Show simple item record

dc.contributor.advisorLi, Yaoguo
dc.contributor.authorWoolf, Rachel Vest
dc.date.accessioned2007-01-03T05:41:19Z
dc.date.accessioned2022-02-09T08:41:57Z
dc.date.available2007-01-03T05:41:19Z
dc.date.available2022-02-09T08:41:57Z
dc.date.issued2013
dc.identifierT 7353
dc.identifier.urihttps://hdl.handle.net/11124/80050
dc.description2013 Fall.
dc.descriptionIncludes illustrations (some color), color maps.
dc.descriptionIncludes bibliographical references (pages 65-66).
dc.description.abstractAn extensive time lapse gravity data set was acquired over the Coso geothermal field near Ridgecrest, California starting in 1987, with the latest data set acquired in 2013. In this thesis I use these gravity data to obtain a better understanding of mass changes occurring within the geothermal field. Geothermal energy is produced by flashing naturally heated ground water into steam which is used to turn turbines. Brine and re-condensed steam are then re-injected into the reservoir. A percentage of the water removed from the system is lost to the process. The time lapse gravity method consists of gravity measurements taken at the same locations over time, capturing snap shots of the changing field. After careful processing, the final data are differenced to extract the change in gravity over time. This change in gravity can then be inverted to recover the change in density and therefore mass over time. The inversion process also produces information on the three dimensional locations of these mass changes. Thirty five gravity data sets were processed and a subsection were inverted with two different starting times, a sixteen point data set collected continuously between 1991 and 2005, and a thirty-eight point data set collected between 1996 and 2005. The maximum change in gravity in the 1991 data group was -350 microGal observed near station CSE2. For the 1996 data group the maximum gravity change observed over the nine year period was -248 microGal. The gravity data were then inverted using the surface inversion method. Three values of density contrast were used, -0.05 g/cm^3, -0.10 g/cm^3, and -0.20 g/cm^3. The starting surface in 1991 was set to 2,500 ft above sea level. The changes in surfaces were then converted to mass changes. The largest total mass change recovered was -1.39x10^11 kg. This mass value is of the same order of magnitude as published well production data for the field. Additionally, the gravity data produces a better understanding of the spatial distribution of mass loss. The mass loss is concentrated in one area of the field while others remain somewhat constant.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado School of Mines. Arthur Lakes Library
dc.relation.ispartof2010-2019 - Mines Theses & Dissertations
dc.rightsCopyright of the original work is retained by the author.
dc.subjectgravity
dc.subjectgeothermal
dc.subjecttime lapse
dc.subject.lcshGeothermal resources -- California
dc.subject.lcshGravity -- Data processing
dc.subject.lcshGravity stations -- California
dc.subject.lcshInversion (Geophysics)
dc.titleTime lapse gravity monitoring at Coso geothermal field
dc.typeText
dc.contributor.committeememberKrahenbuhl, Richard A.
dc.contributor.committeememberBatzle, Michael L.
dc.contributor.committeememberNakagawa, Masami
thesis.degree.nameMaster of Science (M.S.)
thesis.degree.levelMasters
thesis.degree.disciplineGeophysics
thesis.degree.grantorColorado School of Mines


Files in this item

Thumbnail
Name:
Woolf_mines_0052N_10311.pdf
Size:
18.32Mb
Format:
PDF
Description:
Time lapse gravity monitoring ...

This item appears in the following Collection(s)

Show simple item record