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Geology topics

John H. Schuenemeyer

Publications and source records attributed to John H. Schuenemeyer.

12 recordsLinked to original sources
USGS2013

Aggregation of carbon dioxide sequestration storage assessment units

The U.S. Geological Survey is currently conducting a national assessment of carbon dioxide (CO 2 ) storage resources, mandated by the Energy Independence and Security Act of 2007. Pre-emission capture and storage of CO 2 in subsurface saline formations is one potential method to reduce greenhouse gas emissions and the negative impact of global climate change. Like many large-scale resource assessments, the area under investigation is split into smaller, more manageable storage assessment units (SAUs), which must be aggregated with correctly propagated uncertainty to the basin, regional, and national scales. The aggregation methodology requires two types of data: marginal probability distributions of storage resource for each SAU, and a correlation matrix obtained by expert elicitation describing interdependencies between pairs of SAUs. Dependencies arise because geologic analogs, assessment methods, and assessors often overlap. The correlation matrix is used to induce rank correlation, using a Cholesky decomposition, among the empirical marginal distributions representing individually assessed SAUs. This manuscript presents a probabilistic aggregation method tailored to the correlations and dependencies inherent to a CO 2 storage assessment. Aggregation results must be presented at the basin, regional, and national scales. A single stage approach, in which one large correlation matrix is defined and subsets are used for different scales, is compared to a multiple stage approach, in which new correlation matrices are created to aggregate intermediate results. Although the single-stage approach requires determination of significantly more correlation coefficients, it captures geologic dependencies among similar units in different basins and it is less sensitive to fluctuations in low correlation coefficients than the multiple stage approach. Thus, subsets of one single-stage correlation matrix are used to aggregate to basin, regional, and national scales.

Stochastic Environmental Research and Risk Assessm↗
USGS2013

A framework for quantitative assessment of impacts related to energy and mineral resource development

Natural resource planning at all scales demands methods for assessing the impacts of resource development and use, and in particular it requires standardized methods that yield robust and unbiased results. Building from existing probabilistic methods for assessing the volumes of energy and mineral resources, we provide an algorithm for consistent, reproducible, quantitative assessment of resource development impacts. The approach combines probabilistic input data with Monte Carlo statistical methods to determine probabilistic outputs that convey the uncertainties inherent in the data. For example, one can utilize our algorithm to combine data from a natural gas resource assessment with maps of sage grouse leks and piñon-juniper woodlands in the same area to estimate possible future habitat impacts due to possible future gas development. As another example: one could combine geochemical data and maps of lynx habitat with data from a mineral deposit assessment in the same area to determine possible future mining impacts on water resources and lynx habitat. The approach can be applied to a broad range of positive and negative resource development impacts, such as water quantity or quality, economic benefits, or air quality, limited only by the availability of necessary input data and quantified relationships among geologic resources, development alternatives, and impacts. The framework enables quantitative evaluation of the trade-offs inherent in resource management decision-making, including cumulative impacts, to address societal concerns and policy aspects of resource development.

Natural Resources Research↗
USGS2011

Aggregation of estimated numbers of undiscovered deposits: an R-script with an example from the Chu Sarysu Basin, Kazakhtan: Chapter B in Global mineral resource assessment

Mineral resource assessments completed by the U.S. Geological Survey during the past three decades express geologically based estimates of numbers of undiscovered mineral deposits as probability distributions. Numbers of undiscovered deposits of a given type are estimated in geologically defined regions. Using Monte Carlo simulations, these undiscovered deposit estimates are combined with tonnage and grade models to derive a probability distribution describing amounts of commodities and rock that could be present in undiscovered deposits within a study area. In some situations, it is desirable to aggregate the assessment results from several study areas. This report provides a script developed in open-source statistical software, R, that aggregates undiscovered deposit estimates of a given type, assuming independence, total dependence, or some degree of correlation among aggregated areas, given a user-specified correlation matrix.

Chu Sarysu Basin↗
USGS2010

Aggregation methodology for the circum-arctic resource appraisal

This paper presents a methodology that intends to aggregate the results of a recent assessment of undiscovered conventional oil and gas resources of the Arctic by the U.S. Geological Survey. The assessment occurred in 48 geologically defined regions called assessment units. The methodology includes using assessor specified pair-wise correlations as the basis to construct a correlation matrix. Sampling from this matrix generates more realistic uncertainty estimates of aggregated resources than if assumptions of total independence or total dependence are made. The latter two assumptions result in overly narrow or overly broad estimates. Aggregation results for resources in regions north of the Arctic Circle are presented.

Mathematical Geosciences↗
USGS2009

Assessment of undiscovered oil and gas in the Arctic

Among the greatest uncertainties in future energy supply and a subject of considerable environmental concern is the amount of oil and gas yet to be found in the Arctic. By using a probabilistic geology-based methodology, the United States Geological Survey has assessed the area north of the Arctic Circle and concluded that about 30% of the world’s undiscovered gas and 13% of the world’s undiscovered oil may be found there, mostly offshore under less than 500 meters of water. Undiscovered natural gas is three times more abundant than oil in the Arctic and is largely concentrated in Russia. Oil resources, although important to the interests of Arctic countries, are probably not sufficient to substantially shift the current geographic pattern of world oil production.

Science↗
USGS2003

Methodology and Results for the Assessment of Oil and Gas resources, National Petroleum Reserve, Alaska

Oil and gas resources in each of the 24 plays within the National Petroleum Reserve in Alaska (NPRA) were estimated using a play analysis. Assessors specified geologic attributes, risks, and number of prospects for each play. Some specifications established distributions, while others were given as single values. From this information, sizes of oil and gas accumulations were simulated using a Monte Carlo algorithm. The number of such accumulations considered in a given simulation run was obtained from the distribution of the number of prospects. Each prospect in each successful simulation run was risked. This process yielded size-frequency distributions and summary statistics for the various petroleum categories. Estimates of remaining resources from individual plays were then aggregated, and measures of uncertainty computed. Technically recoverable, undiscovered oil beneath the Federal part of NPRA likely ranges between 5.9 and 13.2 billion barrels, with a mean (expected) value of 9.3 billion barrels. Technically recoverable, undiscovered nonassociated natural gas for the same area likely ranges between 39.1 and 83.2 trillion cubic feet, with a mean (expected) value of 59.7 trillion cubic feet. Mean values of the corresponding associated dissolved gas and natural gas liquid are 10.3 trillion cubic feet and 1.4 billion barrels respectively.

Open-File Report↗
USGS2002

Frontier areas and resource assessment: Case of the 1002 area of the Alaska North Slope

The U.S. Geological Survey's 1998 assessment of the 1002 Area of the Arctic National Wildlife Refuge significantly revised previous estimates of the area's petroleum supply potential. The mean (or expected) value of technically recoverable undiscovered oil for the Study Area (Federal 1002 Area, adjacent State waters, and Native Lands) is estimated at 10.4 billion barrels of oil (BBO) and for the Federal 1002 Area the mean is 7.7 BBO. Accumulation sizes containing the oil are expected to be sufficiently large to be of economic interest. At a market price of $21 per barrel, 6 BBO of oil in the Study area is expected to be economic. The Assessment's methodology, results, and the reasons for the significant change in assessments are reviewed. In the concluding section, policy issues raised by the assessment are discussed.

Alaska↗
USGS1998

Preliminary report on coal resources of the Wyodak-Anderson coal zone, Powder River Basin, Wyoming and Montana

The National Coal Resource Assessment (NCRA) project by the U.S. Geological Survey is designed to assess US coal with the greatest potential for development in the next 20 to 30 years. Coal in the Wyodak-Anderson (WA) coal zone in the Powder River Basin of Wyoming and Montana is plentiful, clean, and compliant with EPA emissions standards. This coal is considered to be very desirable for development for use in electric power generation. The purpose of this NCRA study was to compile all available data relating to the Wyodak- Anderson coal, correlate the beds that make up the WA coal zone, create digital files pertaining to the study area and the WA coal, and produce a variety of reports on various aspects of the assessed coal unit. This report contains preliminary calculations of coal resources for the WA coal zone and is one of many products of the NCRA study. Coal resource calculations in this report were produced using both public and confidential data from many sources. The data was manipulated using a variety of commercially available software programs and several custom programs. A general description of the steps involved in producing the resource calculations is described in this report.

North Dakota, South Dakota, Montana, Wyoming↗
USGS1998

Preliminary report on methodology for calculating coal resources of the Wyodak-Anderson coal zone, Powder River basin, Wyoming and Montana

The National Coal Resource Assessment of the Wyodak-Anderson coal zone includes reports on the geology, stratigraphy, quality, and quantity of coal. The calculation of resources is only one aspect of the assessment. Without thorough documentation of the coal resource study and the methods used, the results of our study could be misinterpreted. The task of calculating coal resources included many steps, the use of several commercial software programs, and the incorporation of custom programs. The methods used for calculating coal resources for the Wyodak-Anderson coal zone vary slightly from the methods used in other study areas, and by other workers in the National Coal Resource Assessment. The Wyodak-Anderson coal zone includes up to 10 coal beds in any given location. The net coal thickness of the zone at each data point location was calculated by summing the thickness of all of the coal beds that were greater than 2.5 ft thick. The amount of interburden is not addressed or reported in this coal resource assessment. The amount of overburden reported is the amount of rock above the stratigraphically highest coal bed in the zone. The resource numbers reported do not include coal within mine or lease areas, in areas containing mapped Wyodak-Anderson clinker, or in areas where the coal is extrapolated to be less than 2.5 ft thick. The resources of the Wyodak-Anderson coal zone are reported in Ellis and others (1998). A general description of how the resources were calculated is included in that report. The purpose of this report is to document in more detail some of the parameters and methods used, define our spatial data, compare resources calculated using different grid options and calculation methods, and explain the application of confidence limits to the resource calculation.

Open-File Report↗