scholarly journals The Cavendish Field, Block 43/19, UK North Sea

2020 ◽  
Vol 52 (1) ◽  
pp. 131-141 ◽  
Author(s):  
N. Wasielka ◽  
J. G. Gluyas ◽  
H. Breese ◽  
R. Symonds
Keyword(s):  
Grain Size ◽  
Continental Shelf ◽  
North Sea ◽  
Water Depth ◽  
Reservoir Quality ◽  
Low Permeability ◽  
Gas Field ◽  
Upper Carboniferous ◽  
Northern Margin

AbstractThe Cavendish Field is located in UK Continental Shelf Block 43/19a on the northern margin of the Outer Silverpit Basin of the Southern North Sea, 87 miles (140 km) NE of the Lincolnshire coast in a water depth of 62 ft (18.9 m). The Cavendish Field is a gas field in the upper Carboniferous Namurian C (Millstone Grit Formation) and Westphalian A (Caister Coal Formation) strata. It was discovered in 1989 by Britoil-operated well 43/19-1. Production started in 2007 and ceased in 2018. Gas initially in place was 184 bcf and at end of field life 98 bcf had been produced. The field was developed by three wells drilled through the normally unmanned platform into fluvio-deltaic sandstone intervals that had sufficiently good reservoir quality to be effective reservoirs. The majority of the formation within closure comprises mudstones, siltstones and low permeability, non-reservoir-quality feldspathic sandstones. The quality of the reservoir is variable and is controlled by grain size, feldspar content and diagenesis. The field is a structural trap, sealed by a combination of intra-Carboniferous mudstones and a thick sequence of Permian mudstones and evaporites.

Depositional facies, diagenetic clay minerals and reservoir quality of Rotliegend sediments in the Southern Permian Basin (North Sea): a review

Clay Minerals ◽  
1982 ◽  
Vol 17 (1) ◽  
pp. 55-67 ◽  
Author(s):  
U. Seemann
Keyword(s):  
Clay Minerals ◽  
North Sea ◽  
Effective Porosity ◽  
Hydrocarbon Exploration ◽  
Reservoir Quality ◽  
Burial Diagenesis ◽  
Permian Basin ◽  
Northern Margin ◽  
The North

AbstractThe Southern Permian Basin of the North Sea represents an elongate E-W oriented depo-centre along the northern margin of the Variscan Mountains. During Rotliegend times, three roughly parallel facies belts of a Permian desert developed, these following the outline of the Variscan Mountains. These belts were, from south to north, the wadi facies, the dune and interdune facies, and the sabkha and desert lake facies. The bulk of the gas reservoirs of the Rotliegend occur in the aeolian dune sands. Their recognition, and the study of their geometry, is therefore important in hydrocarbon exploration. Equally important is the understanding of diagenesis, particularly of the diageneticaily-formed clay minerals, because they have an important influence on the reservoir quality of these sands. Clay minerals were introduced to the aeolian sands during or shortly after their deposition in the form of air-borne dust, which later formed thin clay films around the grains. During burial diagenesis, these clay films may have acted as crystallization nuclei for new clay minerals or for the transformation of existing ones. Depending on their crystallographic habit, the clay minerals can seriously affect the effective porosity and permeability of the sands.

The Amethyst Field, Blocks 47/8a, 47/9a, 47/13a, 47/14a, 47,15a, UK North Sea

1991 ◽  
Vol 14 (1) ◽  
pp. 387-393 ◽  
Author(s):  
C. R. Garland
Keyword(s):  
North Sea ◽  
Reservoir Quality ◽  
Geological Model ◽  
Gas Field ◽  
Seismic Parameters ◽  
Recoverable Reserves ◽  
High Production ◽  
Sandstone Formation ◽  
Phased Development ◽  
Overlying Strata

AbstractThe Amethyst gas field was discovered in 1970 by well 47/13-1. Subsequently it was appraised and delineated by 17 wells. It consists of at least five accumulations with modest vertical relief, the reservoir being thin aeolian and fluviatile sandstones of the Lower Leman Sandstone Formation. Reservoir quality varies from poor to good, high production rates being attained from the aeolian sandstones. Seismic interpretation has involved, in addition to conventional methods, the mapping of several seismic parameters, and a geological model for the velocity distribution in overlying strata.Gas in place is currently estimated at 1100 BCF, with recoverable reserves of 844 BCF. The phased development plan envisages 20 development wells drilled from four platforms, and first gas from the 'A' platforms was delivered in October 1990. A unitization agreement is in force between the nine partners, with a technical redetermination of equity scheduled to commence in 1991.

The Osprey Field, Blocks 211/18a & 211/23a, UK North Sea*

1991 ◽  
Vol 14 (1) ◽  
pp. 183-189 ◽  
Author(s):  
John W. Erickson ◽  
C. D. Van Panhuys
Keyword(s):  
Crude Oil ◽  
North Sea ◽  
Water Depth ◽  
Middle Jurassic ◽  
Reservoir Quality ◽  
Shetland Islands ◽  
Delta System ◽  
Reservoir Sandstones ◽  
Northern North Sea ◽  
The Uk

AbstractThe Osprey Oilfield is located 180 km northeast of the Shetland Islands in Blocks 211/23a and 211/18a in the UK sector of the northern North Sea. The discovery well 211/23-3 was drilled in January 1974 in a water depth of 530 ft. The trap is defined at around 8500 ft TVSS by two dip and fault closed structures, the main 'Horst Block' and the satellite 'Western Pool'. The hydrocarbons are contained in reservoir sandstones belonging to the Middle Jurassic Brent Group which was deposited by a wave-dominated delta system in the East Shetlands Basin. The expected STOIIP and ultimate recovery are estimated at 158 MMBBL and 60 MMBBL of oil respectively, which represents a recovery factor of 38%. The 'Horst Block' contains 85% of the reserves with an OOWC about 150 ft shallower than in the 'Western Pool'. Reservoir quality is excellent, with average porosities varying from 23-26% and average permeabilities varying from 35-5300 md. The development plan envisages eleven satellite wells, six producers and five water injectors, closely clustered around two subsea manifolds. First production is expected in late 1990/early 1991. The wet crude oil will be piped to the Dunlin 'A' platform for processing and from there to the Cormorant Alpha platform into the Brent System pipeline for export to the Sullom Voe terminal.

Ravenspurn South Field, Blocks 42/29, 42/30, 43/26, UK North Sea

1991 ◽  
Vol 14 (1) ◽  
pp. 469-475 ◽  
Author(s):  
R. D. Heinrich
Keyword(s):  
North Sea ◽  
Reservoir Quality ◽  
Desert Environment ◽  
Gas Field ◽  
Field Development ◽  
Southern North Sea ◽  
Fluvial Processes ◽  
Sandstone Formation ◽  
Aeolian Sands

AbstractThe Ravenspurn South Gas Field is located in the Sole Pit Basin of the Southern North Sea in UKCS Block 42/30, extending into Blocks 42/29 and 43/26. The gas is trapped in sandstones of the Permian Lower Leman Sandstone Formation, which was deposited by aeolian and fluvial processes in a desert environment. Reservoir quality is poor, and variations are mostly facies-controlled. The best reservoir quality occurs in aeolian sands wth porosities of up to 23% and permeabilities up to 90 md. The trap is a NW-SE-striking faulted anticline: top seal is provided by the Silverpit Shales directly overlying the reservoir, and by Zechstein halites. Field development began early in 1988 and first gas was delivered in October 1989. Production is in tandem with the Cleeton Field, about 5 miles southwest of Ravenspurn South, as the Villages project. Initial reserves are 700 BCF and field life is expected to be 20 years.

Diagenetic controlled reservoir quality of South Pars gas field, an integrated approach

2011 ◽  
Vol 343 (1) ◽  
pp. 55-71 ◽  
Author(s):  
Vahid Tavakoli ◽  
Hossain Rahimpour-Bonab ◽  
Behrooz Esrafili-Dizaji
Keyword(s):  
Integrated Approach ◽  
Reservoir Quality ◽  
Gas Field

The Sean fields, Block 49/25a, UK North Sea

2020 ◽  
Vol 52 (1) ◽  
pp. 255-261 ◽  
Author(s):  
R. J. Botman ◽  
J. van Lier
Keyword(s):  
North Sea ◽  
Reservoir Quality ◽  
Late Permian ◽  
High Recovery ◽  
Gas Field ◽  
Sandstone Formation ◽  
Gas Fields

AbstractBlock 49/25a contains the Sean gas fields, Sean North, Sean South and Sean East – collectively known as the Greater Sean area and discovered in 1969. The fields are located in the Southern Gas Basin, about 15 km SE of the Indefatigable gas field. Approximately 1.1 tcf of gas is trapped in a series of fault-bounded dip closures consisting of Permian sandstones belonging to the Leman Sandstone Formation (Rotliegend Group). The reservoir is overlain by evaporites of the Late Permian Zechstein Group. The fields are characterized by excellent Leman reservoir quality, and resources have increased significantly over the years. The reservoir largely behaves as a well-connected tank, which has resulted in high recovery factors (>90%).In 2015, Oranje-Nassau Energie UK Ltd (ONE) took over operatorship of the field through purchasing the rights of both Shell and Esso, giving ONE a 50% operated interest together with SSE E&P UK Ltd (SSE). In 2017, an infill well (SSPD05) was drilled by ONE to test a pop-up structure situated between Sean North and Sean South. The well found, as expected, partially depleted reservoir but has proven to accelerate production and add incremental reserves to the field.

Controls on the reservoir quality of Late Cretaceous Springar Formation deep-water fan systems in the Vøring Basin

2017 ◽  
Vol 8 (1) ◽  
pp. 247-257 ◽  
Author(s):  
Alana Finlayson ◽  
Angela Melvin ◽  
Alex Guise ◽  
James Churchill
Keyword(s):  
Grain Size ◽  
Late Cretaceous ◽  
Clay Content ◽  
Coarse Grained ◽  
Reservoir Quality ◽  
Low Permeability ◽  
Quality Model ◽  
Depositional Facies ◽  
Porosity And Permeability ◽  
Vøring Basin

AbstractA new reservoir quality model is proposed for the Late Cretaceous Springar Formation sandstones of the Vøring Basin. Instead of a depth-related compactional control on reservoir quality, distinct high- and low-permeability trends are observed. Fan sequences which sit on the high-permeability trend are characterized by coarse-grained facies with a low matrix clay content. These facies represent the highest energy sandy turbidite facies within the depositional system, and were deposited in channelized or proximal lobe settings. Fan sequences on the low-permeability trend are characterized by their finer grain size and the presence of detrital clay, which has been diagenetically altered to a highly microporous, illitic, pore-filling clay. These fan sequences are interpreted to have been deposited in proximal–distal lobe environments. Original depositional facies determines the sorting, grain size and detrital clay content, and is the fundamental control on reservoir quality, as the illitization of detrital clay is the main mechanism for reductions in permeability. Core-scale depositional facies were linked to seismic-scale fan elements in order to better predict porosity and permeability within each fan system, allowing calibrated risking and ranking of prospects within the Springar Formation play.

Sign in / Sign up

Export Citation Format

Share Document