100

3200

3300

3400

3500

3600

3700

3800

3900

4000

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20

(C3+C4+C5)/(C1 +C2+C4)

C12 sur C345

C345 sur C124

C ut offs:C 1 < 5000 ppmT G/Sum C cor < 0.7T G/Sum C cor > 1.7N C1*CD PC < 10R OP < 2 m /h

Flett 1

Lamba 1

Lamba 2

Vaila

Gas While Drilling – Gas ratios (after cut offs)

Fig. 4 Well 6004/8a-1 (Anne-Marie) Gas while Drilling

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Faroe, Lic. 005: Wel l 6004/8a-1 (Anne-Marie): Petrophysical Evaluation & Stratigraphy

FlettFlett 11

LambaLamba 11

LambaLamba 22

Fig. 5 Well 6004/8a-1 (Anne-Marie) Gas Shows Intervals

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Flett 1Gas Show Interval

Lamba 1Gas Show Interval


No pay

Flett 1Gas Show Interval



No pay

Fig. 6: Well 6004/8a-1 (Anne-Marie) Gas shows on key seismic line

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3. POST DRILLING SEISMIC INTERPRETATION

An extensive Data Base of reference wells and seismic was used for the revised

interpretation, which framed the understanding of the Anne-Marie structure in a regional

context.

Cambo-1Cambo-1

RosebankRosebank

LindisfarneLindisfarne

SvinoySvinoy

Marjun204/16-1

Marjun204/16-1

204/19-1204/19-1

VágarAirport

LonganLongan

MarimasMarimas

BrugdanBrugdan

WilliamWilliam Cambo-1Cambo-1

RosebankRosebank

LindisfarneLindisfarne

SvinoySvinoy

Marjun204/16-1

Marjun204/16-1

204/19-1204/19-1

VágarAirport

LonganLongan

MarimasMarimas

BrugdanBrugdan

WilliamWilliam

Fig

. 7: Anne-Marie and the reference offset well data base

3.1 Seismic Data Volume

The post drilling interpretation was carried out over the dedicated 3D CRS

reprocessed seismic volume (in excess of 1100 km2) and by balancing the surrounding

seismic 3D volumes to achieve an acceptable homogeneity of polarity, amplitude

frequency content, and reflectors geometry.

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SeisWorks Project l5a10crs2877 sq kmCRSv3 20101103 sq km

SeisWorks Project l5a10crs2877 sq kmCRSv3 20101103 sq km

Fig. 8: SeisWorks Project l5a10crs incorporating CRS v3 2010

Several prominent seismic markers were selected and identified by means of the

calibrated sonic log and the twt/depth pairs derived from the well seismic VSP

acquisition.

A synthetic seismogram was generated to achieve a reliable match of seismic

markers with the major acoustic boundaries and tops in the well.

Top Balder and Top of the Flett Basalt were the key anchor points.

It must be noted that while the original VSP calibration was performed with as

Zero Phase Seismic (North Sea) Polarity, for the final interpretation, the 3D CRS Volume

of reference was displayed as Zero Phase, Lithological Polarity, i.e. an Increase of

Acoustic Impedance in the logs corresponds to a Peak on the seismic trace.

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Key Horizons (not all shown):

Top Stronsay Shale

Top Balder

Top Lower Hildasay Sst

Top Flett Basalt

Flett 1 Gas Interval

Lamba 1 Gas Interval

Lamba 2 Gas

Top Vaila

Fig. 9: Post-drilling seismic interpretation, selected seismic markers

2800

3200

2800

3200

Fig. 10: Post-drilling seismic interpretation, well seismic calibration

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Fig. 11: Seabed Time Depth Pairs at Control Wells

Fig. 12: Seabed to Top Stronsay Shale Time Depth Pairs

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Fig. 13: Top Stronsay Shale to Lower Hildasay Sst TWT/ Depth Pairs

S NS N

Top Flett 1 Gas Shows, unedited twtTop Flett 1 Gas Shows, unedited twt

Base T38

Hyaloclastic Hyaloclastic ““deltadelta””

Sills, Dykes & faultingSills, Dykes & faulting

T38 DLS

Flett 1

T50/T45 Fluvio-Marine Reservoirs

Flett Upper Lavas

Fig. 14: Anne-Marie, Seismic Calibration (S/N transect)

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Fig. 15: Anne-Marie, Seismic Calibration Detail (SW/NE transect)

3.2 Stratigraphic and sequences calibration

The ages of the picked horizons were benchmarked by means of the Ichron Ltd.

stratigraphic framework and their significance in the palaeogeography domain has been

further studied in the bio-stratigraphic and sequence stratigraphic context (* see also

Eni Spa “Integrated Geological Study”).

The post drilling seismic interpretation was aimed at producing reliable maps to

compute the Volumetric and to estimate Gas Original In Place of the Annemarie trap.

The identification of possible remaining prospects and the revision of the basis for

the petroleum system elements were also major scope of work.

A very important element for the interpretation was an attempt to properly frame

the occurrence of the volcanic sequence for identifying the relationship and the nature of

the transition to the sedimentary series crossed by the offset well in the Palaeocene

Flett/Lamba/Vaila formations.

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AnneAnne--Marie, Marie, Eni 2010 Eni 2010

NESE NESE

SvinoySvinoy,,BP, 2001 BP, 2001

MarimasMarimas,,Eni, 2003 Eni, 2003

MarjunMarjun, , Hess, 2001Hess, 2001

OIL in T10OIL in T10 DRYDRY DRYDRY GAS in T40, T38, 35 Eq.GAS in T40, T38, 35 Eq. Fig. 16: Un-interpreted South to North key regional transect

Major sequence boundaries have been recognised as bounding major stratigraphic

sequences, which were matched against both the well to seismic tie of their respective

sequences and the lateral expression of the seismic geometries and facies packages.

Several seismic resolvable packages have been identified in the Early Tertiary

succession (Late Palaeocene /Early Eocene) of the Faroe-Shetland Basin.

These packages have been tied to the key wells: 6004/8a-1 Anne-Marie, 6004/12-

1 Svinoy, 204/13-1 Tornado and 204/14-1 Suilven, 6005/15-1 Longan, 6004/17-1

Marimas, 6004/12-1 Svinoy, 6004/8a-1 Anne-Marie and 204/10-1 Cambo.

The regional seismic data were of sufficient quality for propagating away from the

said wells the basic lithological and stratigraphic element and pick the major

unconformities and sequence boundaries.

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Anne-Marie, Eni 2010

Svinoy,BP, 2001

Marimas,Eni, 2003

Fig. 17: Calibrated Regional Transect Marimas/Svinoy/Anne-Marie

The seismic interpretation and the integrated geological study pointed out that the

unconformities recorded in Anne Marie mark major changes in basin configuration and

are likely associated with uplift and erosion.

Two major unconformities have been recognized on the basis of well facies and

stratigraphy.

The first important stratigraphic surface, from bottom upwards, in the lower part of

Early Thanetian (base of the T36 sequence), represents the base of the Lamba

Formation (L1) Lower Faroe Lavas Mb., that unconformably overlies siliciclastic

sediments of the Vaila Formation.

The second high-rank stratigraphic surface represents the base of the Flett

Formation (Upper Faroe Lavas Mb.) that unconformably overlies the Upper Lamba (L2)

Tuff Member.

Furthermore, a prominent downlap surface is recognised at the base of the Lamba

Tuffs, just around where the core 1 was cut (“Lamba 1 Gas shows” interval

associated).

All those surfaces have been established on seismic data and FMI, as well as

prominent changes in Sonic Log trend and expression.

Allowing for the limited seismic resolution at depth and as consequence of the

Basalt energy adsorption, the seismic facies for each of the Unconformity bounded

sequences stand up quite evident in the CRS reprocessed data volume.

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3.3 Anne-Marie structure regional interpretation

Anne-Marie structure is interpreted as a prominent apron remaining for most of

the Palaeocene as a partly submerged palaeo high, which in turn, had separated two

segments of the Faroe-Shetland Basin, to the West of the Corona Ridge.

The stratigraphy and the structural analysis point out to the presence of a

persistent volcanic depositional corridor which graded by interfingering and prograded

over the coeval, truly sedimentary, deep water beds for the most of the Palaeocene

(T35 to T45 age).

Fig. 18: Anne-Marie to Suilven Transect, main sequences boundaries.

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Fig. 19: Anne-Marie to Longan Transect, main sequences boundaries.

The geometrical relationship of the volcanic dominated deposits and the

sedimentary ones have been investigated in the hope that some large stratigraphic

traps could have been identified within the Licence 005.

Unfortunately, it became rather evident that the Licence area is mostly occupied

by the volcanic apron drilled at the 6004/8a-1 location and there is no room for the

presence of any sizeable closure involving quality reservoirs.

The interfingering of volcanic and sediments does not bear but a vague expression

on amplitude and it is further controlled by a pattern of faulting, along the major

NW/SE and NE/SW conjugate strikes. However, there are clear evidences of seismic of

clino-stratifications and downlap surfaces, which have also interpreted with the good

quality FMI data.

Hyaloclastic clinoforms link the Anne-Marie palaeo-high, basalt lava dominated

plateau to the more basinal sedimentary facies, for good part of the T36/T38 time

intervals.

The overall T38/T40 sequence, is capped by the extensive final flow of the massive

Flett Formation Basalt, which is finally overlain by the important regressive episode of

the earliest Eocene.

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A remarkable number of dykes and sills, crossing the primary reflections at

variable angle, have been detected and proved in the borehole.

In particular, within the “Vaila” a couple of dolerite sills were clearly identified on

both FMI and seismic and they appear in correspondence of a fault. This type of

occurrence and geometry are very much similar to the outcrop examples of both the

Faroe Islands and Greenland.

On top of the obvious reference to the studies available for the Faroe Islands, an

established analogue case for the evolution of the Volcanic and volcaniclastic

sequences was used as reference: the Kangerlussuaq Basin of Eastern Greenland.

The Streymoy sill, Satan Mt. Streymoy, after Passey 2008

Climbing Sills along Climbing Sills along FaultsFaultsClimbing Sills along Climbing Sills along FaultsFaults

Fig. 20: Faroese Outcrop and seismic: volcanic dykes & sills expression

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Fig. 21: Anne-Marie Relationships between volcanogenic ridges and adjacent

depocentres

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4. LICENCE 005 RESIDUAL POTENTIAL

The significant gas shows recorded in the Anne-Marie well demonstrate the

occurrence of an active Petroleum System within the Licence 005 area.

However, the Flett Basalt appears as having behaved as a regional seal,

preventing, on this side of the Basin, any further migration of hydrocarbons from the

supposed deeply seated source into the high quality reservoir of T50/T45 Age (Balder,

“Cambo” and Hildasay sandstones).

The lack of hydrocarbon charge above the Flett Basalt and the lack of effective

reservoir below are substantially condemning the potential for sizeable discoveries within

the Licence area.

The key seismic horizons have been mapped and checked for possible closures,

without any positive feed back: within the Licence, there is no sizeable closure of any

type, a part from the one drilled by the Anne-Marie well.

All these concepts notwithstanding, an analysis of the remaining Prospectivity in

Licence 005 has been carried out for three crucial intervals:

□ The T50-T45 (post-Basalt) section.

□ The T45-T36 section.

□ The T35 and older section.

4.1 T50/T45 (post-Basalt) section

Fair to good reservoir section was logged in the T50 “Cambo Sandstone” and

Hildasay Sandstone units: average net/gross around 40% and porosity often largely

above 20%.

These shallowing upward fluvio-marine (deltaic and lagoonal) sandstones are likely

to be developed across much of the Licence 005 area, but, the mapped horizons at T50

level to T45 shows a general plunging nose to the SE, where only a small structural

closure has been identified (namely, Erestor), to the west of the larger Anne-Marie one.

Furthermore, there is no evidence for significant hydrocarbon migration up into the

post-Basalt section.

It could be argued that at the depth of the T50/T45 Reservoirs, given the petro-

acoustic character and considering the seismic data quality, the occurrence of

Hydrocarbons should have generated recognisable Direct Hydrocarbon Indicators (DHIs)

or, at least, some hints of those.

Instead, even the CRS seismic Volume does not shows any evidence: amplitude

maps are displaying with sufficient detail, the palaeo-morphology of the post-Basalt

sedimentary succession, but no evidence for Oil or Gas charge can be interpreted.

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6004/8a-1

Erestor

Fig. 22: T45 Top Lower Hildasay Sandstone Depth Map (m)

6004/8a6004/8a--11

ErestorErestor

Fig. 23: T45 Top Lower Hildasay Sandstone Hard Amplitude Map

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4.2 The T45/T36 section

The Anne-Marie well encountered a much thicker volcanic/volcaniclastic section

than expected that also spanned a wider than expected age range (T45 to T36).

Such a thick T45/T36 volcanic/volcaniclastic sequence (some 1125m) is developed

over much of Licence 005, and no effective reservoir was identified within it, as direct

consequence of its volcanic dominated nature.

Evidences for this section, derived from the core facies study, support the

deposition in a submarine (at the base) to sub-aerial (at the top) environment.

Reservoir potential of the volcanic/volcaniclastic is very poor, also as consequence

of an unstable volcanic mineralogy and extensive diagenesis.

Even the cored Hyaloclastite units with high porosity (30%) have very low to

negligible permeability (<1mD).

The nature of the depositional setting and the very low net-to-gross of potential

reservoir units mean that there is a significant risk that any productive intervals are

restricted laterally and locally isolated, making for low recovery factors.

6004/8a-1

Fig. 24: T45 Top Gas Shows Interval Flett 1, Depth Map (m)

Even though no reservoir potential exists in the volcanic and volcaniclastic units

encountered at Anne-Marie, there could be potential in laterally equivalent siliciclastic

systems in Licence 005.

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If T45/T36 siliciclastic sandstones occur, then they will be located along the

southern boundary of the licence 005, given the accepted hypothesis clastic input from

the South and South East.

However, little potential is seen on the flank of the Anne-Marie apron, for

hypothetic T45/T36 reservoirs which are only likely to occur along the southern

boundary of Licence, where they would have still received a significant input of volcanic

material, and where no lateral structural or stratigraphic closures have been identified to

create any potential trap.

Flett Upper Lavas

Volcanic Apron

Fig. 25: Anne-Marie Flett Key S/N arbitrary line

The revised seismic interpretation and mapping for the Licence 005 area only

shows some potential for modest dip closures at the Flett 1 level (over and west of

Erestor), where, unfortunately, it is only plausible to expect the presence of massive

volcanic products and volcaniclastic tuffs, as consequence of moving toward the

emission centres.

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4.3 The T35 and older section

The Anne-Marie well, before reaching TD, penetrated some 170m of T35 Vaila Fm,

where 6 SWC and two MDTs (both tight) were taken.

This Vaila sequence is made up by very fine grained turbidites and deep marine

shale with laminae of silt and very fine sand and has been intruded by basalt dykes and

sills. The absence of coarse clastics (which were encountered at Svinoy to the south) in

the logged lithology and the seismic regional interpretation are suggestive of a distal

setting or a position in a sheltered and persisting palaeo-high running through the

Licence 005.

No primary reservoir potential has been identified in this Vaila section, while the

overlaying Gas Show Interval (referred as Lamba 2) appears to be linked to a fault zone

intruded by a dolerite dyke.

Fig. 26: Anne-Marie CPI and Lithofacies of T35 Vaila Formation

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The potential of the siliciclastic Vaila and older section in Licence 005 is considered

very poor.

Little potential is also foreseen for effective Vaila sandstones deeper in the section

because, even if those are well developed, the burial depth is likely to result in poor

reservoir quality.

Moreover, Vaila Fm at depth is extremely tectonised, compartmentalised and

intruded by sills and dykes, as clearly shown on seismic by both vertical and time slices.

No credible map of solid reservoir is possible, nor is it easy to envisage a

sufficiently thick reservoir with high net to gross ratio.

All this taken into account, the chances of making a significant discovery are

extremely low, while the risk of drilling through an unpredictable lithology are

considerable high.

Fig. 27: Anne-Marie Near Top Vaila T35/Base Lamba T36, TWT

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Time Slice 3660msecTime Slice 3660msecTime Slice 3660msecTime Slice 3660msec

Fault associated Sills

Fig. 28: Anne-Marie W/E Seismic Transect, details at Total Depth

6004/8a-1

Note: strong W/E and NW/SE fault lineaments, multiple round saucer shaped sills/dykes

Time Slice 3660msec @ TD

Fig. 29: Anne-Marie, Vaila Fm. time slice at Total Depth

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4.4 Final conclusions

The drilling of the Anne-Marie prospect by the 6004/8a-1 exploration well has

fundamentally exhausted the possibility of finding, within the Licence 005, a sizeable

hydrocarbon accumulation which could be deemed of commercial value.

The charge of hydrocarbon is consisting of Gas with few traces of heavier

components, which could be only interpreted as the remaining of a migration pathway

from a still undetermined source rock, likely through a network of faults, being the fetch

area of Anne-Marie rather limited and the occurrence of efficient carriers hard to

visualise.

The Anne-Marie closure is not charged at the Post-Basalt level and it does not

contain any quality reservoir from the Top Basalt (actually, an effective seal) down to

the finely grained, fault and sills compartmentalised, Vaila Formation drilled at Total

Depth.

As for the deeper section, below the Total Depth, the seismic data are strongly

suggestive of a heavily faulted sequence, intruded by sills and dykes, possibly made up

by distally sourced fine sediment interspersed with the early volcanic material: effective

porosity and lateral continuity are therefore extremely unlike.

The Anne-Marie closure virtually coincides with the areal extension of the Licence,

with the modest exception of the Erestor nose, where, again, it is unlikely to predict the

development of reservoir facies and the relief of the structure are at best minimal.

Eni Demark through the presented data and interpretations had reached the

conclusion that no further studies or activities are worth to be carried out over the

Licence 005 and the Licence is to relinquished at the 31st October expiry date.

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5. ANNEX 1: REPORTS DELIVERED TO JARDFEINGI AND JV PARTNERS

5.1 ENI IN HOUSE REPORTS:

END OF WELL DRILLING REPORT ENI DENMARK DCW

VSP Well Seismic Data processing ENI HQ-GEPO

Geochemical Characterisation of Head space gases and gas shows

ENI HQ-GEBA

INTEGRATED GEOLOGICAL STUDY

Petrophysical follow up and Formation evaluation FMI/STRATIGRAPHY

ENI HQ-GICA-SPES

Water and pressurized sample characterisation ENI HQ-LAIP-LAAP-GEBA

Final Well Composite ENI DENMARK

Final Well report ENI DENMARK

5.2 OUTSOURCED CONTRACTORS REPORTS:

ROUTINE CORE ANALYSIS and PETROGRAPHIC STUDY KIRK PETROPHYISICS

BIOSTRATIGRAPHIC ANALYSES ICHRON Ltd

Wire Line Logging Set SCHLUMBERGER

Log While Drilling Set PATHFINDER

MUDLOGGING GEOSERVICES

faroe islands-licence 005 · 2019. 8. 5. · the 23rd july 2010 and reached the commitment td of...

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