The Hewett Field satellites: Big Dotty, Little Dotty, Deborah, Della, Dawn and Delilah, Blocks 48/29a, 48/30a, UK North Sea

2020 ◽  
Vol 52 (1) ◽  
pp. 203-216 ◽  
Author(s):  
J. A. Hook
Keyword(s):  
Fault Zone ◽  
North Sea ◽  
The Other ◽  
Reservoir Quality ◽  
Marked Contrast ◽  
Strategic Role ◽  
Sandstone Formation ◽  
Water Cut

AbstractSix satellite fields have been developed through the Hewett Field facilities: Big Dotty, Little Dotty, Deborah, Della, Dawn and Delilah. Little Dotty has produced from both the Leman Sandstone Formation (LSF) and Bunter Sandstone Formation (BSF) whilst the other satellites are exclusively LSF developments. The LSF reservoir quality exhibits a marked contrast across the Dowsing Fault Zone, which separates the inboard satellites to the SW from the outboard satellites to the NE. The inboard satellites, Big Dotty, Little Dotty and Dawn, display the best reservoir quality, reflecting their lesser depth of maximum burial. These fields share a strong aquifer, exhibited a rapid water-cut development and are now shut-in. The greater depth of maximum burial experienced by the outboard satellites, Deborah, Della and Delilah, is reflected in poorer reservoir quality along with weaker aquifers that are also more compartmentalized. These remain in production and will achieve higher recovery factors. Big Dotty was developed from a wellhead platform whereas the other fields were developed as subsea tie-backs. Collectively, these satellite fields have produced some 0.9 tcf of gas, playing an important strategic role in offsetting the production decline in the Hewett Field and extending the life of the asset.

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 Hewett Field, Blocks 48/28a, 48/29a, 48/30a, 52/4a and 52/5a, UK North Sea

2020 ◽  
Vol 52 (1) ◽  
pp. 189-202 ◽  
Author(s):  
J. A. Hook
Keyword(s):  
Fault Zone ◽  
North Sea ◽  
Structural Evolution ◽  
Field Development ◽  
Southern North Sea ◽  
Sandstone Formation ◽  
The Uk ◽  
Basin Margin ◽  
Sour Gas

AbstractThe Hewett Field has been in production for some 50 years. Unusually for a Southern North Sea field in the UK Sector, there has been production from several different reservoirs and almost entirely from intervals younger than the principal Leman Sandstone Formation (LSF) reservoir in the basin. Some of these reservoirs are particular to the Hewett area. This reflects the location of the field at the basin margin bound by the Dowsing Fault Zone, which has influenced structural evolution, deposition and the migration of hydrocarbons. The principal reservoirs are the Permo-Triassic Hewett Sandstone (Lower Bunter), Triassic Bunter Sandstone Formation (BSF) (Upper Bunter) and Permian Zechsteinkalk Formation. There has also been minor production from the Permian Plattendolomit Formation and the LSF. Sour gas is present in the BSF only. Several phases of field development are recognized, ultimately comprising three wellhead platforms with production from 35 wells. Gas is exported onshore to Bacton, where the sour gas was also processed. Peak production was in 1976 and c. 3.5 tcf of gas has been recovered. Hewett has also provided the hub for six satellite fields which have produced a further 0.9 tcf of gas. It is expected that the asset will cease production in 2020.

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.

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.

The Guinevere Field, Block 48/17b, UK North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 723-730 ◽  
Author(s):  
M. Lappin ◽  
D. J. Hendry ◽  
I. A. Saikia
Keyword(s):  
Fault Zone ◽  
North Sea ◽  
Production System ◽  
Early Permian ◽  
Gas Field ◽  
East Anglia ◽  
Southern North Sea ◽  
Fault Block ◽  
Sandstone Formation ◽  
The Uk

AbstractThe Guinevere Gas Field was discovered in January 1988 by the Mobil-operated well 48/17b-5. The field lies in the UK Sector of the Southern North Sea and occupies Block 48/17b. The field is located within the footwall of the Dowsing Fault Zone on the western flank of the Sole Pit Basin. Guinevere is a compressional northwesterly-trending fault block that comprises Early Permian Leman Sandstone Formation (Rotliegend Group) reservoir, sourced from the Carboniferous below and sealed by Later Permian Zechstein evaporates above.The Guinevere Gas Field is estimated to contain 90 BCF of recoverable gas reserves and was brought on-stream in June 1993 using a single not-normally-manned minimum facilities platform. Field life is predicted to be 13 years. Gas and condensate are evacuated though the Lancelot Area Production System (LAPS) to the onshore Bacton gas terminal in East Anglia.

The Malory Field, Block 48/12d, UK North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 771-776
Author(s):  
R. E. O'Brien ◽  
M. Lappin ◽  
F. Komlosi ◽  
A. Loftus
Keyword(s):  
North Sea ◽  
Upper Permian ◽  
Reservoir Quality ◽  
Lower Permian ◽  
Burial Depth ◽  
Recoverable Reserves ◽  
Adjacent Structures ◽  
Sandstone Formation ◽  
The Uk ◽  
Hydrocarbon Charge

AbstractThe Malory Field straddles blocks 48/12d and 48/12c of the UK Sector of the Southern North Sea on the western margin of the Sole Pit Trough. The field is located within an upthrown part of the Dowsing Fault Zone and was discovered by the Mobil operated well 48/12d-9 in early 1997.The Malory Field is a small fault-bounded horst structure with expected recoverable reserves of 75 BSCF. The reservoir consists of a 249 ft-section of Lower Permian, Rotliegendes Leman Sandstone Formation sandstones, is sourced from the Carboniferous Westphalian Coal Measures below, and is sealed by overlying Upper Permian Zechstein evaporites.Reservoir quality is generally good with an average porosity of 14.7% and core permeabilities (Kh) between 0.2 and 1651 mD. This preservation of reservoir quality is attributed to a combination of the structure being located on a broad palaeostructural high, with a lower maximum burial depth than adjacent structures and associated lower compactional porosity loss, the presence of an early hydrocarbon charge and the preferential precipitation of chlorite over illite cements.

scholarly journals Lithostratigraphy and depositional history of the Danish Triassic

1980 ◽  
Vol 4 ◽  
pp. 1-59
Author(s):  
Finn Bertelsen
Keyword(s):  
North Sea ◽  
The Other ◽  
Basin Evolution ◽  
Depositional History ◽  
Southern North Sea ◽  
History Of ◽  
Shale Formation ◽  
Sandstone Formation

The Triassic deposits of the Danish territory are mapped, described and characterized by means of wire line log motifs. Three facies provinces are recognized: A southern and central Germano-type Facies Province, a Northern Marginal Facies Province fringing the basin center, and a Central Graben Facies Province with affinities to the Southern North Sea Basin. The traditional German lithostratigraphic nomenclature previously used in the Germano-type Facies Province is proposed replaced by a system composed of four groups each of two formations corresponding to four Triassic megaphases of sedimentation: Bacton Group including Bunter Shale Formation and Bunter Sandstone Formation, Lolland Group (new) including Ørslev Formation (new) and Falster Formation (new), Jylland Group (new) including Tønder Formation (new) and Oddesund Formation (new), and Mars Group (new) including Vinding Formation and Gassum Formation. In the other facies provinces the nomenclature previously proposed for the Central and Southern North Sea is adopted. A summary of the basin evolution is given for each formation description.

The Davy, Bessemer, Beaufort and Brown Fields, Blocks 49/23, 49/30a, 49/30c, 53/5a, UK North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 705-712 ◽  
Author(s):  
C. W. McCrone
Keyword(s):  
North Sea ◽  
Horizontal Well ◽  
Reservoir Quality ◽  
3D Seismic ◽  
Commercial Viability ◽  
Playa Lake ◽  
Technical Advances ◽  
Sandstone Formation ◽  
The Uk ◽  
Gas Fields

abstractDavy, Bessemer, Beaufort and Brown are a series of small to moderate (30-200 BCF) dry gas fields, which span the southeastern corner of the UK Southern North Sea Rotliegend Play fairway. Davy was discovered in 1970; however, it was not until 1989 that Bessemer and subsequently Beaufort in 1991 were drilled. These fields were developed and brought on-stream by Amoco licence groups in 1995/96. More recently the Brown Field was discovered in October 1998 with first gas seven weeks later. The commercial viability of these relatively small accumulations is the result of technical advances across several fronts: 3D seismic imaging, horizontal well technology and minimum offshore facilities.In the Bessemer and Beaufort area, the Rotliegend Leman Sandstone Formation reservoir (250 ft) primarily consists of stacked aeolian dune sandstones of good reservoir quality (porosity 17%, permeability 10-1000mD). However, in the Davy and Brown area there is greater variation in the Rotliegend isopach (300-700 ft) and the nature of facies present e.g., aeolian dune, sabkha and playa lake.The fields are tied back from the Bessemer and Davy mono-tower platforms via 15 km and 43 km pipelines, respectively, to the compression facilities on the Indefatigable 23AT platform.

The Juliet Field, Block 47/14b, UK North Sea

2020 ◽  
Vol 52 (1) ◽  
pp. 217-225 ◽  
Author(s):  
D. J. Offer
Keyword(s):  
Production Rate ◽  
North Sea ◽  
Horizontal Wells ◽  
Reservoir Quality ◽  
Burial History ◽  
Gas Field ◽  
High Production Rate ◽  
High Production ◽  
Sandstone Formation ◽  
East West

AbstractThe abandoned Juliet gas field is a small, highly compartmentalized, accumulation situated south and east of the Amethyst Gas Field. It was discovered in 2008 by well 47/14b-10 and flowed first gas on 5 January 2014. The field consists of at least two culminations within a very low-relief east–west-orientated fault-bounded anticline. The reservoir comprises aeolian sandstones of the Permian, Rotliegend Group, Leman Sandstone Formation. Reservoir quality varies from good to moderate, with a high production rate achieved from horizontal wells.Seismic time-to-depth conversion is affected by Quaternary seabed channels, chalk burial history and a rapid thickening in the Basalanhydrit Formation located over the east of the field, associated with the edge of the Zechstein Basin.Gas-in-place at pre-development was expected to be 105 bcf, with reserves of 67 bcf. The field was developed using two horizontal wells and a subsea tie-back to the Pickerill Field, 22 km to the east. Since development, the field appears to be more compartmentalized than initially expected.

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