• 2-D bed sediment transport modeling of a reach on the Sagavanirktok River, Alaska

      Ladines, Isaac A.; Toniolo, Horacio; Barnes, David; Schnabel, Bill (2019-05)
      Conducting a 2-D sediment transport modeling study on the Sagavanirktok River has offered great insight to bed sediment movement. During the summer of 2017, sediment excavation of two parallel trenches began in the Sagavanirktok River, in an effort to raise the road elevation of the Dalton Highway to remediate against future floods. To predict the time in which the trenches refill with upstream sediment a 2-D numerical model was used. Three scenarios: (1) a normal cumulative volumetric flow, (2) a max discharge event, and (3) a max cumulative volumetric flow, were coupled with three sediment transport equations: Parker, Wilcock-Crowe and Meyer Peter and Müller for a total of 9 simulations. Results indicated that scenario (1) predicted the longest time to fill, ranging from 1-6 years followed by scenario (2), an even shorter time, and scenario (3) showing sustained high flows have the capability to nearly refill the trenches in one year. Because the nature of this research is predictive, limitations exist as a function of assumptions made and the numerical model. Therefore, caution should be taken in analyzing the results. However, it is important to note that this is the first time estimates have been calculated for an extraction site to be refilled on the Sagavanirktok River. Such a model could be transformed into a tool to project filling of future material sites. Ultimately, this could expedite the permitting process, eliminating the need to move to a new site by returning to a site that has been refilled from upstream sediment.
    • Alaska Arctic coastal plain gravel pad hydrology: impacts to dismantlement removal and restoration operations ; a study on the human - hydrology relationship in Arctic environments

      Miller, Ori; Barnes, David L.; Stuefer, Svetlana L.; Shur, Yuri (2019-08)
      To guard against thawing permafrost and associated thaw subsidence, the oil facilities in the Arctic are constructed on gravel pads placed on top of the existing arctic tundra, however the impacts of this infrastructure to the sensitive hydrology are not fully understood. Production in some of the older fields is on the decline; however oil exploration in the Arctic Coastal Plain is resulting in the discovery and development of new reserves. In the coming years, old sites will need to be decommissioned as production transitions to new sites. New facilities will also need to be designed and constructed. Oil companies in Alaska have historically conducted operations under leases issued through the Alaska Department of Natural Resources. The leases stipulate that once resource extraction operations are completed, the facilities must be decommissioned and the sites restored, however they are often vague in their requirements and are variable in their specifics from lease to lease. As the oil companies transition to the new sites, decisions must be made regarding what should be done with vacated gravel pads. The construction of gravel pads essentially destroys underlying arctic tundra. In undisturbed areas in the Arctic, the tundra itself creates an insulating layer that limits the seasonal thaw depth to around 0.5 m. Removal of this layer causes thaw depths to greatly increase impacting the stability of the ground and the hydrology of the surrounding area. Because of this impact, other possible restoration techniques are being considered, such as vegetating and leaving the pads in place. Water movement is one of the major driving factors in the arctic contributing to permafrost degradation. Groundwater carries with it heat, which is transferred to the soil as the groundwater moves. Therefore, hydrology plays a major role in the stability of the arctic environment. This is especially relevant in areas where gravel pads exist. Gravel pads are anthropogenic structures that have significant water storage potential. Because of the unique conditions in the Arctic, pore-water flow through these gravel pads is not yet well understood. The purpose of this study is to develop a more complete scientific understanding of the driving forces behind pad pore-water movement. This study expands on fieldwork from a prior hydrological field study conducted by others. The prior study is expanded through this work by developing an associated groundwater model to the gravel pad from the field study to examine the flow through it and the controlling factors for this flow. The study site used for this project is located in Prudhoe Bay and is the pad constructed for the very first production well in Prudhoe Bay in 1968. This study demonstrates that it is the topography of the silt layer beneath the gravel pads that is the most significant factor controlling pad pore-water movement. The results from the modeling study will assist engineers and environmental scientists in better understanding the groundwater flow. This understanding will aid in the decommissioning and restoration process and help inform decision making in regards to the future of the existing pads. The results may also be used to inform the development of new infrastructure such that any new pads which are built may be constructed with their relationship to the local hydrology more in mind.
    • Alaska-Canada Rail Link Economic Benefits

      Watts, Teresa; Peter Wallis Consulting Limited; Metz, Paul A. (2019-07)
      Construction of the 1,740 km Alaska-Canada Rail Link (ACRL) between Fort Nelson, BC and Delta Junction, Alaska to join the North American rail system to the Alaska Railroad will result in tremendous economic benefits for Canada and the US. The ACRL will provide valuable additional east-west rail capacity and tidewater access to the Pacific, hugely benefitting not only the Yukon and Eastern Alaska regions, into which it will introduce rail transport for the first time, but throughout both countries. The economic benefits of ACRL construction are consistent with Canadian government’s desire to promote Northern development and comparable in significance to those of Canadian Pacific Railway in the 1880’s and the St. Lawrence Seaway in the 1950’s. Construction of the ACRL alone will bring unprecedented economic stimulus to the region in terms of job creation, wages and income tax revenue over multiple years. Table 7-1 below summarizes the benefits from ACRL construction for the Yukon, BC and Canada as a whole. However, these estimates are conservative as they exclude benefits associated with pre-construction activities, railway operation post-construction, sales taxes and corporate taxes as well as all such benefits that will accrue to Alaska and the US.
    • Alkali-surfactant-polymer (ASP) flooding - potential and simulation for Alaskan North Slope reservoir

      Ghorpade, Tejas S. (2014-09)
      Enhanced oil recovery (EOR) is essential to recover bypassed oil and improve recovery factor. Alkaline-surfactant-polymer (ASP) flooding is a chemical EOR method that can be used to recover heavy oil containing organic acids from sandstone formations. It involves injection of alkali to generate in situ surfactants, improve sweep efficiency, and reduce interfacial tension (IFT) between displacing and displaced phase, and injection of a polymer to improve mobility ratio; typically, it is followed by extended waterflooding. The concentration of alkali, surfactant, and polymer used in the process depends on oil type, salinity of solution, pressure, temperature of the reservoir, and injection water quality. This project evaluates the effect of waterflooding on recovery, calculates the recovery factor for ASP flooding, and optimum concentration of alkali, surfactant, and polymer for an Alaskan reservoir. Also, the effects of waterflooding and improvement with ASP flooding are evaluated and compared. Studies of these effects on oil recovery were analyzed with a Computer Modeling Group (CMG)-generated model for the Alaskan North Slope (ANS) reservoir. Based on a literature review and screening criteria, the Western North Slope (WNS) 1 reservoir was selected for the ASP process. A CMG - WinProp simulator was used to create a fluid model and regression was carried out with the help of actual field data. The CMG - WinProp model was prepared with a 5 spot well injection pattern using the CMG STARS simulator. Simulation runs conducted for primary and waterflooding processes showed that the recovery factor increased from 3% due to primary recovery to 45% due to waterflooding at 500 psi drawdown for 60 years with a constant producing gas oil ratio (GOR). ASP flooding was conducted to increase recovery further, and optimum ASP parameters were calculated for maximum recovery. Also, effect of alkali, surfactant and polymer on recovery was observed and compared with ASP flood. If proved effective, the use of ASP chemicals for ANS reservoirs to increase the recovery factor could replace current miscible gas injection with chemical EOR. It will help to develop chemical flooding processes for heavier crude oil produced in harsh environments and create new horizons for chemical industries in Alaska.
    • Alternative project delivery in rural Alaska: experiences, quality and claims

      Monta, Katrina L.; Pehrson, Gerald S.; Cryer, Matthew N. (2015-12)
      The popularity of alternative project delivery systems has expanded beyond the private sector and into the public sector. Alaska embodies unique challenges that may present obstacles while using alternative project delivery systems. This analysis will provide an understanding of alternative project delivery systems in Alaska and how local experiences, quality and claims are affected. Alaska's unique characteristics present both challenges and opportunities for implementing alternative project delivery systems. This report begins with a discussion of experiences from several rural Alaska projects, and how alternative project delivery systems can be utilized. Some impacts that alternative project delivery systems have on quality are then presented, including a perspective on quality and recommendations for achieving customer satisfaction. A treatment of construction claims is then provided, followed by conclusions and recommendations for stakeholders in selecting an appropriate project delivery system. Alternative project delivery systems were researched by means of scholarly literature reviews, professional interviews and seminars. The report of these findings is intended to provide owners and contractors with a concise presentation of the challenges and advantages for using alternative project delivery systems in Alaska.
    • Application of design of experiments for well pattern optimization in Umiat oil field: a natural petroleum reserve of Alaska case study

      Gurav, Yojana Shivaji; Dandekar, Abhijit; Patil, Shirish; Khataniar, Santanu; Clough, James; Patwardhan, Samarth (2020-05)
      Umiat field, located in Alaska North Slope poses unique development challenges because of its remote location and permafrost within the reservoir. This hinders the field development, and further leads to a potential low expected oil recovery despite latest estimates of oil in-place volume of 1550 million barrels. The objective of this work is to assess various possible well patterns of the Umiat field development and perform a detailed parametric study to maximize oil recovery and minimize well costs using statistical methods. Design of Experiments (DoE) is implemented to design simulation runs for characterizing system behavior using the effect of certain critical parameters, such as well type, horizontal well length, well pattern geometry, and injection/production constraints on oil recovery. After carrying out simulation runs using a commercially available simulation software, well cost is estimated for each simulation case. Response Surface methodology (RSM) is used for optimization of well pattern parameters. The parameters, their interactions and response are modeled into a mathematical equation to maximize oil recovery and minimize well cost. Economics plays a key role in deciding the best well pattern for any field during the field development phase. Hence, while solving the optimization problem, well costs have been incorporated in the analysis. Thus, based on the results of the study performed on selected parameters, using interdependence of the above mentioned methodologies, optimum combinations of variables for maximizing oil recovery and minimizing well cost will be obtained. Additionally, reservoir level optimization assists in providing a much needed platform for solving the integrated production optimization problem involving parameters relevant at different levels, such as reservoir, wells and field. As a result, this optimum well pattern methodology will help ensure optimum oil recovery in the otherwise economically unattractive field and can provide significant insights into developing the field more efficiently. Computational algorithms are gaining popularity for solving optimization problems, as opposed to manual simulations. DoE is effective, simple to use and saves computational time, when compared to algorithms. Although, DoE has been used widely in the oil industry, its application in domains like well pattern optimization is novel. This research presents a case study for the application of DoE and RSM to well optimization in a real existing field, considering all possible scenarios and variables. As a result, increase in estimated oil recovery is achieved within economical constraints through well pattern optimization.
    • Applications of trend surface analysis and geologic model building to mineralized districts in Alaska

      Heiner, L.E.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1967)
      The Mineral Industry Research Laboratory, University of Alaska, has investigated the application of computers and statistics to mineral deposits in Alaska. Existing programs have been adapted and new ones written for the computers available at the University. The methods tested are trend surface analysis and geologic model making. An existing coeffecient of association program was converted to Fortran IV , but was not applied to an Alaskan problem. A trend surface is a mathematically describable surface that most closely approximates a surface representing observed data. In geologic model making, regression analysis is used to determine what geologic features are significant as ore controls. Coefficient of association compares samples to each other on the basis of a variable being present or absent. Trend surfaces were computed for dips and s t r i k e s of geologic features ( v e i n s , f a u l t s , bedrock) for Southeastern Alaska, the Chichagof district , and the Hyder district . Results for the f i r s t two are presented as maps. Trend surfaces and residual maps were prepared for geochemical data from the Slana district, Alaska. A mineral occurrence model was made for a portion of the Craig Quadrangle, and potential values were computed for c e l l s in the area. Appraisals of potential values by five geologists are compared with those of the model. An IBM 1620 multiple regression program is included.
    • An assessment of suspended sediment transport in Arctic Alaskan rivers

      Lamb, Erica K.; Toniolo, Horacio; Schnabel, William; Kane, Douglas (2013-05)
      Provided here is an initial assessment of suspended sediment transport in several rivers on the North Slope of Alaska. This study was divided into two parts: the Umiat project, which involved the Chandler, Anaktuvuk and Itkillik Rivers, and the NPR-A study, which considered Prince, Seabee and Fish Creeks, as well as a brief look at the lkpikpuk River, Otuk Creek, Judy Creek and the Ublutuoch River. Methods used included depth-integrated suspended sediment samples, grab samples, automatic pump-style samplers, discharge measurements, bed sediment grain size analysis and the inclusion of a variety of meteorological measurements from other projects. With slightly less than two years of data collection from May 2011 to September 2012, an initial analysis was completed. Suspended sediment rating curves developed for the Anaktuvuk and Chandler Rivers over the two-year study period revealed a strong correlation between suspended sediment concentration (SSC) and discharge. The most data was collected for the Anaktuvuk and Chandler Rivers; on these rivers, suspended sediment discharge was also analyzed, showing that over 90% of suspended sediment transport occurred during the spring melt period in 2011. Spring melt was not measured in 2012, so analysis was only completed for 2011.
    • Attenuation of the herbicide glyphosate along railroad corridors in Alaska

      Ballou, Nellie B. (2011-05)
      Following the application of glyphosate in the formulation of AquaMaster® at two contrasting sub-arctic zones along the railroad corridor in Alaska, attenuation of the herbicide glyphosate was investigated. Study sites were established in continental and coastal zones. Glyphosate soil attenuation was similar to temperate regions during the growing season but exhibited an extended persistence during the winter months. Although glyphosate microbial degradation likely slowed during winter, both sites showed evidence of slight glyphosate degradation during the winter months. The coastal site attenuated more rapidly than the continental site which is presumably due to increased rainfall relative to the continental site. Glyphosate attenuation at the coastal site was likely driven by dispersion while microbial degradation was responsible for the attenuation of glyphosate at the continental site. Movement to subsurface soils (10-25 cm) at low concentrations was observed at both sites with slightly more transport at the coastal site than the continental site. Glyphosate transport to groundwater along railroad corridors was not conclusive. Vegetation cover reduction was reduced at the continental site but could not be determined at the coastal site.
    • Automatic detection of sensor calibration errors in mining industry

      Pothina, Rambabu; Ganguli, Rajive; Ghosh, Tathagata; Lawlor, Orion; Barry, Ronald (2017-12)
      Sensor errors cost the mining industry millions of dollars in losses each year. Unlike gross errors, "calibration errors" are subtle, develop over time, and are difficult to identify. Economic losses start accumulating even when errors are small. Therefore, the aim of this research was to develop methods to identify calibration errors well before they become obvious. The goal in this research was to detect errors at a bias as low as 2% in magnitude. The innovative strategy developed relied on relationships between a variety of sensors to detect when a given sensor started to stray. Sensors in a carbon stripping circuit at a gold processing facility (Pogo Mine) in Alaska were chosen for the study. The results from the initial application of classical statistical methods like correlation, aggregation and principal component analysis (PCA), and the signal processing methods (FFT), to find bias (±10%) in "feed" sensor data from a semi-autogenous (SAG) grinding mill operation (Fort Knox mine, Alaska) were not promising due to the non-linear and non-stationary nature of the process characteristics. Therefore, those techniques were replaced with some innovative data mining techniques when the focus shifted to Pogo Mine, where the task was to detect calibration errors in strip vessel temperature sensors in the carbon stripping circuit. The new techniques used data from two strip vessel temperature sensors (S1 and S2), four heat exchanger related temperature sensors (H1 through H4), barren flow sensor (BARNFL) and a glycol flow sensor (GLYFL). These eight sensors were deemed to be part of the same process. To detect when the calibration of one of the strip vessel temperature sensors, S1, started to stray, tests were designed to detect changes in relationship between the eight temperature sensors. Data was filtered ("threshold") based on process characteristics prior to being used in tests. The tests combined basic concepts such as moving windows of time, ratios (ratio of one sensor data to data from a set of sensors), tracking of maximum values, etc. Error was triggered when certain rules were violated. A 2% error was randomly introduced into one of the two strip vessel temperature data streams to simulate calibration errors. Some tests were less effective than others at detecting the simulated errors. The tests that used GLYFL and BARNFL were not very effective. On the other hand, the tests that used total "Heat" of all the heat exchanger sensors were very effective. When the tests were administered together ("Combined test"), they have a high success rate (95%) in terms of True alarms, i.e., tests detecting bias after it is introduced. In those True alarms, for 75% of the cases, the introduction of the error was detected within 39.5 days. A -2% random error was detected with a similar success rate.
    • Climatic and physiographic drivers of peak flows in watersheds in the North Slope of Alaska

      Hinzman, Alexa Marion Hassebroek; Stuefer, Svetlana; Arp, Christopher; Barnes, David (2017-08)
      The failure to accurately predict peak discharge can cause large errors in risk analysis that may lead to damage to structures and in some cases, death. Creating linear regression (LR) equations that accurately predict peak discharges without historic data provides a method to estimate flood peaks in ungauged watersheds on the North Slope of Alaska. This thesis looks at the independent variables that drive, or are significant in predicting snowmelt peak discharge in the North Slope watersheds. The LR equations created use independent variables from meteorological data and physiographic data collected from four watersheds, Putuligayuk River, Upper Kuparuk River, Imnavait Creek and Roche Moutonnée Creek. Meteorological data include snow water equivalent (SWE), total precipitation, rainfall, storage, length of melt. Physiographic data summarize watershed area (2.2 km2 to 471 km2) and slope (0.15:100 to 2.7:100). This thesis compared various Flood Frequency Analysis techniques, starting with Bulletin 17B, multiple USGS regional methods and finally created LR equations for each watershed as well as all four watersheds combined. Five LR equations were created, three of the LR equations found SWE to be a significant predictor of peak flows. The first equation to estimate peak flows for all watersheds used only area and had a high R2 value of 0.72. The second equation for all watersheds included area and a meteorological independent variable, SWE. While the evidence presented here is quite promising that meteorological and physiographic data can be useful in estimating peak flows in ungauged Arctic watersheds, the limitations of using only four watersheds to determine the equations call for further testing and verification. More validation studies will be needed to demonstrate that viable equations may be applied to all watersheds on the North Slope of Alaska.
    • Cofiring coal and biomass at Aurora Power Plant in Fairbanks, Alaska

      Wright, Zackery; Huang, Daisy; Nicholls, David; Peterson, Rorik; Schnabel, William (2016-05)
      Biomass energy has been a topic of great interest over the previous few years in Alaska; especially when various fuel sources were priced at a record high. Interior Alaska has the potential to utilize woody biomass to offset the use of coal in many of its power generating facilities. In this study, woody biomass in the form of clean aspen (Populus tremuloides) chips was cofired with Usibelli coal at the Aurora Power Plant facility in downtown Fairbanks, Alaska. Biomass was successfully cofired at low average rates of 2.4% and 4.81% of total energy value. Combustion gasses were analyzed using measuring probes in the exhaust stack. The 2.4% biomass test saw, on average, an increase in CO and CO₂ by 95ppm and 2%, respectively. A decrease in NOx of 1ppm was observed. During the 4.81% biomass test, CO increased by 83ppm, NOx decreased by 18ppm, and CO decreased by 1%. Opacity increased by 0.1% during the 2.4% biomass test and 0.17% during the 4.81% biomass test. The challenges facing a small scale facility in Interior Alaska are also presented. The testing exemplified that the use of biomass in stoker/grate boilers in Alaska is technically feasible with relative ease. No technical barriers to cofiring at low levels on an on-going basis were found at the Aurora Power Plant and this conclusion would likely hold true at similar facilities in interior Alaska.
    • A comprehensive analysis of the oil fields of the North Slope of Alaska: their use as analogs, recent exploration, and forecasted royalty and production tax revenue

      Michie, Joshua J.; Patil, Shirish; Dandekar, Abhijit; Khataniar, Santanu; Sonwalker, Vikas (2018)
      Revenues from petroleum production supply most of the revenue for unrestricted general funds for the State of Alaska. As such, variations in the price of oil, decline from existing production and new developments greatly affect the money available for the state to spend on everything from roads to education. This study reviewed all producing oil fields on the North Slope, characterized their reservoir performance and forecasted future production. This was coupled with analysis of recent exploration discoveries and ongoing project developments to forecast future North Slope production and create potential royalty and production tax revenue forecasts. After 40 years of production, Prudhoe Bay remains the dominant field on the North Slope, accounting for 45% of current production. Relatively large changes in the non-anchor field pools are only able to change North Slope production by a couple of percent due to the nature of their size compared to Prudhoe Bay, Kuparuk and Alpine. New developments however, are able to materially contribute to changes in North Slope production if they are large enough. With continued activity in the many fields, creating an accurate forecast is challenging, however, without new developments, the Trans Alaska Pipeline will need to make changes to accommodate low flow rates. Currently identified new developments have the potential to extend current production rates 10-20 years. Some of these announced developments and discoveries have announced productivity rates that are not realistic compared to analog well performance, and will likely require many more wells to achieve the announced rates and volumes.
    • Connecting Alaskans: mixed-use safety and accessibility challenges in rural environments

      Sorensen, Carrie L.; Belz, Nathan; Goddard, Scott; Barnes, David (2017-12)
      Connectivity in transportation networks, or lack thereof, is a challenge that many people have to deal with. Alaska has many rural communities that are inaccessible by conventional modes of transportation. In order for people to reach these communities and move between them unconventional modes of transportation are needed. However, very few studies have been done on unconventional transportation modes such as ATVs and snowmachines and the level to which they contribute to connecting people and how to help limit traumatic injuries of users. This study focuses on Alaska and three primary datasets. First, the Pacific North West Transportation Survey developed by the University of Alaska Fairbanks and the University of Idaho. Second, Alaska Trauma Registry data obtained from Division of Public Health and Safety. Thirdly, publicly available GIS transportation network and populated place data. These three data sets accomplish the following objectives: (1) document preferences and perceptions of mixed-use safety, (2) to better understand the reasons for injuries and fatalities involving ATVs and snowmachines, and (3) to identify potential mixed-use conflict areas by geographic mapping of traumas. From this analysis a better understanding of ATV mode use was discovered. ATVs are used for a variety of trip purposes including: commuting, running errands, chores, and recreation. ATVs are used on and near roadways 24% of the time. There are twice as many ATV-related traumas in connected places than in isolated places, and 3 times more ATV related traumas in highway connected places than secondary road connected places. Snowmachines are used on and near roadways 23% of the time and have 3 times as many traumas in highway connected places than secondary road connected places. Highway connected places have a significantly higher risk of having ATV and snowmachine traumas than road connected places. This indicates that part of the issue could be the amount of traffic in connected areas, or perhaps the frequency of use of ATVs rather than automobiles in non-connected areas leading to fewer mixed-use scenarios.
    • Continued Field Evaluation of Precutting for Maintaining Asphalt Concrete Pavements with Thermal Cracking

      Liu, Jenny; Zhao, Sheng; McHattie, Robert (Center for Environmentally Sustainable Transportation in Cold Climates, 2017-08)
      In continuation of a previously completed project entitled Evaluate Presawn Transverse Thermal Cracks for Asphalt Concrete Pavement, this project was a further effort to understand important variables in the thermal cracking process through continued field monitoring of three precutting test sites in Interior Alaska. The test sites included (1) Phillips Field Road, precut in 1984 (≈ west ¼ mile of this road), (2) Richardson Highway precut in 2012 (≈ MP 343–344), and (3) Parks Highway precut in 2014 (≈ MP 245–252). Preliminary results at relatively short periods (up to 4 years) indicate that precutting is an economically promising way to control natural thermal cracks. Even short-term economic benefits appear to range between about 2% and 21%. The degree to which precutting works for an AC pavement appears to be a function of the thickness and general structural robustness of new construction. Shorter precut spacing, along with stronger and/or thicker pavement structures, looks promising with respect to crack control. Continuing evaluation and monitoring of test sections are needed to recommend an effective design methodology and construction practice for Alaska and cold areas of other northern states.
    • Design of a micro-hydrokinetic electric power generation system

      Han, Rui (2011-08)
      The objective of this thesis project is to design a Micro-Hydrokinetic Power Generating (MHPG) system to generate electricity from sustainable and distributed hydrokinetic resources. The system is developed from a patent held by one of our team members, Robert Kallenberg. The MHPG does not require a dam or diversion, thus avoiding the negative environmental impacts associated with dams. The project could also help some communities to make use of their locally available hydrokinetic resources and significantly reduce their electricity costs. Reviewing of the literature in hydrokinetic electric power generation technology shows that hydrokinetic projects developed to date have largely made use of hydro turbine systems. These hydro turbines have a strong potential to cause fish mortality, while by design, the MHPG has little chance of causing mortality due to its gentle motion. On the other hand, the build-up of debris on a conventional hydro turbine can easily disable or even destroy the turbine, while the hydro foil in our device is generally oriented with the angle of attack less than 30 degree from the current, keeping debris build up at a minimum. The state of the art software COMSOL Multiphysics has been used as our numerical analysis tool. The interaction of water and the designed foil in a straight rectangular turbulent channel is modeled, explicitly, using two conservation laws: conservation of momentum and conservation of mass. The incompressible Navier-Stokes application mode in COMSOL Multiphysics has been used in this simulation to solve the distribution of the pressure and the velocity filed. Results show that the oscillating hydro foil has the potential to surpass the efficiency of a conventional turbine, and is deployable in relatively low velocity streams. Future project development suggestions will be presented focusing on further improvements electric machinery design and system integration. Finally, the prototype of the device has been fabricated and tested in natural rivers. The first test in Chena River, AK, verified the design by showing that the prototype can move in an oscillating manner. The second test in San Gabriel River, CA, shown that the designed Scotch Yoke, which was used to convert linear motion into rotational motion, could be efficiently integrated with the motion generation system. Future test work including permanent magnetic generator coupling and energy efficiency measurement need to be carefully studied concerning the system efficiency and maintenance.
    • Economic assessment of Alaska North Slope hydrate-bearing reservoir regional production development schemes

      Nollner, Stephanie P.; Dandekar, Abhijit; Patil, Shirish; Ning, Samson; Khataniar, Santanu (2015)
      The objective of this project was to evaluate the economic feasibility of producing the upper C sand of the Prudhoe Bay Unit L Pad gas-hydrate-bearing reservoir. The analysis is based on numerical modelling of production through depressurization completed in CM G STARS by a fellow UAF graduate student, Jennifer Blake, (2015). A staged field development plan was proposed, and the associated capital and operating costs were estimated using Siemens's Oil and Gas Manager planning software and costing database. An economic assessment was completed, incorporating the most common royalties, the current taxes laws applicable to conventional gas development, and most recent tariff estimates. The degree of vertical heterogeneity, initial average hydrate saturation, well spacing and well type had a significant impact on the regional gas production profiles in terms of cumulative volume produced, and more importantly, the expediency of gas production. The volume that is economically recoverable is highly dependent on how the field is developed. A field that has higher vertical heterogeneity and corresponding lower average initial hydrate saturation is most economically produced using horizontal wells at 160 acre spacing; the acceleration of gas production outweighs the increased drilling costs associated with the longer wells and tighter well spacing. The choice of development scenario does not impact the project economics significantly given a field that has lower vertical heterogeneity; however, development using horizontal wells at 320 acre spacing is marginally more economic than the alternatives. Assuming a Minimum Attractive Rate of Return of 20%, the minimum gas price that would allow economic production of ANS gas hydrates was found to be $29.83 per million British thermal units; this value is contingent on the reservoir having high average initial hydrate saturation and being developed with horizontal wells at 320 acre spacing. A slightly higher gas price of $36.18 per million British thermal units would allow economic production of a reservoir having low average initial hydrate saturation that is developed with horizontal wells at 160 acre spacing.
    • Electromagnetic heating of unconventional hydrocarbon resources on the Alaska North Slope

      Peraser, Vivek; Patil, Shirish L.; Khataniar, Santanu; Sonwalkar, Vikas S.; Dandekar, Abhijit Y. (2012-05)
      The heavy oil reserves on the Alaska North Slope (ANS) amount to approximately 24-33 billion barrels and approximately 85 trillion cubic feet of technically recoverable gas from gas hydrate deposits. Various mechanisms have been studied for production of these resources, the major one being the injection of heat into the reservoir in the form of steam or hot water. In the case of heavy oil reservoirs, heat reduces the viscosity of heavy oil and makes it flow more easily. Heating dissociates gas hydrates thereby releasing gas. But injecting steam or hot water as a mechanism of heating has its own limitations on the North Slope due to the presence of continuous permafrost and the footprint of facilities. The optimum way to inject heat would be to generate it in-situ. This work focuses on the use of electrical energy for heating and producing hydrocarbons from these reservoirs. Heating with electrical energy has two variants: high frequency electromagnetic (EM) heating and low frequency resistive heating. Using COMSOL ® multi-physics software and hypothetical reservoir, rock, and fluid properties an axisymmetric 2D model was built to study the effect of high frequency electromagnetic waves on the production of heavy oil. The results were encouraging and showed that with the use of EM heating, oil production rate increases by ~340% by the end of third year of heating for a reservoir initially at a temperature of 120°F. Applied Frequency and input power were important factors that affected EM heating. The optimum combination of power and frequency was found to be 70 KW and 915 MHz for a reservoir initially at a temperature of 120°F. Then using CMG-STARS ® software simulator, the use of low frequency resistive heating was implemented in the gas hydrate model in which gas production was modeled using the depressurization technique. The addition of electrical heating inhibited near-wellbore hydrate reformation preventing choking of the production well which improved gas production substantially.
    • End-to-end well planning strategies for Alaska north slope directional wells

      Mahajan, Neeraj Hemant; Khataniar, Santanu; Patil, Shirish; Dandekar, Abhijit; Fatnani, Ashish (2018-05)
      Directional well planning has gained special attention in the Alaska North Slope (ANS) as operators are being compelled to drill increasing numbers of wells from already congested pads because of low oil prices, Capex restrictions, and environmental regulations. This research focuses on two major components of directional well planning: anti-collision and torque and drag analysis in Schrader Bluff, Milne Point. The drilling pattern at the ANS implies very high wellbore collision risk, especially at the shallower section, which affects the safety of drilling operations. However, satisfying anti-collision norms is not the solitary step towards successful well planning. Integration of anti-collision results with torque and drag analysis is essential in evaluating the safety and feasibility of drilling a particular well path and avoiding drill string failures. In the first part of the study, three well profiles (horizontal, slant, and s-shaped) were planned for each of the two new targets selected in the Schrader Bluff OA sand. Initially, this part of the research compared the performance of the newly developed Operator Wellbore Survey Group (OWSG) error model and the industry-standard Industry Steering Committee for Wellbore Surveying Accuracy (ISCWSA) error model. To provide effective guidelines, the results of error model comparison were used to carry out sensitivity analyses based on four parameters: surface location, well profiles, survey tools, and different target locations in the same sand. The results of this study aid in proposing an improved anti-collision risk management workflow for effective well planning in Arctic areas. The second part of the study investigates the drillability of the well paths planned using the improved anti-collision risk management workflow. Furthermore, this part of the research aims at defining the end point limits for critical well planning parameters, including inclination and dogleg, such that within these limits, the well path satisfies anticollision as well as torque and drag considerations. These limits were generated using a drill string optimized in terms of steerable tool, drill pipe size, mud rheology, trip speed, rotational speed, and weight on bit (WOB) during drilling and tripping out operations. The results of this study would help reduce the cumbersome iterative steps and narrow down the design domain for any well to be drilled on the North Slope of Alaska.
    • Engineering economic analysis of a rail extension from Dunbar siding to Livengood, Alaska

      Bohart, Charles W.; Metz, Paul A.; Huang, Scott L.; Misra, Debasmita (2011-12)
      The Dunbar Siding to Livengood rail extension study is an economic prefeasibility investigation, and is conducted from two perspectives as a cost benefit analysis. The first perspective is, that of the Alaska Railroad Corporation (ARRC) in which the capital and operating costs of the proposed extension are recovered through the revenue stream resulting from the out-bound mineral freight loads, the in-bound re-supply freight loads, and the potential commuter passenger service to mining projects and communities in the Livengood area. The second perspective is that of the private sector in which a shipping sensitivity and employee transport analysis with respect to mining project developments. The large mineral resource base within the Dunbar-Livengood Corridor indicates an excellent freight potential with generous benefits for Alaska's economy of greater than $2 billion annually in gross revenues; whereas, resource and rail development are synergistic.