Petroleum geology of the Cygnus gas field, UK North Sea: from discovery to development

2017 ◽  
Vol 8 (1) ◽  
pp. 307-318 ◽  
Author(s):  
Ross Catto ◽  
Samantha Taggart ◽  
Gareth Poole
Keyword(s):  
North Sea ◽  
High Water ◽  
Poor Quality ◽  
Log Analysis ◽  
Permian Basin ◽  
Gas Field ◽  
Flow Rates ◽  
Southern North Sea ◽  
Sandstone Formation ◽  
The Uk

AbstractThe Cygnus Field, operated by ENGIE E&P UK Limited, is located in UK Southern North Sea blocks 44/11 and 44/12. The reservoir comprises sandstones of the Permian Leman Sandstone Formation and Carboniferous Ketch Formation.Cygnus was first drilled in 1988 by well 44/12-1, which encountered gas shows in sandstones in the Leman Sandstone Formation whilst targeting a Carboniferous objective. The initial evaluation indicated the presence of poor-quality reservoir with conventional log analysis indicating high water saturations. Further appraisal activity ceased until 2002 when a group led by ENGIE E&P UK Limited were awarded the licence in the 20th round having recognized the missed pay potential. Through appraisal drilling, a second reservoir (the Carboniferous Ketch Formation) was discovered and the Leman Sandstone Formation was proven to be capable of achieving stabilized flow rates greater than 30 MMscf/d.The Cygnus discovery now proves that a northern-sourced Leman Sandstone Formation play fairway exists, establishing an extension of the Rotliegend play to the northern feather edge of the Southern Permian Basin. The Cygnus Field's estimated ultimate recoverable volume is forecast to be 760 Bscf, making it the largest field discovered in the UK Southern North Sea in the last 30 years.

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.

Chiswick and Kew fields, Blocks 49/4a, 49/4b, 49/4c, 49/5a and 49/5b, UK North Sea

2020 ◽  
Vol 52 (1) ◽  
pp. 142-150 ◽  
Author(s):  
W. Smit
Keyword(s):  
North Sea ◽  
Primary Objective ◽  
Permian Basin ◽  
Current Estimate ◽  
Gas Field ◽  
Gas Recovery ◽  
Domal Structure ◽  
Exploration Drilling ◽  
Sandstone Formation ◽  
The Uk

AbstractThe Chiswick Field is a Carboniferous gas field located in UK Blocks 49/4a and 49/4b in the Southern North Sea, approximately 18 km NW of the Markham Field, close to the UK–Netherlands median line. The Kew Field is situated approximately 3 km NE of the Chiswick Field. The Kew structure is a NW–SE-trending horst separated from the Chiswick Field, a large anticlinal domal structure, by a major NW–SE fault and a structural low. The productive reservoir units are Carboniferous (Westphalian A and B) fluvial sandstones.Both fields are situated on the eastern edge of the Silverpit Basin (part of the Southern Permian Basin). The initial exploration drilling had Leman Sandstone Formation as the primary objective, but the first wells encountered a tight Permian reservoir with gas-bearing Carboniferous reservoirs, subsequently appraised and developed.The current estimate for the gas initially in place of Chiswick and Kew is respectively 687 bcf and 85 bcf in the Carboniferous reservoir. The fields to date (Q4 2018) have produced respectively 220 bcf and 33 bcf sales gas. Gas recovery is through natural depletion from hydraulically fractured, horizontal development wells.

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.

The Victor Field, Blocks 49/17, 49/22, UK North Sea

1991 ◽  
Vol 14 (1) ◽  
pp. 503-508 ◽  
Author(s):  
Robert A. Lambert
Keyword(s):  
North Sea ◽  
Early Permian ◽  
Gas Field ◽  
Eastern Flank ◽  
Southern North Sea ◽  
Recoverable Reserves ◽  
Fault Block ◽  
Sandstone Formation

AbstractThe Victor gas field lies in the Southern North Sea Gas Province on the eastern flank of the Sole Pit Basin. The field straddles Blocks 49/17 and 49/22, and is situated approximately 140 km off the Lincolnshire coast. Victor was discovered in April 1972 and is operated by Conoco (UK) Ltd on behalf of BP, Mobil and Statoil. The structure is an elongated tilted fault block, trending NW-SE. The reservoir sands are contained in the Leman Sandstone Formation (Rotliegendes Group) of Early Permian age, and consist mainly of stacked aeolian and fluvial sands with a gross thickness of 400-450 ft across the field. Porosities vary from 16-20%, with permeabilities ranging from 10 md to 1000 md in the producing zones. Initial gas in place is estimated at about 1.1 TCF with recoverable reserves of the order of 900 BCF. The field was brought on-stream in October 1984, and the five producing wells deliver, on average, 200 MMSCFD through the Viking Field 'B Complex' to the Conoco/BP terminal at Theddlethorpe in Lincolnshire

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 Esmond, Forbes and Gordon Fields, Blocks 43/8a, 43/13a, 43/15a, 43/20a, UK North Sea

1991 ◽  
Vol 14 (1) ◽  
pp. 425-432 ◽  
Author(s):  
F. J. Ketter
Keyword(s):  
North Sea ◽  
Arid Environment ◽  
Gas Production ◽  
Alluvial Fan ◽  
Southern North Sea ◽  
Offshore Installations ◽  
Porosity And Permeability ◽  
Sandstone Formation ◽  
The Uk

AbstractThe three separate fields, Esmond, Forbes and Gordon form the Esmond Gas Complex in Quadrant 43 in the UK Southern North Sea. The Bunter Sandstone Formation is the reservoir in each of the separate, seismically defined, simple, anticlinal structures. The Bunter Sandstone correlates well across the three structures and is composed of a 400-500 ft thick interval containing individual channel sandstones deposited in an arid environment on an alluvial fan. Porosity and permeability are controlled by original texture and by subsequent diagenesis. Reservoir communication within the Bunter reservoir is good though locally tortuous.First gas production started in July 1985. Four offshore installations have allowed gas to be produced at full contract (plateau) rates of 200 MMSCFD without major interruption. Ultimate sales gas reserves are approximately 530 BCF.

The West Sole Field, Block 48/6, UK North Sea

1991 ◽  
Vol 14 (1) ◽  
pp. 517-523 ◽  
Author(s):  
D. A. Winter ◽  
B. King
Keyword(s):  
Continental Shelf ◽  
North Sea ◽  
Gas Production ◽  
Permian Basin ◽  
The West ◽  
Depositional Facies ◽  
Reservoir Sandstones ◽  
Sandstone Formation ◽  
The Uk ◽  
Coal Measures

AbstractWest Sole is located in the Sole Pit area of the Southern North Sea Permian Basin in UK Block 48/6. The field was discovered in 1965 and was the first commercial discovery in the UK Continental Shelf. Gas Production commenced in 1967. Initial reserves are 1.873 TCF of which 1.335 TCF had been produced by the end of 1989. Gas is trapped in aeolian sandstones of the Permian Lower Leman Sandstone Formation. Three depositional facies are recognized, comprising aeolian dune, fluvial and sabkha. The aeolian dune facies form the principal reservoir sandstones, in units up to 40 m (131 ft) thick. However, permeability is reduced due to pervasive illite cementation, such that it averages 3 md in the dune sandstones. Productivity is enhanced in the southern part of the field by 'open' gas-filled fractures, generated during the Alpine inversion. The trap was also amplified at this stage and comprises a faulted inversion anticline trending NW-SE. The source rock is the Westphalian Coal Measures, lying directly beneath the reservoir.

The Indefatigable Field, Blocks 49/18, 49/19, 49/23, 49/24, UK North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 741-747 ◽  
Author(s):  
C. W. McCrone ◽  
M. Gainski ◽  
P. J. Lumsden
Keyword(s):  
North Sea ◽  
Seismic Survey ◽  
3D Seismic ◽  
Gas Field ◽  
Recoverable Reserves ◽  
Phases Of Development ◽  
Four Blocks ◽  
Sandstone Formation ◽  
Well Data ◽  
The Uk

abstractIndefatigable is a mature dry gas field on the northeastern margin of the UK Southern North Sea Rotliegend Play fairway. The field was discovered, 49/18-1, by the Amoco operated group in 1966 and subsequent appraisal drilling established that the field extended over four blocks (i.e. 49/18, 49/19, 49/23 & 49/24). There have been several phases of development, initial production concentrated on the main horst block with first gas in 1971, followed by the west flank area in 1977/78. Then in 1987/88 the SW and SE Indefatigable satellite accumulations were brought on-stream.The Rotliegend Leman Sandstone Formation reservoir primarily consists of stacked aeolian dune sandstones (150-400 ft) of good reservoir quality (porosity 15%, permeability 100-1000 mD). However, the integration of the 1992/93 3D seismic survey, well data, reservoir pressure and production data has lead to a much more complex view of the field with 11 gas-water contacts and 15 reservoir compartments.This has resulted in an upward revision of the gas initially-in-place from 5.2 to 5.6 TCF and recoverable reserves from 4.4 to 4.7 TCF. Current work is focused on maximizing recovery from the various reservoir compartments and accessing this additional potential.

Problems Experienced During and After Installation of Gas Compression in UK Southern North Sea

1983 ◽  
Author(s):  
A. D. Simnett
Keyword(s):  
North Sea ◽  
Transmission System ◽  
Gas Field ◽  
Southern North Sea ◽  
Gas Compression ◽  
Series Configuration ◽  
The Uk

This paper relates the problems encountered with the operation of series configuration gas compression since its introduction in 1976 to the Leman Gas Field in the UK Southern North Sea gas transmission system. Various topics are addressed with the problem described and the adopted solution. Although solutions to these problems can be achieved by different methods, it is hoped that by relating these experiences, future operators embarking on offshore compression can take account during design stages and hence dispel the need of expensive modifications to plant offshore.

Sign in / Sign up

Export Citation Format

Share Document