scholarly journals Diagenetic related flat spots within the Paleogene Sotbakken Group in the vicinity of the Senja Ridge, Barents Sea

2019 ◽  
Vol 26 (3) ◽  
pp. 373-385 ◽  
Author(s):  
Manzar Fawad ◽  
Nazmul Haque Mondol ◽  
Irfan Baig ◽  
Jens Jahren
Keyword(s):  
Biogenic Silica ◽  
Oil And Gas ◽  
Barents Sea ◽  
Rock Physics ◽  
Gas Oil ◽  
Seismic Profiles ◽  
Oil And Gas Exploration ◽  
Fine Grained ◽  
Ridge Area

Rock physics analyses of data from a wildcat well 7117/9-1 drilled in the Senja Ridge area, located in the Norwegian Barents Sea, reveal changes in stiffness within the fine-grained Paleogene Sotbakken Group sediments, caused by the transformation of opal-A to opal-CT, and opal-CT to quartz. These changes manifest as flat spots on 2D seismic profiles. These flat spots were mistaken as hydrocarbon–water contacts, which led to the drilling of well 7117/9-1. Rock physics analyses on this well combined with a second well (7117/9-2) drilled further NW and updip on the Senja Ridge indicate overpressure within the opal-CT-rich zones overlying the opal-CT to quartz transformation zones in the two wells. The absence of opal-A–opal-CT and opal-CT–quartz flat spots on seismic in the second well is attributed to differences in the temperature and timing of uplift. Amplitude v. angle (AVA) modelling indicates both the opal-A–opal-CT and opal-CT–quartz interface points plot on the wet trend, whereas modelled gas–brine, oil–brine and gas–oil contacts fall within quadrant-I. These findings will be useful in understanding the nature of compaction of biogenic silica-rich sediments where flat spots could be misinterpreted as hydrocarbon-related contacts in oil and gas exploration.

Basin-wide rock-physics analysis in Campeche Basin, Gulf of Mexico — Phase II: Reservoir rock and fluid properties

2021 ◽  
Vol 40 (10) ◽  
pp. 716-722
Author(s):  
Yangjun (Kevin) Liu ◽  
Michelle Ellis ◽  
Mohamed El-Toukhy ◽  
Jonathan Hernandez
Keyword(s):  
Oil And Gas ◽  
Rock Physics ◽  
Clay Content ◽  
American Petroleum Institute ◽  
P Wave ◽  
Reservoir Rock ◽  
Gas Oil ◽  
Amplitude Variation With Offset ◽  
Fluid Properties ◽  
The Impact

We present a basin-wide rock-physics analysis of reservoir rocks and fluid properties in Campeche Basin. Reservoir data from discovery wells are analyzed in terms of their relationship between P-wave velocity, density, porosity, clay content, Poisson's ratio (PR), and P-impedance (IP). The fluid properties are computed by using in-situ pressure, temperature, American Petroleum Institute gravity, gas-oil ratio, and volume of gas, oil, and water. Oil- and gas-saturated reservoir sands show strong PR anomalies compared to modeled water sand at equivalent depth. This suggests that PR anomalies can be used as a direct hydrocarbon indicator in the Tertiary sands in Campeche Basin. However, false PR anomalies due to residual gas or oil exist and compose about 30% of the total anomalies. The impact of fluid properties on IP and PR is calibrated using more than 30 discovery wells. These calibrated relationships between fluid properties and PR can be used to guide or constrain amplitude variation with offset inversion for better pore fluid discrimination.

Planning for Construction Work in Cold Climate Regions

2012 ◽  
Author(s):  
Ove T. Gudmestad ◽  
Daniel Karunakaran
Keyword(s):  
Construction Projects ◽  
Oil And Gas ◽  
Barents Sea ◽  
Weather Conditions ◽  
Cold Climate ◽  
Construction Work ◽  
Oil And Gas Exploration ◽  
Weather Forecasts ◽  
Physical Conditions ◽  
Polar Low

With increased interests in oil and gas exploration in cold climate regions, it is not realistic that all construction activities can take place during the short summer and work will continue into the early fall and possibly later. The offshore contractors must, therefore, be ready to participate in construction work in these regions during an extended season, i.e. outside the summer season with milder weather conditions. It is also important that some key work-intensive activities (e.g. pipe laying) can start as early as possible in the season. This paper will discuss the challenges associated with construction work in cold climate regions with emphasis on the physical conditions, in particular with reference to Polar Low Pressures and the potential for icing, as well as the logistics of working long distances from established supply bases. Large uncertainties in weather forecasts call for proper management decisions accounting for the specifics of the area. Long periods of “waiting on weather” might result and management must have the patience to wait until safe operations can commence. Emphasis will be on the Barents Sea where recent hydrocarbon findings have proven very encouraging and where a huge area soon will be opened for exploration, following the agreement on the border between Norway and Russia, potentially calling for joint Norwegian–Russian construction projects (Bulakh et al., 2011).

Three years (2017-19) of field observation of the marginal ice the Western Barents Sea

2020 ◽  
Author(s):  
Nataliya Marchenko
Keyword(s):  
Sea Ice ◽  
Laser Scanning ◽  
Oil And Gas ◽  
Barents Sea ◽  
Mechanical Tests ◽  
Point Of View ◽  
The Arctic ◽  
Oil And Gas Exploration ◽  
Ice Floes ◽  
The University

<p>Knowledge of sea ice state (distribution, characteristics and movement) is interesting both from a practical point of view and for fundamental science. The western part of the Barents Sea is a region of increasing activity – oil and gas exploration may growth in addition to traditional fishing and transport. So theinformation is requested by industry and safety authorities.</p><p>Three last years (2017-19) the Arctic Technology Department of the University Centre in Svalbard (UNIS) performed expeditions on MS Polarsyssel in April in the sea ice-marginal zone of the Western Barents Sea, as a part of teaching and research program. In (Marchenko 2018), sea ice maps were compared with observed conditions. The distinguishing feature of ice in this region is the existence of relatively small ice floes (15-30 m wide) up to 5 m in thickness, containing consolidated ice ridges. In (Marchenko 2019) we described several such floes investigated by drilling, laser scanning and ice mechanical tests, on a testing station in the place with very shallow water (20 m) where ice concentrated. In this article, we summarise three years results with more attention for level ice floes and ice floe composition, continuing to feature ice condition in comparison with sea ice maps and satellite images.</p><p>These investigations provided a realistic characterization of sea ice in the region and are a valuable addition to the long-term studies of sea ice in the region performed by various institutions.</p>

Transfer Zone Characteristics in No. II Fault Zone and its Control on Petroleum, TaZhong Area

2011 ◽  
Vol 356-360 ◽  
pp. 3009-3015
Author(s):  
Yu Hang Zhang ◽  
Xing Yan Li ◽  
Zhi Feng Yan
Keyword(s):  
Fault Zone ◽  
Oil And Gas ◽  
Structural Evolution ◽  
Strike Slip ◽  
Fault Analysis ◽  
Seismic Profiles ◽  
Oil And Gas Exploration ◽  
Detachment Faults ◽  
Tazhong Area ◽  
Transfer Zone

According to interpreted cautiously with 2D and 3D seismic profiles, the typical transfer zone was identified in No.Ⅱ fault zone of TaZhong area, near the TaZhong 46 well of central uplift belt in Tarim basin. Discussed the transfer zone characteristic on the basis of seismic interpretation, it’s clearly triangle transfer zone and caused by strike-slip affection. Using structural analysis method, it is indicated that the transfer zone composed by thrusting-detachment faults. According to structural evolution analysis, the transfer zone had been affecting constantly by transpression during the caledonian-late hercynian, Analyzing geologic setting and regional geology characteristic, TaZhong No.Ⅱ fault zone are sinistral transpression strike-slip fault. Analysis the control action of transfer zone’s for trap, reservoir, hydrocarbon migration and sedimentary, the Transfer zone have the advantage target for oil and gas exploration.

An Expert-Based Model for Reliability Analysis of Arctic Oil and Gas Processing Facilities

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Masoud Naseri ◽  
Javad Barabady
Keyword(s):  
Oil And Gas ◽  
Barents Sea ◽  
Weather Conditions ◽  
Operating Conditions ◽  
Oil And Gas Exploration ◽  
Oil Processing ◽  
Life Data ◽  
Expert Opinions ◽  
Exploration And Production ◽  
Criticality Analysis

Oil and gas companies are expanding their operations in the remote Arctic offshore with harsh weather conditions such as the Barents Sea. One of the major challenges in reliability assessment of production plants operating in such areas is lack of life data accounting for the adverse effects of harsh operating conditions. The aim of this study is to develop an expert-based model to assess the reliability of oil and gas exploration and production plants operating in Arctic regions. Expert opinions are used to modify the life data available in normal-climate locations, which are considered as the base area, to account for the effects of operating conditions. The proposed model is illustrated by assessing the reliability of an oil processing train in the Western Barents Sea. Additionally, based on a criticality analysis, some design modifications are suggested to improve the reliability of the processing train.

scholarly journals Recognition of the pre-salt regional structure of Kwanza basin, offshore in West Africa, derived from the satellite gravity data and seismic profiles

2020 ◽  
Vol 17 (6) ◽  
pp. 956-966
Author(s):  
Longjun Qiu ◽  
Zhaoxi Chen ◽  
Yalei Liu
Keyword(s):  
Oil And Gas ◽  
Gravity Data ◽  
Shielding Effect ◽  
Regional Structure ◽  
Seismic Profiles ◽  
Satellite Gravity ◽  
Oil And Gas Exploration ◽  
Tectonic Model ◽  
Salt Structure ◽  
Seismic Reflection Profiles

Abstract Kwanza basin, located on the west coast of Africa and the east side of the South Atlantic Ocean, has the potential for deep-water oil and gas exploration. Previous studies have shown that the pre-salt system within the area has high potential for oil and gas storage. However, due to the shielding effect of the evaporating salt rock during the Aptian period, the quality of seismic reflection profiles of the pre-salt layers is poor. This means that the pre-salt sequences, the main fault, the scale and distribution pattern of the rift are not clear. To clarify the pre-salt regional structure pattern and further guide pre-salt exploration, we carried out a series of analyses and target processing of seismic and gravity data. Further, combining other available geological and lithology data as well as a tectonic model, we put forward a new understanding of the pre-salt structure of Kwanza basin. The research shows that the Kwanza basin can be divided into three uplift belts below the salt layer, which are distributed in the NW–SE trending direction. The three key profiles illustrate the distribution of uplift and depression in detail. The explained structural highs distributed in the outer Kwanza basin may be related to oil and gas reservoir. This study could provide the geophysical basis for the re-interpretation of the pre-salt seismic sequence, the strategic selection of pre-salt oil and gas and the next exploration deployment.

Dynamics of Ice Milling and Breaking During Arctic Ship Steering Operations

2014 ◽  
Author(s):  
Erno Keskinen ◽  
Jori Montonen ◽  
Nikhil Sharma ◽  
Michel Cotsaftis
Keyword(s):  
Complex Analysis ◽  
Oil And Gas ◽  
Barents Sea ◽  
Arctic Zone ◽  
Bending Vibrations ◽  
Cross Sectional ◽  
Oil And Gas Exploration ◽  
Cantilever Structure ◽  
Ice Field ◽  
Propulsion Unit

Interest to sailing in arctic zone is increasing, as due to the climatic change, the seasons when northeast and northwest passages are open enough for see transportation, are getting every year longer and longer. Some other activities like oil and gas exploration and drilling at Barents Sea require also regular sea traffic connections to be opened. Sea operations at arctic zone are challenging, because thick ice generates a high magnitude dynamic load against the hull and the propulsion units. Turning and backward sailing in thick ice field are the most critical operations, in which the steerable propulsion units are in totally different service as in the regular open sea cruising. In such operations the ice field, when guided downwards along the slope of the hull, is broken to large plates, which then are fed against the propulsion unit. The steering propulsion unit itself is a vertically mounted inverse mast column, at the top of which the horizontally spinning propeller(s) can be vertically turned to follow the steering commands. Such cantilever structure is now under random collision process when the column is breaking the underwater ice plates to smaller blocks. For hydrodynamic reasons the column has a limited cross-sectional area as compared to the propeller area making it sensitive to bending vibrations. Another dynamic interaction with ice is coming from the periodical blade-ice contact when the ice blocks pushed down to the propulsion depth are completely milled by the units. These two parallel dynamic processes have been the reason for several serious damages and losses of propulsion units leading to expensive service operations by means of support vessels. The purpose of this study has been to model the underwater propulsion system with all essential structures, parts and interactions with the surrounding fluid field and floating ice blocks. This brings a complex analysis, in which random collisions and periodical machining forces are loading the elastic hull-mounted inverse mast column with high end mass. The response behavior led to predictions for the reasons of the observed damages especially in case of collapsed bolt connections in the units.

Decision on oil and gas exploration in an Arctic area: Case study from the Norwegian Barents Sea

2009 ◽  
Vol 47 (6) ◽  
pp. 832-842 ◽  
Author(s):  
Jon Rytter Hasle ◽  
Urban Kjellén ◽  
Ole Haugerud
Keyword(s):  
Oil And Gas ◽  
Barents Sea ◽  
Oil And Gas Exploration ◽  
Arctic Area
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