scholarly journals Installation of submarine cables and pipes in shallow waters and connecting them to the shore by the method of horizontal directional drilling

2021 ◽  
Vol 286 ◽  
pp. 04007
Author(s):  
Valeriu-Florian Vasilescu ◽  
Dumitru Dinu

This article presents the horizontal directional drilling (HDD) as one of the most suitable technique used to reduce the impact on the environment during the submarine pipe and cable installation process, especially in the coastal area and shallow waters. HDD is a technique used to drill a subsea tunnel or under other designated area with the goal to pull a pipe or other facility through the drilled underground tunnel. With the development of the offshore natural gas and wind industry, the demand for the construction of transfer pipeline and cables has also increased. The installation of submarine pipelines and cables can have negative effects on the marine environment. This is one of the main reasons that construction and operation of offshore wind energy systems has been and continues to be regarded with scepticism by environmental activists, despite the undeniable benefits of this renewable energy source. The main objectives of this article are to emphasize the importance of using this technique but also to highlight the benefits, in particular by significantly reducing the impact on the marine environment.

2021 ◽  
Vol 1 (2021) ◽  
pp. 43-51
Author(s):  
Valeriu-Florian VASILESCU ◽  
Dumitru DINU

"This article presents the main methods of installing submarine cables used in the offshore wind industry and the impact they have on the marine environment. From this article, the reader will be able to understand the basic principles that are taken into account from the design phase of a submarine cable, principles that seek to streamline their installation, operation and maintenance and their impact on the marine environment. Given the scale of the development of the wind industry, especially offshore, the length of submarine cables that provide energy transport from the wind farm to shore consumers is also constantly growing. The construction and operation of offshore wind energy systems has been and continues to be regarded with scepticism by environmental activists. Despite the undeniable benefits of this renewable energy source, the impact on the marine environment must also be taken into consideration. We studied the most efficient methods of installing submarine cables in the offshore wind industry – study which also includes analysing the behaviour of submarine cables and analysing ships’ movement during cable transport and installation. This article is only part of a major research on the installation of submarine cables in the offshore wind industry. In terms of the frequency and relatively short duration of submarine cable installation operations, on a small strip of up to 8m, the disturbances and impact caused by these operations are considered minor and are preferred compared to bottom trawling operations and dredging, which are repetitive and more extensive. A single impact, such as cable burial operations, is preferred to continuous, multiple or recurrent impacts. [1] "


Author(s):  
Saeed Delara ◽  
Kendra MacKay

Horizontal directional drilling (HDD) has become the preferred method for trenchless pipeline installations. Drilling pressures must be limited and a “no-drill zone” determined to avoid exceeding the strength of surrounding soil and rock. The currently accepted industry method of calculating hydraulic fracturing limiting pressure with application of an arbitrary safety factor contains several assumptions that are often not applicable to specific ground conditions. There is also no standard procedure for safety factor determination, resulting in detrimental impacts on drilling operations. This paper provides an analysis of the standard methods and proposes two alternative analytical models to more accurately determine the hydraulic fracture point and acceptable drilling pressure. These alternative methods provide greater understanding of the interaction between the drilling pressures and the surrounding ground strength properties. This allows for more accurate determination of horizontal directional drilling limitations. A comparison is presented to determine the differences in characteristics and assumptions for each model. The impact of specific soil properties and factors is investigated by means of a sensitivity analysis to determine the most critical soil information for each model.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Konstantinos Kapsalis ◽  
Maria Kavvalou ◽  
Ioanna Damikouka ◽  
Olga Cavoura

AbstractOil spills at sea pose risks to the marine environment and to the economy of many nations. Marine ecosystems are very vulnerable and precious as producers of oxygen and as regulators of climate. Therefore, their protection and preservation are necessary. In the event of an oil spill, anthropogenic clean-up activities and natural weathering processes can minimize the negative effects on marine organisms, and the marine environment in general. The target of this study was to investigate the status of the sea along the coastline of the Saronic Gulf, Greece, a year after the sinking of the Agia Zoni II oil tanker. Seawater samples from 15 sampling locations from Phlisvos coast to Anavissos, an area easily approached by bathers with recreational interest, were collected and analysed for total petroleum hydrocarbons. Concentrations up to a maximum of 56.6 μg/L were detected. Despite the large extent of the initial hydrocarbon pollution, the immediate clean-up operations and natural weathering and/or sorption processes have reduced the impact of the spill on surface waters.


Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3152
Author(s):  
Stoyan Kanev

Active wake control (AWC) is an operational strategy for wind farms that aims at reducing the negative effects of wakes behind wind turbines on the power production and mechanical loads at the wind turbines’ downstream. For a given wind direction, the strategy relies on collaborative control of the machines within each row of turbines that affect each other through their wakes. The vast amount of research performed during the last decade indicates that the potential upside of this technology on the annual energy production of a wind farm can be as high as a few percentage points. Although these predictions on the potential benefits are quite significant, they typically assume full availability of all turbines within a row operating under AWC. However, even though the availability of offshore wind turbines is nowadays quite high (as high as 95%, or even higher), the availability of a whole row of turbines is shown to be much lower (lower than 60% for a row of ten turbines). This paper studies the impact of turbine downtime on the power production increase from AWC, and concludes that the AWC is robust enough to be kept operational in the presence of turbines standing still.


2021 ◽  
Vol 9 (8) ◽  
pp. 819
Author(s):  
Carina Juretzek ◽  
Ben Schmidt ◽  
Maria Boethling

Pile driving is one of the most intense anthropogenic noise sources in the marine environment. Each foundation pile may require up to a several thousand strokes of high hammer energy to be driven to the embedded depth. Scientific evidence shows that effects on the marine environment have to be anticipated if mitigation measures are not applied. Effective mitigation measures to prevent and reduce the impact of pile driving noise should therefore be part of regulation. The role of regulators is to demonstrate and assess the applicability, efficiency and effectiveness of noise mitigation measures. This requires both, scientific knowledge on noise impacts and the con-sideration of normative aspects of noise mitigation. The establishment of mitigation procedures in plans and approvals granted by regulatory agencies includes several stages. Here, we outline a step-wise approach in which most of the actions de-scribed may be performed simultaneously. Potential measures include the appropriate maritime spatial planning to avoid conflicts with nature conservation, site development for offshore wind farms to avoid undesirable activities in time and space, coordination of activities to avoid cumulative effects, and the application of technical noise abatement systems to reduce noise at the source. To increase the acceptance of noise mitigation applications, technical measures should fulfil a number of requirements: (a) they are applicable and affordable, (b) they are state-of-the-art or at least advanced in development, (c) their efficiency can be assessed with standardised procedures. In this study, the efficiency of noise mitigation applied recently in offshore wind farm construction projects in the German North Sea is explained and discussed with regard to the regulation framework, including the technical abatement of impulsive pile driving noise.


Author(s):  
Manley Osbak ◽  
Alireza Bayat ◽  
Carrie Murray

The risks, associated with horizontal directional drilling (HDD) can have a significant impact on project schedule and cost. Contractors, engineers and owners are generally aware of the potential impact of this risk, but the awareness is largely qualitative in nature, and is thereby limiting for pointed decision making and the development of measured risk mitigation. Without quantitative information, industry stakeholders are without the means to evaluate risk strategies and identify appropriate risk mitigation measures in a manner that adequately develops and supports the business case for risk mitigation. As a result, the industry often has little choice other than to resort to accepting the risk and hoping for the best or transferring the risk using contractual methods. In order to move to a position of active assessment and mitigation, the industry needs quantitative information about the overall impact of risk as well as a comprehensive enumeration of risk events, the probability of occurrence and the impact of individual events. This paper looks at the general impact of risk as has occurred on 100 medium and large HDD projects. The general impact, in terms of schedule (and by extension, cost), serves to illuminate the need for structured risk mitigation. The paper also lists the risk events that have occurred on these 100 projects, as well as the frequency of occurrence, the average schedule impact and the Risk Index of each event type.


Author(s):  
Jeeyun Oh ◽  
Mun-Young Chung ◽  
Sangyong Han

Despite of the popularity of interactive movie trailers, rigorous research on one of the most apparent features of these interfaces – the level of user control – has been scarce. This study explored the effects of user control on users’ immersion and enjoyment of the movie trailers, moderated by the content type. We conducted a 2 (high user control versus low user control) × 2 (drama film trailer versus documentary film trailer) mixed-design factorial experiment. The results showed that the level of user control over movie trailer interfaces decreased users’ immersion when the trailer had an element of traditional story structure, such as a drama film trailer. Participants in the high user control condition answered that they were less fascinated with, absorbed in, focused on, mentally involved with, and emotionally affected by the movie trailer than participants in the low user control condition only with the drama movie trailer. The negative effects of user control on the level of immersion for the drama trailer translated into users’ enjoyment. The impact of user control over interfaces on immersion and enjoyment varies depending on the nature of the media content, which suggests a possible trade-off between the level of user control and entertainment outcomes.


2020 ◽  
pp. 41-50
Author(s):  
Ph. S. Kartaev ◽  
I. D. Medvedev

The paper examines the impact of oil price shocks on inflation, as well as the impact of the choice of the monetary policy regime on the strength of this influence. We used dynamic models on panel data for the countries of the world for the period from 2000 to 2017. It is shown that mainly the impact of changes in oil prices on inflation is carried out through the channel of exchange rate. The paper demonstrates the influence of the transition to inflation targeting on the nature of the relationship between oil price shocks and inflation. This effect is asymmetrical: during periods of rising oil prices, inflation targeting reduces the effect of the transfer of oil prices, limiting negative effects of shock. During periods of decline in oil prices, this monetary policy regime, in contrast, contributes to a stronger transfer, helping to reduce inflation.


2019 ◽  
pp. 46-64 ◽  
Author(s):  
Vladimir V. Klimanov ◽  
Sofiya М. Kazakova ◽  
Anna A. Mikhaylova

The article examines the impact of various socio-economic and financial indicators on the resilience of Russian regions. For each region, the integral index of resilience is calculated, and its correlation dependence with the selected indicators is revealed. The study confirms the relationship between fiscal resilience and socio-economic resilience of the regions. The analysis of panel data for 75 regions from 2007 to 2016 shows that there are significant differences in the dynamics of indicators in different periods. In particular, the degree of exposure to the negative effects of the crises of 2008—2009 and 2014—2015 in non-resilient regions is higher than in resilient ones.


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