scholarly journals Electrochemically Enhanced Deposition of Scale from Chosen Formation Waters from the Norwegian Continental Shelf

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 542
Author(s):  
Benjamin Udo Emmel ◽  
Kamila Maria Gawel ◽  
Mohammad Hossain Bhuiyan ◽  
Malin Torsæter ◽  
Laura Edvardsen

Reservoir formation waters typically contain scaling ions which can precipitate and form mineral deposits. Such mineral deposition can be accelerated electrochemically, whereby the application of potential between two electrodes results in oxygen reduction and water electrolysis. Both processes change the local pH near the electrodes and affect the surface deposition of pH-sensitive minerals. In the context of the plugging and abandonment of wells, electrochemically enhanced deposition could offer a cost-effective alternative to the established methods that rely on setting cement plugs. In this paper, we tested the scale electro-deposition ability of six different formation waters from selected reservoirs along the Norwegian continental shelf using two experimental setups, one containing CO2 and one without CO2. As the electrochemical deposition of scaling minerals relies on local pH changes near the cathode, geochemical modelling was performed to predict oversaturation with respect to the different mineral phases at different pH values. In a CO2-free environment, the formation waters are mainly oversaturated with portlandite at pH > 12. When CO2 was introduced to the system, the formation waters were oversaturated with calcite. The presence of mineral phases was confirmed by powder X-ray diffraction (XRD) analyses of the mineral deposits obtained in the laboratory experiments. The geochemical-modelling results indicate several oversaturated Mg-bearing minerals (e.g., brucite, dolomite, aragonite) in the formation waters but these, according to XRD results, were absent in the deposits, which is likely due to the significant domination of calcium-scaling ions in the solution. The amount of deposit was found to be proportional to the concentration of calcium present in the formation waters. Formation waters with a high concentration of Ca ions and a high conductivity yielded more precipitate.

2001 ◽  
Vol 2001 (1) ◽  
pp. 345-347 ◽  
Author(s):  
Kari Stokke ◽  
Jon Rødal

ABSTRACT The Norwegian Clean Seas Association for Operating Companies (NOFO) is responsible for oil spill response, planning, and preparedness on behalf of the companies that are operating on the Norwegian continental shelf The responsibility includes initial response offshore, as well as coastal protection and shoreline cleanup. NOFO is developing a plan for regional oil spill preparedness to be implemented in 2001. The plan is based on risk assessment and covers planned oil production activities in the Norwegian offshore sector. Previously, NOFO's oil spill response plan was based on authority requirements and recognized standards. NOFO is now proposing a risk-based approach, aiming to identify the need for oil spill response in different areas of the Norwegian sector. The new approach is based on estimated probability of oil spill situations, dimensioning oil spill scenarios, and oil drift modeling to define arrival time to shore, coastal areas at risk, and amount of oil that may possibly reach the shore. The risk-based approach is an alternative to traditional “worst case” considerations and allows implementation of more cost-effective measures.


2019 ◽  
Author(s):  
Sarah Gasda ◽  
Ivar Aavatsmark ◽  
Bahman Bohloli ◽  
Helge Hellevang ◽  
Jan Nordbotten ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.


2006 ◽  
Vol 129 (3) ◽  
pp. 298-303 ◽  
Author(s):  
V. M. Andreev ◽  
A. S. Vlasov ◽  
V. P. Khvostikov ◽  
O. A. Khvostikova ◽  
P. Y. Gazaryan ◽  
...  

Results of a solar thermophotovoltaic (STPV) system study are reported. Modeling of the STPV module performance and the analysis of various parameters influencing the system are presented. The ways for the STPV system efficiency to increase and their magnitude are considered such as: improvement of the emitter radiation selectivity and application of selective filters for better matching the emitter radiation spectrum and cell photoresponse; application of the cells with a back side reflector for recycling the sub-band gap photons; and development of low-band gap tandem TPV cells for better utilization of the radiation spectrum. Sunlight concentrator and STPV modules were designed, fabricated, and tested under indoor and outdoor conditions. A cost-effective sunlight concentrator with Fresnel lens was developed as a primary concentrator and a secondary quartz meniscus lens ensured the high concentration ratio of ∼4000×, which is necessary for achieving the high efficiency of the concentrator–emitter system owing to trap escaping radiation. Several types of STPV modules have been developed and tested under concentrated sunlight. Photocurrent density of 4.5A∕cm2 was registered in a photoreceiver based on 1×1cm2GaSb cells under a solar powered tungsten emitter.


2021 ◽  
Author(s):  
Subhadeep Sarkar ◽  
Mathias Horstmann ◽  
Tore Oian ◽  
Piotr Byrski ◽  
George Lawrence ◽  
...  

Abstract One of the crucial components of well integrity evaluation in offshore drilling is to determine the cement bond quality assuring proper hydraulic sealing. On the Norwegian Continental Shelf (NCS) an industry standard as informative reference imposes verification of cement length and potential barriers using bonding logs. Traditionally, for the last 50 years, wireline (WL) sonic tools have been extensively used for this purpose. However, the applicability of logging-while-drilling (LWD) sonic tools for quantitative cement evaluation was explored in the recent development drilling campaign on the Dvalin Field in the Norwegian Sea, owing to significant advantages on operational efficiency and tool conveyance in any well trajectory. Cement bond evaluation from conventional peak-to-peak amplitude method has shown robust results up to bond indexes of 0.6 for LWD sonic tools. Above this limit, the casing signal is smaller than the collar signal and the amplitude method loses sensitivity to bonding. This practical challenge in the LWD realm was overcome through the inclusion of attenuation rate measurements, which responds accordingly in higher bonding environments. The two methods are used in a hybrid approach providing a full range quantitative bond index (QBI) introduced by Izuhara et al. (2017). In order to conform with local requirements related to well integrity and to ascertain the QBI potential from LWD monopole sonic, a wireline cement bond log (CBL) was acquired in the first well of the campaign for comparison. This enabled the strategic deployment of LWD QBI service in subsequent wells. LWD sonic monopole data was acquired at a controlled speed of 900ft/h. The high-fidelity waveforms were analyzed in a suitable time window and both amplitude- and attenuation-based bond indexes were derived. The combined hybrid bond index showed an excellent match with the wireline reference CBL, both in zones of high as well as lower cement bonding. The presence of formation arrivals was also in good correlation with zones of proper bonding distinguishable on the QBI results. This established the robustness of the LWD cement logging and ensured its applicability in the rest of the campaign which was carried out successfully. While the results from LWD cement evaluation service are omnidirectional, it comes with a wide range of benefits related to rig cost or conveyance in tough borehole trajectories. Early evaluation of cement quality by LWD sonic tools helps to provide adequate time for taking remedial actions if necessary. The LWD sonic as part of the drilling BHA enables this acquisition and service in non-dedicated runs, with the possibility of multiple passes for observing time-lapse effects. Also, the large sizes of LWD tools relative to the wellbore ensures a lower signal attenuation in the annulus and more effective stabilization, thereby providing a reliable bond index.


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