Direct detection using AVO, Central Graben, North Sea

Geophysics ◽  
1992 ◽  
Vol 57 (2) ◽  
pp. 313-325 ◽  
Author(s):  
Allan G. Snyder ◽  
Keith H. Wrolstad
Keyword(s):  
North Sea ◽  
Direct Detection ◽  
Clay Content ◽  
Multiple Reflections ◽  
Well Control ◽  
The United Kingdom ◽  
Fluid Saturation ◽  
Amplitude Versus Offset ◽  
On Line ◽  
Well Data

An amplitude versus offset (AVO) study was undertaken for Lines ECL-1 and -2 and Well A of the United Kingdom North Sea to determine if variations in fluid saturation can be detected in Eocene sand mounds. These features are a major play in this area. The Eocene sands contain gas and oil in Well A. Elastic modeling using the well data was done to match the seismic common midpoint (CMP) gather. Target zone fluid saturations in the model were then altered to investigate changes in AVO and stacked trace response. The model and field data were processed using the same processing steps and parameters. Seismic offset dependent amplitude stack (SODAS), a color display system, was used to display the AVO results for the field and model data. It was found that gas, oil, and water sands could be distinguished from each other, though full and partial gas saturation were indistinguishable. Clay content, porosity, and multiple reflections also had important effects on the AVO response. On the basis of the hydrocarbon indicators that were investigated we then interpreted the hydrocarbon limits on Line ECL-1 with well control and evaluated Line ECL-2, which has an undrilled prospect. From our analysis, we concluded that waterbearing sands were most likely present in the prospect area on Line ECL-2, though the data is rather inconclusive.

Triassic stratigraphy of the southern North Sea Basin

1968 ◽  
Vol 254 (790) ◽  
pp. 1-36 ◽  
Keyword(s):  
North Sea ◽  
West Germany ◽  
Palynological Analysis ◽  
North West ◽  
Subsurface Geology ◽  
Southern North Sea ◽  
The North ◽  
The United Kingdom ◽  
The North Sea ◽  
Well Data

Intensive drilling activity, particularly in the United Kingdom part of the North Sea, has greatly increased our knowledge of the subsurface geology of north-west Europe. The Triassic, perhaps more than any other system, has provided results of a special interest. In this paper a stratigraphical study of the Triassic System of the southern North Sea basin has been undertaken by lithological and palynological analysis. The type Germanic Triassic and the dated Alpine Triassic are briefly reviewed. The facies development of the Germanic Triassic is traced by means of subsurface data from north-west Germany and the northern Netherlands into the North Sea. Further studies of the onshore Triassic of England from subsurface well data and surface outcrop sections are discussed. The results, particularly those from wells in the North Sea, provide a lead to the understanding of the position of the English Triassic of Keuper and Bunter within the framework of the Germanic Triassic.

Health care Online

2000 ◽  
Vol 1 (2) ◽  
pp. 24-25
Keyword(s):  
Health Care ◽  
Health Care Policy ◽  
Central Government ◽  
Medical Profession ◽  
Medical Opinion ◽  
Proactive Approach ◽  
The United Kingdom ◽  
Wide Range ◽  
On Line ◽  
The Subject

The BMJ has always been recognised as a leading medical journal for a wide range of subjects, and has always been useful for nurses to access for up to date and current medical opinion. Recently the BMJ has diversified to take on a more political nature, with its content reflecting a more proactive approach to influencing health care policy in the United Kingdom by the medical profession. As such the BMJ has become extremely useful for identifying opinions of current ‘hot topics’ for nurses that are headline news such as nurse consultants, hospital administration and central government policy. However, one problem remains, trying to find the original copy in the library will remain difficult. After spending the best part of an hour to suddenly realise that ‘how silly you are for not realising that BMJ March 1997 is filed in the British Journal of Nursing section 1998!!’ is often a frustrating and demoralising experience - particularly if after finding the article you find it has nothing to do with the subject that you are researching. This problem is to be banished forever with the BMJ website. The full BMJ is available free on line. The excellent search engine is particularly useful and is accurate when matching target articles. All articles are available for ‘full text’ downloads free of charge.

The Pressure Dependence of the Archie Cementation Exponent for Samples from the Ordovician Goldwyer Shale Formation in Australia

SPE Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Zhiqi Zhong ◽  
Lionel Esteban ◽  
Reza Rezaee ◽  
Matthew Josh ◽  
Runhua Feng
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Complex Impedance ◽  
Clay Content ◽  
Exchange Capacity ◽  
Shale Formations ◽  
Fluid Saturation ◽  
Confining Pressures ◽  
Log Interpretation

Summary Applying the realistic cementation exponent (m) in Archie’s equation is critical for reliable fluid-saturation calculation from well logs in shale formations. In this study, the cementation exponent was determined under different confining pressures using a high-salinity brine to suppress the surface conductivity related to the cation-exchange capacity of clay particles. A total of five Ordovician shale samples from the Canning Basin, Australia, were used for this study. The shale samples are all illite-rich with up to 60% clay content. Resistivity and porosity measurements were performed under a series of confining pressures (from 500 to 8,500 psi). Nuclear magnetic resonance (NMR) was used to obtain porosity and pore-size distribution and to detect the presence of residual oil. The complex impedance of samples was determined at 1 kHz to verify the change in pore-size distribution using the POLARIS model (Revil and Florsch 2010). The variation of shale resistivity and the Archie exponent m at different pressures is caused by the closure of microfractures at 500 psi, the narrowing of mesopores/macropores between 500 and 3,500 psi, and the pore-throat reduction beyond 3,500 psi. This study indicates that unlike typical reservoirs, the Archie exponent m for shale is sensitive to depth of burial because of the soft nature of the shale pore system. An equation is developed to predict m under different pressures after microfracture closure. Our study provides recommended experimental procedures for the calculation of the Archie exponent m for shales, leading to improved accuracy for well-log interpretation within shale formations when using Archie-basedequations.

Depositional Modelling of UK North Sea Alba Field Reservoir

1992 ◽  
Vol 10 (4-5) ◽  
pp. 300-320
Author(s):  
Ian W. Thomas ◽  
John D. Collinson ◽  
Colin M. Jones
Keyword(s):  
North Sea ◽  
Middle Eocene ◽  
Oil Field ◽  
Seismic Survey ◽  
Linear Feature ◽  
The United Kingdom ◽  
Submarine Channel ◽  
Partial Filling ◽  
Detailed Interpretation ◽  
Central North Sea

The Alba Field is contained within block 16/26 of the Central North Sea of the United Kingdom. This oil field was discovered in 1984 by Chevron UK Ltd with the 16/26–5 well and has been appraised by 16 wells and sidetracks. The field is currently being developed and is scheduled to achieve first production around the end of 1993. A 3-D seismic survey, acquired in 1989, has greatly enhanced delineation of the field. It is a NW-SE trending linear feature approximately 5.25 miles (8.5 kms) in length with adjacent satellite structures. The reservoir sands comprise the Nauchlan Member of the Alba Formation (Horda Group) and are primarily of Middle Eocene age. Gross sand thicknesses in excess of 400 ft (120 m) are present within the field area with porosities ranging up to 38% and permeabilities of the order of 2800 mD. The sands were deposited as a series of submarine channel fills whose mutual relationships present problems of detailed interpretation. Channel sandbodies appear to be discontinuous along their length for a variety of reasons including erosive relief on the base of the channel, and partial filling of channels otherwise filled by mud.

scholarly journals Geological evolution of the Chalk Group in the northern Dutch North Sea: inversion, sedimentation and redeposition

2018 ◽  
Vol 156 (07) ◽  
pp. 1265-1284
Author(s):  
EVA VAN DER VOET ◽  
LEONORA HEIJNEN ◽  
JOHN J. G. REIJMER
Keyword(s):  
North Sea ◽  
Late Cretaceous ◽  
Seismic Survey ◽  
Structural Elements ◽  
The North ◽  
Show Evidence ◽  
New Finding ◽  
The North Sea ◽  
Thickness Variations ◽  
Well Data

AbstractIn contrast to the Norwegian and Danish sectors, where significant hydrocarbon reserves were found in chalk reservoirs, limited studies exist analysing the chalk evolution in the Dutch part of the North Sea. To provide a better understanding of this evolution, a tectono-sedimentary study of the Late Cretaceous to Early Palaeogene Chalk Group in the northern Dutch North Sea was performed, facilitated by a relatively new 3D seismic survey. Integrating seismic and biostratigraphic well data, seven chronostratigraphic units were mapped, allowing a reconstruction of intra-chalk geological events.The southwestward thickening of the Turonian sequence is interpreted to result from tilting, and the absence of Coniacian and Santonian sediments in the western part of the study area is probably the result of non-deposition. Seismic truncations show evidence of a widespread inversion phase, the timing of which differs between the structural elements. It started at the end of the Campanian followed by a second pulse during the Maastrichtian, a new finding not reported before. After subsidence during the Maastrichtian and Danian, renewed inversion and erosion occurred at the end of the Danian. Halokinesis processes resulted in thickness variations of chalk units of different ages.In summary, variations in sedimentation patterns in the northern Dutch North Sea relate to the Sub-Hercynian inversion phase during the Campanian and Maastrichtian, the Laramide inversion phase at the end of the Danian, and halokinesis processes. Additionally, the Late Cretaceous sea floor was characterized by erosion through contour bottom currents at different scales and resedimentation by slope failures.

List of Publications Recording the Results of Researches carried out under the Auspices of the Marine Biological Association of the United Kingdom in their Laboratory at Plymouth or on the North Sea Coast from 1886–1900

1900 ◽  
Vol 6 (1) ◽  
pp. 115-135
Keyword(s):  
United Kingdom ◽  
North Sea ◽  
Biological Association ◽  
The North ◽  
Marine Biological Association ◽  
The United Kingdom ◽  
The North Sea ◽  
Different Parts ◽  
Sea Coast ◽  
North Sea Coast

The following list has been classified, so far as practicable, according to subjects, in order that it may be useful for purposes of reference. The list does not include publications recording the results of observations made on material supplied by the Association to workers in different parts of the country, of which a considerable amount is sent out each year.

scholarly journals Discriminatory expressions, the young and social networks: The effect of gender

Comunicar ◽  
2016 ◽  
Vol 24 (46) ◽  
pp. 67-76 ◽  
Author(s):  
David Dueñas-Cid ◽  
Paloma Pontón-Merino ◽  
Ángel Belzunegui-Eraso ◽  
Inma Pastor-Gosálbez
Keyword(s):  
Social Network Sites ◽  
The Internet ◽  
Redes Sociales ◽  
The United Kingdom ◽  
Cultural Minorities ◽  
On Line ◽  
Las Mujeres ◽  
La Red ◽  
Methodological Strategy ◽  
Do So

In the framework of the «Project I: CUD» (Internet: Creatively Unveiling Discrimination), carried out in the United Kingdom, Italy, Belgium, Romania and Spain, we conducted a study into the expressions of discrimination used by young people on social network sites (SNS). To do so we designed a methodological strategy for detecting discriminatory content in 493 Facebook profiles and used this strategy to collect 363 examples for further analysis. Our aims were to compile information on the various types of discriminatory content and how they function online in order to create tools and strategies that can be used by trainers, teachers and families to combat discrimination on the Internet. Through this study we have detected patterns between young men and young women that reveal that there is a feminine and a masculine way of behaving on the Internet and that there are different ways of expressing discrimination on SNS. Men tend to be more direct in their posting and sharing of messages. Their messages, which are also more clearly discriminatory, focus more on discrimination towards ethnic groups and cultural minorities. Women, on the other hand, tend to use indirect (reactive) discriminatory strategies with a less obvious discriminatory component that mainly focuses on sociocultural status and physical appearance. En el marco del Proyecto «I:CUD» (Internet: Desenmascarando la discriminación creativamente), llevado a cabo en el Reino Unido, Italia, Bélgica, Rumanía y España, hemos desarrollado una investigación sobre las expresiones de discriminación utilizadas por los jóvenes en las redes sociales (SNS). Para la realización de esta investigación, se ha diseñado una estrategia metodológica de detección de contenidos discriminatorios en 493 perfiles de Facebook que ha permitido encontrar 363 ejemplos para su análisis. El objetivo de la misma ha sido la obtención de información acerca de los tipos de contenidos discriminatorios y su forma de funcionamiento on-line, para facilitar la creación de herramientas y estrategias para luchar contra la discriminación en la Red, y su utilización por parte de formadores, docentes y familias. Como resultado, hemos detectado algunos patrones diferenciales entre hombres y mujeres jóvenes que nos permiten afirmar la existencia de una forma femenina y otra masculina de comportarse en Internet y un uso diferencial de las SNS en relación con la discriminación. En cuanto a ésta, los hombres tienden a tener más actividad directa (publicando y compartiendo mensajes), con contenidos más claramente discriminatorios y, sobretodo, centrados en la discriminación hacia grupos étnicos y minorías culturales. Las mujeres, por su parte, tienden a utilizar estrategias de discriminación no directas (reactivas), con una menor evidencia del componente discriminatorio. Ellas, mayoritariamente, dirigen las actitudes discriminatorias hacia la situación sociocultural y la apariencia física.

On-Line Process Optimization in a North Sea Field

1997 ◽  
Author(s):  
Y. Jalali ◽  
W. Van Wassenhove ◽  
C. Romano ◽  
R. Pickles
Keyword(s):  
Process Optimization ◽  
North Sea ◽  
On Line ◽  
Line Process

scholarly journals An invasive alien bivalve apparently provides a novel food source for moulting and wintering benthic feeding sea ducks

2019 ◽  
Vol 73 (1) ◽  
Author(s):  
Johanna Kottsieper ◽  
Philipp Schwemmer ◽  
Nele Markones ◽  
Anthony D. Fox ◽  
Stefan Garthe
Keyword(s):  
North Sea ◽  
Food Source ◽  
Spatial Scales ◽  
Food Resource ◽  
Sea Ducks ◽  
Novel Food ◽  
Important Prey ◽  
The United Kingdom ◽  
Sea Coast ◽  
North Sea Coast

AbstractSince its introduction from North America in the 1970s, the American razor clam Ensis leei (M. Huber, 2015) has successfully spread throughout North Sea coasts from Spain to Norway and the United Kingdom to the western Baltic. We investigated the distribution and abundance of this non-indigenous bivalve species as a potential novel food resource for common scoter Melanitta nigra (Linnaeus, 1758) along the eastern German North Sea coast. Highest densities of flightless moulting and wintering common scoters coincided with areas of high E. leei abundance. Other European studies showed common scoters extensively feed on E. leei. Even with these findings, it remains difficult to demonstrate convincingly that E. leei constitutes a major food source for common scoter in the German North Sea during their non-breeding season. However, our study suggests that E. leei has become an important prey item for internationally important concentrations of common scoters at large spatial scales.

scholarly journals On the Manufacture of Drift Bottles

1922 ◽  
Vol 12 (4) ◽  
pp. 700-716 ◽  
Author(s):  
E. W. Nelson
Keyword(s):  
United Kingdom ◽  
North Sea ◽  
Biological Association ◽  
Marine Biological ◽  
The North ◽  
Marine Biological Association ◽  
The United Kingdom ◽  
The North Sea

In the spring of 1920 the Ministry of Agriculture and Fisheries approached the Marine Biological Association of the United Kingdom with a view to the Association undertaking the manufacture of a large number of “Drift Bottles,” to be used in an extensive research into the resultant movements of the waters of the North Sea.

Sign in / Sign up

Export Citation Format

Share Document