scholarly journals Array data acquisition with wireless LAN telemetry as applied to shallow water tomography in the Barents Sea

1992 ◽  
Author(s):  
K. von der Heydt ◽  
J. Kemp ◽  
J. Lynch ◽  
J. Miller ◽  
C. S. Chiu
2021 ◽  
Author(s):  
Maria Cecilia Bravo ◽  
Yon Blanco ◽  
Mauro Firinu ◽  
Tosi Gianbattista ◽  
Eriksen Martin ◽  
...  

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.


2021 ◽  
pp. 398-415
Author(s):  
N.V. Politova ◽  
◽  
T.N. Alekseeva ◽  
N.V. Kozina ◽  
M.D. Kravchishina ◽  
...  

The paper presents data from grain size and mineralogical analyzes of surface bottom sediment samples obtained on several cruises of the R/V Akademik Mstislav Keldysh (2016–2018) from different parts of the Barents Sea. Pebble and gravel material is found in surface sediments in the form of impurities scattered throughout the sea. Such a chaotic distribution pattern is apparently associated with ice separation. Coarse material is most common in the Barents Sea off the coast of the Kola Peninsula, off the coast of Novaya Zemlya, Spitsbergen, where it accumulates due to coastal abrasion. In addition, a fraction >1 mm is widespread at depths where fine fractions are stirred and leached. The most common sediments in coastal shallow water are sands. Sands (0.1–1 mm) are widespread in the southern and southeastern regions of the sea, in the region of the Pechora polygon, the Kaninsky shallow water, the Kola Peninsula, and in the northwest, off the coast of Svalbard. With increasing depth, the sands are replaced by mixed sediments with a low admixture of pelite. Pelitic sediments are prevalent in the central part of the sea. Precipitation with a pelitic fraction (<0.01 mm) of more than 50% occupy about 70% of the Barents Sea. They are widespread in deep-sea hollows and trenches, as well as in the numerous fiords of the North Island of Novaya Zemlya and Franz Josef Land. Surface sediments have a predominantly terrigenous composition; only at the border with the Norwegian Sea the proportion of biogenic material increases. The mineral composition of sediments is dominated by quartz and feldspars, clay minerals are mainly represented by illite, smectite and kaolinite.


Author(s):  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova

Identification of water masses in areas with complex water dynamics is a complex task, which is usually solved by the method of expert assessments. In this paper, it is proposed to use a formal procedure based on the application of the method of optimal multiparametric analysis (OMP analysis). The data of field measurements obtained in the 68th cruise of the R/V “Academician Mstislav Keldysh” in the summer of 2017 in the Barents Sea on the distribution of temperature, salinity, oxygen, silicates, nitrogen, and phosphorus concentration are used as a data for research. A comparison of the results with data on the distribution of water masses in literature based on expert assessments (Oziel et al., 2017), allows us to conclude about their close structural similarity. Some differences are related to spatial and temporal shifts of measurements. This indicates the feasibility of using the OMP analysis technique in oceanological studies to obtain quantitative data on the spatial distribution of different water masses.


Sign in / Sign up

Export Citation Format

Share Document