• Factors influencing zooplankton populations in Alaskan sockeye salmon (Oncorhynchus nerka) nursery lakes: insights from limnological and paleolimnological analyses

      Sweetman, Jon N.; Finney, Bruce; Barry, Ronald; Hughes, Nicholas (2001-08)
      The relative importance of sockeye salmon, invertebrate predators, and other environmental factors in structuring the size and abundance of zooplankton populations was examined in a series of 23 lakes from southern Alaska. Zooplankton abundance was strongly related to sockeye density, along with nutrient availability and alkalinity. The mean size of Bosmina longirostris, the dominant herbivorous cladoceran, was positively correlated with the abundance of the predatory copepod, Cyclops columbianus. Changes in the size and abundance of Bosmina remains over the past 300-500 years were then determined for sediments from two lakes on Kodiak Island, Alaska. The zooplankton communities showed varying responses to past changes in salmon populations, resulting from relative changes in the magnitude of adult salmon-derived nutrient loading and in predation pressure from juvenile sockeye and cyclopoid copepods. Knowledge of how various factors impact zooplankton can have important implications for the effective management of sockeye within these lake systems.
    • Factors that contribute to rural provider retention, service utilization, and engagement in mentorship by cultural experts

      Gifford, Valerie M.; Rivkin, Inna; Lower, Timothy; Koverola, Catherine; Brems, Christiane (2012-05)
      A substantial amount of time, money, and other resources are expended on recruiting behavioral health providers to fill vacant positions in rural Alaska. This exhaustive drain on resources is perpetual due to the high turnover rates of providers. This exploratory qualitative study utilized grounded theory methodology to investigate personal qualities of providers and other factors contributing to long-term retention of providers relocating to Alaska's Bering Strait Region from elsewhere, community members utilizing the provider's services, and the provider's engagement in cultural mentorship to facilitate the integration of culture into their practice. Furthermore, factors contributing to local provider retention were examined. Key informant interviews were conducted with 21 healthcare providers living and working in the region long-term. A theory emerged that connected provider retention to community member service utilization and cultural mentorship. Results indicated that providers who are open, willing to learn, good listeners, calm, friendly, respectful, flexible, compassionate, genuine and possess a sense of humor, humility, and ability to refrain from imposing personal values, beliefs and worldviews upon others are a good fit for living and work in rural Alaska. Such qualities facilitate a provider achieving professional and personal satisfaction through building relationships and creating opportunities for cultural mentorship, professional support, and social support. These opportunities enhance the delivery of quality services that are culturally appropriate and well-utilized by community members, which, in turn, increase provider satisfaction and retention. Recommendations are made to healthcare organizations regarding recruitment and retention strategies. Recruitment strategies include careful screening of potential applications for specific qualities and enlisting local community members and students into the healthcare field. Retention strategies include professional support by way of a comprehensive orientation program, clinical supervision, cultural mentorship, and continuing education training opportunities that focus on cultural competency. Recommendations for retention of local providers include professional development incentives and opportunities that qualify local providers for positions typically held by outside providers.
    • The Fairbanks Four: hopeless innocence and the flawed system that escorted them to stagnant wrongful convictions

      Hill, Meghan (2014)
      This project explores factors that lead to wrongful convictions with a case study from 1997 on the sensitive claim of innocence on the Fairbanks, Alaska community: The John Hartman murder. As the representative model throughout the project, this sexual assault and murder case of the accused Fairbanks Four will be examined. Through a multi-disciplinary scope, the topic will be approached through numerous accounts of research, interviews, and field-work. By dissecting the Fairbanks Four case and applying it to the research of the burdensome appeals process, the supporting factors are apparent in the practices that lead to wrongful convictions. In the synopsis, methods that lead to convictions, as well as the inconsistent wavering time table, will be disclosed. Further, counter methods to tactics currently practiced and how to avoid time delays of such a rigorous and often hopeless process will also be included. With underdog defense organizations such as The Innocence Project and The Alaska Innocence Project growth and expansion, we increasingly see success in the overturn of wrongful convictions throughout the United States. This paper will argue and highlight the systemic faults in the current convictions process and identify recommendations to modify such faults in relation to the case study of the Fairbanks Four.
    • Fairbanks juvenile recidivism case study: a comparison of criminogenic needs and case planning of recidivists and non-recidivists

      Dompeling, Tracy A. (2015-08)
      Research has shown that addressing criminogenic needs of offenders, both juvenile and adult, can reduce the likelihood of recidivism. Utilizing the Risk Need Responsivity theory (Andrews, Bonta, & Hoge, 1990; Andrews, Zinger, et al., 1990), the hypothesis for this small case study of youth recidivist and non-recidivists in interior Alaska was developed to compare data to determine if what is identified in research models to reduce recidivism correlated to what was applied in practice with juvenile offenders. Specifically this comparative case study intended to show that youth who had case plans which were identified to be "inadequate," that they had fewer than 75% of the identified criminogenic needs from their YLS/CMI addressed on their case plan, would be more likely to recidivate. Further, youth who had case plans which were identified to be "adequate," that they had greater than 75% of their identified criminogenic needs from their YLS/CMI addressed on their case plan, would be less likely to recidivate.The case study also compared case plans of recidivists and non-recidivists in the use of dynamic criminogenic needs and any subsequent impact on recidivism. After the statistical analysis of both the efficacy of case plans addressing individual criminogenic needs as well as the efficacy of case plans addressing dynamic criminogenic needs and their impact on reduction of recidivism, only the later analysis of dynamic criminogenic needs was able to reject the null hypothesis; that inclusion of criminogenic needs on a case plan has no impact on recidivism.
    • A familiar & favorite terror

      Medlin, Zackary; Burleson, Derick; Coffman, Chris; Hill, Sean; Stanley, Sarah (2013-12)
      The collection A Familiar & Favorite Terror explores love and violence, how the two are entangled and how that entanglement is constitutive of a self. It wants to show how love is a form of violence to the self, demanding a fracture. These poems view love, and not just romantic love, as a breaking of the self, both in its binding and its severing. With love there is always a hole, or a not quite whole. That's where these poems want to dig - but not dig up - and sift through the ways we fill this void. And while this collection is decidedly personal, tracing it lineage through books such as John Berryman's Dream Songs and Robert Lowell's Life Studies, it is not confessional - there is rarely guilt or shame associated with the speaker. Instead, the self in these poems, and the poems themselves, are unapologetically postmodern; if Berryman and Lowell are ancestors to these poems, then their immediate family would be contemporary poets like Bob Hicok, Tony Hoagland, Dean Young, and Matthew Zapruder. These poems build their foundation on the unstable, seismically active terrain of pop-culture and the mutable, multiple self that peoples that land. They are at times lyrical, surreal, referential, earnestly ironic, ironically earnest, recursive, discursive, and maybe even downright ugly. Ultimately, however, even though these poems are disparate insular experiences of a self, they are reaching out in the only way they know how to: by existing in the world. The speakers, by sharing these experiences, are asking the question: `I'm not alone it this, am I?' which is also a way of telling a reader, 'No, you are not alone in this.'
    • A farmers guide to evaluate soil health using physical, chemical, and biological indicators on an agricultural field in Alaska

      Cole, Cory J.; Zhang, Mingchu; Matney, Casey; Karlsson, Meriam (2018-12)
      Farmers across Alaska face many challenges. These challenges include climate extremes, wind and water erosion, weed pressure, crop pests, and nutrient-poor soils. Cover crops, crop rotation, crop residue, and tillage management are common conservation practices used to address soil related resource concerns. Research in the continental United States has shown that these soil conservation practices improve soil health. Resource managers are trying to determine the usefulness of soil health indicators to assess conservation practices in Alaska. The objective of this project was to provide Alaskan farmers, conservation planners, and land managers with a background on soil health, soil health indicators, soil health assessments, and the use of conservation practices to improve soil health. Establishing linkages between soil conservation practices and soil health indicators will allow individuals to focus conservation efforts on improving soil conditions, evaluate soil management practices and techniques over time to determine trends, make qualitative comparisons of soil health among management systems, and provide tested measures of soil health (indicators) that will allow farmers and land managers to make more informed resource decisions. Numerous studies were conducted across Alaska to gauge the success of cover cropping, crop rotation, and reduced tillage (no-till). Improvements in physical, chemical, and biological indicators were documented. After one year of study, most cover crops resulted in lower bulk density at the soil surface compared to conventional tillage. Among the cover crop treatments, the perennial forage grass Timothy (Phleum pratense var. Engmo) ranked highest in soil organic matter, soil water content, and improvement to the soil structure. Preliminary data from this project has been gathered to develop an Alaska specific Soil Health Assessment Card and supplementary User Guide.
    • “FATE MUST FIND SOMEONE TO SPEAK THROUGH”: CHRISTIANITY, RAGNARÖK, AND THE LOSS OF ICELANDIC INDEPENDENCE IN THE EYES OF THE ICELANDERS AS ILLUSTRATED BY GÍSLA SAGA SÚRSSONAR

      Mjolsnes, Grete E.; Grossweiner, Karen; Ruppert, James; Bartlett, D.A. (2008-12)
      Iceland surrendered political control to the Norwegian monarchy in 1262, but immediately resented their choice. The sagas about reliance on the Norwegians, clearly illustrating that the Icelanders knew where this path was leading them. Gísla Saga is a particularly interesting text to examine in light of the contemporaneous political climate, as it takes place in the years leading up to the conversion but was written between the conversion and the submission to Norwegian rule. Though Gísla does not explicitly comment on either the conversion or the increase in Norwegian influence, close examination illuminates ambiguity in the portrayal of Christian and pagan characters and a general sense of terminal foreboding. This subtle commentary becomes clearer when one reads Gísla Saga in light of the story of Ragnarök, the death of the gods and the end of the Norse world. Characters and images in Gísla Saga may be compared with the events of Ragnarök, the apocalyptic battle between the Æsir and the giants, illustrating how the Christian conversion and Norwegian submission brought about the end of Iceland’s golden age by destroying the last home of the Norse gods. In order to closely compare the events of Gísla Saga with those of Ragnarök, I have chosen to work with the final battle as it is described in the Volspá, or The Prophesy of the Seeress, one of the Elder Edda, of which I have translated the Codex Regis and Hauksbók manuscript versions, in order to deal closely and specifically with the text. Finally I discuss images of Ragnarök, as it is told in the Voluspá, which appear in Gísla, drawing close the ties between Christianization and Norwegian rule and the ways in which Icelanders recognized this conversion as the end of their world.
    • Fate of fertilizer nitrogen in a subarctic agricultural soil

      Knight, Charles Winsett; Sparrow, Stephen D. (1988)
      A nitrogen balance approach was taken to determine the fate of fertilizer nitrogen in a subarctic agricultural soil. Urea and calcium nitrate fertilizers were compared in a three-year spring barley recrop field study. Methods of N application included incorporating the N fertilizer into the soil during spring tillage versus broadcasting it on the soil surface after planting. $\sp{15}$N labeled urea was applied on one-meter square subplots within the main fertilizer plots. Nitrogen transformations and movement were monitored with ammonia volatilization traps, suction cup lysimeters, deep soil cores, plant tissue samples, and grain samples. Environmental data including precipitation, soil temperatures and soil moisture tensions were collected. Fertilizer N loss by ammonia volatilization was negligible, amounting to only a few grams N/ha/day. Rate of urea hydrolysis was rapid in the cool soil and was not considered to be a limiting factor affecting N availability to the crop. There appeared to be a little nitrate leaching during the growing season, but some may have occurred between cropping seasons. Only 16 percent of the fertilizer N could not be detected when the crop was physiologically mature, and that loss was accredited mostly to denitrification. Fertilizer N use efficiency, determined by the Difference Method, was 73 and 60 percent for calcium nitrate and urea, respectively. When the crop was physiologically mature, average fertilizer N recovery rates determined by the Isotope Dilution Method were: 40 percent in the plants, 43 percent immobilized in the soil, 1 percent available in the soil, and 16 percent unrecovered. Barley yields were not significantly affected by N source, but plants took up more N where nitrate had been applied. Position of N placement had little effect on either N loss or barley yield, but the surface application of N resulted in delayed barley maturity when spring rains were deficient.
    • The fate of nitrogen pollution in high-latitude winter: investigations using a 1-D photochemical model

      Joyce, Patrick L. (2011-12)
      Simulations using a 1-D photochemical model were performed to analyze the fate of NOx pollution in a high-latitude winter environment. Modeled pollution emissions were constrained by observations from downtown Fairbanks and the model reproduced dilution of NOx on timescales in agreement with field measurements on the edge and outside of the urban area of Fairbanks. The model was updated from previous versions to include calculations of reactions of N₂O₅ on aerosol particles and an empirically-derived value for dry deposition velocity of N₂O₅ to the snowpack, which acts as a competing loss of N₂O₅. It was found that dry deposition of N₂O₅ causes a significant fraction of N₂O₅ loss near the snowpack, but reactions on aerosol particles dominate loss of N₂O₅ over the total atmospheric column. Sensitivity experiment results indicate a strong sensitivity to urban area density (affecting NO flux), season and clouds (affecting photolysis), and weather and climate (affecting temperature), implying a strong sensitivity of the results to urban planning and climate change. Model simulations produced large amounts of secondary ammonium nitrate downwind of the polluted area due to NOx oxidation and subsequent reactions with ammonia on aerosol particles.
    • Fatigue behavior of conventional and rubberized asphalt mixes

      Saboundjian, Stephan K.; Raad, Lutfi; Lee, Jonah H.; Hulsey, J. Leroy; Succarieh, Mohamed; Gislason, Gary (1999)
      One of the main distress modes of flexible pavements is the fatigue cracking of the asphalt concrete surface layer. The addition of crumb-rubber modifier (CRM), obtained from scrap tires, to asphalt-aggregate mixtures has shown promise in enhancing their fatigue behavior. In this study, conventional unmodified and CRM modified asphalt-aggregate mixtures are evaluated in terms of their fatigue behavior. Controlled-strain flexural beam fatigue tests are conducted in the laboratory over a wide range of temperatures. Experimental results are compared in terms of flexural, tensile and compressive stiffnesses, phase angle, fatigue life and cumulative dissipated energy. Results showed that CRM mixes are more flexible than unmodified mixes, and that mix fatigue resistance is enhanced by the addition of CRM. Furthermore, a method of converting controlled-strain test data into equivalent controlled-stress behavior is presented. Experimental results revealed the existence of two types of controlled-strain stiffness-ratio variations. For each type of variation, an equivalent controlled-stress stiffness-ratio variation with cycles is derived. Using the predicted variations, fatigue lives for both modes of loading are determined. Predictions showed that, at a given temperature, controlled-stress mode of loading yields, as expected, shorter fatigue lives than its controlled-strain counterpart. An implicit validation of the proposed conversions revealed that fatigue equation parameters K and n for the different mixes fit within the range of values obtained from the literature for controlled-stress conditions. In addition, a fatigue life model, applicable to the haversine pattern of loading used in this study, is presented. The model takes into account the cumulative dissipated energy to failure, mode-of-loading, and initial phase angle, strain and stiffness of the mix. Analogy with the traditional strain-based fatigue equation revealed that K is a temperature-dependent parameter, whereas n and m are independent of mix temperature. A decrease in K is associated with an increase in temperature. The newly developed model is then used to predict fatigue lives of conventional and CRM mixes in typical pavement structures. For this purpose, a finite element-based mechanistic analysis is used. Results revealed the enhanced fatigue resistance of CRM mixes in comparison to unmodified conventional mixes.
    • Fatty acid profiles of Alaskan Arctic forage fishes: evidence of regional and temporal variation

      Dissen, Julia; Hardy, Sarah; Horstmann-Dehn, Lara; Oliveira, Alexandra (2015-08)
      Fatty acids, the main components of lipids, are crucial for energy storage and other physiological functions in animals and plants. Dietary fatty acids are incorporated and conserved in consumer tissues in predictable patterns and can be analyzed in animal tissues to determine the composition of an individual's diet. This study measured the variation in fatty acid profiles of three abundant Arctic forage fish species, Arctic Cod (Boreogadus saida), Canadian Eelpout (Lycodes polaris), and Longear Eelpout (Lycodes seminudus) across multiple years (2010-2013) and geographic locations (Beaufort and Chukchi seas). These fishes are important prey items of marine mammals, sea birds, and predatory fishes, and as such they serve as a critical trophic step connecting lower trophic-level production to higher level predators. Analyzing forage fish fatty acid profiles across multiple years and geographic locations can provide insight into system-level trends in lipid transfer through the Arctic ecosystem. Fatty acid profiles differed among species, with Arctic Cod having higher concentrations of pelagic zooplankton indicator fatty acids, and Eelpout species containing higher concentrations of indicators for benthic prey. While the two Eelpout species displayed major overlap in fatty acid profiles, differences in individual fatty acids may represent niche separation between Canadian and Longear Eelpout in the Beaufort Sea. In addition to variation between species, fatty acid profiles also differed in Arctic Cod between the Beaufort and Chukchi seas, and among collection years. High lipid content and energy-rich fatty acid classes observed in Chukchi Sea Arctic Cod relative to the Beaufort Sea Arctic Cod may indicate favorable feeding conditions in this region over the years sampled, and high energy density of Arctic Cod as prey. Despite the within-species variation observed, the results of this study suggest that Alaskan Arctic forage fish with different foraging ecology can be distinguished based on fatty acid profile, which could be useful in studies that use fatty acid data to characterize diets of top predators.
    • Fault-hosted AU mineralization, Ester Dome, Alaska

      Cameron, Cheryl E. (2000-12)
      The Rhyolite gold prospect near Fairbanks, Alaska, appears to be different from most intrusion-related Au depositions within the Fairbanks area (e.g., Ryan Lode and Fort Knox), as it is located along a low-angle fault and is spatially associated with a quartz monozonite sill. A 1:60,000 scale geologic map was prepared using soil samples, airborne geophysical data, and mapping based on core and surface samples collected during 1998 and 1999. Mineralization does not appear to be temporally related to the quartz-monzodiorite sill, although mineralized fluids apparently used the sill as a pathway. ⁴⁰Ar/³⁹Ar dates of chloritized biotite from the intrusive (>75 Ma), sericite in mineralized gouge (9̃0 Ma), and white micas from metamorphic rocks (1̃00 Ma) correlate with dates from other plutonic-related deposits in the Fairbanks area ... Au-Ag, Au-Bi, and Au-As ratios suggest that the Rhyolite prospect is intrusion-related but distal to the causative body.
    • Faunal analysis of the historic component at Healy Lake Village site, Interior Alaska

      Hilmer, Hilary A.; Potter, Ben; Clark, Jamie; Reuther, Joshua (2019-08)
      The historic period in Interior Alaska was a dynamic time that led to many cultural changes for Native Alaskan communities across the state. Starting in the early 1700s, Russian and Euroamerican explorers began interacting with Native Alaskan groups living on the coast and by the end of the 18th century - early 19th century, Interior Alaskan groups were being directly affected. Due to western influences, Native groups, such as the Upper Tanana Athabascans, began to rely on a cash economy, causing them to settle to year-round villages, trade with the Euroamericans for non-local goods (i.e., flour, guns, buttons, glass, and nails), and work on construction projects in order to provide for their families. All of these changes appeared to cause a division between the traditional way of life and the new Euroamerican way of living. Healy Lake Village site (XBD-00020) is a multi-component site with occupations spanning the terminal Pleistocene into the Holocene. It is located approximately 100 miles southeast of present day Fairbanks on the shores of Healy Lake in the Upper Tanana Athabascan territory. The village was a summer fishing camp until ~A.D. 1910; it became a year-round village soon after the construction of a trading post at Healy Lake. The well-preserved faunal remains excavated from the Upper Cultural level (dating to A.D. 1880 - 1946) at Healy Lake Village site provide a significant opportunity to address fundamental questions relating to subarctic hunter-gatherer subsistence economies. This research employs concepts from human behavioral ecology and world-systems theory to address questions relating zooarchaeological patterns in the data in terms of taphonomy, human procurement, and processing decisions, as well as historic period land use strategies and trade practices. In this thesis, I explore the possibility that the residents at Healy Lake Village site were affected by Euroamerican influences, specifically in regards to their subsistence economies. However, the results suggest that hunting practices were not drastically altered. The residents still relied heavily on local game as their primary source of subsistence with minor inclusions of western goods, such as canned meat and flour.
    • Faunal and lithic analyses from the Matcharak Peninsula site (AMR-00196) northern archaic context: Lake Matcharak, Central Brooks Range, Alaska

      Keeney, Joseph W.; Potter, Ben; Clark, Jamie; Reuther, Josh; Rasic, Jeff (2019-05)
      This thesis focuses on the Matcharak Peninsula site (AMR-00196 or MPS), located on the east side of Lake Matcharak in the upper Noatak River valley of Alaska's central Brooks Range. The MPS contains a substantial and well-preserved collection of faunal remains dating to between 6190±35 and 3780±35 14C years BP, along with side-notched projectile points and microblade technology. Radiometric dating and stone tools attribute the collection to the Northern Archaic tradition, making MPS unique for yielding the largest and most well-preserved collection of faunal remains reported from a Northern Archaic context to date. This project analyzed both faunal and lithic materials to identify a more robust suite of human behaviors, better assess post-depositional processes, and delineate between cultural components. This project first focuses on intrasite activities and site function within a larger system of land use, indicating that MPS functioned repeatedly throughout the middle Holocene as a short-term hunting camp and late-stage hunting tool repair location that was occupied between the late spring and early fall. A small number of individual caribou dominate the faunal assemblage, but a narrow range of other Brooks Range prey species are also present including Dall's sheep and locally available fish and Arctic ground squirrel. This project then develops broader interpretations about the Northern Archaic tradition, investigating technological, mobility, and subsistence strategies by mid-Holocene Brooks Range hunter-gatherers. The inhabitants practiced logistical mobility and organized special task groups when resources were leaner, and came together in aggregated communities to engage in communal hunts when caribou were reliably abundant. Lithic raw material use at MPS reflects a broader Northern Archaic trend of favoring less common obsidian for maintainable tool components, and more commonly available cherts for more heavily engineered and reliable implements such as inset-microblade weapons. Finally, this thesis explores side-notched and inset-microblade projectile weapon armatures in the context of hunting strategies at MPS and other sites, suggesting that bifacially-tipped projectiles were more effective at hunting medium-range targets while inset-microblades were designed for long-range strategies.
    • Feasibility Of Farm-To-School In Alaska: A State-Wide Investigation Of Perspectives From School Food Service Professionals

      Herron, Johanna Ruth; Bersamin, Andrea; Lopez, Ellen; Barry, Ronald; Henry, David (2013)
      Childhood obesity is a significant public health concern and schools are a key setting for prevention. The majority of U.S. children are enrolled in school where they consume a large portion of their daily energy. Farm-to-school programs are a promising strategy for preventing childhood obesity in school-aged children. The overall objective of this study was to conduct a baseline assessment of Alaska school food service professionals' perspectives of using local foods. Specific objectives were to: 1) Assess interest in utilizing local foods, 2) Identify perceived barriers to purchasing local foods, and 3) Determine resources needed to facilitate local food procurement. A survey was administered to all school food service professionals in Alaska (n = 74) who oversee the National School Lunch Program in their program site or district. The survey consisted of open and close-ended questions, comprising six domains: interest, perceived benefits, perceived usefulness, perceived barriers, and future needs. Descriptive statistics were performed on all variables. The majority (80-96%) of school food service professionals reported interest in utilizing local foods in the school meal programs. School food service professional's reported concern with finding a reliable supply (67%) and the cost (46%) of locally sourced foods. Nearly all (92%) school food service professional's agreed that information about what foods are available, where to purchase them, and USDA purchasing regulations would be useful. Farm-to-school strategies are attainable in Alaska. Interest is high, and perceived barriers and challenges are consistent with national findings. The most useful resources identified could be accommodated through increased communication and use of existing resources.
    • Feasibility of using standard targets to measure sound attenuation in rivers with varying suspended sediment loads

      Pfisterer, Carl T. (2002-12)
      In this study I examined the feasibility of using standard targets to measure sound attenuation in water due to suspended sediment. I determined that the variability of the target strength measurements was sufficiently high to prevent the use of this measure in obtaining accurate attenuation estimates. Average target strength values for a 1.5 inch tungsten carbide sphere differed by as much as 11.4 dB with spreads of the upper and lower 90% values as high as 18 dB. This high variability was likely due to a combination of factors that include multipath signal returns (exacerbated by relatively high transducer side lobes) and inaccuracies in the off-axis correction calculation. Although the goal to determine a relationship between suspended sediment and attenuation was not achieved, theoretical models suggest the contribution of suspended sediment to overall sound attenuation can be significant and, in certain circumstances, the main contributor to overall signal loss.
    • Feasibility study of in-situ heat generation for oil reservoirs underlying the permafrost

      Kargarpour, Mohammad Ali; Ahmadi, Mohabbat; Awoleke, Obadare; Hanks, Catherine (2017-05)
      Development of a heavy oil reservoir is a challenging issue in the oil industry. One of the major issues in heavy oil recovery is its high viscosity; so, using heating methods for producing oil have been developed and employed from the early 1950s. The existing relatively thick permafrost layer which overlays the heavy oil reservoirs of the North Slope of Alaska creates additional complexities for development of these heavy oil reservoirs. Applying any heating oil recovery process in regular way to these heavy oil Alaskan reservoirs would potentially jeopardize the permafrost layer. A down-hole heat generation system has been developed that uses a chemical and a special catalyst to generate heat. The effluent of this system would be steam and nitrogen. The system can be installed in a well string and at the bottom of the injector well. This thesis investigates the feasibility of employing this system for development of the heavy oil reservoirs that underlie the permafrost. The results of this study can be used for any steam injection process which uses any device for down-hole steam generation. The STARS module of the CMG reservoir simulation package is used for this study. In the model, live oil with a viscosity of about 30,000 cp is used. By examining several models with vertical and horizontal wells, a 3-D model with two horizontal injector and producer wells is ultimately constructed for final runs. Different sensitivities are run to find out the optimum operational parameters. Based on the results, a lateral well length of 800 ft in the middle of a reservoir with length of a 1250 ft is selected as a base case. Areal grid block size of 10 ft × 10 ft with the layer thickness of 10 ft in a reservoir with thickness of 50 ft is employed. To minimize the down-hole well bore temperature of the producer, just the last 50 ft (out of 800 ft of lateral length) at the toe of the well is opened to flow. Three different steam injection processes are examined: Steam Assisted Gravity Drainage (SAGD), Cyclic SAGD (CSAGD) and Cyclic Steam Stimulation (CSS). Simulation results reveal that the producer well bore temperature in optimum cases for SAGD, CSAGD and CSS is more than 140 ˚F, 110 ˚F and 100 ˚F, respectively. Also, the 10-year simulation period oil recoveries for optimum cases of SAGD, CSAGD and CSS are about 35%, 18% and 12%, respectively. On the other hand, results show applying any steam injection recovery method (SAGD, CSAGD or CSS) can only be recommended when the thickness of the overlying Sagavanirktok sand formation (which separates the permafrost from the heavy oil reservoir) is equal or more than 300 ft. The results also show that the addition of nitrogen has negative effect on the oil recovery. Based on the results, it is recommended to employ SAGD or CSAGD, but employ a system to cool the producer well-string to avoid melting the permafrost. A simple system of cooling the producer well-string is suggested.