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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Digital outcrop mapping of a reservoir-scale incised valley fill, Sego Sandstone, Book Cliffs, Utah

Fey, Matthew F. 02 June 2009 (has links)
Outcrop analog studies have long been used to define subsurface correlation strategies and improve predictions of reservoir heterogeneities that can complicate production behavior. Recent advancements in geographic information software, 3D geologic modeling techniques, and survey equipment have the potential to revolutionize outcrop analog studies. A workflow is developed to create digital outcrop models using a reflectorless total station, a digital camera, Erdas Photogrammetry Module™, and Gocad™ to document complex stratal variations across kilometers-long outcrops. Combining outcrop digital elevation models with orthorectified photographs and detailed sedimentologic logs provides a framework for static 3D reservoir analog models. Developed methodologies are demonstrated by mapping rock variations and stratal geometries within several kilometers-long, sub-parallel exposures of the Lower Sego Sandstone in San Arroyo Canyon, Book Cliffs, Utah. The digital outcrop model of the Lower Sego Sandstone documents complex bedding geometry and facies distribution within two sharp-based sandstone layers. A mapping of allostratigraphic surfaces through the digital outcrop model provided a framework in which to analyze facies variations. These surfaces included: 1) Basal erosion surfaces of these layers interpreted to have formed by tidal erosion of the sea floor during shoreline regression; 2) a high relief erosion surface within the upper layer interpreted to have formed during lowstand fluvial incision; and 3) top contacts of layers defined by abrupt fining to marine shale, which are interpreted to record marine ravinement during transgression. Facies variations within the lower layer include low sinuosity distributary channel deposits incised into highly marine bioturbated sandstone. Deposits above the high-relief erosion surface within the upper layer are a classic valley fill succession, which processes upward from lowstand fluvial channel deposits, to heterolithic estuarine deposits, and finally to sandy landward-dipping beds of an estuarine mouth shoal deposit. The digital outcrop model allows surfaces and facies observation to be mapped within a structured 3D coordinate system to define reservoir analog models.
2

Digital outcrop mapping of a reservoir-scale incised valley fill, Sego Sandstone, Book Cliffs, Utah

Fey, Matthew F. 02 June 2009 (has links)
Outcrop analog studies have long been used to define subsurface correlation strategies and improve predictions of reservoir heterogeneities that can complicate production behavior. Recent advancements in geographic information software, 3D geologic modeling techniques, and survey equipment have the potential to revolutionize outcrop analog studies. A workflow is developed to create digital outcrop models using a reflectorless total station, a digital camera, Erdas Photogrammetry Module™, and Gocad™ to document complex stratal variations across kilometers-long outcrops. Combining outcrop digital elevation models with orthorectified photographs and detailed sedimentologic logs provides a framework for static 3D reservoir analog models. Developed methodologies are demonstrated by mapping rock variations and stratal geometries within several kilometers-long, sub-parallel exposures of the Lower Sego Sandstone in San Arroyo Canyon, Book Cliffs, Utah. The digital outcrop model of the Lower Sego Sandstone documents complex bedding geometry and facies distribution within two sharp-based sandstone layers. A mapping of allostratigraphic surfaces through the digital outcrop model provided a framework in which to analyze facies variations. These surfaces included: 1) Basal erosion surfaces of these layers interpreted to have formed by tidal erosion of the sea floor during shoreline regression; 2) a high relief erosion surface within the upper layer interpreted to have formed during lowstand fluvial incision; and 3) top contacts of layers defined by abrupt fining to marine shale, which are interpreted to record marine ravinement during transgression. Facies variations within the lower layer include low sinuosity distributary channel deposits incised into highly marine bioturbated sandstone. Deposits above the high-relief erosion surface within the upper layer are a classic valley fill succession, which processes upward from lowstand fluvial channel deposits, to heterolithic estuarine deposits, and finally to sandy landward-dipping beds of an estuarine mouth shoal deposit. The digital outcrop model allows surfaces and facies observation to be mapped within a structured 3D coordinate system to define reservoir analog models.
3

Architecture of the upper Sego Sandstone, Book Cliffs, Utah

Birkhead, Stanley Scott 12 April 2006 (has links)
This study maps the facies architecture and geometry of stratigraphic surfaces within the tide-influenced upper Sego Sandstone exposed in the Book Cliffs between Crescent Junction and Thompson Springs, Utah. A bedding diagram was constructed by correlating 32 measured stratigraphic logs across this 8.5 kilometer strike-oblique outcrop to interpret depositional environments and the sequence stratigraphic setting of this tidally-influenced sandstone. Five facies associations are defined: marine shale, lower shoreface, tidally-influenced bedsets, heterolithic tidal bedsets, and tidal flat deposits. Vertical facies trends define two sandy intervals separated by a marine shale, that are interpreted to record episodic progradation of deltaic shorelines. Erosion surfaces at the base of these intervals are interrupted to record tidal scouring of the sea floor during falling stage regression. Sandstone-bodies within these intervals shingle westward recording delta lobes that thinned and became more heterolithic. Although sandstone intervals are interpreted to record progradation, internal cross stratification is dominantly tidal-flood oriented. This is interpreted to record preferential preservation of bedload transported by flood tidal currents onshore, even though net sediment was directed offshore in a suspended ebb-oriented hypopycnal plume and as fluid mud during uncommon river floods. Deposits above high-relief erosion surfaces observed to cut down into the upper Sego Sandstone do not meet the criteria for incised valley fills. These surfaces are interpreted to record tidal current enlargement of distributary channels after abandonment. Such incisions thus do not necessarily record changes in sea level.
4

Geologically-based permeability anisotropy estimates for tidally-influenced reservoir analogs using lidar-derived, quantitative shale character data

Burton, Darrin 16 June 2011 (has links)
The principle source of heterogeneity affecting flow behavior in conventional clastic reservoirs is discontinuous, low-permeability mudstone beds and laminae (shales). Simple ‘streamline’ models have been developed which relate permeability anisotropy (kv/kh ) at the reservoir scale to shale geometry, fraction, and vertical frequency. A limitation of these models, especially for tidally-influenced reservoirs, is the lack of quantitative geologic inputs. While qualitative models exist that predict shale character in tidally-influenced environments (with the largest shales being deposited near the turbidity maximum in estuaries, and in the prodelta-delta front), little quantitative shale character data is available. The purpose of this dissertation is to collect quantitative data to test hypothetical relationships between depositional environment and shale character and to use this data to make geologically-based estimates of for different reservoir elements. For this study, high-resolution, lidar point-clouds were used to measure shale length, thickness, and frequency. This dissertation reports a novel method for using distance-corrected lidar intensity returns to distinguish sandstone and mudstone lithology. Lidar spectral and spatial data, photo panels, and outcrop measurements were used to map and quantify shale character. Detailed shale characteristics were measured from four different tidally-influenced reservoir analogs: estuarine point bar (McMurray Formation, Alberta, Canada), tidal sand ridge (Tocito Sandstone, New Mexico), and unconfined and confined tidal bars (Sego Sandstone, Utah). Estuarine point bars have long (l=67.8 m) shales that are thick and frequent relative to the other units. Tidal sand ridges have short (l=8.6 m dip orientation) shales that are thin and frequent. Confined tidal bars contain shales that are thin, infrequent, and anisotropic, averaging 16.3 m in length (dip orientation). Unconfined tidal bars contain nearly equidimensional (l=18.6 m dip orientation) shales with moderate thicknesses and vertical frequency. The observed shale geometries agree well with conceptual models for tidal environments. The unique shale character of each unit results in a different distribution of estimated . The average estimated kv/kh values for each reservoir element are: 8.2*10^4 for estuarine point bars, 0.038 for confined tidal bars, 0.004 for unconfined tidal bars, and 0.011 for tidal sand ridges. / text
5

An evaluation of the impact of the Non-ferrous Metals Crime Combating Committee on copper cable theft

Liebenberg, Andre Sarel 11 1900 (has links)
English, Zulu and Northern Sotho summaries / This study aims to evaluate the Non-Ferrous Metals Crime Combating Committee's impact on combating copper cable theft in South Africa. Data was collected via in-depth interviews with awaiting trial detainees charged with copper cable theft at the Pollsmoor Correctional Centre in the Western Cape; members of the Mpumalanga and Gauteng Provincial Non-Ferrous Metals Crime Combating Committee; members of Business Against Crime South Africa; and investigators attached to Combined Private Investigations who investigate copper theft nationally. The in-depth interviews provided a comprehensive understanding of participant experiences relating to the impact of the Non-Ferrous Metals Crime Combating Committee on the combating of copper cable theft in South Africa. Moreover, the researcher performed a thorough literature study of the phenomenon locally and internationally. Research findings indicate shortcomings in the Non-Ferrous Metals Crime Combating Committee's effectiveness, limiting its impact on preventing copper cable theft. Based on these findings, the study recommends that the Non-Ferrous Metals Crime Combating Committee be replaced with a specialised South African Police Service Non-Ferrous Metals Theft Unit. Consequently, this study puts forward a set of recommendations proposing a systematic pro-active plan to address and minimise copper cable theft in South Africa. The proposed plan convincingly presents practical solutions to minimise copper cable theft and contributes to the current body of scholarship on copper cable theft in South Africa. / Inhloso yalolu cwaningo ukuhlola umthelela wohlelo lwe-Non-Ferrous Metals Crime Combating Committee mayelana nokuqedwa kokutshontshwa kwentambo yogesi (copper cable). Idatha iqoqwe ngokusebenzisa izinhlolovo ezijulile ezenziwa ngokusebenzisa iziboshwa eziboshelwe izintambo zikagesi ezisamele ukugwetshwa ejele lase Pollsmoor Correctional Centre ngaseNtshonalanga Kapa, amalunga eMpumalanga and Gauteng Provincial Non-Ferrous Metals Crime Combating Committee, amalunga eBusiness Against Crime South Africa kanye nabaphenyi abahambisana nophiko lweCombined Private Investigations oluphenya ukutshontshwa kwezintambo zikagesi ezweni lonke. Lezi zinhlolovo ezijulile zinikeze ulwazi olubanzi lwabadlalindima olumayelana nomthelela weNon-Ferrous Metals Crime Combating Committee mayelana nokuqedwa kokutshontshwa kwezintambo zikagesi. Ngaphezu kwalokho, umcwaningi wenze ucwaningo olunzulu lombhalo wobuciko mayelana nokutshontshwa kwezintambo zikagesi lapha ekhaya kanye nasemhlabeni wonke jikelele. Ulwazi olutholakele lukhombisa iziqi ezikhinyabeza ukusebenza kahle kweKomithi mayelana nokuvimbela umthelela walo mayelana nokutshontshwa kwezintambo zikagesi. Ngezizathu ezisuselwa phezu kwalolu lwazi, lolu cwaningo lubeka phambili isethi lezincomo ezinganceda iKomiti ekuqiniseni umthintela walo ngokuhlongoza uhlelo olugqugquzelayo lokunciphisa izinga lokutshontshwa kwezintambo zikagesi eNingizimu Afrika. Lolu hlelo oluhlongoziwe ngaphandle kokungabaza lwethula izixazululo ezenzeka empilweni yangempela ukunciphisa ukwetshiwa kwezintambo zikagesi kanti lokhu kunegalelo kwiziko lamanje futhi luqhubekisa iziko lamanje lwezifundo esimayelana nokwetshiwa kwezintambo zikagesi. / Maikemisetso a thutelo ye ke go lekola khuetso ya Komiti ya Twantsho ya Bosenyi bja Dimetale tse di Sego tsa Tshipi ka ga go lwantsha kutso ya megala ya koporo. Datha e kgobokeditswe ka mokgwa wa ditherisano tse di tseneletsego tseo di sepeditswego le mahodu a megala ya koporo ao a golegilwego ao a letetsego go sekiswa Senthareng ya Tshokollo ya Pollsmoor go la Kapa Bodikela, maloko a Diprofense tsa Mpumalanga le Gauteng a Komiti ya Twantsho ya Bosenyi bja Dimetale tse di sego tsa Tshipi, maloko a Dikgwebo tsa Kgahlanong le Bosenyi tsa Afrika Borwa le banyakisisi bao ba dirisanago le Dinyakisiso tsa Praebete tse Kopantswego tseo di nyakisisago kutso ya koporo kemong ya bosetshaba. Ditherisano tse di tseneletsego tse di file kwesiso ka botlalo ya maitemogelo a batseakarolo ye e sepelelanago le khuetso ya Komiti ya Twantsho ya Bosenyi bja Dimetale tse di sego tsa Tshipi ka ga go lwantsha kutso ya megala ya koporo. Gape, monyakisisi o dirile thutelo ya dingwalo ka botebo ya kutso ya megala ya koporo tikologong ya leagong le kemong ya boditshabatshaba. Dikhwetso tsa dinyakisiso di supa mafokodi ao a lebanego bokgoni bja Komiti tshitisong ya khuetso ya yona go kutso ya megala ya koporo. Go ya ka dikhwetso tse, thutelo ye e hlagisa sehlopha sa dikeletso tseo di ka thusago Komiti go tswetsa khuetso ya yona pele ka go sisinya leano la go itokisetsa seemo se ka diregago ka mokgwa wo o beakantswego go fokotsa kutso ya megala ya koporo ka Afrika Borwa. Leano leo le sisintswego le hlagisa ka mo go kgodisago ditharollo tse di ka phethagatswago go fokotsa kutso ya megala ya koporo ka gona la ba la seabe go le go tswetsa pele popego ya bjale ya borutegi ka ga kutso ya megala ya koporo. / Criminology and Security Science / Ph. D. (Criminal Justice)

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