Shallow-marine reservoir development in extensional diaper-collapse minibasins: An integrated subsurface case study from the Upper Jurassic of the Cod terrace, Norwegian North Sea

AAPG Bulletin ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 2019-2055 ◽  
Author(s):  
Aruna S. Mannie ◽  
Christopher A.-L. Jackson ◽  
Gary J. Hampson
Keyword(s):  
North Sea ◽  
Upper Jurassic ◽  
Shallow Marine ◽  
Reservoir Development

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

Clay Minerals ◽  
1986 ◽  
Vol 21 (4) ◽  
pp. 537-564 ◽  
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.

scholarly journals Jurassic lithostratigraphy and stratigraphic development onshore and offshore Denmark

2003 ◽  
Vol 1 ◽  
pp. 145-216 ◽  
Author(s):  
Olaf Michelsen ◽  
Lars H. Nielsen ◽  
Peter N. Johannessen ◽  
Jan Andsbjerg ◽  
Finn Surlyk
Keyword(s):  
North Sea ◽  
Middle Jurassic ◽  
Upper Jurassic ◽  
Lower Jurassic ◽  
Coarse Grained ◽  
Late Triassic ◽  
New Members ◽  
Shallow Marine ◽  
Central North Sea ◽  
Sea Area

A complete updated and revised lithostratigraphic scheme for the Jurassic succession of the onshore and offshore Danish areas is presented together with an overview of the geological evolution. The lithostratigraphies of Bornholm, the Danish Basin and the Danish Central Graben are described in ascending order, and a number of new units are defined. On Bornholm, the Lower–Middle Jurassic coal-bearing clays and sands that overlie the Lower Pliensbachian Hasle Formation are referred to the new Sorthat Formation (Lower Jurassic) and the revised Bagå Formation (Middle Jurassic). In the southern Danish Central Graben, the Middle Jurassic succession formerly referred to the Lower Graben Sand Formation is now included in the revised Bryne Formation. The Lulu Formation is erected to include the uppermost part of the Middle Jurassic succession, previously referred to the Bryne Formation in the northern Danish Central Graben. The Upper Jurassic Heno Formation is subdivided into two new members, the Gert Member (lower) and the Ravn Member (upper). The organic-rich part of the upper Farsund Formation, the former informal ‘hot unit’, is established formally as the Bo Member. Dominantly shallow marine and paralic deposition in the Late Triassic was succeeded by widespread deposition of offshore marine clays in the Early Jurassic. On Bornholm, coastal and paralic sedimentation prevailed. During maximum transgression in the Early Toarcian, sedimentation of organic-rich offshore clays took place in the Danish area. This depositional phase was terminated by a regional erosional event in early Middle Jurassic time, caused by uplift of the central North Sea area, including the Ringkøbing–Fyn High. In the Sorgenfrei–Tornquist Zone to the east, where slow subsidence continued, marine sandy sediments were deposited in response to the uplift. Uplift of the central North Sea area was followed by fault-controlled subsidence accompanied by fluvial and floodplain deposition during Middle Jurassic time. On Bornholm, deposition of lacustrine muds, fluvial sands and peats dominated. The late Middle Jurassic saw a gradual shift to shallow marine deposition in the Danish Central Graben, the Danish Basin and Skåne, southern Sweden. During the Late Jurassic, open marine shelf conditions prevailed with deposition of clay-dominated sediments while shallow marine sands were deposited on platform areas. The Central Graben received sand by means of sediment gravity flows. The clay sediments in the Central Graben became increasingly rich in organic matter at the Jurassic–Cretaceous transition, whilst shallow marine coarse-grained deposits prograded basinwards in the Sorgenfrei– Tornquist Zone.

Complex Unconventional Wells Addressing Difficult Reservoir Development : A Case Study of West Kuwait Jurassic Reservoirs

2007 ◽  
Author(s):  
Naveen Kumar Verma ◽  
Fahed Al-Medhadi ◽  
Adnan Aiesh Al Shamali ◽  
Natarajan Dakshinamurthy ◽  
Saad Awad Matar ◽  
...  
Keyword(s):  
Reservoir Development
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