Prudhoe Bay Research Articles

Factors influencing harvest success for an Arctic under-ice subsistence fishery

Long-term fisheries datasets are particularly rare in Arctic environments and are essential to understanding the variability in harvest rates. We analyzed 30 years of harvest monitoring data and compared results to fish monitoring data from nearshore waters of Prudhoe Bay, Alaska, to determine the importance of age-0 recruitment and intra-annual factors on subsequent harvests of Arctic cisco in the Colville River delta (CRD), Alaska. While age-0 recruitment to Prudhoe Bay was positively associated with annual harvest success in the CRD, wind and salinity patterns and subsistence fishing location and timing also contributed significantly in explaining adult harvest variability. Harvest rates were highest closest to the river mouth and early in the season. Harvest rates increased with increasing salinity up to 25 ppt, then declined. As the climate changes in the region, we may see shifts in nearshore ocean and river conditions which will impact recruitment and fishing activity. These long-term monitoring efforts will continue to inform sustainable fisheries management in the face of a rapidly changing climate, and with ongoing infrastructure development in the region.

Landscape patterns of carbon fluxes in natural and disturbed ice-wedge-polygon tundra

ABSTRACT The degradation of ice-rich permafrost ecosystems due to climate change and infrastructure development strongly impacts carbon exchange dynamics in tundra landscapes. This study investigates the effects of surficial geology and infrastructure disturbances from road dust and flooding on vegetation and trace gas fluxes in polygonal ice-wedge tundra in arctic Alaska. We compared CO2 and CH4 fluxes from closed-chamber measurements at common landform elements (polygon centers, troughs, and rims) at a natural site and a disturbed site within the Prudhoe Bay Oil Field. Relationships among environmental parameters, plant species composition, and trace gas fluxes were assessed through nonmetric multidimensional scaling. Map extrapolations showed spatial variations in midsummer landscape-level ecosystem productivity and CH4 efflux at the various geologic landforms. Highest carbon uptake occurred in ice-rich drained thaw lake basins with aquatic, graminoid-dominated polygon troughs. In contrast, wet, featureless areas associated with more recently drained, ice-poor thaw lake basins showed a net carbon loss even during summer. The damming effect of road infrastructure led to deeply flooded, minimally vegetated troughs with low ecosystem respiration and high CH4 fluxes close to the road. This work highlights the importance of the complex interactions among surficial geology, landform elements, vegetation type, and disturbance factors in understanding carbon exchange dynamics in ice-rich permafrost environments.

3-D Geological Modeling for Numerical Flow Simulation Studies of Gas Hydrate Reservoirs at the Kuparuk State 7-11-12 Pad in the Prudhoe Bay Unit on the Alaska North Slope

3-D Geological Modeling for Numerical Flow Simulation Studies of Gas Hydrate Reservoirs at the Kuparuk State 7-11-12 Pad in the Prudhoe Bay Unit on the Alaska North Slope

Characterization of the Structural–Stratigraphic and Reservoir Controls on the Occurrence of Gas Hydrates in the Eileen Gas Hydrate Trend, Alaska North Slope

One of the most studied permafrost-associated gas hydrate accumulations in Arctic Alaska is the Eileen Gas Hydrate Trend. This study provides a detailed re-examination of the Eileen Gas Hydrate Trend with a focus on the gas hydrate accumulation in the western part of the Prudhoe Bay Unit. This integrated analysis of downhole well log data and published geophysical data has provided new insight on structural, stratigraphic, and reservoir controls on the occurrence of gas hydrates in the Eileen Gas Hydrate Trend. This study revealed the relatively complex nature of the gas hydrate occurrences in the Eileen Gas Hydrate Trend, with gas hydrates present in a series of coarsening upward, laterally pervasive, mostly fine-grained sand beds exhibiting high gas hydrate saturations. Most of the gas hydrate-bearing reservoirs in the Eileen Gas Hydrate Trend are laterally segmented into distinct northwest- to southeast-trending fault blocks, occur in a combination of structural–stratigraphic traps, and are only partially hydrate filled with distinct down-dip water contacts. These findings suggest that the traditional parts of a petroleum system (i.e., reservoir, gas source, gas migration, and geologic timing of the system formation) also control the occurrence of gas hydrates in the Eileen Gas Hydrate Trend.

“Blue-Eyed Arabs” & the Silver Snake: Alaskan petrocultures and the Trans-Alaska pipeline system

Following fierce construction controversies in the late 1960s and the early 1970s, the Trans-Alaska Pipeline System became a familiar cultural hallmark and the most iconic pipeline in the world. This article argues that the realization of the Trans-Alaska Pipeline System changed Alaska’s culture and global imaginaries of Alaska. TAPS forged overlapping and evolving petrocultures; rather than a uniform and static oil culture, the pipeline’s social valence ebbed and flowed with the passage of time and the transit of Arctic oil from Prudhoe Bay through Prince William Sound. The pipeline became a gauge not only for the State’s revenues, but also for the economic and cultural consciousness of its people. Yet there was always a subset of Alaskans who warned of the deleterious effects of the pipeline on Alaska’s environment, polity, culture and ancestral lifeways.

Disparate permafrost terrain changes after a large flood observed from space

AbstractThe 2015 spring flood of the Sagavanirktok River inundated large swaths of tundra as well as infrastructure near Prudhoe Bay, Alaska. Its lasting impact on permafrost, vegetation, and hydrology is unknown but compels attention in light of changing Arctic flood regimes. We combined InSAR and optical satellite observations to quantify subdecadal permafrost terrain changes and identify their controls. While the flood locally induced quasi‐instantaneous ice‐wedge melt, much larger areas were characterized by subtle, spatially variable post‐flood changes. Surface deformation from 2015 to 2019 estimated from ALOS‐2 and Sentinel‐1 InSAR varied substantially within and across terrain units, with greater subsidence on average in flooded locations. Subsidence exceeding 5 cm was locally observed in inundated ice‐rich units and also in inactive floodplains. Overall, subsidence increased with deposit age and thus ground ice content, but many flooded ice‐rich units remained stable, indicating variable drivers of deformation. On average, subsiding ice‐rich locations showed increases in observed greenness and wetness. Conversely, many ice‐poor floodplains greened without deforming. Ice wedge degradation in flooded locations with elevated subsidence was mostly of limited intensity, and the observed subsidence largely stopped within 2 years. Based on remote sensing and limited field observations, we propose that the disparate subdecadal changes were influenced by spatially variable drivers (e.g., sediment deposition, organic layer), controls (ground ice and its degree of protection), and feedback processes. Remote sensing helps quantify the heterogeneous interactions between permafrost, vegetation, and hydrology across permafrost‐affected fluvial landscapes. Interdisciplinary monitoring is needed to improve predictions of landscape dynamics and to constrain sediment, nutrient, and carbon budgets.

Petroleum++: SPE’s Uses of Artificial Intelligence and Board Meeting Update

In this month’s column, I will share news on the recent SPE Board of Directors meeting in Saudi Arabia and SPE’s utilization of artificial intelligence (AI). The first of the Board’s quarterly meetings of the year is usually held virtually where several administrative items are discussed and the nomination process for the new Board members gets started. The last meeting of the year is held in conjunction with the SPE Annual Technical Conference and Exhibition (ATCE). The middle two meetings are usually held in areas with significant industry operations that gives the Board an opportunity to meet the leaders of SPE sections and regions. The spring 2023 meeting was held for the first time in Dhahran, Saudi Arabia. Below are some of the key decisions reached at the meeting. - Approved the nominating committee’s recommendations for the 2025 SPE President—Olivier Houzé; Data Science and Engineering Analytics Technical Director—Sushma Bhan; Asia Pacific Regional Director—Hazli Sham Kassim; Europe Regional Director—Pierre Emmanuel d’Huart; Latin America and the Caribbean Regional Director—Carlos Alberto Pedroso; North American Regional Director—Kim Oracheski; and the Russia and Caspian Regional Director—Alexey Borisenko. More information about these volunteers was published in the April JPT. - Approved the budget for SPE’s fiscal year 2024, which runs from 1 April 2023 to 31 March 2024. - Reviewed the activities for selling the building in Richardson, Texas. - Updated the process for countries/sections that wish to be considered for an exception to the membership dues. - Removed the requirement for students to provide a full technical paper for participation in the Regional Student Paper Contest. - Approved SPE CCUS International Conference and Exhibition, October 2023, in Al Khobar, Saudi Arabia. - Formed a work group to develop a long-term plan for SPE’s flagship event, ATCE. - Approved SPE policy on AI-generated content in publications (details on the policy are available here). - Updated the Charitable Contribution Policy when SPE donates to areas where our members are affected by natural disasters like hurricanes and earthquakes. In conjunction with the meeting in Dhahran, Board members attended the monthly meeting of the Kingdom of Saudi Arabia Section, with about 500 members, to discuss local and Society-level activities. Saudi Aramco arranged for the Board to visit the Shaybah field operations and the natural wildlife sanctuary in the Rub’ al-Khali, or Empty Quarter. It is interesting how the challenges of operating a large oilfield facility in a remote area like the Empty Quarter are like what I used to see with operations of the Prudhoe Bay and Kuparuk fields in the North Slope of Alaska. It is telling the extent of what we do to provide the world with energy it needs when at airports like in Anchorage next to the counters of United, American, and Alaska Airlines, there were counters for ARCO, BP, and ExxonMobil. The next Board meeting in July 2023 will be held in Kuala Lumpur. I am looking forward to connecting with our colleagues at Petronas as well as other employers and stakeholders in the area.

Patterns in avian reproduction in the Prudhoe Bay Oilfield, Alaska, 2003–2019

The Arctic Coastal Plain is one of the most important avian breeding grounds in the world; however, many species are in decline. Arctic‐breeding birds contend with short breeding seasons, harsh climatic conditions, and now, rapidly changing, variable, and unpredictable environmental conditions caused by climate change. Additionally, those breeding in industrial areas may be impacted by human activities. It is difficult to separate the impacts of industrial development and climate change; however, long‐term datasets can help show patterns over time. We evaluated factors influencing reproductive parameters of breeding birds at Prudhoe Bay, Alaska, 2003–2019, by monitoring 1265 shorebird nests, 378 passerine nests, and 231 waterfowl nests. We found that nest survival decreased significantly nearer high‐use infrastructure for all guilds. Temporally, passerine nest survival declined across the 17 years of the study, while there was no significant evidence of change in their nest density. Shorebird nest survival did not vary significantly across years, nor did nest density. Waterfowl nest density increased over the course of the study, but we could not estimate nest survival in all years. Egg predator populations varied across time; numbers of gulls and ravens increased in the oilfields 2003–2019, while Arctic fox decreased, and jaeger numbers did not vary significantly. Long‐term datasets are rare in the Arctic, but they are crucial for understanding impacts to breeding birds from both climate change and increasing anthropogenic activities. We show that nest survival was lower for birds nesting closer to high‐use infrastructure in Arctic Alaska, which was not detected in earlier, shorter‐term studies. Additionally, we show that Lapland longspur nest survival decreased across time, in concert with continent‐wide declines in many passerine species. The urgency to understand these relationships cannot be expressed strongly enough, given change is continuing to happen and the potential impacts are large.

Flood Management: Solving Conformance or Sweep Efficiency Problems: Part 1

_ Since the advent of secondary recovery mechanisms, waterflooding or gas displacement, the oil industry has suffered from a variety of problems that yield inefficient displacement of hydrocarbon fluids during flooding. The industry has also suffered from a very low success rate at correcting these poor sweep efficiency problems. The first three articles in this series are designed to enhance our ability to identify, characterize, solve, and evaluate performance of solutions applied to conformance or sweep efficiency problems. This process structure will allow us to discuss key elements that should generate a higher success rate in solving conformance problems. Part 1 of this series focuses on candidate selection and problem clarification or problem understanding which are the first two elements of Fig 1. Overview The process wheel shown in Fig. 1 is used to identify the steps most production engineering companies take as they work through their conformance or sweep efficiency problems. This provides a basis by which we can discuss the various elements of solving these problems. The companies I have worked for chose to call this “conformance engineering.” Let’s define conformance engineering as: The process of utilizing reservoir and wellbore information to understand the flood performance and then use that understanding to adjust aspects of the flood which results in improved oil recovery. That is the working definition this series of articles will use for conformance engineering. I think we can all agree that this includes a large variety of sweep efficiency problems. These range from deep reservoir displacement fluid control issues to near-wellbore control issues and every combination of these elements. This includes issues for controlling displacing fluids at the injector or the producer. We can also use this to understand and characterize human-induced floods vs. natural processes. Strong water aquifer drives have the same displacement mechanisms as waterflooding. They have significant differences to elements like the pressure source, which is broad for aquifer drive and a very specific point source of pressure for pattern floods. In addition, a strong aquifer drive utilizes gravity segregation to enhance the efficiency of the drive where a pattern waterflood can suffer from gravity underrun. This is one of the reasons a peripheral waterflood can be a very effective secondary recovery process. We also consider fields where natural gas cap expansion drives oil displacement. In some fields, the gas cap is supported by gas reinjection. Prudhoe Bay is a prime example where there is no market for natural gas, so gas reinjection into the gas cap and gas cap expansion becomes a strong recovery mechanism for this field. For the sake of this JPT article series we will consider any flood process whether natural or induced to be part of flood management basics.

Detecting changes in the distribution of calling bowhead whales exposed to fluctuating anthropogenic sounds

This paper describes an analysis approach designed to detect the effects of fluctuating anthropogenic underwater sound on the distribution of calling bowhead whales (Balaena mysticetus) during migration. The anthropogenic sounds in this case were associated with an offshore oil production island (Northstar Island) in the Beaufort Sea northwest of Prudhoe Bay, Alaska, but the method has wider applicability. In autumn, bowhead whales migrate westward at varying distances offshore where some are exposed to Northstar sounds. Anthropogenic effects, if present, were hypothesised to be most pronounced in the southern (proximal) part of the migration corridor. Underwater sound levels were measured continuously ca. 500m from Northstar, and locations of calling whales were determined by a seafloor array of directional acoustical recorders. Weighted quantile regression related the 5th quantile of offshore call distance to anthropogenic sounds and other covariates. Case weights were inversely proportional to both probability of detection and location uncertainty. Due to potential dependencies in call locations, block permutation of uncorrelated whale call clusters was used to assign significance levels to coefficients in the quantile regression model. Statistical model selection was used to determine the anthropogenic sound measures most correlated with the 5th quantile of offshore call distances, after allowing for natural within-season variation quantified by day–night changes, distance of the call east or west of Northstar, and date. Data used to illustrate the method were collected over 29 days in September 2003 and included 25,176 bowhead calls. The estimated offshore distance of the 5th quantile call was 0.67km (95% confidence interval 0.31 to 1.05km) farther offshore when tones associated with Northstar were recorded in the 10–450Hz band during the 15 minutes just prior to each call. The method has been applied successfully to similar data collected near Northstar in other years, and may be useful in other studies that simultaneously collect data on animal locations and fluctuating stimuli.

Overlap between bowhead whales (Balaena mysticetus) and vessel traffic in the North American Arctic and implications for conservation and management

Collisions between vehicles and wildlife is a global conservation concern, and vessel strikes are a leading cause of serious injury and mortality for baleen whales. Yet vessel strikes have rarely been studied in the Arctic. Vessel traffic is increasing throughout the Arctic as sea ice is declining, leading to increased overlap between vessels and whales. We examined hypothetical vessel strike risk for the Bering-Chukchi-Beaufort (BCB) and Eastern Canada-West Greenland (ECWG) populations of bowhead whales during the open-water shipping season. We used satellite telemetry and aerial survey data to calculate monthly relative density of both populations, and satellite vessel tracking data to calculate monthly vessel density and speed. We estimated vessel strike risk by multiplying whale density by vessel density corrected by vessel speed. For the BCB population, the highest relative risk was near Utqiaġvik and Prudhoe Bay, Alaska, USA, and near Tuktoyaktuk, Northwest Territories, Canada. For the ECWG population, the highest risk was in the Gulf of Boothia, Cumberland Sound, and near Isabella Bay, Nunavut, Canada. Strike risk was highest in August and September, corresponding with monthly trends in vessel traffic. This study provides important information for focussed monitoring and to minimize/mitigate the threat of vessel strikes to bowhead whales. Although vessel strike risk is presently lower for these populations than for other temperate large cetacean populations, bowhead whale behaviour and projected increases in traffic elevates their risk in the Arctic. Measures to mitigate vessel strike risk to bowhead whales will likely benefit other Arctic marine mammals like beluga and narwhal.

Atmospheric Circulation Drivers of Extreme High Water Level Events at Foggy Island Bay, Alaska

The northern coast of Alaska is experiencing significant climatic change enhancing hazards from reduced sea ice and increased coastal erosion. This same region is home to offshore oil/gas activities. Foggy Island Bay is one region along the Beaufort Sea coast with planned offshore oil/gas development that will need to account for the changing climate. High water levels impact infrastructure through coastal erosion and flooding hazards. In this study, 21 high water level events exceeding the top 95th percentile were identified at the gauge in Prudhoe Bay, Alaska (adjacent to Foggy Island Bay) over 1990–2018. All 21 events, and many non-extreme days with elevated water levels, were associated with strong westerly winds according to station records. Storm systems were generally found to be a key driver of westerly winds in the region according to downscaled reanalysis and storm track data. A dynamically downscaled global climate model projection from CMIP5 indicated that days with westerly wind events may become more frequent as storms strengthen and have longer durations by 2100 in the Foggy Island Bay region. Coupled with the anticipated continued decline in sea ice, the northern coast of Alaska may experience more frequent high water events over the next ~80 years.

Barrier islands influence the assimilation of terrestrial energy in nearshore fishes

We examined the relative importance of landscape features on estuarine fish trophic structure and dependence on terrestrial organic matter (OMterr) in four barrier island lagoon systems along the Alaskan Beaufort Sea coast. Our study compared two relatively large lagoon systems characterized by high river discharge and relatively free ocean water exchanges (central region near Prudhoe Bay, Alaska) with two highly protected lagoons characterized by low river discharge and limited exchange with ocean waters (eastern region near Kaktovik, Alaska). We hypothesized that freshwater discharge would be a strong determinant of food web structure for both resident marine and diadromous fishes if more discharge increases availability of OMterr relative to lagoons with limited or no river inputs. To consider differences in trophic characteristics in fishes between study regions, we estimated community-wide measures of trophic structure (hereafter, community metrics) and the relative use of OMterr from mixing models using stable isotope composition (δ13C and δ15N; muscle tissue) among 12 species and identified the influences of region and body size. Fish captured in lagoons well protected by barrier islands had more distinct and diverse isotopic niches relative to those in more exposed lagoons based on community metrics. The use of OMterr by nearshore fishes in both regions was substantial and was >50% for diadromous species. Between regions, OMterr use differed in 6 of the 8 species considered but was not consistently higher in one region. The relative importance of OMterr varied with fish size in 7 of 10 species considered, with more OMterr used by smaller individuals. This work highlights the importance of OMterr to Arctic fishes and fisheries, some of which are of subsistence importance, even when feeding grounds are primarily marine. We propose that landscape features, particularly barrier islands, play an important role in structuring nearshore food webs. Barrier islands may provide a previously undocumented ecosystem service of increasing food web complexity, which may promote system resilience.

The spatial and temporal influence of infrastructure and road dust on seasonal snowmelt, vegetation productivity, and early season surface water cover in the Prudhoe Bay Oilfield

Increased industrial development in the Arctic has led to a rapid expansion of infrastructure in the region. Localized impacts of infrastructure on snow distribution, road dust, and snowmelt timing and duration feeds back into the coupled Arctic system causing a series of cascading effects that remain poorly understood. We quantify spatial and temporal patterns of snow-off dates in the Prudhoe Bay Oilfield, Alaska, using Sentinel-2 data. We derive the Normalized Difference Snow Index to quantify snow persistence in 2019–2020. The Normalized Difference Vegetation Index and Normalized Difference Water Index were used to show linkages of vegetation and surface hydrology, in relationship to patterns of snowmelt. Newly available infrastructure data were used to analyze snowmelt patterns in relation infrastructure. Results show a relationship between snowmelt and distance to infrastructure varying by use and traffic load, and orientation relative to the prevailing wind direction (up to 1 month difference in snow-free dates). Post-snowmelt surface water area showed a strong negative correlation (up to −0.927) with distance to infrastructure. Results from field observations indicate an impact of infrastructure on winter near-surface ground temperature and snow depth. This study highlights the impact of infrastructure on a large area beyond the direct human footprint and the interconnectedness between snow-off timing, vegetation, surface hydrology, and near-surface ground temperatures.

Geological Reservoir Characterization of a Gas Hydrate Prospect Associated with the Hydrate-01 Stratigraphic Test Well, Alaska North Slope

Geological reservoir characterization is essential for accurate evaluation of gas production performance from gas hydrate reservoirs. Particularly, the understanding of reservoir architecture and heterogeneity is of great importance since these are considered as major controls on fluid hydrodynamic and thermodynamic conditions. This study deals with well log and three-dimensional (3-D) vertical seismic profile (VSP) data acquired from the Hydrate-01 Stratigraphic Test Well within the 7-11-12 prospect, Prudhoe Bay Unit, Alaska North Slope and reports on the results of geological/geophysical evaluation related to the geological structure and reservoir properties of the 7-11-12 prospect. The structural trends of the target reservoirs, based on well correlations, are mostly consistent with the predrill prediction using the surface seismic data, and infer the existence of subseismic faults cutting through the Hydrate-01 well. The 3-D VSP data confirm a down-to-the-east normal fault that offsets the reservoir units across the Hydrate-01 well, which is concordant with the well identification of the same fault, and indicate a northeast-dipping relay structure associated with the overstepping normal faults. The edge enhancement attribute associated with discontinuity generated from the 3-D VSP data shows small faults/fractures, possibly as part of a complex fault network within the imaged normal fault system. These results reveal that the 3-D VSP data provide detailed structural information that is not present from the surface seismic data. The Hydrate-01 well log data confirm the occurrence of gas hydrate at high saturation in the two targeted sand units (B1 and D1 sands), and the comparison to a nearby pre-existing well (7-11-12 well) shows the same general trend in gas hydrate saturation as a map of seismic impedance generated from surface seismic data. The well log data also suggest that the base of gas hydrate occurrence in the Hydrate-01 and 7-11-12 wells is almost aligned at the same depth in both of the targeted B1 and D1 sand reservoirs. Especially for the D1 sand in the Hydrate-01 well, the resistivity logs show a sharp transition from high gas hydrate saturation to fully water-saturated within the D1 sand, suggesting a common gas hydrate/water contact. The results of this study will be used to construct the geological models needed for reservoir simulation studies and they can provide important insights into the geological factors that control the occurrence of gas hydrate on the Alaska North Slope.

Sensitivity and Uncertainty Analysis for Natural Gas Hydrate Production Tests in Alaska

The Japan Research and Development Consortium for Pore Filling Hydrate in Sand (MH21-S), the U.S. Department of Energy National Energy Technology Laboratory (DOE NETL), and the U.S. Geological Survey (USGS) are planning a long-term production test from gas hydrate (methane hydrate) bearing reservoirs in the Prudhoe Bay Unit in northern Alaska. Prediction of gas and water production using 2D reservoir simulation models can be very useful for decision-making for long-term production testing. However, the input parameters applied to the simulation model, which are essentially based on the most likely values obtained from the well-log interpretation and core sample measurements of the Hydrate-01 stratigraphic test well (STW), have some degrees of uncertainty. In this study, to evaluate the impact of uncertainties in the input model on the prediction results of gas and water production as well as to analyze how each input parameter contributes to the uncertainties of prediction results, we conducted uncertainty analysis and parameter sensitivity analysis based on two different methods (the regression-based method and the Sobol’ method). The sensitivity analyses reveal that the parameters regarding relative permeability (exponential of the gas relative permeability (Ng) and residual gas saturation (Sgcr)) and the intrinsic/effective permeability of the lower B1 sand significantly contribute to the uncertainties of the gas and water production predictions. In addition, the uncertainty analyses reveal that the P50 value of cumulative gas production can result in less than the reference case with the most likely values for the input parameters due to the uncertainty of Ng. These results indicate that reducing the uncertainties of gas relative permeability and residual gas saturation is essential for more reliable numerical simulations both for prediction of test well performance and subsequent history matching of field test results.

Convolutional Neural Networks for Automated Built Infrastructure Detection in the Arctic Using Sub-Meter Spatial Resolution Satellite Imagery

Rapid global warming is catalyzing widespread permafrost degradation in the Arctic, leading to destructive land-surface subsidence that destabilizes and deforms the ground. Consequently, human-built infrastructure constructed upon permafrost is currently at major risk of structural failure. Risk assessment frameworks that attempt to study this issue assume that precise information on the location and extent of infrastructure is known. However, complete, high-quality, uniform geospatial datasets of built infrastructure that are readily available for such scientific studies are lacking. While imagery-enabled mapping can fill this knowledge gap, the small size of individual structures and vast geographical extent of the Arctic necessitate large volumes of very high spatial resolution remote sensing imagery. Transforming this ‘big’ imagery data into ‘science-ready’ information demands highly automated image analysis pipelines driven by advanced computer vision algorithms. Despite this, previous fine resolution studies have been limited to manual digitization of features on locally confined scales. Therefore, this exploratory study serves as the first investigation into fully automated analysis of sub-meter spatial resolution satellite imagery for automated detection of Arctic built infrastructure. We tasked the U-Net, a deep learning-based semantic segmentation model, with classifying different infrastructure types (residential, commercial, public, and industrial buildings, as well as roads) from commercial satellite imagery of Utqiagvik and Prudhoe Bay, Alaska. We also conducted a systematic experiment to understand how image augmentation can impact model performance when labeled training data is limited. When optimal augmentation methods were applied, the U-Net achieved an average F1 score of 0.83. Overall, our experimental findings show that the U-Net-based workflow is a promising method for automated Arctic built infrastructure detection that, combined with existing optimized workflows, such as MAPLE, could be expanded to map a multitude of infrastructure types spanning the pan-Arctic.

Permafrost Degradation Impacts on the Trans-Alaska Pipeline

The Trans-Alaska Pipeline System transports warm crude oil over 800 miles through a 4-ft-diameter pipeline (i.e., the “mainline”) from Prudhoe Bay on Alaska's North Slope to the Valdez Marine Terminal on the Gulf of Alaska. TAPS traverses three major mountain ranges, several active faults, and continuous and discontinuous permafrost terrain. Permafrost is generally defined as ground that remains at or below 32°F for at least two consecutive years. Permafrost with temperatures between 32°F and 30°F is generally referred to as “warm permafrost,” while permafrost with temperatures below 30°F is referred to as “cold permafrost.”

Analysis of the technology for increasing the recovery and intensification of hydrocarbon production

The analysis and improvement of the method of additional stimulation of horizontal wells – carrying out multi-zone hydraulic fracturing, which allows to significantly increase the productivity of the well, increase the drainage area, which is especially important in formations with low permeability. In this paper, the oil recovery methods used at the Yuzhnoye field, the method of modeling hydraulic fracturing were considered, and hydraulic fracturing of a highly permeable formation was simulated for two wells 1 and 3 (double-wellbore) in this field. The optimization of the hydraulic fracture design is aimed at creating a fracture of maximum conductivity and minimum length. Since neocom is a highly permeable formation, the TSO (tipscreenout) technology is proposed for hydraulic fracturing – this is end screening. This TSO technology is successfully applied at the Prudhoe Bay field (USA), in the Gulf of Mexico, Indonesia, the North Sea, Canada, Brazil, Venezuela, Vietnam, Saudi Arabia. In Russia, an example of successful design and execution is the hydraulic fracturing operation with TSO in well 4370 of the Muravlenkovskoye field, Noyabrskneftegaz company. The hydraulic fracturing method will increase the vertical permeability and unite the disparate parts of the reservoir, which will make it possible to more efficiently develop the reserves of the Neocomian deposits in the field, system for electricity consumption for the purpose of short-term forecasting of electricity consumption.

Scientific Results of the Hydrate-01 Stratigraphic Test Well Program, Western Prudhoe Bay Unit, Alaska North Slope

The United States Department of Energy, the MH21-S Research Consortium of Japan, and the United States Geological Survey are collaborating to enable gas hydrate scientific drilling and extended-duration reservoir response testing on the Alaska North Slope. To feasibly execute such a test, a location is required that is accessible from existing roads and gravel pads and that can be occupied without disrupting ongoing industry operations. A review of potential locations meeting these criteria determined the likely occurrence of gas hydrate in two fine-grained marginal-marine sands of Tertiary age in the vicinity of the inactive “Kuparuk State 7-11-12” exploration pad in the western Prudhoe Bay Unit (PBU). Existing well and seismic data for that site were insufficient to preclude the potential for free gas occurrence within the deeper (and most prospective) target sand. Therefore, with support from the PBU Working Interest Owners, Alaska Department of Natural Resources, and Petrotechnical Resources Alaska, the Hydrate-01 Stratigraphic Test Well (STW) was drilled in December 2018 to confirm the suitability of the site for future gas hydrate scientific testing. The Hydrate-01 well was successfully drilled to −3290 ft (1003 m) subsea vertical depth at a bottom hole location of approximately 900 ft (∼275 m) east of the surface location. The drilling program featured acquisition of a full suite of logging while drilling data, the collection of side-wall pressure cores, and the installation of distributed temperature and distributed acoustic sensor fiber-optic cables. The log data acquired confirmed the occurrence of gas hydrate at high saturation in two target sands. Integrated evaluation of log and sidewall core data provide petrophysical and geomechanical property information that allow for potential reservoir response to depressurization to be simulated. The deeper “B1 sand” is deemed to be most favorable for reservoir response testing as a result of confirmed gas hydrate occurrence in sediments of high intrinsic permeability, location within 100 ft (30 m) of the base of gas hydrate stability, and minimal risk for direct communication with permeable water-bearing (hydrate-free) zones. The shallower “D1 sand” provides a secondary target that is differentiated by colder in situ temperatures and the interpreted direct hydraulic communication to a lower section of non-hydrate-bearing, water-saturated sand. The Hydrate-01 log data also confirm the occurrence of at least one sub-seismic fault in close proximity to the B1 sand reservoir. To better image the distribution of the gas-hydrate-bearing reservoir sections and associated faults, a three-dimensional (3D) vertical seismic profile was conducted in early 2019 using the distributed acoustic sensors installed as part of the Hydrate-01 STW completion. Detailed two-dimensional (2D) and 3D geologic models have been constructed to enable numerical simulations to inform the planning for potential future scientific tests of reservoir response to depressurization at the site.