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Abstract The prediction of practical ice loads for ships operating in ice-covered waters is fundamental to the calibration of ice class requirements and improvement of Polar ship structural design. Data collected from full-scale instrumentation campaigns is highly valuable, not only for identifying characteristics of ice loads during actual service experience, but also for benchmarking ice class selection and informing future design decisions. This paper presents results of a study focused on utilizing full scale ice impact data for practical Arctic engineering applications. Three (3) bow-shoulder ice impact events were selected from the Varandey shuttle tanker field data set; representing both peak force and peak local pressure events. The 4D pressure method was used to apply the real-time/real-space pressure panel data directly to a finite element model of the bow in order to assess the structural response. Subsequently, these ice loads were applied to lighter structural hull configurations, to benchmark their capability under the same loading events. The results provide unique insight to the response of different ice class structures to real ice impact measurements.
- North America > United States (0.68)
- North America > Canada > Newfoundland and Labrador > Newfoundland (0.29)
- Transportation > Marine (1.00)
- Energy > Oil & Gas > Upstream (1.00)
Abstract This paper reviews the use of intelligent chemical tracer technology that provides quantitative insight into the inflow distribution across the reservoir interval. Arctic developments are frequently characterized by complex reservoir geology, challenging directional drilling requirements and complicated wellbore design. Understanding the permeability distribution that is encountered in these wells is key to optimizing the future well placement and field reservoir management decisions. Assessing permeability distribution is best performed by measuring the reservoir inflow distribution under flowing conditions. Acquiring inflow distribution using conventional technologies, such as production logging tools, is very problematic in the arctic operational environment where wireline intervention into live wells is a major risk and cost. Intelligent tracer technology provides insight into the inflow distribution without requiring any intervention into the well or major modification to the completion design. Unique chemical tracers are incorporated in polymers comprising an intelligent tracer system. These tracer systems are embedded into completion components during the manufacturing process. The completion components are assembled as part of the completion without any impact to normal operations. The components containing the tracer systems are placed at strategic locations along the completion interval. Inflow from the reservoir contacts the intelligent tracers which release unique chemical molecules that can be detected at 1 part per trillion. Each of the tracers contain a unique molecule. The flow from the reservoir transports the molecules to the surface where samples of the well's production are acquired and analyzed for the concentration of each type of molecule. The concentration profile of each type of molecule is used to assess the inflow occurring at that location. This capability can yield answers to very valuable reservoir management questions such as: Are all the intervals producing? What is the relative contribution of each interval? Where is water break-thru occurring? Two independent mathematical models have been developed that provide the ability to quantitatively determine the reservoir inflow that is associated with the change in the molecular concentration. These models are referred to as the tracer arrival method and the flush out method. This paper reviews how intelligent tracers work, laboratory testing to develop quantitative interpretation models and case histories that demonstrate the validity of the mathematical model.
Oil Exploration and its Relationship to the World of Trapped Micron Scale Fluids: A Review of the Applications of Fluid Inclusion Microscopy to the Study of Aqueous and Hydrocarbon Fluid Dynamics in Sedimentary Basins
Feely, M. (National University of Ireland Galway) | Costanzo, A. (National University of Ireland Galway) | Hunt, J. (National University of Ireland Galway) | Wilton, D. (Memorial University) | Carter, J. (Nalcor Energy)
Abstract Fluid inclusions are micron scale samples of aqueous and hydrocarbon fluids trapped in annealed microfractures developed during burial, or earlier in authigenic minerals e.g. quartz and/or calcite during cementation. Microscopic studies are carried out on specially prepared doubly polished fluid inclusion wafers (~ 150 microns thick) of well core, sidewall core and cuttings. Using a combination of transmitted light and UV light microscopy, laser Raman microscopy and microthermometry, facilitates the collation and comparison of fluid inclusion data. Textural and compositional data relating to the trapping history of fluids can be further constrained using P-T modelling software. The results of fluid inclusion studies of North Atlantic offshore basins i.e. Irish, and Newfoundland and Labrador offshore sectors highlight the use of these analytical and fluid modelling techniques. For example, Porcupine Basin aqueous basinal fluids trapped in cements are consistently of low to moderate salinity (<10 eq. wt.% NaCl), comparable to those found elsewhere on the Atlantic margins e.g. UK Rockall, West of Shetland region, and in the Jeanne d'Arc Basin offshore Newfoundland and may reflect the paucity of evaporites at depth in these regions (Parnell et al., 1999, Parnell et al., 2001 and Feely and Parnell 2003). Migration of at least two chemically distinct hydrocarbon fluids occurred post cementation, as lateral flow along Jurassic sandstones with limited vertical flow along faults (Conliffe et al., 2009). In the Saglek Basin offshore Labrador both monophase (liquid) and two-phase (liquid + vapour) hydrocarbon fluid inclusions occur in the Cretaceous Markland Formation. The two-phase hydrocarbon inclusions yield homogenisation temperatures of ~80°C. The aqueous fluid inclusions represent low temperature (~100°C) and low salinity (~5 eq.wt% NaCl) fluids, and are similar to those recorded in the Porcupine Basin offshore Ireland. P-T modelling of these fluids indicate trapping pressures and temperatures of ~300 bars and ~110° C.
- Europe (1.00)
- North America > Canada > Newfoundland and Labrador > Labrador (0.79)
- North America > Canada > Newfoundland and Labrador > Newfoundland > North Atlantic Ocean (0.34)
- Geology > Rock Type > Sedimentary Rock (1.00)
- Geology > Mineral (0.92)
- Geology > Geological Subdiscipline > Geochemistry (0.68)
- South America > Colombia > Mirador Formation (0.99)
- North America > United States > California > Monterey Formation (0.99)
- North America > Canada > Newfoundland and Labrador > Newfoundland > Nova Scotia > North Atlantic Ocean > Atlantic Margin Basin > Scotian Basin (0.99)
- (14 more...)
- Reservoir Description and Dynamics > Fluid Characterization > Phase behavior and PVT measurements (1.00)
- Reservoir Description and Dynamics > Fluid Characterization > Fluid modeling, equations of state (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (0.89)
Abstract As arctic regions become more accessible for oil and gas exploration and development, the need for subsea export pipelines and flowlines will continue to grow. To reduce risks to the pipeline from hazards of natural or geologic origin, it is critical to consider a more sophisticated approach to route selection compared to traditional manual routing practices based on only the shortest length of pipe or connectivity to existing infrastructure. Arctic environments have unique geologic complexities compared to other types of subsea environments. It is important to identify and avoid or mitigate significant hazards such as ice gouges, strudel scours, or permafrost upheaval zones for subsea pipeline routes in arctic environments. In this paper, we demonstrate a workflow to identify and map multiple geohazards, incorporate pipeline-related criteria, classify and weight features based on their inferred risk to a subsea pipeline, develop a composite map of hazards, and perform GIS-based, leastcost pipeline routing techniques to produce the optimal pipeline route options. This approach has been used in deepwater and shallow water settings around the world. We will demonstrate the advantages of following this methodology using multibeam echosounder (MBES) bathymetry data from an arctic location to illustrate the approach for a hypothetical pipeline project in the early stages of development.
- North America > United States (0.70)
- North America > Canada > Newfoundland and Labrador > Newfoundland (0.29)
Parallel Channel Tests During Ice Management Operations in The Arctic Ocean
Lu, Wenjun (Norwegian University of Science and Technology) | Lubbad, Raed (Norwegian University of Science and Technology) | Løset, Sveinung (Norwegian University of Science and Technology) | Skjetne, Roger (Norwegian University of Science and Technology)
Abstract During ice management operations, creating narrow parallel channels with icebreakers can effectively reduce ice floe sizes for the protected vessel/structure. Yet too narrow channel spacing requirement shall lead to excessive or even unpractical ice management operations. Empirical experience shows an almost 1:1 relationship between ‘downstream floe size’ and ‘parallel channel spacing’ while designing an ice management operation. However, before this paper, there exists no dedicated parallel channel tests with strictly controlled channel spacing and sufficient instrumentation to quantify such relationship. In this paper, we report two parallel channel tests, which have been conducted in September 2015 during an expedition to the Arctic Ocean with icebreakers, Oden and Frej. During the test, helicopter images and an onboard camera were utilised to document the parallel channel fracturing events. With the collected data, we strive to quantify if there is a prominent relationship between parallel channel spacing and the corresponding managed ice floe size. In order to analyse the floe size distribution and its relationship with channel spacing from helicopter images, we developed an image segmentation method that propagates visually identifiable seeding cracks in the image. In addition, onboard camera images were utilised to yield the frequency of parallel channel fracturing events. Given the ice conditions and Oden's specific structural form, with all the different channel spacing tested, it turned out that a channel spacing over 200 m would already prohibit the development of parallel channel fracturing events. Most of the observed events take place when the spacing is smaller than around 100 m. In addition, as was expected, more frequent fractures are taking place with narrower channel spacing, e.g., distances smaller than 30 m. The relationship between managed ice floe size and channel spacing are studied. It is found that almost all (100%) of the produced downstream floe sizes are smaller than twice the channel spacing; 90% of them are smaller than 1.5 times of the spacing; and the majority of them (from 46% to 80%, depending on the spacing distance) are smaller than 1 time of the channel spacing. With such quantified relationships, we can practically estimate the size of the managed ice floes based on known/expected channel spacing.
Integrated Design and Analysis for Virtual Arctic Simulation Environment
Hamilton, Matthew (Avalon Holographies Inc.) | Maynard, Aaron (GRI Simulations Inc.) | Jujuly, Muhammad (Memorial Univeristy) | Adeoti, Ibraheem (Memorial Univeristy) | Rahman, Aziz (Memorial Univeristy) | Adey, Matthew (GRI Simulations Inc.)
Abstract We present an integration of new capabilities of simulation and visualization for subsea analysis and design into an existing virtual arctic simulation environment (VASE). The existing system (previously presented) provides interactive, high-fidelity simulation capabilities for remotely-operated vehicles (ROV) in arctic environments for subsea trenching along with support for visualization of integrated data from sub-bottom and multibeam sonar imaging devices. This paper describes integration of the existing VASE with computation fluid dynamics (CFD) simulation capability for simulation of flow assurance and fluid-structure interaction design issues relevant to arctic subsea oil and gas field design. The presented integrated simulation system allows for rapid, streamlined evaluation of pipeline designs in an integrated data, whole-field context. In particular, detailed analysis of pipeline fatigue risk factors due to slugging and effects of hydrate formation can be performed through integrated CFD analysis capabilities. The system's intuitive pipeline design allows for rapid alteration of pipe and flow lines in response to feedback from bathymetry and soil data, ROV accessibility requirements and structural analysis through flow induced vibration and fluid structure-interaction simulations. It is demonstrated how various pipeline and jumper designs can be rapidly created in the VASE with design strategies motivated by the integrated whole field data visualization environment. Once pipe and jumper designs are specified, they can be exported for external analysis. We demonstrate this analysis through two fluid-structure interaction models (slugging and hydrate formation model). This allows for effective design in arctic environments, including design of pipeline routes in context of trenching and general management of cold water conditions. Overall, the system can also serve to function as a planning and data management system for subsequent training of pilots for inspection as part of asset integrity management.
- North America > Canada > Newfoundland and Labrador (0.47)
- Europe (0.47)
Abstract In 2016 Nalcor Energy installed subsea cables across the Strait of Belle Isle, which comprises part of the Lower Churchill Transmission Project linking Muskrat Falls, Labrador, and Soldier's Pond, Newfoundland. The cable crossing site is southwest of a shoal which filters out deeper draft icebergs which could potentially contact and damage the cable. An initial study in 2011 was followed by iceberg tracking and current monitoring programs at the cable crossing site and a final study incorporating these data 2015-2016. This paper describes the application of a drift-based Monte Carlo model to assess iceberg risk to cables laid on the seabed in the Strait of Belle Isle. The model considers the effect of iceberg rolling which could potentially result in icebergs increasing draft and contacting cables laid on the seabed. Modeled iceberg drift was based on field observations, and measured and modeled currents. Based on results from the 2011 analysis it was decided to use directional drilling to route the initial portions of the cable from shore to break-put locations on the seabed in water depths in excess of 70 m. Rock dumping is used to stabilize the cables on the seabed at deeper water depths. Due to the extreme difficulties in trenching the very strong seabed or tunneling across the Strait of Belle Isle, the selected solution offers the most technically feasible and cost-effective solution for cable routing across the Strait of Belle Isle.
Experimental Investigation of Wave Loads on Ice Masses at Different Proximity to Fixed Offshore Structure
Sayeed, Tanvir (OCRE- National Research Council of Canada, Faculty of Engineering and Applied Science, Memorial University of Newfoundland) | Colbourne, Bruce (Faculty of Engineering and Applied Science, Memorial University of Newfoundland) | Molyneux, David (Faculty of Engineering and Applied Science, Memorial University of Newfoundland) | Akinturk, Ayhan (OCRE- National Research Council of Canada)
Abstract Wave driven iceberg and bergy bits’ impact load with an offshore structure is an important design concern. Hydrodynamic interaction between iceberg / bergy bit and an offshore structure in close proximity is an important factor that governs the impact load. Recently, a set of experiments has been conducted at Ocean Engineering Research Center (OERC) at Memorial University of Newfoundland to measure the wave loads on different sized spherical ice masses at different proximity to a fixed structure. A six component dynamometer was used to measure the loads in a quasi-static manner in six regular head waves. The objective was to investigate change in wave loads as the ice mass approaches to the structure. The experimental results show that the distance to wavelength ratio dictates the corresponding wave loads in horizontal and vertical directions. The mean drift force in the horizontal direction becomes negative (against the direction of wave propagation) for most of the cases when the body is close to the structure. Also, as the body is positioned closer to the structure, the non-dimensional RMS forces in the horizontal direction decrease and the non-dimensional RMS forces in the vertical direction increase.
- Research Report > Experimental Study (0.69)
- Research Report > New Finding (0.48)
Abstract Icebreakers as such have been sailing for some 120 years. At first they were just a bit stronger than ordinary commercial vessels. Propulsion solution was steam engines connected to propeller. During the first decades not much development took place. As the marine diesel engines started to replace the steam engines and advances in electric devices took place, first diesel-electric icebreakers were built in the 1930ies. During the next 40 years this solution became more or less a standard for such ships. Next step was the development of the electric drive itself. New smaller AC-motors gave room for new thinking and podded drives came into the picture in the early 1990ies. Simultaneously there were also development exercises on mechanical devices like CP-propellers and Z-drives during 1970ies and −80ies. Today we have available and most commonly used; traditional fixed pitch propellers with conventional shaft lines, mechanical Z-drives and podded drives, all driven by electric motors. The operational profile and mission of the vessel will dictate how the icebreaker will be furbished. This paper discusses the development history of icebreaker propulsion. Recently there have been delivered and designed new icebreakers, icebreaking shuttle tankers and LNG carriers. Many of these vessel concepts are relying on podded propulsion system. AZIPOD propulsion has been selected to many of these vessels as it provides excellent ice performance for the vessel, good torque characteristics for the propeller and there already exists proven track record of ice operations. This paper will outline important design considerations when developing diesel-electric podded propulsion system.
- Europe (1.00)
- North America > United States (0.95)
- Asia (0.68)
- North America > Canada > Newfoundland and Labrador (0.46)
- Transportation > Marine (1.00)
- Government > Military (1.00)
- Transportation > Freight & Logistics Services > Shipping (0.87)
- (2 more...)
Abstract The Colville River originates in the remote western Brooks Mountain Range in Alaska's Arctic and empties into the Beaufort Sea, a marginal water body of the Arctic Ocean. The river, which is frozen for more than six months each year and floods in spring, is approximately 560 kilometers long and is one of the northernmost major rivers in North America. The river separates the established oil and gas fields of Alaska's North Slope from the previously undeveloped National Petroleum Reserve - Alaska (NPR-A) to the west. A key component of required infrastructure to accommodate development of the resources was a series of four bridges across distributaries of the Colville River that provided access between the Alpine Field and NPR-A. The longest of the four bridges was a 430-meter structure across the Nigliq Channel, the largest distributary of the Colville River. This paper describes the significant design and construction challenges that had to be overcome to successfully complete the Nigliq Channel Bridge.
- North America > United States > Alaska > North Slope Basin > Western North Slope > Colville River Field > Alpine Field > Kingak Formation (0.99)
- North America > United States > Alaska > North Slope Basin > Prudhoe Bay Field (0.99)