Development of a Geothermal Well Database for Estimating In-Field EGS Potential in the State of Nevada

ABSTRACT Recent successes at Department of Energy (DOE)-funded Enhanced Geothermal System (EGS) demonstration projects have shown that EGS techniques can be used in existing hydrothermal fields to enhance the permeability of geothermal wells, converting previously "dry" wells into commercially-viable ones (Desert Peak EGS Project, DOE Award: DE-FC6-02ID14406). The application of EGS techniques to dry wells in existing hydrothermal fields, defined here as "in-field EGS," has the potential to increase or help maintain generation capacity at hydrothermal power plants. The amount of in-field EGS potential depends on the number and status of dry wells at existing hydrothermal power plants, and their location with respect to the geothermal reservoir and other geothermal wells in the field. To aid in estimating the in-field EGS potential, the authors are developing a database containing and consolidating the publically available information on full-sized geothermal wells at hydrothermal power plants. The goal of this database development was to identify the name, location, and status of all full-sized geothermal wells drilled to date. Early design and population of the database focused on wells at hydrothermal power plants in Nevada. The database was created by aggregating and cleaning data from publically available datasets. The initial database was then examined for missing or possibly erroneous data and corrected using original source documents such as well logs, permitting documents, etc. and the data source of the information updated as well. The database was designed to track data sources for each well data point, so that information can be traced back to its original source. The resulting design allows the database to be continually updated and improved as new information becomes available and for original data sources to be identified when conflicting or erroneous information about a well is uncovered or if further information from the original data source is desired. Although it is still in development, the geothermal well database will eventually be used to help estimate in-field EGS resource potential in the U.S. Results and summary information from the master geothermal well database is currently expected to be publically available at the end of 2014

The meter of Guthlac B: a generative model

The approach to Old English (OE) poetic meter traditionally taken is to describe the meter in terms of a list of foot or verse (half-line) types. It has been suggested that this approach, however, is open to criticism on several points First, a list of metrical types is unconstrained in that there is no principled reason why other members may not be added to the list. Second, such a theory includes no constraints on substitutions; any metrical type may always be substituted for any other. A description in the form of a list therefore cannot rule out unmetrical lines (Halle and Keyser “Iambic Pentameter”). This thesis proposes a model of OE poetic meter based on Hanson and Kiparsky’s parametric theory of universal meter. Hanson and Kiparsky argue that the constituents relevant to meter are not arbitrary or conventional, such as a list of foot or verse types, but are just those that are also relevant to language. They propose that all poetic meters are comprised of binary feet, which, like the phonological constituents defining prominence in language, consist of a strong (S) member which is the head, or prominent position, and a weak (W) member which is an unprominent position. Structure parameters establish headedness (either SW or WS) and the number of feet in a line, A position parameter defines the maximal amount of prosodic material that may occupy a given metrical position in terms of phonological constituency: mora (μ), syllable (ϭ), foot (∅), or word (λ). Prominence rules define first, whether S positions must contain prominent constituents and/or whether W positions must contain unprominent constituents; and second, whether prominence is defined by weight, strength, or stress (“Best of all Possible Verse”). The model I have proposed for OE defines the meter in terms of a fixed number of binary left-headed (SW) feet together with constraints on both S and W positions: S positions must contain stressed syllables, further defined as the heads of prosodic words; and W may contain the heads of prosodic words only if they are prosodically weak. No metrical position may contain more than a minimal word (λmin).Arts, Faculty ofEnglish, Department ofGraduat