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> Forside > Arkiv > GHEXIS > GHEXIS Newsletter No. 14

Ghexis newsletter No.14 - December 1998

 
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Newsletter No. 14 - December 1998
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Headlines:

1: New exploration opportunities - West Greenland
2: New petroleum exploration strategy for Greenland soon to be released
3: Well-defined play types for future exploration in the Nuussuaq region
4: Nuussuaq information package - an extension now available
5: GRO#3 well information package now available
6: Previous exploration and Survey activities in the Nuussuaq region
7: Exploration activities summer 1998
8: A new promising prospect with DHIs west of Disko


New exploration opportunities - West Greenland

The Nuussuaq region in West Greenland offers new exploration opportunities after grønArctic energy inc. had to relinquish their licence onshore Nuussuaq earlier this year. A recently released quantitative log-interpretation of the GRO#3 exploration well on Nuussuaq suggests the presence of several untested sandstone units with fairly high hydrocarbon saturations.

To ensure that interested companies will have sufficient time to evaluate the exploration potential of the Nuussuaq region, the Greenlandic and Danish Governments have decided to modify the open door policy for these onshore areas. Thus, all applications for licences in the region received before 1 October 1999 will be handled simultaneously after that date. A draft model licence will be available early in 1999.

This issue of Ghexis contains a more detailed description of possible play types in the Nuussuaq region. All relevant exploration data from the region have been collected into two data packages by GEUS. These packages are described in more detail on the following pages. A brief outline of the exploration history and studies by GEUS is also given.

Last summer, offshore West Greenland saw increased exploration activity. More details on these activities are given below. During the last year, GEUS has been able to delineate a promising prospect west of the island of Disko, where an extensive region with bright spots and AVO anomalies occurs. A summary is given at the end of this issue of Ghexis.

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New petroleum exploration strategy for Greenland soon to be released

On the political side, the transfer of the Mineral Resources Administration to the Greenlandic Government is now in effect and all administrative matters concerning mineral resources in Greenland are dealt with by the Bureau of Minerals and Petroleum (BMP) in Nuuk. In order to stimulate petroleum exploration activities around Greenland, it has recently been decided jointly by the Greenlandic and Danish Governments to develop a new exploration strategy (see press release of 1 October 1998 on BMP's web-site: www.bmp.gl/news).

Thus, a working group has been set up which consists of members from the Bureau of Minerals and Petroleum (BMP), the Danish Energy Agency (DEA), the Geological Survey of Denmark and Greenland (GEUS) and the National Environmental Research Institute (NERI). Contacts have been made to various companies for them to contribute their views on how exploration of the various regions on- and offshore Greenland could best be promoted in the coming years.

A decision will be made as to whether the open door policy in the region south of 70°30'N in West Greenland should continue or whether a more formal scheme of licensing rounds will be initiated. The working group is due to report in early 1999. Until this happens, the open door policy that has applied to most areas offshore West Greenland has been suspended.

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Well-defined play types for future exploration in the Nuussuaq region

Recent developments show that the Nuussuaq region is not just an interesting area for analogue studies to evaluate offshore data. It is now an area with well-documented hydrocarbon exploration possibilities in its own right. The major break-through came in the early 90s with the discovery of widespread oil seepage followed by geophysical documen-tation that the depth to basement is much greater than previously realised. A marine seismic survey in Vaigat - the sound between Disko and Nuussuaq - and in Uummannaq Fjord north of Nuussuaq has demonstrated the presence of large rotated fault blocks. Field work and studies of cores and well logs have demonstrated widespread and thick sandstone reservoir units containing hydrocarbons.

Well-defined play types for future exploration in the Nuussuaq region. Click to enlarge

There is still limited knowledge about source rocks, especially of their thickness and generative potential, as only few intervals have been penetrated during drilling. However, GEUS analyses of seeping oils have revealed the existence of two regional source rocks: a Paleocene deltaic to marine source rock, and a marine source rock of presumed Cenomanian-Turonian age. Three additional source rocks with a more limited areal extent have also been recognised from the geochemical fingerprints of the oils in the seeps (see Ghexis Newsletter 12, October 1997).

At least two play types have been demonstrated

One of the most promising targets on western Nuussuaq, northern Disko and in the nearby offshore areas are Paleocene sandstone reservoirs deposited in incised valley systems that are up to 200 m deep and several kilometres wide. The sandstones are of fluvial-eustarine-marine origin and have Paleocene marine shales as lateral and top seals. Source rocks could be either Paleocene deltaic or marine shales or Upper Cretaceous marine shales. Traps are a combination of stratigraphic traps and structural traps controlled by large rotated fault blocks.

Recent reinterpretation of the petrophysical log data by GEUS may have confirmed the presence of this play type in the GRO#3 well. Several sandstone intervals in the uppermost part of the drilled section show good porosity and fairly high hydrocarbon saturations.

A second, more widespread play type consists of marine channel sandstones as potential reservoirs with lateral and top seals consisting of Upper Cretaceous marine shales. Source rocks are anticipated to be of Upper Cretaceous age and traps are expected to be structurally controlled within rotated fault blocks. This play has good possibilities for stacked sandstone reservoirs.

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Nuussuaq information package - an extension now available

Since the early 90s, numerous papers and reports on the geology, palynology, sedimentology and organic geochemistry of the Disko-Nuussuaq-Svartenhuk Halvø region have been published both in GEUS publications and in international journals. To help the industry in gathering these data, many of these reports and papers have been compiled in a 5-volume information package which was issued by GEUS in April 1997 (see Ghexis no. 11, April 1997). An extension of this information package is now ready for release.

The extension consists of 3 volumes including 22 of the latest papers dealing with the geology and prospectivity of the on- and offshore basins in the Nuussuaq region together with GEUS reports on palynology, organic geochemistry and lithological and petrophysical evaluation of the GRO#3 well.

All eight volumes are sold by GEUS at a price of DKK 10,000 incl. postage. For a full list of contents please contact GEUS (e-mail: ghexis@geus.dk). The extension package will be sent free of charge to existing purchasers of the original information package.

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GRO#3 well information package now available

Data and results from the grønArctic GRO#3 well have also been compiled and are ready for distribution in a well information package. The package comprises reports concerning the drilling and testing results together with transparency and digital copies of wireline logs. The package can be purchased from the Geological Information and Datacentre at GEUS for a price of DKK 25,000. Group escalations are available if the package is bought simultaneously by the group members. Digital wireline logs are available in Landmark Stratworks format for DKK 3,500.

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Previous exploration and Survey activities in the Nuussuaq region

grønArctic made substantial exploration efforts from 1994 to 1998

The Canadian based company grønArctic energy inc. (later to change its name to grønArctic resources inc.) undertook a search for hydrocarbons in the Nuussuaq area from the autumn of 1994 until they gave up their licence in the spring of 1998 due to problems of financing a planned seismic survey. The company invested more than US $ 10 million in exploration during this period.

In 1994, an 800 m deep slim-core hole (GANW#1) was drilled under a non-exclusive pro-specting licence. In May 1995, an exclusive licence was granted to explore for and exploit hydrocarbons on western Nuussuaq. Drilling of 3 further slim-core holes was the main work programme for the first year. The three holes, GANK#1 and GANE#1 on central Nuussuaq and GANT#1 on northern Nuussuaq, reached depths of 400-900 m. They gave promising results as both intervals with gas under pressure and oil-impregnated intervals were encountered in the Paleocene volcanics and the underlying sediments of Late Cretaceous-Paleocene age.

In early 1996, grønArctic completed an airborne geophysical survey and in August of the same year the first conventional oil exploration well onshore Greenland, GRO#3, was spudded. The well reached TD at 2996 m after penetrating 312 m of volcanics at the top and a number of underlying sandy and shaly successions. A full suite of petrophysical wireline logs and a VSP were acquired. Eight zones in the lower part of the well were tested, but the drill stem tests showed tight intervals. All data and reports from the well are now released and available from GEUS as a well data package (see previous page).

GEUS and other public studies provide the basis for future exploration

Since the beginning of the 90s, the Survey and its collaboration partners have carried out a substantial amount of research in the area. Initially, the work focused on sedimentological, stratigraphical and geochemical studies of outcrops in order to predict reservoir and source rocks in neighbouring offshore basins. However, discoveries of extensive oil seepage including five different oil types have shown that the Nuussuaq basin not only has an exploration potential in its own right but also that the gas-prone reputation of the West Greenland shelf region had to be revised.

Two stratigraphic slim-core wells have been drilled in the region, one on Nuussuaq (Marraat-1) in 1993 and one on Svartenhuk Halvø (Umiivik-1) in 1995. In 1994 two short, combined reflection and refraction seismic lines were acquired onshore southern Nuussuaq and Svartenhuk Halvø. On the Nuussuaq line, a surprisingly thick sedimentary succession (up to 8 km) was recognised in a rotated fault block. This structural style was confirmed by more regional marine seismic lines acquired in 1995 in the fiords around Nuussuaq. A comprehen-sive study of the region's structural geology is 'in press' in Marine and Petroleum Geology.

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Exploration activities summer 1998

Fylla site survey and new seismic spec data acquired off West Greenland

The offshore areas of West Greenland have seen increased exploration activities during the summer of 1998. Apart from work carried out under the two offshore licences presently active, two spec surveys have also been acquired this summer by the Fugro-Geoteam/Danpec group and by Nunaoil, respectively. Furthermore, a project on a non-exclusive basis involving reprocessing of older seismic data has been initiated by the Fugro-Geoteam/Danpec group.

The Statoil group continued their work in the Fylla licence area by acquiring a site survey in two areas in preparation for their first exploration well planned to be drilled in 1999. A total of 442 km shallow seismic data and 64 drop cores (0.8 to 3.0 metres long) were obtained. Statoil used the Fugro-Geoteam vessel 'Geo-Scanner' for this purpose.

After completion of the site survey, the Fugro-Geoteam/Danpec group acquired 3126 km multichannel seismic data on a speculative basis just north and south of the Fylla licence area using the 'Geo-Scanner' with ties to the 1977 Nukik-1 and Nukik-2 wells (N-1 and N-2, see map).

Exploration activities summer 1998. Click to enlarge

Nunaoil A/S continued their acquisition of non-exclusive seismic data off West Greenland, mainly east and north of the Sisimiut-West licence area with a tie to the 1977 Hellefisk-1 well (H-1, see map). A total of 1610 km data were acquired.

The Phillips group initiated their work on their newly signed Sisimiut-West licence by acquiring a few seismic lines using Nunaoils 'Thetis'.

GEUS continued field work in the Disko-Nuussuaq region. The work concentrated on sedimentological and stratigraphic studies of the Cretaceous-Paleocene sedimentary succession and on structural studies of the overlying volcanic rocks. New oil seeps were discovered on the west coast of Disko which substantially enlarged the area where oil seeps are found in the region.

Contact adresses:

Fugro-Geoteam AS

Danpec A/S

Nunaoil A/S

Att.: Jan Lutro / Zyg Sarnowski

Att.: Jens Chr. Olsen

Att.: Lars Beksgaard 

Hoffsjef Løvenskiolds vei 31 c

Veras Allé 7

Pilestræde 52, 3

P.O. Box 50 Røa

N-0701 Oslo

DK-2720 Vanløse

DK-1112 Copenhagen K

Norway

Denmark

Denmark

Tel: +47 22 13 46 00

Tel: +45 38 74 59 50

Tel: +45 33 32 29 32 

Fax: +47 22 13 46 46

Fax: +45 38 74 94 89

Fax: +45 33 32 31 65 

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A new promising prospect with DHIs west of Disko

A promising prospect about 50 km to the west of the island of Disko has recently been identified by GEUS. Strongly reflecting horizons ('bright spots') can be seen on four seismic lines acquired by GEUS in 1995. The bright spots occur above a horst block that is closed at top basalt level. The structure dips from east to west and closes at about 1500 metres depth. The shallowest part of the structure is at around 1000 metres depth and is covered by 800-1300 metres of sediment. Water depths are approximately 200 m.

The bright spots are visible at top basalt level and also at a horizon occurring about 200 metres above the basalts. They extend approximately 55 km in the north-south direction and from 7 to 23 km in the east-west direction, an area of approximately 1000 square kilometres that coincides approximately with the structural closure mapped at top basalt level. AVO (Amplitude Versus Offset) studies on two of the seismic lines show that the bright spots exhibit strong AVO anomalies. These features together form Direct Hydrocarbon Indicators (DHIs) that could show the presence of large quantities of hydro-carbons.

A new promising prospect with DHIs west of Disko. Click to enlarge

On Disko and on Nuussuaq to the northeast, oil staining and seepage is common in outcropping Paleocene basalts especially close to or within regional fracture zones. The oil was generated from source rocks within the thick Cretaceous-Paleocene sedimentary succession underlying the basalts. It is therefore entirely possible that oil generated offshore could have migrated through the basalts and been trapped in reservoirs in the overlying sediments.

A short review of this prospect will soon appear in the forthcoming 'Review of Greenland Activities 1997'. Further information on the prospect may be obtained by contacting GEUS.

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BUREAU OF MINERALS AND PETROLEUM (BMP)
Government of Greenland, P.O. Box 930, DK-3900 Nuuk, Greenland
Tel.: +299 34 68 00, Fax.: +299 32 43 02, E-mail: bmp@gh.gl
Homepage: www.bmp.gl

GEOLOGICAL SURVEY OF DENMARK AND GREENLAND (GEUS)
Øster Voldgade 10, DK-1350 Copenhagen K, Denmark
Tel.: +45 38 14 20 00, Fax.: +45 38 14 20 50, E-mail: geus@geus.dk
Homepage: www.geus.dk

ISSN 0909-0630 



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Last modified: 10 March 2002 © GEUS
GHEXIS is published by GEUS in co-orporation with the Bureau of Minerals and Petroleum, Government of Greenland
GHEXIS publiceres af GEUS i samarbejde med Råstofdirektoratet, Grønlands Hjemmestyre
GHEXIS Newsletter No. 14