The Case History of a High-Resolution Seismic Survey in the Central North Sea

The Alba Field is contained within block 16/26 of the Central North Sea of the United Kingdom. This oil field was discovered in 1984 by Chevron UK Ltd with the 16/26–5 well and has been appraised by 16 wells and sidetracks. The field is currently being developed and is scheduled to achieve first production around the end of 1993. A 3-D seismic survey, acquired in 1989, has greatly enhanced delineation of the field. It is a NW-SE trending linear feature approximately 5.25 miles (8.5 kms) in length with adjacent satellite structures. The reservoir sands comprise the Nauchlan Member of the Alba Formation (Horda Group) and are primarily of Middle Eocene age. Gross sand thicknesses in excess of 400 ft (120 m) are present within the field area with porosities ranging up to 38% and permeabilities of the order of 2800 mD. The sands were deposited as a series of submarine channel fills whose mutual relationships present problems of detailed interpretation. Channel sandbodies appear to be discontinuous along their length for a variety of reasons including erosive relief on the base of the channel, and partial filling of channels otherwise filled by mud.

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A Case History of Casing Directional Drilling in the Norwegian Sector of the North Sea

10.2118/112560-ms ◽

2008 ◽

Cited By ~ 2

Author(s):

Kevin Arthur Bourassa ◽

Tove Husby ◽

Rick Deuane Watts ◽

Dale Oveson ◽

Tommy M. Warren ◽

...

Keyword(s):

North Sea ◽

Case History ◽

Directional Drilling ◽

The North ◽

History Of ◽

The North Sea

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A case history of high resolution seismic methods for exploration of shallow oil deposits in Suriname

53rd EAEG Meeting ◽

10.3997/2214-4609.201411031 ◽

1991 ◽

Author(s):

P. Goerdajal ◽

J. A. C. Meekes ◽

M. H. Mulder

Keyword(s):

High Resolution ◽

Case History ◽

Seismic Methods ◽

History Of ◽

Oil Deposits

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Aluminosilicate diagenesis in a Tertiary sandstone-mudrock sequence from the central North Sea, UK

Clay Minerals ◽

10.1180/claymin.1996.031.4.10 ◽

1996 ◽

Vol 31 (4) ◽

pp. 523-536 ◽

Cited By ~ 8

Author(s):

J. M. Huggett

Keyword(s):

Electron Beam ◽

Electron Microscope ◽

High Resolution ◽

Mass Balance ◽

North Sea ◽

Chemical Interaction ◽

Point Counting ◽

Resolution Electron ◽

Tertiary Sandstone ◽

Central North Sea

AbstractMudrocks and sandstones from the Palaeocene of the central North Sea have been studied to assess the petrology, diagenesis and extent of any chemical interaction between the two lithologies. Authigenic and detrital minerals have been distinguished using a variety of electron microscope techniques. Small but significant quantities of authigenic minerals, which would not be detected by conventional petrographic tools, have been detected through the use of high-resolution electron beam techniques. Sandstone mineralogy has been quantified by point counting, and mudrock mineralogy semi-quantified by XRD. The detrital and authigenic mineralogy in the sandstone is almost identical to that found in the mudrock. The principal difference is in the relative proportions. Qualitative mass balance suggests that cross-formational flow has not been significant in either clay or quartz diagenesis.

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Diagenesis of the shallow marine Fulmar Formation in the Central North Sea

Clay Minerals ◽

10.1180/claymin.1986.021.4.08 ◽

1986 ◽

Vol 21 (4) ◽

pp. 537-564 ◽

Cited By ~ 28

Author(s):

D. J. Stewart

Keyword(s):

Clay Mineral ◽

North Sea ◽

Large Scale ◽

Shear Zones ◽

Upper Jurassic ◽

Burial Diagenesis ◽

Secondary Porosity ◽

Shallow Marine ◽

History Of ◽

Central North Sea

AbstractThe diagenetic history of the Upper Jurassic Fulmar Formation of the Central North Sea is described with emphasis on the Fulmar Field. The Fulmar Formation was deposited on a variably subsiding shallow-marine shelf under the influence of halokinetic and fault movements. The sediments are extensively bio-destratified although large-scale cross-bedding is locally preserved. The dominant mechanism of deposition is thought to have been storm-generated currents. Soft-sediment deformation structures are common and are attributed to syn- and post-depositional dewatering of the sandstones. The dewatering was associated with fractures and shear zones which reflect tectonic instability resulting from periodic salt withdrawal and/or graben fault movements. The dewatering may have been initiated by repacking of the sediments during earth movements or by the gradual build-up and sudden release of overpressures due to compaction and/or clay mineral dehydration during rapid burial at the end of the Cretaceous. The formation is composed of arkosic sandstone of similar composition to Triassic sandstones from which it was probably derived. The sandstones also contain limited amounts of marine biogenic debris including sponge solenasters, bivalve shells, rare ammonites and belemnites. Initial diagenesis began with an environment-related phase during which quartz and feldspar overgrowths and chalcedony and calcite cements were precipitated. These cements appear to form concretions adjacent to local concentrations of sponge debris and shell debris, respectively, and were disturbed after their formation by fracturing and dewatering. This was followed by an early burial stage of diagenesis which resulted in extensive dolomite cementation and minor clay mineral authigenesis (illite and chlorite). The last phase of mineral growth was probably pyrite. During early burial diagenesis, secondary porosity after feldspar and/or carbonate was produced, although the exact timing is not clear. The lack of both stylolitic developments and extensive illitization indicates that the late burial diagenesis stage was never reached, although sufficient clay diagenesis occurred to destroy all traces of mixed-layer illite-smectite (present in some shallower wells). The main control on reservoir behaviour is primary depositional fabric. Diagenesis only overprints these controls. Locally-cemented fracture sets act as baffles to fluid flow, but they are not extensive and the reservoir acts as one unit.

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High resolution biostratigraphic zonation for the UK central North Sea Paleocene

Marine and Petroleum Geology ◽

10.1016/j.marpetgeo.2020.104400 ◽

2020 ◽

Vol 117 ◽

pp. 104400 ◽

Cited By ~ 4

Author(s):

Manuel Vieira ◽

Salih Mahdi ◽

Nicholas Holmes

Keyword(s):

High Resolution ◽

North Sea ◽

The Uk ◽

Central North Sea

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