Pub Date : 2019-12-01DOI: 10.1080/22020586.2019.12072937
T. Wise, S. Thiel, R. Dutch, M. Pawley, K. Robertson
Summary We integrate seismic tomographic models and filtered gravity anomaly maps to investigate the compositional variations in the SCLM of Australia. We find zones of relative enrichment and depletion coinciding with the spatial extent of major thermal events. Anomalous regions of enrichment may represent subduction metasomatism of the lithospheric mantle, or refertilisation due to asthenospheric upwelling. Regions of apparent depletion signify high-degree melt extraction from a previously more enriched lithosphere.
{"title":"Metasomatic/depletion events affecting Cratons and “cratons”","authors":"T. Wise, S. Thiel, R. Dutch, M. Pawley, K. Robertson","doi":"10.1080/22020586.2019.12072937","DOIUrl":"https://doi.org/10.1080/22020586.2019.12072937","url":null,"abstract":"Summary We integrate seismic tomographic models and filtered gravity anomaly maps to investigate the compositional variations in the SCLM of Australia. We find zones of relative enrichment and depletion coinciding with the spatial extent of major thermal events. Anomalous regions of enrichment may represent subduction metasomatism of the lithospheric mantle, or refertilisation due to asthenospheric upwelling. Regions of apparent depletion signify high-degree melt extraction from a previously more enriched lithosphere.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":"118 1","pages":"1 - 4"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88021270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1080/22020586.2019.12073164
J. Pearce, T. Blach, G. Dawson, Y. Melnichenko, G. Southam, S. Golding, J. Bahadur, D. Paterson
Summary Shale oil and gas is of recent interest in Australia, and the Roseneath, Epsilon and Murteree (REM) shales of the Cooper Basin, Australia, are unconventional gas targets. Shales have a high proportion of porosity in the submicron scale and hydraulic stimulation of USA shales has historically employed high volumes of water with dilute HCl, proppants and various chemicals. Supercritical (sc) CO2 has also been used as a fracture fluid in water sensitive formations. In addition, shales may contain high concentrations of potentially toxic or regulated components such as U, As, Pb, or BTEX which may be released to production water. Improper disposal or treatment of waste water has caused recent environmental concerns in the USA. REM shales were characterised with various techniques including high resolution synchrotron XFM for association of metals with specific minerals. Several metals and As were associated with sulphides in coal pores; Mn with siderite, and Pb with pyrite cements. Shales were reacted with dilute HCl or scCO2-water +/- SO2. The fraction of SANS gas accessible meso-pores was highest in the Epsilon Formation core. Siderite dissolved in HCl reactions, and the fraction of open meso-pores increased. Fe-rich precipitates formed in scCO2 reactions and mesopores partly closed. Mobilised concentrations of Pb, Fe, U, and Na were highest from the reactions with dilute HCl. Understanding the mineral sources of metals and their potential release with different fracture fluids may result in better predictions and mitigation options for production water. Reactions of minerals such as siderite, and sulphides may release regulated metals to production water.
{"title":"Experimental acid and scCO2 reactions of Roseneath, Epsilon and Murteree gas shales: Opening or closing of gas accessible pores and metal release to water","authors":"J. Pearce, T. Blach, G. Dawson, Y. Melnichenko, G. Southam, S. Golding, J. Bahadur, D. Paterson","doi":"10.1080/22020586.2019.12073164","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073164","url":null,"abstract":"Summary Shale oil and gas is of recent interest in Australia, and the Roseneath, Epsilon and Murteree (REM) shales of the Cooper Basin, Australia, are unconventional gas targets. Shales have a high proportion of porosity in the submicron scale and hydraulic stimulation of USA shales has historically employed high volumes of water with dilute HCl, proppants and various chemicals. Supercritical (sc) CO2 has also been used as a fracture fluid in water sensitive formations. In addition, shales may contain high concentrations of potentially toxic or regulated components such as U, As, Pb, or BTEX which may be released to production water. Improper disposal or treatment of waste water has caused recent environmental concerns in the USA. REM shales were characterised with various techniques including high resolution synchrotron XFM for association of metals with specific minerals. Several metals and As were associated with sulphides in coal pores; Mn with siderite, and Pb with pyrite cements. Shales were reacted with dilute HCl or scCO2-water +/- SO2. The fraction of SANS gas accessible meso-pores was highest in the Epsilon Formation core. Siderite dissolved in HCl reactions, and the fraction of open meso-pores increased. Fe-rich precipitates formed in scCO2 reactions and mesopores partly closed. Mobilised concentrations of Pb, Fe, U, and Na were highest from the reactions with dilute HCl. Understanding the mineral sources of metals and their potential release with different fracture fluids may result in better predictions and mitigation options for production water. Reactions of minerals such as siderite, and sulphides may release regulated metals to production water.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":"13 1","pages":"1 - 4"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80030768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1080/22020586.2019.12073250
S. Johnson
Summary State- and federal-generated pre-competitive geoscience data is critical for exploration success. These relatively low-cost but high-quality regional-scale datasets ultimately reduce the financial risk to explorers by reducing the search space and allowing a more targeted use of exploration expenditure. In Western Australia, over 20 years of geological mapping and associated research in the Capricorn Orogen has led to a robust understanding of the orogen architecture and its temporal and thermal evolution. Recent in situ geochronology work in the northern part of the orogen, has bridged the gap between prospect-scale ‘exploration’ geoscience data with regional- and province-scale data, ultimately leading to a better understanding of the regional-scale drivers and pathways for gold mineralization in this part of the orogen. This information is critical for exploration models as it opens up older parts of the northern Capricorn basins that were traditionally considered unprospective, and refines and focusses exploration strategies to target the major crustal structures and their ancillary structures.
{"title":"Twenty years of pre-competitive geoscience data in the Capricorn Orogen: the link between mineral systems and crustal evolution","authors":"S. Johnson","doi":"10.1080/22020586.2019.12073250","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073250","url":null,"abstract":"Summary State- and federal-generated pre-competitive geoscience data is critical for exploration success. These relatively low-cost but high-quality regional-scale datasets ultimately reduce the financial risk to explorers by reducing the search space and allowing a more targeted use of exploration expenditure. In Western Australia, over 20 years of geological mapping and associated research in the Capricorn Orogen has led to a robust understanding of the orogen architecture and its temporal and thermal evolution. Recent in situ geochronology work in the northern part of the orogen, has bridged the gap between prospect-scale ‘exploration’ geoscience data with regional- and province-scale data, ultimately leading to a better understanding of the regional-scale drivers and pathways for gold mineralization in this part of the orogen. This information is critical for exploration models as it opens up older parts of the northern Capricorn basins that were traditionally considered unprospective, and refines and focusses exploration strategies to target the major crustal structures and their ancillary structures.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":"88 1","pages":"1 - 3"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86109352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1080/22020586.2019.12073052
J. S. Holmes, J. L. Grigson
Summary The Pilgangoora lithium-tantalum project encompasses a globally significant Li-Ta pegmatite district which formed in the late-Mesoarchaean, along the western margin of the East Pilbara Terrane in Western Australia. Regional field mapping, coupled with local petrographic and micro-analytical investigation into lithium and tantalum mineralisation at Pilgangoora, have allowed a first step towards developing a mineral system-type model for rare-metal pegmatites, that looks beyond the internal features of the trap site, and considers factors such as the triggers, potential sources, and pathways of rare-metal pegmatite magmas. The Li-Ta pegmatite sheets and dykes at Pilgangoora are composite bodies of three paragenetically distinct magmatic phases, each showing differing degrees of ductile strain. The intrusions are structurally controlled and were emplaced within the strain halo of a regional shear zone that is kinematically distinct from, and overprinting of, deformational structures and fabrics belonging to earlier orogenic events in the East Pilbara Terrane. A crystallisation age of 2845 ± 4 Ma for tantalite, obtained during this study, is ~15 m.y. younger than a proximal pluton of the high-K Split Rock Supersuite. This seemingly rules out direct derivation of the rare-metal pegmatite magma from what has traditionally been considered the most likely parent granitic intrusive suite. Along with the evidence for multi-phase parageneses, such a timing relationship is at odds with the currently accepted paradigm for rare-metal pegmatite genesis. The new constraints on rare-metal pegmatite genesis identified as part of this study form valuable exploration criteria, which may be applied locally to locate additional resources and, longer term, more strategically to review and target lithium-bearing pegmatite fields throughout Western Australia.
{"title":"Pilgangoora Lithium-Tantalum Project: deposit geology and new constraints on rare-metal pegmatite genesis","authors":"J. S. Holmes, J. L. Grigson","doi":"10.1080/22020586.2019.12073052","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073052","url":null,"abstract":"Summary The Pilgangoora lithium-tantalum project encompasses a globally significant Li-Ta pegmatite district which formed in the late-Mesoarchaean, along the western margin of the East Pilbara Terrane in Western Australia. Regional field mapping, coupled with local petrographic and micro-analytical investigation into lithium and tantalum mineralisation at Pilgangoora, have allowed a first step towards developing a mineral system-type model for rare-metal pegmatites, that looks beyond the internal features of the trap site, and considers factors such as the triggers, potential sources, and pathways of rare-metal pegmatite magmas. The Li-Ta pegmatite sheets and dykes at Pilgangoora are composite bodies of three paragenetically distinct magmatic phases, each showing differing degrees of ductile strain. The intrusions are structurally controlled and were emplaced within the strain halo of a regional shear zone that is kinematically distinct from, and overprinting of, deformational structures and fabrics belonging to earlier orogenic events in the East Pilbara Terrane. A crystallisation age of 2845 ± 4 Ma for tantalite, obtained during this study, is ~15 m.y. younger than a proximal pluton of the high-K Split Rock Supersuite. This seemingly rules out direct derivation of the rare-metal pegmatite magma from what has traditionally been considered the most likely parent granitic intrusive suite. Along with the evidence for multi-phase parageneses, such a timing relationship is at odds with the currently accepted paradigm for rare-metal pegmatite genesis. The new constraints on rare-metal pegmatite genesis identified as part of this study form valuable exploration criteria, which may be applied locally to locate additional resources and, longer term, more strategically to review and target lithium-bearing pegmatite fields throughout Western Australia.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":"8 1","pages":"1 - 6"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88340745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1080/22020586.2019.12073051
J. Vearncombe
Summary Criticism of the exploration and mining industry for failing to find enough new deposits and open new mines is misplaced. Significant growth in the size of gold Resources on many mines of the Yilgarn Craton has occurred well after the deposit was discovered and after mining had commenced. Brownfields exploration is commonly (but not always) socially, environmentally and politically acceptable. It is easier to add to an operation than it is to permit and fund a new operation. The record of successful brownfield exploration in Western Australia is outstanding with 100% to 1000% additions to endowment recorded at many gold operations in Western Australia in recent years. This success more than covers the perceived, but not proven, short fall from greenfield exploration.
{"title":"West Australian gold resources: crisis or hubris?","authors":"J. Vearncombe","doi":"10.1080/22020586.2019.12073051","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073051","url":null,"abstract":"Summary Criticism of the exploration and mining industry for failing to find enough new deposits and open new mines is misplaced. Significant growth in the size of gold Resources on many mines of the Yilgarn Craton has occurred well after the deposit was discovered and after mining had commenced. Brownfields exploration is commonly (but not always) socially, environmentally and politically acceptable. It is easier to add to an operation than it is to permit and fund a new operation. The record of successful brownfield exploration in Western Australia is outstanding with 100% to 1000% additions to endowment recorded at many gold operations in Western Australia in recent years. This success more than covers the perceived, but not proven, short fall from greenfield exploration.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":"56 1","pages":"1 - 2"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87324886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1080/22020586.2019.12073044
M. Sharlov, I. Buddo, Alexander Pisarnitskiy, N. Misurkeeva, I. Shelohov
Summary The transient electromagnetic method (TEM) survey was carried out within one of the private house area to allocate the fresh water reservoirs in Greece. There are two challenges that make the problem complex. The first is noisy settings for geophysical survey: populated area with power lines, pipes, houses etc. The second challenge is uncertainties with water-bearing reservoirs. According to geological settings and water-bearing reservoirs location, geophysical survey had to maintain penetration depth up to 250-300 m. For this task DC (direct current) methods are not applicable whereas induction electromagnetic sounding like Transient electromagnetic method (TEM) in the near field zone can show superior results. Therefore TEM survey was carried out. To ensure the high quality of TEM data the special algorithms of electromagnetic noise attenuation were applied. From TEM results it was found, that at a depth of about 180–280 m in the southeastern part of the study area, one can expect the presence of fresh water, and the resistance values are 80 Ω·m.
{"title":"Shallow transient electromagnetic method application for groundwater exploration: case study from Greece","authors":"M. Sharlov, I. Buddo, Alexander Pisarnitskiy, N. Misurkeeva, I. Shelohov","doi":"10.1080/22020586.2019.12073044","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073044","url":null,"abstract":"Summary The transient electromagnetic method (TEM) survey was carried out within one of the private house area to allocate the fresh water reservoirs in Greece. There are two challenges that make the problem complex. The first is noisy settings for geophysical survey: populated area with power lines, pipes, houses etc. The second challenge is uncertainties with water-bearing reservoirs. According to geological settings and water-bearing reservoirs location, geophysical survey had to maintain penetration depth up to 250-300 m. For this task DC (direct current) methods are not applicable whereas induction electromagnetic sounding like Transient electromagnetic method (TEM) in the near field zone can show superior results. Therefore TEM survey was carried out. To ensure the high quality of TEM data the special algorithms of electromagnetic noise attenuation were applied. From TEM results it was found, that at a depth of about 180–280 m in the southeastern part of the study area, one can expect the presence of fresh water, and the resistance values are 80 Ω·m.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":"68 1","pages":"1 - 5"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81271772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1080/22020586.2019.12073105
Cericia Martinez, J. Gunning, Juerg Hauser
Summary Probabilistic inversions of wide angle reflection and refraction data for crustal velocity models are regularly employed to understand the robustness of velocity models that can be inferred from these data. It is well understood that the uncertainties associated with the picks of individual arrivals contribute to overall model uncertainty. Typically only a modicum of effort is devoted to quantifying uncertainty in the traveltime picks; a constant noise estimate is commonly assigned to a given class of arrivals. Further, determining the class of arrivals is often left to the behest of the interpreter, contributing additional uncertainty to the data that is both difficult to quantify and may be altogether incorrect. Given the crucial role data uncertainty plays in characterising model robustness, there is a need to thoroughly and appropriately quantify uncertainty in the traveltime data which itself is inferred from the waveform. Here we propose a method that treats arrival or phase classification as part of the velocity model building (inversion) framework using the well-established expectation-maximization (EM) algorithm.
{"title":"Combining arrival classification and velocity model building using expectation-maximization","authors":"Cericia Martinez, J. Gunning, Juerg Hauser","doi":"10.1080/22020586.2019.12073105","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073105","url":null,"abstract":"Summary Probabilistic inversions of wide angle reflection and refraction data for crustal velocity models are regularly employed to understand the robustness of velocity models that can be inferred from these data. It is well understood that the uncertainties associated with the picks of individual arrivals contribute to overall model uncertainty. Typically only a modicum of effort is devoted to quantifying uncertainty in the traveltime picks; a constant noise estimate is commonly assigned to a given class of arrivals. Further, determining the class of arrivals is often left to the behest of the interpreter, contributing additional uncertainty to the data that is both difficult to quantify and may be altogether incorrect. Given the crucial role data uncertainty plays in characterising model robustness, there is a need to thoroughly and appropriately quantify uncertainty in the traveltime data which itself is inferred from the waveform. Here we propose a method that treats arrival or phase classification as part of the velocity model building (inversion) framework using the well-established expectation-maximization (EM) algorithm.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":"26 1","pages":"1 - 4"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84823794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1080/22020586.2019.12073184
Roshanak Vadoodi, Thorkild M Rasmussen, Maxim Yu Smirnov
Summary Broadband magnetotelluric data were recorded at 104 sites between 2015-2018 in northern Sweden to image the geoelectrical upper and lower crustal structures. Data processing was performed using a robust multi-remote reference technique. The dimensionality analysis of the phase tensors indicate complex 3D structures in the area. A 3D crustal model of the electrical conductivity structure was derived based on 3D inversion of the data. Processing of regional potential field data was performed and structural information derived from these data were compared with the 3D conductivity model. Locations of known mineralizations are compared to the regional geophysical data in order to investigate how the regional geophysical data can be used for better informed mineral exploration. The analyses indicate that regional geophysical can provide very useful information with respect to the prospectivity of different areas.
{"title":"Regional magnetotelluric and potential field data analyses related to mineral exploration of the Fennoscandian Shield, Sweden","authors":"Roshanak Vadoodi, Thorkild M Rasmussen, Maxim Yu Smirnov","doi":"10.1080/22020586.2019.12073184","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073184","url":null,"abstract":"Summary Broadband magnetotelluric data were recorded at 104 sites between 2015-2018 in northern Sweden to image the geoelectrical upper and lower crustal structures. Data processing was performed using a robust multi-remote reference technique. The dimensionality analysis of the phase tensors indicate complex 3D structures in the area. A 3D crustal model of the electrical conductivity structure was derived based on 3D inversion of the data. Processing of regional potential field data was performed and structural information derived from these data were compared with the 3D conductivity model. Locations of known mineralizations are compared to the regional geophysical data in order to investigate how the regional geophysical data can be used for better informed mineral exploration. The analyses indicate that regional geophysical can provide very useful information with respect to the prospectivity of different areas.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":"13 1","pages":"1 - 4"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84972825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1080/22020586.2019.12072947
Shuich Desaki, Yuki Kobayashi, Peter Miklavs
Summary In this study, we performed rock physics analysis and modelling in the Browse Basin, in which we analysed the relationships among elastic properties of end-member (EM) sandstone (SST) and EM-shale, and then, modelled the properties of non-EM-SST and non-EM-shale to simulate seismic amplitude responses at boundaries of realistic litho-facies. We found that the elastic properties of SST of the basin has similar trends to those in other basins; therefore, we adopted existing rock physics relationships with minor adjustments. On the other hand, it was found that the careful consideration of mineralogy and overpressure is required in the EM-shale trend analysis. The observed data was well defined by a semi-empirical rock physics model including the effect of the volume of clay (Vcl) variation and by an “Equivalent depth method” which accounts for overpressure. To express the elastic behaviour in mixed sand-clay systems, we adopted a “Triangular diagram model” and the established trends of defined EM facies. Simulated properties from this approach agree well with actual data from the Browse Basin.
{"title":"Statistical rock physics analysis and modelling in the Browse Basin","authors":"Shuich Desaki, Yuki Kobayashi, Peter Miklavs","doi":"10.1080/22020586.2019.12072947","DOIUrl":"https://doi.org/10.1080/22020586.2019.12072947","url":null,"abstract":"Summary In this study, we performed rock physics analysis and modelling in the Browse Basin, in which we analysed the relationships among elastic properties of end-member (EM) sandstone (SST) and EM-shale, and then, modelled the properties of non-EM-SST and non-EM-shale to simulate seismic amplitude responses at boundaries of realistic litho-facies. We found that the elastic properties of SST of the basin has similar trends to those in other basins; therefore, we adopted existing rock physics relationships with minor adjustments. On the other hand, it was found that the careful consideration of mineralogy and overpressure is required in the EM-shale trend analysis. The observed data was well defined by a semi-empirical rock physics model including the effect of the volume of clay (Vcl) variation and by an “Equivalent depth method” which accounts for overpressure. To express the elastic behaviour in mixed sand-clay systems, we adopted a “Triangular diagram model” and the established trends of defined EM facies. Simulated properties from this approach agree well with actual data from the Browse Basin.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":"14 1","pages":"1 - 6"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90539631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1080/22020586.2019.12073004
C. Dempsey, R. Benson, G. O’Halloran, O. Schenk, A. Karvelas, S. Tewari
Summary The Exmouth Sub-basin forms one of several Jurassic depocentres in the greater Carnarvon Basin and has been prolific in terms of hydrocarbon production with approximately 1 Bbbls of oil and over 1 Tcf of gas discovered/produced to date. The sub-basin was recently covered for the first time with a contiguous, high quality, deep-record 3D seismic survey that has enabled detailed structural and stratigraphic mapping over its full extent, providing new insights into the tectono-stratigraphic history of the area. These interpretations along with those incorporating the sub-basins thermal history and gross depositional environments were used to constrain an integrated petroleum systems model with the ultimate aim of representing hydrocarbon distribution and future exploration potential.
{"title":"New insights into the Exmouth Sub-basin: tectono-stratigraphic evolution","authors":"C. Dempsey, R. Benson, G. O’Halloran, O. Schenk, A. Karvelas, S. Tewari","doi":"10.1080/22020586.2019.12073004","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073004","url":null,"abstract":"Summary The Exmouth Sub-basin forms one of several Jurassic depocentres in the greater Carnarvon Basin and has been prolific in terms of hydrocarbon production with approximately 1 Bbbls of oil and over 1 Tcf of gas discovered/produced to date. The sub-basin was recently covered for the first time with a contiguous, high quality, deep-record 3D seismic survey that has enabled detailed structural and stratigraphic mapping over its full extent, providing new insights into the tectono-stratigraphic history of the area. These interpretations along with those incorporating the sub-basins thermal history and gross depositional environments were used to constrain an integrated petroleum systems model with the ultimate aim of representing hydrocarbon distribution and future exploration potential.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":"1 1","pages":"1 - 9"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89703843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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