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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

Geometry and continuity of fine-grained reservoir sandstones deformed within an accretionary prism - Basal Unit, West Woodbourne

Blackman, Ingrid Maria 30 September 2004 (has links)
The Basal Unit of West Woodbourne Field in Barbados is a 250 m thick succession of finely-interbedded sandstones and mudstones deposited by Paleogene, fine-grained, deep-water systems off the northern South American margin and deformed as sediments were translated to the subduction zone of the Caribbean and Atlantic plates. Closely spaced gamma ray, neutron, density, spontaneous potential, formation microimager and dip meter logs, limited core, and published reports of local outcrops, were used to define three scales of vertical stratigraphic variation within this 1.5 km2 field: (1) decimeters to meters thick log facies; (2) meters to tens of meters thick log successions; and (3) tens to hundred meter thick intervals that are continuous laterally across the field. These variations record changes in sediment supply and depositional energy during progradation and abandonment events varying in scale from local shifts in distributary channels to regional changes in sediment transport along the basin. Well log correlations suggest the Basal Unit comprises a turbidite fan system (250 m thick) trending north to northeast, composed of six, vertically-stacked, distributary channel complexes. Three architectural elements are identified within each distributary channel complex: (1) Major amalgamated channels (30-40 m thick, 150-200 m wide and at least 900 m long) pass down depositional dip into proximal second-order channels that bifurcate basinward (15-20 m thick, symmetric successions); (2) Lobe deposits (20-50 m thick, 400 m wide, and at least 400 m long) are composed of upward-coarsening successions that contain distal second-order channels (1-10 m thick); and (3) Laterally extensive overbank deposits (5-10 m thick), which vertically separate distributary channel-lobe complexes. Reservoir heterogeneities within the Basal Unit are defined by the lateral extent and facies variations across a hierarchy of strata within channel-lobe complexes. Although laterally extensive muddy overbank deposits generally inhibit vertical communication between stacked channel-lobe complexes, in places where high-energy first-order channel sandstones incise underlying muddy overbank deposits, sandstones in subsequent intervals are partially connected. The Basal Unit is bounded on the southwest by a northwest-southeast trending fault that rises 30 degrees towards the northwest to define a structural trap on the northeast side of the field.
2

Geometry and continuity of fine-grained reservoir sandstones deformed within an accretionary prism - Basal Unit, West Woodbourne

Blackman, Ingrid Maria 30 September 2004 (has links)
The Basal Unit of West Woodbourne Field in Barbados is a 250 m thick succession of finely-interbedded sandstones and mudstones deposited by Paleogene, fine-grained, deep-water systems off the northern South American margin and deformed as sediments were translated to the subduction zone of the Caribbean and Atlantic plates. Closely spaced gamma ray, neutron, density, spontaneous potential, formation microimager and dip meter logs, limited core, and published reports of local outcrops, were used to define three scales of vertical stratigraphic variation within this 1.5 km2 field: (1) decimeters to meters thick log facies; (2) meters to tens of meters thick log successions; and (3) tens to hundred meter thick intervals that are continuous laterally across the field. These variations record changes in sediment supply and depositional energy during progradation and abandonment events varying in scale from local shifts in distributary channels to regional changes in sediment transport along the basin. Well log correlations suggest the Basal Unit comprises a turbidite fan system (250 m thick) trending north to northeast, composed of six, vertically-stacked, distributary channel complexes. Three architectural elements are identified within each distributary channel complex: (1) Major amalgamated channels (30-40 m thick, 150-200 m wide and at least 900 m long) pass down depositional dip into proximal second-order channels that bifurcate basinward (15-20 m thick, symmetric successions); (2) Lobe deposits (20-50 m thick, 400 m wide, and at least 400 m long) are composed of upward-coarsening successions that contain distal second-order channels (1-10 m thick); and (3) Laterally extensive overbank deposits (5-10 m thick), which vertically separate distributary channel-lobe complexes. Reservoir heterogeneities within the Basal Unit are defined by the lateral extent and facies variations across a hierarchy of strata within channel-lobe complexes. Although laterally extensive muddy overbank deposits generally inhibit vertical communication between stacked channel-lobe complexes, in places where high-energy first-order channel sandstones incise underlying muddy overbank deposits, sandstones in subsequent intervals are partially connected. The Basal Unit is bounded on the southwest by a northwest-southeast trending fault that rises 30 degrees towards the northwest to define a structural trap on the northeast side of the field.
3

Sedimentologic and Petrographic Evidence of Flow Confinement In a Passive Continental Margin Slope Channel Complex, Isaac Formation, Windermere Supergroup, British Columbia, Canada

Billington, Tyler 16 October 2019 (has links)
At the Castle Creek study area in east-central British Columbia a well-exposed section about 450 m wide and 30 m thick in the (Neoproterozoic) Isaac Formation was analyzed to document vertical and lateral changes in a succession of distinctively heterolithic strata. Strata are interpreted to have been deposited on a deep-marine levee that was sandwiched between its genetically related channel on one side and an erosional escarpment sculpted by an older (underlying) channel on the other. Flows that overspilled the channel (incident flow) eventually encountered the escarpment, which then set up a return flow oriented more or less opposite to the incident (from the channel) flow. This created an area of complex flow that became manifested in the sedimentary record as a highly tabular succession of intricately interstratified sand and mud overlain by an anomalously thick, plane-parallel interlaminated sand-mud unit capped finally by a claystone.
4

Seismic sequence stratigraphy of Pliocene-Pleistocene turbidite systems, Ship Shoal South Addition, Northwestern Gulf of Mexico

Kim, Booyong 30 September 2004 (has links)
During the Late Pliocene to Middle Pleistocene Ages, sediments of the study area were deposited in the intra-slope salt withdrawal basin where sand-prone sediments deposited as turbidite lobes and channel fills are the main reservoirs of the Northern Gulf of Mexico. The main purpose of this study was to identify and characterize these sand-prone sediments. Sequence stratigraphic analysis of well logs, biostratigraphic data, and 3-D seismic data provided a chronostratigraphic framework of the study area, within which seismic facies analysis was carried out. Each sequence was subdivided into separate seismic bodies characterized by specific amplitude, coherence of reflectors, and shape of reflectors. The descriptions of each seismic facies combined with well logs were compared with turbidite facies models to infer their geological information. Five turbidite elements were identified: depositional channel fills and overbank deposits, erosional channel fills, turbidite lobes, mud turbidite fills and sheets and hemipelagic and pelagic drapes. Depositional channel fills are usually deposited in lower parts of interpreted sequences, surrounded by shale-prone overbank deposits. The lateral variation of these turbidite elements was revealed by horizon slices, in which depositional channels are generally trending NE-SW or NNE-SSW with elongated sinuous forms. Well logs indicate that depositional channel fills usually consist of bell or cylinder type sand-prone sediments. Turbidite lobe was found only in the 1.1-0.8 Ma sequence, in which it laps out onto the underlying sequence boundary and shows high-amplitude and a high-coherence of mound shape. This facies is interpreted as sand-prone, but wells available penetrated only the marginal parts of this facies and showed poor reservoir qualities. Horizon slices could partly reveal its lapout boundary due to the limitation of vertical seismic resolution. Mud turbidite fills and sheets are the most dominant turbidite facies, which usually occurred in the upper parts of sequences and overlain by hemipelagic and pelagic drapes. Hemipelagic and pelagic drapes were deposited very widely, wrapping down the previous topography with consistent thickness throughout the basin. Erosional channel was observed only in the 0.8-0.7 Ma sequence where it cut into the underlying sequence and was filled by shale-prone sediments. Depositional channel fills and turbidite lobes are the main reservoir facies in the study area. Seismic facies analysis using vertical seismic sections and horizon slices combined with lithology data made it possible to identify and systematically describe these sand prone turbidite elements in intra-slope salt withdrawal basin.
5

Caractérisation des systèmes sédimentaires profonds en contexte de rift actif : étude intégrée des affleurements Plio-Pléistocène et des données sismiques du Golfe de Corinthe, Grèce / Deep-water syn-rift sedimentary systems from Plio-Pleistocene outcrops and seismic lines of Gulf of Corinth deposits (Greece)

Rubi, Romain 29 October 2018 (has links)
Le profil de dépôt syn-rift d’un Gilbert-delta et de son prodelta du Pléistocène moyen est documenté dans le Rift de Corinthe en Grèce, à partir d’études de terrain et d’un modèle photogrammétrique. Les études de terrain ont permis de mettre en évidence quatre typologies de bottomsets avec des facies, des associations de facies et des géométries spécifiques : (1) des bottomsets de sables et de graviers, (2) un épisode d’érosion et de bypass, (3) un bottomset de sables fins et de silts, (4) un bottomset de sables massifs. Ces typologies sont intégrées dans le cadre stratigraphique du delta. Dans le prodelta associé, deux moats actifs remplis de sables et de conglomérats sont limités par un drift confiné. L’axe des moats migre à contre pente et est perpendiculaire au delta. Dans l’axe des moats, une séquence normale est remaniée en une séquence inverse dans la partie avale sous l’action des courants de fond. Le drift asymétrique développe une sediment-wave sur son flanc long avec deux séquences : (1) une séquence turbiditique strato- et grano-décroissante directement sur une surface d’érosion et (2) une séquence contouritique bi-gradationelle avec des rides de courant, des bancs ondulés, de la bioturbation et des encroutements ferrugineux. De nouvelles cartes d’horizon, structurales, morphodésimentaires et d’épaisseurs sont proposées à partir de l’interprétation des données sismiques avec un pas de temps de 100 ka. Ces éléments documentent la formation d’un système mixte contouritique et turbiditique profond dans le Golfe de Corinthe. Au Sud deux systèmes se développent en pied de pente : un système de bottomsets gravitaires et un système de moat érodant et remobilisant les sédiments pour former des drifts. Au Nord, la pente est remaniée en sediment-wave et par des moats perchés qui produisent des plastered drifts. A 0,4 Ma, un système dominé par les coutourites, dans le Golfe de Corinthe, indique une possible ouverture à l’Est et à l’Ouest. / Middle Pleistocene Gilbert-type delta and prodelta in the Rift of Corinth, Greece, are investigated combining field methods and photogrammetric 3D model to document an entire early synrift sedimentological profile. Field works document four different dynamics in Gilbert-type bottomset deposits, each one of which is characterized by a specific range of facies, facies associations and geometries: (1) the sandy-gravelly bottomset, (2) the erosional-bypass stage, (3) the fine-grained bottomset and (4) the massive-sandy bottomset. The bottomset typologies are integrated within the stratigraphic delta context. In the associated prodelta, two active sandy-conglomeratic moats are limited by a confined drift. The prodelta moat axis are perpendicular to the delta and migrate upslope. In the moat axis, a normal-to-inverse grading sequence evolution is correlated down-flow under bottom-current processes. The asymmetric drift presents a sediment-wave architecture on its long side within two sequences : (1) a normal turbidite sequence with a sharp erosional base and massive silt to shale and (2) a contourite bi-gradational sequence affected by red crust, wavy bedding, current ripples and bioturbation. New interpretations of seismic data resulting in horizon, structural, morphosedimentary, and thickness maps, for the offshore Corinth Rift, at a 100 kyr time scales document a mixed turbiditic and contouritic deep water system. The Southern slope break presents a mixed system between gravity-driven bottomset and bottom-current moats which rework and depose drifts. The Northern slope is meanly reworked by sediment-wave and perched drift which can produced plastered drifts. At 0.4 Ma, a contouritic sedimentary system dominates the Gulf of Corinth and indicates an opening at both West and East tips.
6

Architecture of Deep-Marine Interchannel Deposits: Isaac Formation, Windermere Supergroup (Neoproterozoic), Southern Canadian Cordillera

Davis, Leena 08 February 2011 (has links)
The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.
7

Depositional Architecture of a Near-Slope Turbidite Succession: Upper Kaza Group, Windermere Supergroup, Castle Creek, British Columbia, Canada

Rocheleau, Jonathan 26 July 2011 (has links)
An expansive panel of well exposed (periglacial) strata of the Upper Kaza Group permitted a detailed study of the stratal architecture of proximal basin floor deposits in the Neoproterozoic Windermere turbidite system. Detailed stratigraphic and petrographic analyses identified six lithofacies: poorly-sorted, clast-rich mudstone (F1), thin-bedded siltstone and mudstone (F2), thick-bedded, massive sandstone (F3), medium-scale, cross-stratified sandstone (F4), mudstone-clast breccia (F5), and medium-bedded turbidites (F6). The spatial distribution of these facies identify five architectural elements: heterolithic feeder channel deposits (FA1), thin-bedded intralobe turbidites (FA2), terminal splay deposits (FA3), distributary channel deposits (FA4), and isolated scours (FA5). FA 1-4 are genetically related and form the basic building blocks of large-scale basin floor depositional lobes. FA 5, which is isolated to the stratigraphic top of the study area, is interpreted to have formed in a base-of-slope setting, and its superposition on FA 1-4 suggests the long-term progradation of the Windermere turbidite system.
8

Architecture of Deep-Marine Interchannel Deposits: Isaac Formation, Windermere Supergroup (Neoproterozoic), Southern Canadian Cordillera

Davis, Leena 08 February 2011 (has links)
The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.
9

Depositional Architecture of a Near-Slope Turbidite Succession: Upper Kaza Group, Windermere Supergroup, Castle Creek, British Columbia, Canada

Rocheleau, Jonathan 26 July 2011 (has links)
An expansive panel of well exposed (periglacial) strata of the Upper Kaza Group permitted a detailed study of the stratal architecture of proximal basin floor deposits in the Neoproterozoic Windermere turbidite system. Detailed stratigraphic and petrographic analyses identified six lithofacies: poorly-sorted, clast-rich mudstone (F1), thin-bedded siltstone and mudstone (F2), thick-bedded, massive sandstone (F3), medium-scale, cross-stratified sandstone (F4), mudstone-clast breccia (F5), and medium-bedded turbidites (F6). The spatial distribution of these facies identify five architectural elements: heterolithic feeder channel deposits (FA1), thin-bedded intralobe turbidites (FA2), terminal splay deposits (FA3), distributary channel deposits (FA4), and isolated scours (FA5). FA 1-4 are genetically related and form the basic building blocks of large-scale basin floor depositional lobes. FA 5, which is isolated to the stratigraphic top of the study area, is interpreted to have formed in a base-of-slope setting, and its superposition on FA 1-4 suggests the long-term progradation of the Windermere turbidite system.
10

Characterization of the 3-D Properties of the Fine-Grained Turbidite 8 Sand Reservoir, Green Canyon 18, Gulf of Mexico

Plantevin, Matthieu Francois 30 September 2004 (has links)
Understanding the internal organization of the Lower Pleistocene 8 Sand reservoir in the Green Canyon 18 field, Gulf of Mexico, helps to increase knowledge of the geology and the petrophysical properties, and hence contribute to production management in the area. Interpretation of log data from 29 wells, core and production data served to detail as much as possible a geological model destined for a future reservoir simulation. Core data showed that the main facies resulting from fine-grained turbidity currents is composed of alternating sand and shale layers, whose extension is assumed to be large. They correspond to levee and overbank deposits that are usually associated to channel systems. The high porosity values, coming from unconsolidated sediment, were associated to high horizontal permeability but generally low kv/kh ratio. The location of channel deposits was not obvious but thickness maps suggested that two main systems, with a northwest-southeast direction, contributed to the 8 Sand formation deposition. These two systems were not active at the same time and one of them was probably eroded by overlying formations. Spatial relationships between them remained unclear. Shingled stacking of the channel deposits resulted from lateral migration of narrow, meandering leveed channels in the mid part of the turbidite system. Then salt tectonics tilted turbidite deposits and led to the actual structure of the reservoir. The sedimentary analysis allowed the discrimination of three facies A, B and E, with given porosity and permeability values, that corresponded to channel, levee and overbank deposits. They were used to populate the reservoir model. Well correlation helped figure out the extension of these facies.

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