bluuebunny/crossref_metadata_2025 huggingface dataset:
Some issues associated with the preparation of a review of foundation conditions in Great Britain
Authors: Earle David , Marker Brian , Nathanail Paul , Nathanail Judith
Published: April 2008

The Department of the Environment commissioned Wimpey Environmental Limited, with the National House-Building Council, to undertake research to establish whether planners should take greater account of foundation conditions in preparing development plans and in considering planning applications.

Existing information on factors such as compressible ground, shrinkage and swelling, saturated and loose granular deposits, frost susceptibility, groundwater conditions, durability of construction materials, and gas emissions, was reviewed. It was concluded that some of these factors may be material planning considerations whilst others are likely to remain only a matter for site development and Building Control.

Soil survey digital data were used as a basis for 1:250 000 and 1:625 000 scale maps showing the general geographical extent of selected potential foundation problems in Great Britain. These, together with reports, provide information on ground conditions to planners and developers which will help to increase awareness of the problems and of the purposes, procedures and benefits of thorough site investigation. The preparation of the maps was guided by a database of site investigation information which should be of use to those who are undertaking more detailed consideration of sites.
Some geohazards caused by soil mineralogy, chemistry and microfabric: a review
Authors: Bell F. G. , Culshaw M. G.
Published: April 2008

The paper reviews three geohazards: swelling/shrinkage, dispersivity and collapsibility, that are not dramatic and do not usually cause disasters because they rarely result in loss of life, nor cause sudden huge financial losses. However, these unspectacular' geohazards result, over time, in the loss of millions of pounds and in disruption to people's lives due to damage to foundations or loss of land. The geological controls on the hazards are described; all result from the inherent microfabric, mineralogy and/or chemistry of the particular soils affected. From this understanding it is possible to design mitigation and remedial measures that will prevent, or reduce, the effects of these hazards; these measures are presented.
Caledonian igneous rocks of Britain and Ireland
Authors: Brown G. C. , Francis E. H. , Kennan P. , Stillman C. J.
Published: April 2008

The British sector of the Caledonide-Appalachian fold belt, which bridges the Iapetus plate closure zone, has a range of plutonic, volcanic and volcaniclastic lithologies with characteristic space-time variations. The map of Caledonian igneous rocks in the British Isles (Plate 1) is compiled from many sources, some of which predate the use of methods of classification which are based largely on chemical data. In such cases, whilst extensive re-mapping continues, the compilers have had to resort to the collection and analysis of representative samples from the areas in question, the collection sites being based on existing maps. Thus, whilst the references to the mapped areas indicate specific publications, the chemical data on which the coding is based are commonly derived from compilations such as Stillman & Williams (1979) and Stillman & Francis (1979) for volcanic rocks and Sutherland & Pankhurst (1982), Le Bas (1982), Hall (1972) and Brown
et al
. (1981) for plutonic rocks.

The coding system, which is explained fully in the Plate 1 legend, is that accepted by the Plutonics-Volcanics International Working Group of IGCP Project 27 and is intended to provide a shorthand description by which the user of the map may ascertain as much information as possible about the igneous rocks of each locality, many of which cover too small an area on the 1:2 million scale of the map to be reconizable on any conventional system of colour and symbol designation. Given the small scale of Plate 1 the chemical symbols portrayed are a compromise in
Revised World maps and introduction
Authors: Scotese C.R. , McKerrow W. S.
Published: April 2008

We review the highlights of the 1988 symposium on Palaeozoic Biogeography and Palaeogeography, and present a revised set of 20 Palaeozoic base maps that incorporate much of the new data presented at the symposium. The maps include 5 major innovations: (1) A preliminary attempt has been made to describe the motion of the Cathaysian terranes during the Palaeozoic; (2) a more detailed description of the events surrounding the Iapetus Ocean is presented; (3) an alternative apparent polar wandering path for Gondwana has been constructed using the changing distributions of palaeoclimatically restricted lithofacies; (4) new palaeomagnetic data have been incorporated that places Laurentia and Baltica at more southerly latitudes, and adjacent to Gondwana, during the Early Devonian; Siberia is also placed further south in the light of biogeographic data presented at the symposium; (5) Kazakhstan is treated as a westward extension of Siberia, rather than as a separate palaeocontinent. The relationships between climatic changes, sea level changes, evolutionary radiations and intercontinental migrations are discussed
Stratigraphic and palaeogeographic distribution of Palaeozoic oolitic ironstones
Authors: Van Houten F. B. , Hou Hong-Fei
Published: April 2008

The record of Palaeozoic oolitic ironstones reflects second-order Phanerozoic sea-level changes. Middle Cambrian- earliest Ordovician high stand: scattered ironstones developed on low-latitude Laurentia and locally on high southern-latitude NW Africa and Nova Scotia. Early-early Late Ordovician high stand: major and scattered minor ironstones were widespread on high southern-latitude N Africa and Peri-Gondwanan blocks. Minor ones on C Laurentia, NE and SW Baltica, SW Kazakhstan, and NW and SW Siberia, NW Malaysia, and C Australia accumulated in middle and low latitudes, as did all later Palaeozoic ironstones. Latest Ordovician-earliest Silurian low stand: during southern-latitude glaciation minor ironstones were limited to WC Algeria and low-latitude C and SE Laurentia. Early-early Late Silurian high stand: minor ironstones accumulated on NC, WC, and SE South America, N Africa, and Peri-Gondwanan blocks, while major ones developed on NW Africa and CE Laurentia. Latest Silurian-Early Devonian low stand: major ironstones developed on WC Algeria; minor ones on CE Laurentia, several Peri-Gondwanan blocks, N and W Africa, NC South America, and South China. Middle-early Late Devonian high stand: major ironstones accumulated on N Africa, SE Baltica, NW Iberia, and South China; minor ones on SW and CE Laurentia, and NW and SE Middle Europe. Latest Devonian-earliest Carboniferous low stand: well-developed latest Devonian ironstones were limited to N Africa and NW Middle Europe, minor ones to SE Middle Europe and CE Laurentia; minor earliest Carboniferous ones to NW Middle Europe and NC Africa.
The relationship of Ordovician graptolite provincialism to palaeogeography
Authors: Finney Stanley C. , Chen Xu
Published: April 2008

Graptolite biogeography is examined for the late Arenig-Llanvirn when provincialism was at its greatest and the Llandeilo-Caradoc when graptolites were cosmopolitan. This examination incorporates new data from China and recently revised palaeogeographic base maps. Water-mass specificity is considered to be the primary factor affecting graptolite biogeography. On the recently revised base maps, the distribution of Pacific and Atlantic provinces in the late Arenig-Llanvirn is in general consistent with the model of water-mass specificity and the hypothesis that climate cooling associated with the onset of continental glaciation lead to the development of provincialism. However, a small clockwise rotation of South America and a slight northward shift in the position of North America is recommended. The climatic-cooling hypothesis includes the proposal that continued cooling confined graptolites to the tropics where the uniform environment precluded provincialism. The distribution of the cosmopolitan fauna of the
Nemagraptus gracilis
Zone in relationship to the Llandeilo-Caradoc palaeogeography is consistent with this hypothesis, except for the positions of the European platform, Britain, Armorica, and the Carpathians in the mid to high southern latitudes. Either the latitudinal positions of these areas must be shifted substantially to the north, or the climatic-cooling hypothesis mnst be in error.
Cambro-Devonian biogeography of nautiloid cephalopods
Authors: Crick Rex E.
Published: April 2008

The biogeography of Cambro-Devonian nautiloid cephalopods is documented from their origin during Late Cambrian through to the end of the Devonian. The biogeography developed as the consequence of two related sets of events with different magnitudes. Events controlling the biogeography of first order magnitude were geotectonic, either Gondwana glaciation due to plate movement or contraction in size of oceanic ridges related to decreased rates of sea floor spreading, manifested as first and second order eustatic fall in sea level. These first order events separate nautiloid biogeography into four episodes: (1) Late Cambrian; (2) Ordovician; (3) Silurian through Early Devonian; and (4) Middle through Late Devonian. Each began with an expansion in terms of generic diversity and ended with a crisis of some proportion. Only the end of the Late Cambrian episode cannot be explained by geotectonic events.

Events of the second order are both biologic and geotectonic and involve the interaction between the dispersal characteristics of nautiloid cephalopods and plate movements. Due to lack of a planktonic larva and depth restrictions as a function of shell design, the ability of nautiloids to disperse and colonize shallow shelf seas separated by expanses of ocean or depths exceeding shell design limits was minimal. When the width of oceans or depths decreased through some form of geotectonics, nautiloids rapidly radiated and colonized regions as they became available. Thus second order biogeographic episodes tend to evolve from a collection of disjunct patterns with high faunal similarity among faunas of particular landmasses, but with little similarity among separate landmasses, to rapid development of high similarities both among and within faunas of converging landmasses once the physical barrier of distance and water depth is eliminated.
The biogeographic affinities of East Asian corals
Authors: Liao Wei-Hua
Published: April 2008

In East Asia the oldest tabulate and rugose corals appeared in the Early and Middle Ordovician. All rugose corals and most tabulate corals appear to have become extinct at the end of the Permian.

The Ordovician corals of North China were most closely related to the Americo-Siberian region, but those of South China occupied an independent province. The Silurian corals of Junggar, Hinggan, Mongolia, Altai and Tuva are genera characteristic of the Uralian-Cordilleran region. The South China fauna had a close affinity to that of the East Australia in the Early Silurian, but was more akin to that of the Urals and Central Asia in the Middle and Late Silurian. During the Early and Middle Devonian, there were 5 biogeographic provinces in East Asia, all belonging to the Old World Realm: (1) Arctic province; (2) Junggar-Hinggan province; (3) Uralo-Tian Shan province; (4) Palaeotethyan province and (5) South Chin province.

In East Asia, two distinctive zoogeographic provinces are fairly clearly defined: a southern province, with occurrence of
Kueichouphyllum
and a northern province with occurrences of
Gangamophyllum
during the Early Carboniferous. In addition, during the Early Permian, a Uralo-Arctic province was dominated by Durhaminidae and a Tethyan province by Waagenophyllidae.
The Silurian and Early Devonian biogeography of ostracodes in North America
Authors: Berdan Jean M.
Published: April 2008

Silurian and Early Devonian ostracode associations in North America represent at least three ecotypes, a leperditicopid association, a large beyrichiacean association, a mixed association, and possibly a fourth, spinose podocopid association, or Thuringian ecotype. Comparison of the large beyrichiacean association and mixed association ecotypes indicates the presence of three informal ostracode provinces, the Appohimchi, Baltic-British and Cordilleran, which remained relatively constant in geographical position throughout the Silurian and Early Devonian. Plotting the provinces on palaeogeographic maps suggests that temperature was not an important factor in delimiting the provinces, and land barriers, or possibly deep-water troughs as barriers, were the cause of provincial development. Benthic ostracodes differed from other benthic invertebrates such as brachiopods and corals in developing provincialism in the late Llandovery and having it start to decline in the Pragian through the Emsian.
Constraints on Siluran and Early Devonian phytogeographic analysis based on megafossils
Authors: Edwards Dianne
Published: April 2008

The detection of phytogeographic patterns in Silurian and Early Devonian land vegetation is hampered by the dearth of occurrences of megafossils, the absence of consistently precise correlation, unreliability of identification, and the lack of sufficient detailed sampling and information on sediments to permit evaluation of taphonomic influences on composition of assemblages. Interpretation is further complicated by the exceptional evolutionary position of the plants themselves and the lack of extant representatives. There is little information on whole plants, their life histories, their ecological and climatic tolerances. The composition of Ludlow, Pridoli and Lochkovian/Gedinnian assemblages is analysed. Those from Kazakhstan and Siberia are particularly enigmatic. The assemblages are plotted on the appropriate continental reconstructions. Most are clustered on the southeast margin of Laurussia and very few occur at high latitudes. In Ludlow time,
Baragwanathia
dominated assemblages in Australia in contrast with the rhyniophytoid assemblages of Laurussia. New information from Kazakhstan and northwest China adds to the data base in the Pridoli.

Differences in Gedinnian assemblages from South Wales, the Welsh Borderland and Scotland, where sediments have been intensively studied and correlation is based on fish faunas and, more usefully, on palynomorphs, are related to taphonomy, to local vegetation distribution pattern, and to evolutionary changes. World-wide analysis of occurrences shows four distinct assemblages, based on Laurussia, Kazakhstan, Australia and Siberia, the latter being a rare example of high latitude vegetation.
Devonian vertebrate distribution patterns and cladistic analysis of palaegeographic hypotheses
Authors: Young Gavin C.
Published: April 2008

Early Devonian vertebrate faunal provinces are clearly defined for four regions: Euramerica, Siberia, China, and East Gondwana. The presence of osteostracans in southwest Siberia (Tuva, Minusa Basins) suggests either proximity of the Siberian block to Euramerica, or palaeogeographic separation of the Tuva region. The Knoydart fauna of Nova Scotia demonstrates that the Avalon Terrane was connected to Euramerica by Gedinnian time. Widespread antarctilamnid sharks in Gondwana suggest a distinctive Gondwana vertebrate fauna, isolated by marine barriers from Euramerica in the Early - Middle Devonian. Late Devonian patterns indicate faunal communication between Gondwana and Euramerica by Frasnian time, and between China and East Gondwana in the late Famennian. The Late Devonian base maps require anomalously wide latitudinal distributions for some taxa. Displacement of Turkey along the northern margin of Gondwana provides an intermediate occurrence of phyllolepid placoderms between disjunct distributions in Euramerica and East Gondwana, but the fossil data do not necessarily corroborate geological evidence for displacement. Biogeographic data generally must be interpreted in the context of palaeogeographic hypotheses, and lack of integration with geological and geophysical data sets has been a major problem. Hierarchical analysis using cladistic techniques has the potential for integrating biological, geological, and geophysical data, as illustrated in a cladistic analysis of the Williams and Hatcher model of Appalachian terranes. As an adjunct to map representation, an area cladogram enables a historical sequence of palaeogeographic events to be represented on a single diagram, together with crucial supporting evidence; it presents an analysis rather than synthesis of empirical data, and the hypothesis is more exposed to falsification.
Late Palaeozoic bryozoan biogeography
Authors: Ross J. P. R. , Ross C. A.
Published: April 2008

Late Palaeozoic (Carboniferous and Permian) distributions and times of dispersal of bryozoans, fusulinids, and other marine shelf invertebrates were greatly influenced by the effects of land masses converging to form a supercontinent. This convergence modified oceanographic circulation patterns as well as environmental, climatic, and temperature patterns. Sea level fluctuations of 75 to 100 metres having about two million years duration also strongly affected faunal dispersal patterns. At the end of the Early Carboniferous (late Visean through early Bashkirian), the assemblage of Lesser Pangaea disrupted the tropical, subtropical and warm temperate marine shelf faunas which included cryptostomes, trepostomes, and cystoporates. In the middle of the Early Permian (Leonardian), the assemblage of Greater Pangaea further disrupted the marine shelf faunas giving rise to biogeographic provinces and finally realms. In the assembling of Pangaea, the northward transport of plates and cratons caused the northern marine shelf of Pangaea to be moved into cooler and cooler waters. Tectonic movements caused cool ocean currents to be redirected toward the equator along the western marine shelves of Pangaea. Faunal diversity greatly increased apparently as a result of the flow of consistently warm equatorial currents along the eastern marine shelves of Pangaea.
Phytogeographic patterns and continental configurations during the Permian Period
Authors: Ziegler A. M.
Published: April 2008

The climatic influences on vegetation in the present world can serve as an excellent model for the Permian, there being approximately the same level of floral differentiation and the same relatively cold polar regions. Accordingly, a system of present day climatically defined biomes, developed by Walter, is adapted herein for palaeophytogeographic purposes. There are ten biomes altogether which range from the tropical 'everwet' (biome 1) to the polar 'glacial' (biome 10).

Biome 1 is represented by the tropical rainforests of the Cathaysian province
sensu stricto
which was populated by the arborescent lycopods and sphenophytes, and the Gigantopterids which are interpreted as lianas (vines). This is flanked by the lower diversity 'summerwet' biome 2, the Atlantic Province, a zone which today is characterized by savanna vegetation, and in the Permian was represented by the pteridosperm
Callipteris
and the primitive conifers. Biome 3 was effectively 'abiotic' and is expressed geologically by evaporite belts.

The 'winterwet' or Mediterranean climate of today (biome 4) was not well developed in the Permian, or perhaps just not well preserved, but I attribute some low diversity floras of Kazakhstan to this biome. Biome 5, the 'warm temperate' biome is well developed in both hemispheres, and, like biome 1, is characterized by high diversity floras and abundant swamp deposits. Not surprisingly, the biome 5 floras have been mistaken for biome 1 with which they are transitional in the modern world and with which they share similar climatic conditions. In the Permian Angaran Realm, the Pechora Province represents this biome, while the Austroafroamerican Province is the Gondwanan equivalent. Often, biome 5 floras have been simply termed 'mixed'. Proceeding poleward across the 'hard frost line', the cool temperate floras of biome 6 were populated by diverse herbaceous sphenophytes and deciduous trees (the cordaitids of Angara and the similarly diverse glossopterids of Gondwana). Areas in the temperate zone that were remote from moisture sources are assigned to biome 7 and are only known in the southern hemisphere by some aeolian deposits in Argentina. The 'cold temperate' biome 8 is a low diversity equivalent of biome 6, and has been given the name
Gangamopteris
Flora in the southern hemisphere. The 'tundra' environment, biome 9, and the truly glacial deposits, biome 10, are known only from the southern hemisphere.
Palaeogeographic evolution of southwestern Europe during Early Palaeozoic times
Authors: Robardet M. , Paris F. , Racheboeuf P. R.
Published: April 2008

In the Late Ordovician, both SW Europe and Africa were situated in high latitudes. Sedimentary fades and biogeography suggest that these regions were separated by the Rheic (Mid-European) Ocean from Baltica, with the suture lying between the Armorican Massif and the Ardennes. During the Silurian and the Devonian, palaeobiogeographic affinities persisted between S Europe and N Africa. It is concluded that S Europe consisted of several discrete blocks or microplates prior to the Hercynian Orogeny.
Ordovician sedimentary facies and faunas of southwest Europe: palaeogeographic and tectonic implications
Authors: Young T. P.
Published: April 2008

The term st European Platform is introduced for an Ordovician shelf now within the western Variscides. The geometry of the sedimentary facies belts and their faunal variation suggest that it formed a promontory on the Gondwanan margin. The palaeogeography of the platform is discussed with particular reference to the Centro-Iberian/Armorican area, especially central Portugal.

The sedimentary history of the Centro-Iberian/Armorican area was controlled by basement structures. Rapid local subsidence during Early Ordovician extension was followed by later differential subsidence along these early structures. The thin sequences indicate low overall rates of subsidence. The dominantly clastic shallow marine sediments show strong storm influence. Individual sediment packets occur over wide areas indicating little syndepositional relief. The linear nature of facies belts allows reconstruction of the relative orientation of some blocks within the Variscides, and indicates strike-slip faulting during early Variscan events, with subsequent (Carboniferous) rotation of most of Iberia.

Faunas from SW Europe from a homogeneous group related to those of the classic 'Mediterranean Province' areas of Bohemia and Morocco, and more distantly to those of the Avalonian terrane. Faunal migration into the West European Platform from Avalonia accompanied progressive northward drift of the platform, occuring particularly during periods of eustatic sea-level rise in the early Llanvirn, the early Caradoc and the early Ashgill
Stratigraphy of the oil and gas reservoirs: UK Continental Shelf
Authors: Brown Stewart
Published: April 2008

The petroliferous sedimentary basins of the UK Continental Shelf are remarkable for the diversity of their reservoir strata. Reservoir rocks in fields currently in production range in age from Devonian to earliest Eocene, but significant hydrocarbon discoveries have also been made in rocks as as young as the mid-Eocene. The reservoirs are predominantly siliciclastic rocks, with facies ranging from continental fluvial and aeolian, to marine gravity flow deposits from sub-wave base environments.

In this paper stratigraphic context of the producing horizons in the UK Continental Shelf (UKCS), principally the North Sea, is reviewed, and the sedimentation of the reservoir strata placed in an outline geological history. The main producing horizons are described in summary. Matters of stratigraphic terminology and correlation both between fields and between basins are discussed.

A lithostratigraphy for the UK southern North Sea was established by Rhys (1974), and for the central and northern North Sea by Deegan & Scull (1977). Although these schemes have proved to be fairly robust, in the last 13 years the acquisition of new data plus a proliferation of new terms not fully documented in the public domain, argue strongly for a comprehensive revision and rationalization which is beyond the scope of this paper. Attempts in the public domain to standardize nomenclature across international boundaries in the North Sea, pursued by Deegan & Scull (1977) for the UK and Norwegian sectors, have lapsed for the most part in subsequent years.

Economic basement in the UK North Sea can be regarded at present
The Beryl Field, Block 9/13, UK North Sea
Authors: Knutson C. A. , Munro I. C.
Published: April 2008

The Beryl Field, the sixth largest oil field in the UK sector of the North Sea, is located within Block 9/13 in the west-central part of the Viking Graben. The block was awarded in 1971 to a Mobil operated partnership and the 9/13-1 discovery well was drilled in 1972. The Beryl A platform was emplaced in 1975 and the Beryl B platform in 1983. To date, ninety-five wells have been drilled in the field, and drilling activity is anticipated into the mid-1990s.

Commercial hydrocarbons occur in sandstone reservoirs ranging in age from Upper Triassic to Upper Jurassic. Structurally, the field consists of a NNE orientated horst in the Beryl A area and westward tilted fault blocks in the Beryl B area. The area is highly faulted and complicated by two major and four minor unconformities. The seal is provided by Upper Jurassic shales and Upper Cretaceous marls.

There are three prospective sedimentary sections in the Beryl Field ranked in importance as follows: the Middle Jurassic coastal deltaic sediments, the Upper Triassic to Lower Jurassic continental and marine sediments, and the Upper Jurassic turbidites. The total ultimate recovery of the field is about 800 MMBBL oil and 1.6 TCF gas. As of December 1989, the field has produced nearly 430 MMBBL oil (primarily from the Middle Jurassic Beryl Formation), or about 50% of the ultimate recovery. Gas sales are scheduled to begin in the early 1990s. Oil and gas production is forecast until licence expiration in 2018.

The Beryl Fields is located 215 miles northeast of Aberdeen, about 7 miles from the United Kingdom-Norwegian boundary. The field lies within Block 9/13 and covers and area of approximately 12 000 acres in water depths ranging from 350-400 ft. Block 9/13 contains several hydrocarbon-bearing structures, of which the Beryl Fields is the largest (Fig. 1). The field is subdivided into two producing areas: the Beryl Alpha area which includes the initial discovery well, and the Beryl Bravo area located to the north. The estimated of oil originally in place is 1400 MMBBL for Beryl A and 700 MMBBL for Beryl B. The fiel has combined gas in place of 2.8 TCF, consisting primarily of solution gas. Hydrocarbon accumulations occur in six reservoir horizons ranging in age from Upper Triassic to Upper Jurassic. The Middle Jurassic (Bathonian to Callovian) age Beryl Formation is the main reservoir unit and contains 78% of the total ultimate recovery.

The field was named after Beryl Solomon, the wife of Charles Solomon, who was president of Mobil Europe in 1972 when the field was discovered. The satellite fields in Block 9/13 (Nevis, Ness and Linnhe) are named after Scottish lochs.
The South Brae Field, Block 16/7a, UK North Sea
Authors: Roberts Martin J.
Published: April 2008

South Brae Oilfield lies at the western margin of the South Viking Graben, 161 miles northeast of Aberdeen. Oil production began in July 1983 from a single platform located in 368 ft of water. The field originally contained 312 MMBBL of recoverable reserves, and in May 1990, cumulative exports of oil and NGL reached 219 MMBBL. The reservoir lies at depths in excess of 11800 ft TVSS, has a maximum gross hydrocarbon column of 1670 ft, and covers an area of approximately 6000 acres.

The reservoir is the Upper Jurassic Brae Formation which is downfaulted against tight sealing rocks of probable Devonian age at the western margin of the field. The other field margins are constrained by a combination of structural dip and stratigraphic pinchout.

The reservoir is capped by the Kimmeridge Clay Formation, which is also the source of the oil.
The Eider Field, Block 211/16a and 211/21a, UK North Sea
Authors: Wensrich M. D. , Eastwood K. M. , Van Panhuys C. D. , Smart J. M.
Published: April 2008

The Eider Oilfield is located some 160 knortheast of the Shetland Islands mainly in Block 211/16a, part of Production Licence P296, with the southern tip extending into Block 211/2la. The discovery well was drilled in 1976 in a water depth of about 530 ft. Hydrocarbons are trapped at a depth of 8750 ft TVSS in an easterly dipping fault block that is part of the Tern-Eider horst in the East Shetlands Basin. The reservoir is the Middle Jurassic Brent Group, deposited in a wave-dominated delta system. It has an average gross thickness of 259 ft and an average net thickness of 210 ft. Porosities average 23% and permeabilities 375 md. The expected STOIIP and Ultimate Recovery are estimated at 204 MMBBL and 85 MMBBL respectively, representing a recovery factor of 42%.

The field is planned to be developed by five producers drilled along the crest of the structure. Pressure maintenance and sweep (secondary recovery) will be provided by four down-flank water injectors. The Eider production facility is a satellite platform of the neighbouring North Cormorant and Tern platforms and is designed for future unmanned operation. Production started in November 1988 and averaged some 54 000 BOPD. Water injection began in June 1989, using water, piped at injection pressure, from the Tern platform. First stage processing of the crude oil is carried out on the Eider platforms and then it is piped to the North Cormorant platform for further processing. From there it is evacuated via the Cormorant Alpha platform into the Brent System pipeline for export to the Sullom Voe terminal.
The Emerald Field, Blocks 2/10a, 2/15a, 3/11b, UK North Sea
Authors: Stewart D. M. , Faulkner A. J. G.
Published: April 2008

The Emerald Oil Field lies in Blocks 2/10a, 2/15a and 3/1 lb in the UK sector of the northern North Sea. The field is located on the 'Transitional Shelf, an area on the western flank of the Viking Graben, downfaulted from the East Shetland Platform. The first well was drilled on the structure in 1978. Subsequently, a further seven wells have been drilled to delineate the field.

The Emerald Field is an elongate dip and fault closed structure subparallel to the local NW-SE regional structural trend. the 'Emerald Sandstone' forms the main reservoir of the field and comprises a homogeneous transgressive unit of Callovian to Bathonian age, undelain by tilted Precambrian and Devonian Basement Horst blocks. Sealing is provided by siltstones and shales of the overlying Healther and Kimmeridge Clay Formations. The reservoir lies at depths between 5150-5600 ft, and wells drilled to date have encountered pay thicknesses of 42-74 ft. Where the sandstone is hydrocarbon bearing, it has a 100% net/ gross ratio. Porosities average 28% and permeabilities lie in the range 0-1 to 1.3 darcies. Wireline and test data indicate that the field contains a continouous oil column of 200 ft. Three distinct structural culminations exist on and adjacent to the field, which give rise to three separate gas caps, centred around wells 2/10a-4, 2/10a-7 and 2/10a-6 The maximum flow rate achieved from the reservoir to date is 6822 BOPD of 24° API oil with a GOR of 300 SCF/STBBL. In-place hydrocarbons are estimated to be 216 MMBBL of oil and 61 BCF of gas, with an estimated 43 MMBBL of oil recoverable by the initial development plan. initial development drilling began in Spring 1989 and the development scheme will use a floating production system. Production to the facility, via flexible risers, is from seven pre-drilled deviated wells with gas lift. An additional four pre-drilled water injection wells will provide reservoir pressure support.
The Heather Field, Block 2/5, UK North Sea
Authors: Penny Brian
Published: April 2008

The Heather Oil Field is located at the western margin of the East Shetland Basin, in the northern North Sea, and is operated by Unocal UK Ltd. Oil is trapped in Middle Jurassic Brent Group sandstones below 9500 ft TVSS in a highly-faulted reservoir that has undergone considerable diagenetic modification. The field was declared commerical in 1974, began producing in 1978 from a single platform and has recovered 84 MMBBL of oil to date through primary and secondary recovery methods. Ultimate reserves are estimated to be 100 MMBBL of oil.
The Magnus Field, Block 211/7a, 12a, UK North Sea
Authors: Shepherd M.
Published: April 2008

abstract

Magnus is the most northerly producing field in the UK sector of the North Sea. The oil accumulation occurs within sandstones of an Upper Jurassic submarine fan sequence. The combination trap style consists of reservoir truncation by unconformity at the crest of the easterly dipping fault block structure and a stratigraphic pinchout element at the northern and southern limits of the sand rich fan. The reservoir is enveloped by the likely hydrocarbon source rock, the organic rich mudstones of the Kimmeridge Clay Formation.
The Miller Field, Blocks 16/7B, 16/8B, UK North Sea
Authors: Rooksby S. K.
Published: April 2008

The Miller Oil Field is located on the western margin of the South Viking Graben in UKCS Blocks 16/7b and 16/8b. The oil is trapped in Upper Jurassic turbidite sands shed from the Fladen Ground Spur via the Brae complex submarine fan systems. The reservoir sands are of good quality with an average porosity of 16% and permeabilities occasionally in excess of 1 Darcy. The trap is formed within a subtle structural-stratigraphic combination. Overlying slow velocity Lower Cretaceous sediments produce a time flat which, after depth conversion, produces a 3-way dip closed feature. The trap is completed by stratigraphic pinchout of the reservoir sands to the northwest. The most recent (1985) seismic data allow the top reservoir reflector to be picked directly, which was not the case during the exploration and appraisal phase, when only the Top Kimmeridge Clay seismic pick could be made. The estimate of recoverable hydrocarbons is currently 300 MMBBL of oil and 570 BCF of gas. Development drilling commenced early in 1989. No results are yet available.
The Ninian Field, Blocks 3/3 & 3/8, UK North Sea
Authors: Van Vessem E. J. , Gan T. L.
Published: April 2008

The Ninian Field, located in the northern North Sea, lies in the East Shetland Basin on the west side of the Viking Graben. The field straddles Blocks 3/3 and 3/8 and is developed under a unitization agreement with Chevron UK Limited as operator. The structure is a westward tilted fault block. The estimated original oil-in-place contained in the marine-deltaic sandstones of the Middle Jurassic Brent Group, is 2920 MMBBL, of which an estimated 35 to 40% is recoverable. The oil is a paraffinic-naphthenic type with an API gravity of 36°. The field development consists of three fixed platforms with a total of 109 drilling slots. The natural drive in the field is negligible so that water flooding is required. The production of the Ninian Field started in December 1978 and reached a peak of 315 000 BOPD in the summer of 1982. At the end of 1988 over 811 MMBBL had been produced.
The Thistle Field, Blocks 211/18a and 211/19, UK North Sea
Authors: Williams R. R. , Milne A. D.
Published: April 2008

The Thistle Oilfield is located on the western margin of the North Viking Graben in UK Blocks 21l/18a and 211/19. The field was discovered in 1973 by the Halibut Group, operated by the Signal Oil Company. The discovery well was drilled in 1973 and the field was declared commerical before completion of the first two appraisal wells. The extension of the field into Block 211/19 was confirmed by well 211/19-1 drilled in 1974 and the field was subsequently unitized.

The Middle Jurassic Brent Group forms the oil-bearing reservoir sequence. The structure is an easterly dipping, rotated fault block divided into five main compartments by N-S normal faults and E-W cross faults. A 60 slot drilling and production platform was installed in 1976 and production began in February 1978. It is now connected by pipeline to Sullom Voe and production through this link commenced in late 1978. Due to only limited aquifer support, injection wells have been drilled on the east flank of the field, in order to maintain reservoir pressure. In addition, several wells in partly isolated fault blocks are produced by gas lift completions. The current STOIIP is estimated at 794 MMBBL of which 396 MMBBL will ultimately be recovered. Cumulative production to the end of 1988 was 334 MMBBL from 34 production wells, with support from 13 injection wells.
The Balmoral Field, Block 16/21, UK North Sea
Authors: Tonkin P. C. , Fraser A. R.
Published: April 2008

The Balmoral oilfield operated by Sun Oil Britain Ltd, lies within UK blocks 16/21 b and 16/21c, 140 miles off the northeast coast of Scotland. The field was discovered by the drilling of well 16/21-1 in 1975. Andrew Formation sandstones of Late Palaeocene age form the reservoir, which is sealed by Lista Formation claystones. The sandstones are of submarine fan origin sourced from the north and west of the area. The trap is structural, formed by the differential compaction of Tertiary sediments over a Palaeozoic structural high.

The upper section of the reservoir consists of two units of consolidated sandstone (units U and M) of channel-fill origin separated by a channel abandonment claystone (unit SI). Porosities for these sandstone units range from 17-28% and permeabilities are up to 3300 md. The lower section of the reservoir consists of friable sandstones (Unit F), characterized by grain-coating clays which have prevented consolidation. This unit is mainly of submarine fan lobe origin. Porosities range from 20-28% and permeabilities are up to 700 md.

Balmoral came on stream in November 1986. Recoverable reserves are estimated to be 68 MMBBL of undersaturated 39.9° API oil, and annual production remains at the 35 000 BOPD plateau rate.

The oil is produced from 12 wells with reservoir pressure maintained by the injection of water through a further six wells. These are all tied into a floating production vessel (FPV), the first such purpose-built production facility to be used in the North Sea. Production in Balmoral is expected to continue until the year 2001.
The Beatrice Field, Block 11/30a, UK North Sea
Authors: Stevens V.
Published: April 2008

The Beatrice Field was discovered in 1976 in Block 1l/30a within the Inner Moray Firth Basin. The reservoir consists of multilayered Lower and Middle Jurassic sediments containing a STOIIP of 480 MMBBL of high wax crude oil. The reservoir sequence comprises 1100 ft of Hettangian (Lower Jurassic) to Callovian (Middle Jurassic) sandstones, siltstones and claystones. The Beatrice Field is co-sourced by a combination of Devonian and Jurassic rocks. The hydrocarbon trap comprises a tilted faultblock, the top of which is truncated by the main field boundary fault. The field has low energy, and the
P
i
of 2897 psi at 6500 ft TVSS, GOR 126 SCF/STBBL and
P
h
of 635 psi, together with the poor aquifer influx, necessitated the development of water injection from the start of production and use of electrical submersible pumps in all wells. Ultimate oil recovery is expected to be 146 MMBBL. The field has been developed with four platforms at three sites in 133 ft waterdepth. The crude is transported 42 miles by peline to the dedicated oil terminal at Nigg on the Cromarty Firth.
The Crawford Field, Block 9/28a, UK North Sea
Authors: YALIZ A.
Published: April 2008

The Crawford Field was discovered in 1975 in UK Block 9/28 and the first oil was produced in April 1989. The field has a complex structural history. The reservoir is located on a down-faulted, westward tilting faultblock along the western margin of the Viking Graben. The eastern margin of the faultblock is severely truncated at Base Cretaceous level. The main producing zones comprise Middle Jurassic (Brent Group equivalent) and Triassic (Skagerrak Formation) sandstones. The seal is formed by Cretaceous marls and limestones. Reservoir quality and thickness are extremely variable, and drainage areas are limited. The reservoir fluid is a medium gravity oil having a thin gas cap. Oil in-place is in the order of 130 MMBBL but recovery factors are expected to be low.
The Fulmar Field, Blocks 30/16 & 30/llb, UK North Sea
Authors: Stockbridge C. P. , Gray D. I.
Published: April 2008

The Fulmar Field is located on the southwestern margin of the Central Graben in Blocks 30/16 and 30/11b of the UK sector of the North Sea. The field is a partially eroded anticline with steeply dipping flanks formed by the withdrawal of deeper Zechstein salt. The reservoir consists of thick Upper Jurassic, shallow marine, very bioturbated sandstones of the Fulmar Formation and deep marine turbidites interbedded within the Kimmeridge Clay Formation. Seal to the reservoir is provided by the Kimmeridgian shales in the west and Upper Cretaceous chalks which unconformably overlie the Fulmar Formation in the east.

The reservoir section has been subdivided into seven members and 14 reservoir units. Reservoir quality is generally excellent, although there are lower-energy sandstone facies found in the eastern part of the field. The Fulmar oil is highly undersaturated and a secondary gas cap has been created by gas injection.

Two exploration wells were drilled before the field was declared commercial. Development is from a 36 slot steel platform and a six slot template. Oil evacuation is by a floating storage unit and gas evacuation is via the Fulmar gas pipeline. Total STOIIP is 815 MMBBL and ultimate recovery is 462 MMBBL oil and 264 BCF gas. Production started in 1982 and 319 MMBBL oil and 121 BCF gas have been produced by year-end 1988. A total of 80 BCF gas has been re-injected for conservation purposes.
The Kittiwake Field, Block 21/18, UK North Sea
Authors: Glennie K. W. , Armstrong L. A.
Published: April 2008

Kittiwake was discovered by well 21/18-2 within a 7th Round block, part of Production Licence P351. Highly undersaturated oil is present in the Fulmar Formation and Skagerrak Formation reservoir sequences; 70
MMBBL
of reserves is in Fulmar sandstones whereas oil in the Skagerrak is mostly immovable. The field will be developed from a single 16-slot platform with initially 5 producing and 5 water-injection wells. Solution gas is removed via the Fulmar Field pipeline to St Fergus and, as from September 1990, the oil is loaded onto tankers from a single-buoy mooring.
The Maureen Field, Block 16/29a, UK North Sea
Authors: Cutts P. L.
Published: April 2008

The Maureen Oilfield is located on a fault-bounded terrace in Block 16/29a of the UK Sector of the North Sea, at the intersection of the South Viking Graben and the eastern Witch Ground Graben. The field was discovered in late 1972 by the 16/29-1 well, and was confirmed by three further appraisal wells. The reservoir consists of submarine fan sandstones of the Palaeocene Maureen Formation, deposited by sediment gravity flows sourced from the East Shetland Platform. The Palaeocene sandstones, ranging from 140 to 400 ft in thickness, have good reservoir properties, with porosities ranging from 18-25% and permeabilities ranging from 30-3000 md. Hydrocarbons are trapped in a simple domal anticline, elongated NW-SE, which was formed at the Palaeocene level by Eocene/Oligocene-aged movement of underlying Permian salt. The reservoir sequence is sealed by Lista Formation claystones. Geochemical analysis suggests Upper Jurassic Kimmeridge Clay shales have been the source of Maureen hydrocarbons. Estimated recoverable reserves are 210 MMBBL. Twelve production wells have been drilled on the Maureen Field. A further seven water injection wells have been drilled to maintain reservoir pressure.
The Tartan Field, Block 15/16, UK North Sea
Authors: Coward R. N. , Clark N. M. , Pinnock S. J.
Published: April 2008

Tartan Field lies 118 miles northeast of Aberdeen in UK Block 15/16 on the southern flank of the Witch Ground Graben. The Field consists of two major southerly-dipping rotated fault blocks, the 'Upthrown Block' to the south and the 'Downthrown Block' to the north. The primary reservoir comprises Oxfordian-Kimmeridgian shallow marine sandstone of the Piper Formation deposited during a regional marine transgression. The secondary reservoir consists of Volgian turbidites (the 'Hot Lenses') within the Kimmeridge Clay Formation. The accumulations have been sourced from maturation of the Kimmeridge Clay Formation below approximately 10000 ft in adjacent basins. The Piper Formation exhibits markedly different petrophysical properties within each block. A relatively homogeneous intergranular porosity system is present throughout the oil zone of the 'Upthrown Block'. Porosities are lower and more variable in the 'Downthrown Block' as a result of cementation and the presence of an intense compaction fabric. The trapping mechanism is a combination of structural and stratigraphic elements. The Field was discovered in December 1974 by the 15/16-1 well which penetrated 263 ft of Piper Formation sandstone full to base with oil. A further ten straight holes and three sidetracked holes delineated the structure. Tartan Field came onstream in January 1981 and is currently producing 30000 BOPD through eight platform producers, assisted by six subsea water injection wells. Ultimate recoverable reserves are currently estimated at 116 MMBBL of crude oil.
The Camelot Fields, Blocks 53/1a, 53/2, UK North Sea
Authors: Holmes A. J.
Published: April 2008

The Camelot Gas Fields (Camelot North, Northeast and Central-South) lie in Blocks 53/la and 53/2 in the Southern North Sea, some 30 miles (48 km) east of Great Yarmouth. Initial sub commercial discovery wells were drilled in 1967, 1969 and 1972. Further exploration and appraisal drilling was carried out in 1987 and 1988. This paper covers the Field history up to the 53/la-10 appraisal well in June 1988. The Lower Permian, Leman Sandstone Formation is the reservoir, with the gas accumulations trapped in tilted fault terraces. The Leman Sandstone Fm. in the Camelot area is 800 ft thick with a gas column up to 200 ft. Development of the fields will be in two phases. Phase I will consist of 5 wells deviated from the Camelot 'CA' platform to produce reserves from the Camelot North and Central-South Fields. Production commenced in October 1989. Phase II scheduled for 1991/92 will tie-in the Camelot Northeast Field. Gas is exported from the unmanned 'CA' gathering platform via pipeline to Amoco's Leman 'A' complex, from where the gas is transported to shore via the existing Amoco pipeline from Leman to Bacton. Total recoverable reserves for the Camelot Fields are estimated at 215 BCF.