Sustainable use and production of energy in the 21st century

It is foreseen that oil and gas will continue to be the key energy sources in the 21st century. Therefore, it is important that oil and gas be produced in a sustainable way during the next decades. This requires technology development to ensure that the environmental impact and pollution from these activities are minimal. The following aspects are being highlighted in this paper: • Development of projects with the minimum of impact on the environment and problems for local populations. • Sustainable drilling without the use of oil-based mud, and collection of all drilling waste during offshore drilling operations in the most environmentally sensitive areas. • Treatment of produced water, sand and minerals from the well stream to avoid pollution. • Limitation of flaring to be performed only when required for safety reasons. • Continuous checking of pipelines to ensure that gas pipelines are run within their actual pressure capacity and that oil pipelines are not leaking into rivers and lakes. • Provision of sufficient storage capacity for gas to ensure timely delivery of gas during high demand peaks. • Injection of CO2 into sealed underground formations where large quantities are produced, such as at LNG factories. • Optimization of production from existing fields to avoid huge amounts of oil and gas being left in place, following a ‘hit and run’ recovery plan. Furthermore, all primary energy sources need to be converted into end-user energy services known as mechanical work, electricity, heating and cooling. In the process of conversion, only a portion of the primary energy is transformed into the new form, while the rest remains unaltered and is lost. The various forms of energy services produced represent different values or qualities, e.g. heat holds an energy quality ranging from 0 and upwards, depending on the temperature difference which is utilized, as defined by the second law of thermodynamics. Energy efficiency in this context may also be defined as the ratio between energy quality output and input. Practically, all fossil fuels are converted into energy services via combustion and heat, i.e. the conversion efficiency is solely determined by temperatures, meaning that high-energy efficiency can only be obtained at large temperature differences, such as in power generation, while ordinary domestic heating will yield a very low efficiency. Given that some 30–40 % of all fossil fuels today are used for domestic heating, representing an end-user energy quality of (say) 1/10 of what is obtained in modern power generation, there is a large potential globally for energy efficiency improvements, not to mention the associated emission reductions. The obvious solution is to pay more attention to the second law of thermodynamics, i.e. to shift from direct combustion heating to thermodynamic principles, e.g. by the use of electrical-driven heat pumps and/or combined heat and power as another alternative. The objectives of this paper are to highlight how energy production could become more effective, thus leading to a reduction in pollution to land, sea and atmosphere and also to identify how energy production should be carried out to minimize the polluting effects. The goal is to provide a reminder that much can be gained with respect to the reduction of pollution by focusing on cleaner energy production

Analysis of Russian UGS capacity in Europe

Gas is the fuel of choice in Europe for heating, and many expect that gas consumption will continue to increase in the future. On the contrary, European indigenous production decreases, yielding needs to import natural gas primarily from Russia. Travelling long distances from production sites, gas deliveries come by pipelines. Most of them, having operated for decades, have almost depleted their design lifetime, and before long will tend (or have already implemented) to reduce nominal flow pressure and thus flow capacities. To compensate sufficiently for gas peak demands avoiding long, costly and sometimes not practical procedures of changing out pipes, it is suggested to examine the effect of gas storage at European strategic locations to ensure the balance between gas demand and supply. Along with storing gas in a liquid form as LNG, stipulated by need in spacious plants and infrastructure, Underground Gas Storages (UGS) near to the customers are studied and are seen as the most practical way of natural gas preservation in a gaseous form. Conditions provided, pressurized gas is held in underground facilities at key locations, so that it can rapidly be transported to desired regions. Depending on a number of factors, and to suit the different gas supply needs, various types of UGSs are distinguished as follows: • Gas storage in depleted fields. • Gas storages in a water-bearing structures. • Gas storages in salt dome formations. The paper outlooks UGSs across Western and Eastern Europe with focus on the available capacity of the biggest gas supplier to EU- Gazprom Group Company and its storage capacities. An investigation is done to demonstrate the recent change in storage volumes rented and owned, and change in the geography of storages involved. Applying technical and economic criteria, the study shows a need of Russian gas to urope and a need of European UGS facilities for Russian gas

Management of Challenges During the Construction of Offshore Facilities

The construction of offshore facilities for development of oil and gas deposits is preceded by careful Conceptual Studies, Front-End Engineering Design Studies (FEED studies) and a Detailed Engineering phase including accurate construction planning. Still, incidents during the Construction Phase could lead to needs for implementation of physical strengthening of construction details or changes to the construction process. These incidents could emerge from information coming from the construction of other facilities, detection of design errors or aspects which were overseen during the engineering phase. Serious consequences, like loss of assets or fatalities, could occur in case the unexpected information was not assessed and changes were not implemented. In this paper, we report on how the design and construction processes were adjusted during the construction phase of the largest of the North Sea platforms, the Troll offshore gas production facilities, as new information became available while the platform was in the construction phase. The assessment of all incoming information and implementation of mitigating measures led to the successful construction, installation and start-up of gas production from the platform. Of particular importance for the success was the open attitude by the operator of the construction project to allow for voicing of concerns from companies hired to do verification, external reviewers and from project personnel. The lessons learned during the construction of these facilities could be very useful for those involved in the design and construction of large projects, in particular in offshore oil and gas projects where the forces due to waves and currents and the strains due to bending and pressures are not always well known initially. The paper is concluded by a recommendation to listen to those presenting warnings to project management during project execution (including the detailed engineering and construction phases)

Design and installation of high voltage cables at sea

Underwater telecommunication cables have been connecting continents since the 1860s. These days large electric power cables are connecting countries to ensure optimization of energy use. When the production of energy from renewable resources, like wind and solar, are low, energy from other sources may be imported and vice versa. At the moment a cable is planned between Norway (for hydropower) and Scotland (for wind power). Furthermore, large electric power cables are needed offshore to bring electricity from offshore wind turbines to shore and cables are required to bring onshore generated electricity to offshore oil and gas platforms to reduce pollution. Over time, the process of laying cables at sea has developed into a state-of-the-art operation. Now these operations are becoming more technologically advanced and it is possible to lay large diameter electric cables over large distances. A particular challenge occurs in case an unplanned splicing/ jointing will be necessary. In this paper, we explore the design criteria for such cables and the procedures and challenges of installation and splicing. Furthermore, the effects of how dynamic motions of the vessel and sea influence the situation in deep water are explored. We have analysed the effects of waves on vessel motion, and how this may affect the cable during a jointing operation of two cable ends at different water depths. The effects of current forces on the cable are also analysed and how the cable reacts to both current and wave forces. This analysis method can assist in determining the weather criteria for a jointing operation to prevent excessive bending, compression or fatigue damage in the cable. One finding in the analysis is that there are different requirements for laying the cable and the jointing operations. The suitable sea states for jointing are more limited than for laying. When the vessel and the cable are standing still, all bending occurs at the same place in the cable, resulting in increased risk of fatigue damage, hence it is necessary with a calmer sea state for this kind of operation. The examples referred to in the paper are based on realistic assumptions; a summary of these assumptions is included. Furthermore, a HAZID, carried out for cable installation, shows that there are several risks and hazardous events that may occur during the installation operation in connection to the cables integrity. Identifying and handling these risks early may reduce both their probability of occurring and the related consequences

A Laboratory Study of Nonlinear Surface Waves on Water

This paper describes an experimental investigation in which a large number of water waves were focused at one point in space and time to produce a large transient wave group. Measurements of the water surface elevation and the underlying kinematics are compared with both a linear wave theory and a second-order solution based on the sum of the wave-wave interactions identified by Longuet-Higgins & Stewart (1960). The data shows that the focusing of wave components produces a highly nonlinear wave group in which the nonlinearity increases with the wave amplitude and reduces with increasing bandwidth. When compared with the first- and second-order solutions, the wave-wave interactions produce a steeper wave envelope in which the central wave crest is higher and narrower, while the adjacent wave troughs are broader and less deep. The water particle kinematics are also strongly nonlinear. The accumulated experimental data suggest that the formation of a focused wave group involves a significant transfer of energy into both the higher and lower har¬monics. This is consistent with an increase in the local energy density, and the development of large velocity gradients near the water surface. Furthermore, the nonlinear wave-wave interactions are shown to be fully reversible. However, when compared to a linear solution there is a permanent change in the relative phase of the free waves. This explains the downstream shifting of the focus point (Longuet-Higgins 1974), and appears to be similar to the phase changes which result from the nonlinear interaction of solitons travelling at different velocities (Yuen & Lake 1982)

Alarm handling onboard vessels operating in DP mode

This paper explores concerns regarding the design, implementation, and management of alarms in DP vessels that, while in operation, need an incredibly high level of accuracy along with high reliability and safe operations. The Human, Technological, and Organizational factors (HTO) method is primarily used as analysis tool to find weaknesses in alarm handling during DP operations. The research focuses on results collected from Dynamic Positioning Operators (DPO) and instructors. Findings from the survey are presented and compared to the results from past accidents and technical requirements from Petroleum Safety Agency Norway via YA 711. Three accidents from past are referred to picturize the findings from the survey results. Furthermore, the conclusion is given with recommendations reflecting the findings from the survey. The main findings are an urgency to establish a centralized marine accident investigation system which enforces learning and recommendation to make operations safer. In addition, the survey also suggests that prohibition of clients or limiting their access to the bridge is necessary. Manufacturers could focus on research and development of alarm prioritization, on structuring and presentation, and profiting by taking feedback from end-users to make DP operations safer