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M. J. Freeman - One of the best experts on this subject based on the ideXlab platform.

  • provenance of detrital zircons on the western australia coastline implications for the geologic history of the Perth Basin and denudation of the yilgarn craton
    Geology, 1999
    Co-Authors: K. N. Sircombe, M. J. Freeman
    Abstract:

    The age distributions of four detrital zircon samples from Western Australia placer deposits are found to be dominated by Neoproterozoic and Mesoproterozic ages; this outcome challenges a long-held assumption about derivation from the nearby Archean Yilgarn craton. The dominant ages are consistent with derivation from Proterozoic orogens marginal to the Yilgarn craton, including the Pinjarra orogen and Leeuwin block to the west and the Albany-Fraser orogen to the south. The results suggest that these marginal orogens were preferentially uplifted in the Jurassic-Cretaceous rifting event that formed the Perth Basin and subsequently dominated the sedimentary contribution to this Basin. These sediments have since been recycled to form the modern beach-sand placer deposits that reflect their non-Archean provenance despite proximity to the Yilgarn craton. The lack of a sedimentary contribution from the Yilgarn craton to the Perth Basin implies that peneplanation was complete before the Mesozoic and that denudation rates have been minimal ever since.

  • Provenance of detrital zircons on the Western Australia coastline—Implications for the geologic history of the Perth Basin and denudation of the Yilgarn craton
    Geology, 1999
    Co-Authors: K. N. Sircombe, M. J. Freeman
    Abstract:

    The age distributions of four detrital zircon samples from Western Australia placer deposits are found to be dominated by Neoproterozoic and Mesoproterozic ages; this outcome challenges a long-held assumption about derivation from the nearby Archean Yilgarn craton. The dominant ages are consistent with derivation from Proterozoic orogens marginal to the Yilgarn craton, including the Pinjarra orogen and Leeuwin block to the west and the Albany-Fraser orogen to the south. The results suggest that these marginal orogens were preferentially uplifted in the Jurassic-Cretaceous rifting event that formed the Perth Basin and subsequently dominated the sedimentary contribution to this Basin. These sediments have since been recycled to form the modern beach-sand placer deposits that reflect their non-Archean provenance despite proximity to the Yilgarn craton. The lack of a sedimentary contribution from the Yilgarn craton to the Perth Basin implies that peneplanation was complete before the Mesozoic and that denudation rates have been minimal ever since.

K. N. Sircombe - One of the best experts on this subject based on the ideXlab platform.

  • provenance of detrital zircons on the western australia coastline implications for the geologic history of the Perth Basin and denudation of the yilgarn craton
    Geology, 1999
    Co-Authors: K. N. Sircombe, M. J. Freeman
    Abstract:

    The age distributions of four detrital zircon samples from Western Australia placer deposits are found to be dominated by Neoproterozoic and Mesoproterozic ages; this outcome challenges a long-held assumption about derivation from the nearby Archean Yilgarn craton. The dominant ages are consistent with derivation from Proterozoic orogens marginal to the Yilgarn craton, including the Pinjarra orogen and Leeuwin block to the west and the Albany-Fraser orogen to the south. The results suggest that these marginal orogens were preferentially uplifted in the Jurassic-Cretaceous rifting event that formed the Perth Basin and subsequently dominated the sedimentary contribution to this Basin. These sediments have since been recycled to form the modern beach-sand placer deposits that reflect their non-Archean provenance despite proximity to the Yilgarn craton. The lack of a sedimentary contribution from the Yilgarn craton to the Perth Basin implies that peneplanation was complete before the Mesozoic and that denudation rates have been minimal ever since.

  • Provenance of detrital zircons on the Western Australia coastline—Implications for the geologic history of the Perth Basin and denudation of the Yilgarn craton
    Geology, 1999
    Co-Authors: K. N. Sircombe, M. J. Freeman
    Abstract:

    The age distributions of four detrital zircon samples from Western Australia placer deposits are found to be dominated by Neoproterozoic and Mesoproterozic ages; this outcome challenges a long-held assumption about derivation from the nearby Archean Yilgarn craton. The dominant ages are consistent with derivation from Proterozoic orogens marginal to the Yilgarn craton, including the Pinjarra orogen and Leeuwin block to the west and the Albany-Fraser orogen to the south. The results suggest that these marginal orogens were preferentially uplifted in the Jurassic-Cretaceous rifting event that formed the Perth Basin and subsequently dominated the sedimentary contribution to this Basin. These sediments have since been recycled to form the modern beach-sand placer deposits that reflect their non-Archean provenance despite proximity to the Yilgarn craton. The lack of a sedimentary contribution from the Yilgarn craton to the Perth Basin implies that peneplanation was complete before the Mesozoic and that denudation rates have been minimal ever since.

H. K. H. Olierook - One of the best experts on this subject based on the ideXlab platform.

  • Tectonic controls on sediment provenance evolution in rift Basins: Detrital zircon U-Pb and Hf isotope analysis from the Perth Basin, Western Australia
    Gondwana Research, 2019
    Co-Authors: H. K. H. Olierook, N. E. Timms, Milo Barham, Ian C.w. Fitzsimons, Qiang Jiang, Noreen J. Evans, Bradley J. Mcdonald
    Abstract:

    Abstract The role of tectonics in controlling temporal and spatial variations in sediment provenance during the evolution of extensional Basins from initial rifting to continental breakup and passive margin development are not well established. We test the influence of tectonics in a rift Basin that has experienced minimal uplift but significant extension throughout its history: the Perth Basin, Western Australia. We use published zircon U–Pb and Hf isotope data from Basin inception through to continental drift and complement this with new data from samples deposited synchronously with the continental breakup of eastern Gondwana. Three primary source regions are inferred, namely the Archean Yilgarn Craton to the east, the Paleo- and Mesoproterozoic Albany–Fraser–Wilkes Orogen to the south and east, and the Mesoproterozoic and Ediacaran–Cambrian Pinjarra Orogen underlying the rift Basin and comprising the dominant crustal components to the west and southwest. From mid-Paleozoic Basin inception to Early Cretaceous breakup of eastern Gondwana, drainage in the Perth Basin was primarily north- to northwest-directed as evidenced by the dominant Mesoproterozoic detrital zircon cargo, paleodrainage patterns and paleocurrent directions. Thus, provenance was primarily parallel to the rift axis and perpendicular to the extension direction, particularly during periods of thermal subsidence. During episodes of mechanical extension, detrital zircon ages are polymodal and consistently dominated by Paleo- and Mesoproterozoic grains derived from the Albany–Fraser–Wilkes Orogen, but with significant Archean and Neoproterozoic inputs from the rift margins. It is inferred that during mechanical extension the rate of subsidence exceeded sediment supply, which generated Basin-margin scarps and enhanced direct input from the rift shoulders. Detrital zircon spectra from temporally-equivalent samples at the rift margin and in the rift axis reveal that distinct sedimentary routing operated on the flanks. In summary, sediment provenance in the Perth Basin (and probably other rift Basins) is tectonically controlled by: (1) extension direction, (2) episodes of mechanical extension (rift) or thermal subsidence (post-rift), and (3) proximity to rift axis or rift margin.

  • 3D structural and stratigraphic model of the Perth Basin, Western Australia: Implications for sub-Basin evolution
    Australian Journal of Earth Sciences, 2015
    Co-Authors: H. K. H. Olierook, N. E. Timms, Soazig Corbel, J. Wellmann, P. Wilkes
    Abstract:

    The history of rifting and breakup of eastern Gondwana is recorded by the development and fill of the Perth Basin in Western Australia. Knowledge of the structural architecture and stratigraphic geometry of the Perth Basin is essential to understand the evolution of the Western Australian margin and its applications to hydrocarbon and geothermal prospects, and effective aquifer management. This study integrates existing, publicly available geological, gravity, magnetic and digital elevation data to develop the first refined, regional structural and stratigraphic interpretation of the entire onshore and offshore Perth Basin, Western Australia. This new 3D model offers formation depth and thickness predictions in areas of sparse or no data. The model shows significant heterogeneity in the preserved formation thicknesses and depths at both local and regional scales. These differences may have resulted from differential subsidence and/or differential exhumation, but the formation geometries alone cannot disti...

  • Paleodrainage and fault development in the southern Perth Basin, Western Australia during and after the breakup of Gondwana from 3D modelling of the Bunbury Basalt
    Australian Journal of Earth Sciences, 2015
    Co-Authors: H. K. H. Olierook, N. E. Timms, R. E. Merle, F. Jourdan, P. Wilkes
    Abstract:

    The evolution of faults and paleodrainage patterns on the southwestern Australian passive margin during and after the breakup of Gondwana in the Early Cretaceous remains poorly understood. This contribution investigates the fault and paleodrainage evolution in the southern Perth Basin with the use of the ‘Bunbury Basalt’, the only lava flows known to be synchronous with continental breakup. New aeromagnetic data have been integrated with well intersections and outcrop constraints to establish the first 3D model of the Bunbury Basalt. The model reveals that flows are up to 100 m thick and are predominantly confined to two north–south-trending paleovalleys and their tributaries situated in the Bunbury Trough in the southern Perth Basin. The Donnybrook Paleovalley flow ponded in a paleovalley proximal to the Darling Fault and is truncated by the two later flows within the Bunbury Paleovalley, which is positioned centrally in the Bunbury Trough. Offsets of the Bunbury Basalt have been used to identify new nor...

  • sedimentary facies analysis mineralogy and diagenesis of the mesozoic aquifers of the central Perth Basin western australia
    Marine and Petroleum Geology, 2015
    Co-Authors: N. E. Timms, H. K. H. Olierook, Moyra E J Wilson, Claudio Delle Piane, Joseph P Hamilton, Patricia Cope, Laura Stutenbecker
    Abstract:

    Abstract Assessment and successful exploration for, and exploitation of, aquifers in the Perth Basin require knowledge of their petrophysical and sedimentological characteristics and geometries. This study provides a sedimentological and lithofacies analysis of core from the Mesozoic Yarragadee Formation, Cadda Formation, Cattamarra Coal Measures, Eneabba Formation and Lesueur Sandstone of Western Australia recovered from Pinjarra-1, Cockburn-1, Gingin-1 and Gingin-2 wells provide insights into changes in depositional environment over time and space in the central Perth Basin. In studied sections, nine different fluvial-dominated lithofacies have been identified in the Yarragadee Formation, Cadda Formation and Cattamarra Coal Measures that occur in similar proportions, whereas the Lesueur Sandstone is dominated by coarse-grained deposits of high energy fluvial systems. Vertical variation in lithofacies on the order of 10 cm to approximately 2 m vertical scale is observed in all formations and wells. Changes in the lithofacies, linked to local depositional environments, are probably associated with fluvial-alluvial to fluvio-deltaic systems that have complex 3D architecture, including braided and to probably meandering systems, and are affected by channel avulsion. Point counting and automated mineral analysis of thin sections of core showed detrital mineralogy dominated by monocrystalline quartz, with rare polycrystalline quartz, a moderate amount of alkali feldspar and very minor amounts of garnet, organic fragments, muscovite and biotite. These data show a lithofacies-dependence of the proportion of minerals, with little variation between equivalent lithofacies from different depths, formations or wells. Grain size and sorting, that have a first order control on porosity, are strongly lithofacies dependent. Individual lithofacies types show a trend of decreasing porosity with depth due to the increasing effects of compaction, quartz overgrowth cementation and authigenic clay mineral development. Lithofacies and depth are the main controls on permeability, and so lithofacies distribution exerts a key control on hydraulic behaviour.

  • 3D structural and stratigraphic model of the Perth Basin, Western Australia: Implications for sub-Basin evolution
    Australian Journal of Earth Sciences, 2015
    Co-Authors: H. K. H. Olierook, N. E. Timms, J. F. Wellmann, Soazig Corbel, P. G. Wilkes
    Abstract:

    The history of rifting and breakup of eastern Gondwana is recorded by the development and fill of the Perth Basin in Western Australia. Knowledge of the structural architecture and stratigraphic geometry of the Perth Basin is essential to understand the evolution of the Western Australian margin and its applications to hydrocarbon and geothermal prospects, and effective aquifer management. This study integrates existing, publicly available geological, gravity, magnetic and digital elevation data to develop the first refined, regional structural and stratigraphic interpretation of the entire onshore and offshore Perth Basin, Western Australia. This new 3D model offers formation depth and thickness predictions in areas of sparse or no data. The model shows significant heterogeneity in the preserved formation thicknesses and depths at both local and regional scales. These differences may have resulted from differential subsidence and/or differential exhumation, but the formation geometries alone cannot distinguish between these two models if any erosion has occurred. Only the Lower to Middle Jurassic stratigraphy has been minimally eroded and thereby records the net subsidence. This stratigraphic interval shows that subsidence was broadly hinged from south to north, with a greater subsidence rate in the southern and central Perth Basin. Localised differences in thicknesses across adjacent sub-Basins were likely controlled by differential displacement along sub-Basin bounding faults during subsidence and, subsequently, during exhumation episodes. This new 3D model of the entire Perth Basin provides a framework for numerical simulations of fluid and heat flow and large-scale tectonic analysis, such as stratigraphic forward modelling of the southwestern Australian margin.

N. E. Timms - One of the best experts on this subject based on the ideXlab platform.

  • Tectonic controls on sediment provenance evolution in rift Basins: Detrital zircon U-Pb and Hf isotope analysis from the Perth Basin, Western Australia
    Gondwana Research, 2019
    Co-Authors: H. K. H. Olierook, N. E. Timms, Milo Barham, Ian C.w. Fitzsimons, Qiang Jiang, Noreen J. Evans, Bradley J. Mcdonald
    Abstract:

    Abstract The role of tectonics in controlling temporal and spatial variations in sediment provenance during the evolution of extensional Basins from initial rifting to continental breakup and passive margin development are not well established. We test the influence of tectonics in a rift Basin that has experienced minimal uplift but significant extension throughout its history: the Perth Basin, Western Australia. We use published zircon U–Pb and Hf isotope data from Basin inception through to continental drift and complement this with new data from samples deposited synchronously with the continental breakup of eastern Gondwana. Three primary source regions are inferred, namely the Archean Yilgarn Craton to the east, the Paleo- and Mesoproterozoic Albany–Fraser–Wilkes Orogen to the south and east, and the Mesoproterozoic and Ediacaran–Cambrian Pinjarra Orogen underlying the rift Basin and comprising the dominant crustal components to the west and southwest. From mid-Paleozoic Basin inception to Early Cretaceous breakup of eastern Gondwana, drainage in the Perth Basin was primarily north- to northwest-directed as evidenced by the dominant Mesoproterozoic detrital zircon cargo, paleodrainage patterns and paleocurrent directions. Thus, provenance was primarily parallel to the rift axis and perpendicular to the extension direction, particularly during periods of thermal subsidence. During episodes of mechanical extension, detrital zircon ages are polymodal and consistently dominated by Paleo- and Mesoproterozoic grains derived from the Albany–Fraser–Wilkes Orogen, but with significant Archean and Neoproterozoic inputs from the rift margins. It is inferred that during mechanical extension the rate of subsidence exceeded sediment supply, which generated Basin-margin scarps and enhanced direct input from the rift shoulders. Detrital zircon spectra from temporally-equivalent samples at the rift margin and in the rift axis reveal that distinct sedimentary routing operated on the flanks. In summary, sediment provenance in the Perth Basin (and probably other rift Basins) is tectonically controlled by: (1) extension direction, (2) episodes of mechanical extension (rift) or thermal subsidence (post-rift), and (3) proximity to rift axis or rift margin.

  • 3D structural and stratigraphic model of the Perth Basin, Western Australia: Implications for sub-Basin evolution
    Australian Journal of Earth Sciences, 2015
    Co-Authors: H. K. H. Olierook, N. E. Timms, Soazig Corbel, J. Wellmann, P. Wilkes
    Abstract:

    The history of rifting and breakup of eastern Gondwana is recorded by the development and fill of the Perth Basin in Western Australia. Knowledge of the structural architecture and stratigraphic geometry of the Perth Basin is essential to understand the evolution of the Western Australian margin and its applications to hydrocarbon and geothermal prospects, and effective aquifer management. This study integrates existing, publicly available geological, gravity, magnetic and digital elevation data to develop the first refined, regional structural and stratigraphic interpretation of the entire onshore and offshore Perth Basin, Western Australia. This new 3D model offers formation depth and thickness predictions in areas of sparse or no data. The model shows significant heterogeneity in the preserved formation thicknesses and depths at both local and regional scales. These differences may have resulted from differential subsidence and/or differential exhumation, but the formation geometries alone cannot disti...

  • Paleodrainage and fault development in the southern Perth Basin, Western Australia during and after the breakup of Gondwana from 3D modelling of the Bunbury Basalt
    Australian Journal of Earth Sciences, 2015
    Co-Authors: H. K. H. Olierook, N. E. Timms, R. E. Merle, F. Jourdan, P. Wilkes
    Abstract:

    The evolution of faults and paleodrainage patterns on the southwestern Australian passive margin during and after the breakup of Gondwana in the Early Cretaceous remains poorly understood. This contribution investigates the fault and paleodrainage evolution in the southern Perth Basin with the use of the ‘Bunbury Basalt’, the only lava flows known to be synchronous with continental breakup. New aeromagnetic data have been integrated with well intersections and outcrop constraints to establish the first 3D model of the Bunbury Basalt. The model reveals that flows are up to 100 m thick and are predominantly confined to two north–south-trending paleovalleys and their tributaries situated in the Bunbury Trough in the southern Perth Basin. The Donnybrook Paleovalley flow ponded in a paleovalley proximal to the Darling Fault and is truncated by the two later flows within the Bunbury Paleovalley, which is positioned centrally in the Bunbury Trough. Offsets of the Bunbury Basalt have been used to identify new nor...

  • sedimentary facies analysis mineralogy and diagenesis of the mesozoic aquifers of the central Perth Basin western australia
    Marine and Petroleum Geology, 2015
    Co-Authors: N. E. Timms, H. K. H. Olierook, Moyra E J Wilson, Claudio Delle Piane, Joseph P Hamilton, Patricia Cope, Laura Stutenbecker
    Abstract:

    Abstract Assessment and successful exploration for, and exploitation of, aquifers in the Perth Basin require knowledge of their petrophysical and sedimentological characteristics and geometries. This study provides a sedimentological and lithofacies analysis of core from the Mesozoic Yarragadee Formation, Cadda Formation, Cattamarra Coal Measures, Eneabba Formation and Lesueur Sandstone of Western Australia recovered from Pinjarra-1, Cockburn-1, Gingin-1 and Gingin-2 wells provide insights into changes in depositional environment over time and space in the central Perth Basin. In studied sections, nine different fluvial-dominated lithofacies have been identified in the Yarragadee Formation, Cadda Formation and Cattamarra Coal Measures that occur in similar proportions, whereas the Lesueur Sandstone is dominated by coarse-grained deposits of high energy fluvial systems. Vertical variation in lithofacies on the order of 10 cm to approximately 2 m vertical scale is observed in all formations and wells. Changes in the lithofacies, linked to local depositional environments, are probably associated with fluvial-alluvial to fluvio-deltaic systems that have complex 3D architecture, including braided and to probably meandering systems, and are affected by channel avulsion. Point counting and automated mineral analysis of thin sections of core showed detrital mineralogy dominated by monocrystalline quartz, with rare polycrystalline quartz, a moderate amount of alkali feldspar and very minor amounts of garnet, organic fragments, muscovite and biotite. These data show a lithofacies-dependence of the proportion of minerals, with little variation between equivalent lithofacies from different depths, formations or wells. Grain size and sorting, that have a first order control on porosity, are strongly lithofacies dependent. Individual lithofacies types show a trend of decreasing porosity with depth due to the increasing effects of compaction, quartz overgrowth cementation and authigenic clay mineral development. Lithofacies and depth are the main controls on permeability, and so lithofacies distribution exerts a key control on hydraulic behaviour.

  • 3D structural and stratigraphic model of the Perth Basin, Western Australia: Implications for sub-Basin evolution
    Australian Journal of Earth Sciences, 2015
    Co-Authors: H. K. H. Olierook, N. E. Timms, J. F. Wellmann, Soazig Corbel, P. G. Wilkes
    Abstract:

    The history of rifting and breakup of eastern Gondwana is recorded by the development and fill of the Perth Basin in Western Australia. Knowledge of the structural architecture and stratigraphic geometry of the Perth Basin is essential to understand the evolution of the Western Australian margin and its applications to hydrocarbon and geothermal prospects, and effective aquifer management. This study integrates existing, publicly available geological, gravity, magnetic and digital elevation data to develop the first refined, regional structural and stratigraphic interpretation of the entire onshore and offshore Perth Basin, Western Australia. This new 3D model offers formation depth and thickness predictions in areas of sparse or no data. The model shows significant heterogeneity in the preserved formation thicknesses and depths at both local and regional scales. These differences may have resulted from differential subsidence and/or differential exhumation, but the formation geometries alone cannot distinguish between these two models if any erosion has occurred. Only the Lower to Middle Jurassic stratigraphy has been minimally eroded and thereby records the net subsidence. This stratigraphic interval shows that subsidence was broadly hinged from south to north, with a greater subsidence rate in the southern and central Perth Basin. Localised differences in thicknesses across adjacent sub-Basins were likely controlled by differential displacement along sub-Basin bounding faults during subsidence and, subsequently, during exhumation episodes. This new 3D model of the entire Perth Basin provides a framework for numerical simulations of fluid and heat flow and large-scale tectonic analysis, such as stratigraphic forward modelling of the southwestern Australian margin.

Vamegh Rasouli - One of the best experts on this subject based on the ideXlab platform.

  • Lattice simulation of hydraulic fracture containment in the North Perth Basin
    Journal of Petroleum Science and Engineering, 2020
    Co-Authors: X. Wan, Vamegh Rasouli, Branko Damjanac
    Abstract:

    Abstract The results of numerical simulations of hydraulic fracturing based on the concept of lattice, a grain based method, are presented. Five cases of numerical simulations were conducted to analyze the effects of changing rock properties and in-situ stresses on hydraulic fracture propagation and its containment. The study was done based on the data from one of the shale gas wells in the North Perth Basin (NPB) in Western Australia and the hydraulic fracturing lab experimental data on a 50 mm cubical sample. The hydraulic fracturing initiates and propagates within Carynginia Formation surrounded by the Irwin River Coal Measures (IRCM) Formation from the top and Kockatea Formation at the base. The lab experiments were upscaled to both intermediate and field scales to simulate fracture propagation in the viscosity dominated regime. Penetration parameters, including the depth and area of the fracture crossing the interface, were proposed to characterize fracture containment capacity. It was observed that the fracture is contained by both IRCM and Kockatea Formations due to the large contrast between the minimum horizontal stresses in these layers and that of the Carynginia formation. However, as quantified by the penetration parameters, the fracture propagates more easily into the IRCM Formation with higher brittleness than Carynginia Formation. Kockatea Formation with lower brittleness than that of Carynginia Formation inhibits vertical migration of the fracture, i.e. results in more visible fracture containment. The results suggest that decrease in rock brittleness inhibits fracture propagation and lower minimum horizontal stress contrast leads to fracture containment.

  • Geomechanical Characteristics of Gas Shales: A Case Study in the North Perth Basin
    Rock Mechanics and Rock Engineering, 2014
    Co-Authors: Vamegh Rasouli, Andrew Sutherland
    Abstract:

    Gas shales are one type of unconventional reservoirs which have attracted significant attention for gas production in recent years. Gas production from very tight shales requires employment of hydraulic fracturing as a stimulation technique. To design hydraulic fracture operation the mechanical properties of the targeted and surrounding formations should be estimated. Also, the magnitude and orientation of in situ stresses in the field need to be known to estimate the fracture initiation and propagation pressures. This study focuses on gas shale characteristics in the North Perth Basin and uses data corresponding to well Arrowsmith-2 (AS-2) which is the first dedicated shale gas well drilled in Western Australia. A log-based analysis was used to build the rock mechanical model (RMM). The RMM results were used to set up a hydraulic fracturing laboratory experiment. The test was done in the presence of three principal stresses to mimic the real field stress conditions. The test results include the pressure–time curve which was used to estimate the initiation and propagation pressure at that depth. The results were used to draw some practical conclusions related to hydraulic fracturing operation in the field.

  • Significance of compressional tectonic on pore pressure distribution in Perth Basin
    Journal of Unconventional Oil and Gas Resources, 2014
    Co-Authors: Abualksim Ahmad, Reza Rezaee, Vamegh Rasouli
    Abstract:

    Abstract The Perth Basin is one of the major tectonic structures along the western continental margin of Australia and was initially formed through the rifting and break-up of the Indian and Australian plates. The severe tectonic movements accompanied and occurred after the break-up are responsible for the most structural elements and for the distribution of pore pressure in the Basin. Investigations on the well log data from the Perth Basin have identified shale intervals which are characterised as overpressured in some parts of the Basin, whereas similar shale intervals found to be normally pressured in other parts of the Basin. The phenomena of overpressure have frequently been reported while drilling the same intervals. Based on this research, sections with overpressure were observed in the majority of the wells in the basal section of the Kockatea shale where there were less tectonic activities have been recorded. Normal pore pressure was observed in shallower wells in the Kockatea shales which were located within uplifted sections that were more tectonically active areas. Based on the results of this research, the pore pressure distribution in the Kockatea Shale varied significantly from one part of the Perth Basin to another as a result of compressive tectonic stress. Compressional tectonic activities either induced fracturing in shallower localities (e.g. Beagle Ridge, Cadda Terrace and the adjacent terraces) or removed part of the Kockatea Shale as a result of faulting resulting in overpressures being released. Regions with less intensity of the tectonic activities showed an increase in pressure gradients as approaching away from the centre of uplift.

  • in situ stresses in the southern Perth Basin at the gswa harvey 1 well site
    Exploration Geophysics, 2013
    Co-Authors: Vamegh Rasouli, Marina Pervukhina, Tobias M. Müller, Roman Pevzner
    Abstract:

    Knowledge of orientations and magnitudes of present-day stresses is important for different applications including fault reactivation, borehole stability and CO2 injection studies. As part of the West Hub Carbon Capture and Storage project, the GSWA Harvey-1 well was drilled in early 2012. It is located ~115 km south of Perth and is used to assess the suitability for CO2 underground storage. The aim of this study is to estimate the mechanical properties and state of stress fields in the Southern Perth Basin. The analysis is based on the newly acquired log and VSP data and results of a rock mechanical model including vertical profiles of elastic and strength properties as well as identified breakout zones. The results indicate that the stress regime in the region is dominantly strike-slip. It changes to a reverse faulting system at shallow depths of below ~900 m. Stress field orientation is obtained from borehole breakout analysis. The average azimuth of the maximum horizontal stress is 106° and the standa...

  • In-situ stresses in the Southern Perth Basin at the GSWA Harvey-1 well site
    Exploration Geophysics, 2013
    Co-Authors: Vamegh Rasouli, Marina Pervukhina, Tobias M. Müller, Roman Pevzner
    Abstract:

    Knowledge of orientations and magnitudes of present-day stresses is important for different applications includingfaultreactivation,boreholestabilityandCO2injectionstudies.AspartoftheWestHubCarbonCaptureandStorage project, the GSWA Harvey-1 well was drilled in early 2012. It is located ~115km south of Perth and is used to assess the suitabilityforCO2undergroundstorage.Theaimofthisstudyistoestimatethemechanicalpropertiesandstateofstress fields in the Southern Perth Basin. The analysis is based on the newly acquired log and VSP data and results of a rock mechanical model including vertical profiles of elastic and strength properties as well as identified breakout zones. The results indicate that the stress regime in the region is dominantly strike-slip. It changes to a reverse faulting system at shallow depths of below ~900m. Stress field orientation is obtained from borehole breakout analysis. The average azimuth of the maximum horizontal stress is 106 � and the standard deviation is 10 � . This direction of the maximum horizontal stress is broadly consistent with the east-west direction earlier reported for the Perth Basin.