Chemostratigraphy of Triassic successions on the southern Barents Sea Shelf – preliminary results from XRF Core Scanning.

2020 ◽  
Author(s):  
Sigrun Maret Kvendbø Hegstad ◽  
Juha Ahokas ◽  
Matthias Forwick ◽  
Sten-Andreas Grundvåg
Keyword(s):  
Large Scale ◽  
Barents Sea ◽  
Depositional Environments ◽  
Hydrocarbon Exploration ◽  
Marine Geology ◽  
Eurasian Plate ◽  
Preliminary Results ◽  
The Barents Sea ◽  
Xrf Core Scanning ◽  
Drill Cores

<p>The Barents Sea Shelf on the north-western corner of the Eurasian plate has a complex geological history, comprising large-scale processes controlled by plate movements, climatic variations and changing depositional environments. During the last decades, as the search for hydrocarbons within the area gained increased interest, Triassic sequences have been the target of comprehensive investigations. In our project, we test the potential of improving the correlation of Triassic strata using X-ray fluorescence (XRF) core scanning of siliciclastic drill cores.</p><p>XRF core scanning is a frequently used method on soft sediment cores, e.g. within marine geology and palaeo-climate studies. However, the applicability of this method on drill cores from exploration wells from the hydrocarbon industry has not been tested so far. We use this method to establish geochemical stratigraphic parameters, as well as to contribute to the identification of provenances, reconstruct palaeo-envrionments, and support the correlation of drill cores. This provides a novel, fast, inexpensive, and non-destructive method to be applied in hydrocarbon exploration, as well as in studies of lithified siliciclastic sediments in general.</p><p>Triassic intervals from 24 shallow drill cores from the southern Barents Sea (Finnmark Platform, Nordkapp Basin, Svalis Dome, Maud Basin and Bjarmeland Platform) provide the basis for this study. The cores have previously been comprehensively studied and described by IKU (the Norwegian Continental Shelf Institute; today SINTEF Petroleum Research), and studies of provenance and palaeo-environment have also been performed (e.g. Vigran et al., 1986). This data makes it possible to compare the geochemical units established in this study with other stratigraphic information.</p><p>We present preliminary results of establishing geochemical units from XRF core scanning, and the use of these for correlation within known stratigraphic frameworks and between geographic areas, as well as to increase the understanding of changes in provenance and palaeo-environments within these successions in the Barents Sea.</p><p>References:<br>Vigran, J.O., G. Elvebakk, T.L. Leith, T. Bugge, V. Fjerdingstad, R.M. Goll, R. Konieczny, and A. Mørk. 1986. 'Dia-Structure Shallow Drilling 1986. Main data report. IKU Rep. No. 21.3420.00/04/86, 242 pp'.</p><p> </p>

Reservoir Fluid Mapping While Drilling: Untapping the Barents Sea

2021 ◽  
Author(s):  
Maria Cecilia Bravo ◽  
Yon Blanco ◽  
Mauro Firinu ◽  
Tosi Gianbattista ◽  
Eriksen Martin ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Reservoir Characterization ◽  
Barents Sea ◽  
Hydrocarbon Composition ◽  
Hydrocarbon Exploration ◽  
Fluid Type ◽  
Pilot Hole ◽  
Fluid Identification ◽  
The Barents Sea ◽  
Petrophysical Evaluation

Abstract In complex and sensitive environments such as the northern Barents Sea, operations face multiple challenges, both technically and logistically. The use of logging while drilling (LWD) technology mitigates risks and assures acquisition of formation evaluation data in a complex trajectory. All data gathering was performed in LWD and provided the kernel for interpretation; alternate scenarios utilizing pipe conveyed wireline elevated risk factors as well as higher overall costs. Novel technology was required for this data acquisition, including fluid mapping while drilling (FMWD) that allows fluid identification with the use of downhole fluid analysis (DFA) using optical spectrometry as well as the retrieval of downhole fluid samples and a unique sourceless multifunction LWD tool delivering key data for the petrophysical evaluation. This paper presents a case study of the first application of a combination of FMWD and a petrophysical LWD toolstring in the Barents Sea. An excellent contribution to the operator of the PL229 that have pushed the boundaries of the formation sampling while drilling and set the basis to challenge the potentiality of this technique and improve the knowledge of the methodology that are the ultimate goals of this paper. Methods, procedures, process Hydrocarbon exploration, production, and transport in the Barents Sea are challenging. The shallow and complex reservoirs are at low temperature and pressure, potentially with gas caps. The Goliat field is the first offshore oil development in this environment, producing from two reservoirs: Realgrunnen and Kobbe. As part of the Goliat field infill drilling campaign with the aim of adding reserves and increase production, PL229 license operator drilled a highly deviated pilot hole to confirm hydrocarbons contacts in the undrained Snadd formation, which lie between two producing reservoirs. A successful data acquisition would not only provide information on the structure of the reservoir but would also assess the insitu movable fluid: type of hydrocarbon or water. FMWD allowed insitu fluid identification with the use of DFA, enabling RT evaluation of hydrocarbon composition as well as the filtrate contamination prior to filling the sampling bottles for further laboratory analysis. All data was acquired while drilling and using a comprehensive real-time visualization interface. Results, observation, conclusion Extensive prejob planning was conducted to optimize the operation. Dynamic fluid invasion simulations were used to estimate the required cleanup times to reach low contaminations. Simulations showed there was significant advantage in cleanup times when sampling soon after drilling. Honoring the natural environment, a unique sourceless multifunction LWD tool was used to acquire data for petrophysical evaluation-GR, resistivity, radioisotope-free density and neutron porosity, elemental capture spectroscopy, and sigma. Fluid mapping in a single run was key to efficiently resolve the insitu fluid type and composition. Critical hydrocarbon samples were collected soon after the formation was drilled to minimize mud filtrate invasion and reduce cleanup times. Multiple pressure measurements were acquired and six downhole fluid samples at low contamination (∼3% confirmed by laboratory) collected at several stations in variable mobilities. One scanning station was done at a zone were a physical sample was not required to confirm absence of gas cap. The DFA capabilities and ability to assess composition and control the fluid cleanup from surface allowed critical decisions to complete the acquisition program in this remote complex environment, all while drilling. In conclusion, FMWD results facilitated the placement decisions of the horizontal drain in this reservoir. This green BHA is unique in the LWD world. It eliminates radioactive source-handling and all related environmental risks to provide a comprehensive reservoir characterization. FMWD contributes formation pressure and fluid characterization and enables the physical capture of fluid samples in a single run. The combination of these two technologies completed the formation and fluid evaluation needs in this remote and environmentally sensitive area while drilling.

Relationship between salt and crustal tectonics in the Sørvestsnaget Basin, SW Barents Sea

2020 ◽  
Author(s):  
Gaia Travan ◽  
Benjamin Bellwald ◽  
Sverre Planke ◽  
Virginie Gaullier ◽  
Dwarika Maharjan ◽  
...  
Keyword(s):  
Seismic Data ◽  
Potential Field ◽  
Field Data ◽  
Barents Sea ◽  
Hydrocarbon Exploration ◽  
Salt Tectonics ◽  
Potential Field Data ◽  
The Barents Sea ◽  
Western Side ◽  
Seismic Anomalies

<p>The geology of the Barents Sea has been widely studied because of the interest for hydrocarbon exploration. Our study focuses on the SW Barents Sea, on the western side of the Senja Ridge in the Sørvestsnagets Basin, which is still a less deciphered area. Located at the limit of the continental shelf, this deep Cretaceous basin is characterized by a several-kilometer-thick sequence of Cenozoic sediments locally influenced by salt structures. Because of the peculiar rheological characteristics of salt, the deposition of evaporites during Permo-Carboniferous times still represents a key aspect to deeply understand the geological setting because salt tectonics considerably affects the brittle sedimentary cover.</p><p>5,500 km<sup>2</sup> of high-quality 3D seismic data, integrated with potential field data and existing wells, led to the interpretation of the main horizons and unconformities in the sedimentary sequence, with focus on the salt structures.</p><p>The top of the salt is characterized by a strong positive-amplitude reflection in the seismic data, and has been interpreted with a line spacing of 100 m. Subsequent gridding of the interpreted horizon to a bin size of 12.5 m highlights that the geomorphology for the top of the three salt structures is particularly complex, with presence of salt horns and development of minibasins above the salt. Integration of potential field data shows a strong correlation between salt structures and low values in Bouguer-Gravity anomalies. Different families of faults related to salt and to crustal tectonics have been mapped, and strong seismic anomalies related to faults above the salt structures are identified at multiple stratigraphic levels. Part of these faults have been active until 20 000 years ago, and are rarely active at present day.</p><p>The three salt structures interpreted on the western side of the Senja Ridge have a total extent of around 800 km<sup>2</sup> and are mainly the consequence of different pulses of reactive diapirism, due to several diachronous rifting events during the opening of the Barents Sea. After the opening of the Sørvestsnagets Basin, salt tectonics continued and was influenced by crustal movements and glacial sedimentation and erosion in this pull-apart basin setting.</p><p>The presence of the strong seismic anomalies above the salt structures is interpreted as gas accumulations, which makes this topic of particular interest for the future development of the oil and gas industry of the SW Barents Sea.</p>

scholarly journals Large-scale patterns in community structure of benthos and fish in the Barents Sea

Polar Biology ◽  
2016 ◽  
Vol 40 (2) ◽  
pp. 237-246 ◽  
Author(s):  
Edda Johannesen ◽  
Lis Lindal Jørgensen ◽  
Maria Fossheim ◽  
Raul Primicerio ◽  
Michael Greenacre ◽  
...  
Keyword(s):  
Community Structure ◽  
Large Scale ◽  
Barents Sea ◽  
The Barents Sea

scholarly journals Preliminary Results of Marine Electromagnetic Sounding with a Powerful, Remote Source in Kola Bay off the Barents Sea

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Valery Grigoryev ◽  
Sergey Korotaev ◽  
Mikhail Kruglyakov ◽  
Darya Orekhova ◽  
Yury Scshors ◽  
...  
Keyword(s):  
Barents Sea ◽  
Integral Equation Method ◽  
Electromagnetic Sounding ◽  
Geoelectric Model ◽  
Regional Geology ◽  
Preliminary Results ◽  
The Barents Sea ◽  
Long Wave ◽  
Fault Tectonics

We present an experiment conducted in Kola Bay off the Barents Sea in which new, six-component electromagnetic seafloor receivers were tested. Signals from a powerful, remote super-long wave (SLW) transmitter at several frequencies on the order of tens Hz were recorded at the six sites along a profile across Kola Bay. In spite of the fact that, for technical reasons, not all the components were successfully recorded at every site, the quality of the experimental data was quite satisfactory. The experiment resulted in the successful simulation of an electromagnetic field by the integral equation method. An initial geoelectric model reflecting the main features of the regional geology produced field values that differed greatly from the experimental ones. However, step-by-step modification of the original model considerably improved the fit of the fields. Thereby specific features of the regional geology, in particular the fault tectonics, were able to be corrected. These preliminary results open the possibility of inverse problem solving with more reliable geological conclusions.

Natural, artificial or imported? Ice supplies for the German distant-water fisheries as an example of renewable vs. fossil-fuel based supplies

2020 ◽  
Vol 32 (4) ◽  
pp. 848-862
Author(s):  
Ingo Heidbrink
Keyword(s):  
Large Scale ◽  
Bacterial Contamination ◽  
Fossil Fuel ◽  
Barents Sea ◽  
Renewable Resource ◽  
Northern Norway ◽  
The Barents Sea ◽  
Fishing Fleets ◽  
Ice Production ◽  
Distant Water Fishing

From the early decades of the twentieth century the distant-water fishing fleets relied more or less completely on the use of artificially manufactured ice for the preservation of their catches. Large-scale fossil-fuel powered ice factories in the main European fishing ports provided the ice taken onboard trawlers before they left port for the fishing trip. When the fishing grounds of the Barents Sea and the Svalbard region were developed in the 1930s, bunker capacities of trawlers were no longer sufficient for a journey without re-bunkering coal or ice. Northern Norwegian ports therefore became regularly used as bunker stations for coal and ice, with huge natural ice factories being developed in northern Norway for the supply of trawlers. Those with interests in artificial ice production in continental Europe, particularly in Bremerhaven/Geestemünde, started a campaign against the use of natural ice based on the argument that natural ice was unsanitary and would cause bacterial contamination of the fish. Several authorities became involved and finally an expedition by the Reichskuratorium für Technik in der Landwirtschaft was organized to investigate the issue of bacterial contamination of ice manufactured in northern Norway. With the findings of this expedition clearly showing that there was no contamination issue with the natural ice, it became obvious that the whole campaign against natural ice was not guided by quality concerns, but by the commercial interests of German artificial ice producers. In the end, the whole story can be understood as a key example of how a fossil-fuel powered industry tried to push a competitor using a renewable resource (natural ice) out of the market, and how certain authorities were complicit in this attempt.

scholarly journals The Winter Atmospheric Response to Sea Ice Anomalies in the Barents Sea

2014 ◽  
Vol 27 (2) ◽  
pp. 914-924 ◽  
Author(s):  
Jessica Liptak ◽  
Courtenay Strong
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Barents Sea ◽  
Turbulent Heat Flux ◽  
Turbulent Heat ◽  
Atmospheric Response ◽  
Sea Ice Concentration ◽  
The North ◽  
The Barents Sea ◽  
The North Atlantic Oscillation

Abstract The atmospheric response to sea ice anomalies over the Barents Sea during winter was determined by boundary forcing the Community Atmosphere Model (CAM) with daily varying high and low sea ice concentration (SIC) anomalies that decreased realistically from December to February. The high- and low-SIC anomalies produced localized opposite-signed responses of surface turbulent heat flux and wind stress that decreased in magnitude and extent as winter progressed. Responses of sea level pressure (SLP) and 500-mb height evolved from localized, opposite-signed features into remarkably similar large-scale patterns resembling the negative phase of the North Atlantic Oscillation (NAO). Hilbert empirical orthogonal function (HEOF) analysis of the composite high-SIC and low-SIC SLP responses uncovered how they differed. The hemispheric pattern in the leading HEOF was similar for the high-SIC and low-SIC responses, but the high-SIC response cycled through the pattern once per winter, whereas the low-SIC response cycled through the pattern twice per winter. The second HEOF differed markedly between the responses, with the high-SIC response featuring zonally oriented Atlantic and Pacific wave features and the low-SIC response featuring a meridionally oriented Atlantic dipole pattern.

scholarly journals Historical population assessment of Barents Sea harp seals (Pagophilus groenlandicus)

2007 ◽  
Vol 64 (7) ◽  
pp. 1356-1365 ◽  
Author(s):  
Hans J. Skaug ◽  
Lennart Frimannslund ◽  
Nils I. Øien
Keyword(s):  
Large Scale ◽  
Barents Sea ◽  
Sensitivity Study ◽  
Dynamics Model ◽  
Population Assessment ◽  
The Barents Sea ◽  
Lack Of Information ◽  
Pagophilus Groenlandicus ◽  
Population Dynamics Model ◽  
Range Estimate

Abstract Skaug, H. J., Frimannslund, L., and Øien, N. I. 2007. Historical population assessment of Barents Sea harp seals (Pagophilus groenlandicus). – ICES Journal of Marine Science, 64: 1356–1365: –. Harp seals are an important component of the Barents Sea ecosystem. Population size is estimated to have been around 6 million seals in 1875, when large-scale exploitation by Norwegian and Russian hunters started. The estimate is obtained by fitting a population dynamics model to all available sources of data on Barents Sea harp seals, but because of a lack of information about several key parameters in the model, the uncertainty associated with the estimate is large. A sensitivity study involving three different mechanisms for density-dependence results in a range estimate of 3–7 million seals in 1875.

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