ASEG Extended Abstracts最新文献

{"title":"MinEx CRC - Exploration innovation through industry and researcher cooperation","authors":"A. Bailey, D. Giles","doi":"10.1080/22020586.2019.12073085","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073085","url":null,"abstract":"Summary Current declining mineral discovery rates mean fewer future mines. The Mineral Exploration Cooperative Research Centre (MinEx CRC) is a consortium of 36 Participants creating new opportunities for mineral discovery by delivering; 1) more productive, safer and environmentally friendly drilling methods; 2) new technologies for collecting data while drilling and; 3) exploration data on never before sampled rocks in Australia that are hidden but prospective for minerals. The innovative exploration outcomes through industry and researcher cooperation will also grow the high value Mining Equipment, Technology and Services (METS) sector.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90866913","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}

{"title":"Surface passive seismic monitoring by the local use of semblance","authors":"M. J. Khoshnavaz, A. Bόna, K. Chambers, H. Siahkoohi, Alireza Khoshnavaz","doi":"10.1080/22020586.2019.12073042","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073042","url":null,"abstract":"Summary Monitoring of passive seismic sources generated by mining activities and hydraulic fracturing has an important role in hazard analysis and in development of unconventional reservoirs. Surface arrays are vastly used in such monitoring scenarios with the advantage of wider spatial monitoring aperture, thus monitoring larger volumes over downhole arrays. However, signal-to-noise ratio of surface array records is naturally low. That makes application of coherency-based techniques an appropriate option for surface monitoring. Polarity variations corresponding to the source mechanism across the moveout curves/surfaces is a complicating task in the use of coherency-based monitoring methods to locate passive seismic events. To overcome this issue, we suggest a straight-forward approach that applies semblance, as a coherency analysis tool, on separate clusters of stations followed by averaging the results from all the clusters. To evaluate the performance of the suggested approach, we applied it on a semi-synthetic passive seismic data example generated from a reverse-oblique source and compared the result with the outcome from application of the classic coherency-based technique. It shows the ability of the suggested method to overcome polarity variations task, without conducting any polarity correction step.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91033774","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}

{"title":"Case studies on the application of passive seismic horizontal to vertical spectral ratio (HVSR) surveying for heavy mineral sand exploration","authors":"N. Cantwell, Matthew Owers, J. Meyers, Sharna Riley","doi":"10.1080/22020586.2019.12073142","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073142","url":null,"abstract":"Summary This study presents the results from several case studies on the application of passive seismic Horizontal to Vertical Spectral Ratio (HVSR) surveying methods for Heavy Mineral Sand (HMS) deposit subsurface layer detection for exploration and mining. The results from these case studies demonstrate the usefulness of this rapid and low cost survey method to complement HMS deposit mapping and its ability to provide additional stratigraphic information in gaps between drillholes. HMS deposits typically occur in geological settings that are ideal for the application of the passive seismic HVSR method, because HMS deposits are typically shallow and may demonstrate acoustic impedance contrasts relative to surrounding sedimentary deposits or underlying acoustic bedrock. Trial HVSR survey results vary between different styles of heavy mineral sand deposits, from providing a direct estimate of the depth to the top of known HMS mineralisation based on a positive HVSR response from more dense and higher velocity HMS lenses, to detecting parallel silt and clay horizons, sometimes producing an inverted HVSR response, to be used as a bounding marker horizons for HMS deposits, and in many cases detecting the acoustic hard rock basement forming the base to the unconsolidated, young sedimentary deposits and basin fill containing HMS layers. In each case study, the use of a lightweight, self-contained and simple to use seismometer has allowed HMS explorers to carry out surveys quickly and cost effectively, in some remote areas with difficult access, mostly using company field staff following a short training session. The techniques and approaches to process and model HVSR data for shallow stratigraphic mapping during these trial surveys have contributed to advancing the passive seismic HVSR surveying method to become more commonly used for large production surveys.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81909417","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}

{"title":"Managing uncertainty to deliver complex development wells","authors":"Peter J. van Ruth, M. Agarwal, Scott Gagen","doi":"10.1080/22020586.2019.12073106","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073106","url":null,"abstract":"Summary Managing seismic depth uncertainty is a key consideration in placing horizontal development wells into thin reservoir targets. Seismic depth uncertainty has the potential to erode project value through missed reservoir (late landing or reservoir exits) and/or the cost of corrective actions (e.g. sidetracks). The placement of Laverda Canyon development wells in 2018 utilised a 30 Hz full waveform inversion velocity model and deep directional resistivity data in combination with a near real-time depth update process to optimise well placement. Utilising these methods resulted in a significant reduction in seismic depth uncertainty which culminated in the final Laverda Canyon development well (LAV04WI) being successfully geosteered for ~ 2,200 m within a 10-15 m thick reservoir with only one reservoir exit.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84425481","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}

{"title":"Distortion of the Magnetic Field at Paragon Bore, South Australia","authors":"C. Foss, Blair McKenzie, L. Katona","doi":"10.1080/22020586.2019.12073126","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073126","url":null,"abstract":"Summary Magnetic field anomalies measured by the Gawler Craton Aeromagnetic Survey (GCAS) have revealed anomalies of amplitude > 18,000 nT over Paragon Bore. The flying height is 60 metres above ground and depth to basement is 150 metres below ground, so the causative basement sources clearly have magnetizations of extreme intensity. We apply an iterative processing of the GCAS TMI data to a vector-consistent TMI. This also supplies vector component grids which we downward continue to the ground surface and then transform to declination and inclination maps. We invert the measured TMI using a model of multiple ellipsoids to enable inclusion of substantial self-demagnetization effects. Vector components forward computed from the inversion model at ground level are also transformed to declination and inclination maps which closely match those derived from the filter transform. Deviations of declination and inclination about the regional values are -15° to +21° and -14° to +5° respectively. High magnetic susceptibility values reported from borehole intersections (up to 1.6 SI in 2 boreholes) are mostly associated with banded iron formation (BIF) and metasomatic magnetite-rich rocks. These values are about 1/3rd of the equivalent inversion model intersection susceptibilities. We suggest that this apparent discrepancy is due to self-demagnetization effects in the susceptibility measurements and the presence of substantial (possibly viscous) remanent magnetization.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89149664","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}

{"title":"Log dependent approach to predict reservoir facies and permeability in a complicated shaly sand reservoir","authors":"Abdelrahman Elkhateeb, R. Rezaee, A. Kadkhodaie","doi":"10.1080/22020586.2019.12072924","DOIUrl":"https://doi.org/10.1080/22020586.2019.12072924","url":null,"abstract":"Summary The prediction of facies and permeability in complicated reservoirs represents a major challenge that necessitates the usage of advanced statistical techniques. A new approach is presented in this paper to generate a log based continuous facies log and permeability index in the shaly sand of the Irwin River Coal Measures Formation. An integration between the density log and the NMR free fluid index has been carried out. This was done to establish a comprehensive electrofacies model and accommodate the large permeability variations. A new Reservoir Index, equivalent to the Flow Zone Indicator (FZI), has been calculated to allow a quantitative reservoir characterisation that includes facies and permeability independent of any core measurements. The modelled electrofacies and permeability from this analysis showed very effective results of high resolution. In order to calibrate the calculated permeability, the repeat formation tester mobility was used as a reference for the generated model. To further validate the results, the created models have been correlated with the core thin sections and core permeability. Four hydraulic flow units have been identified from the Reservoir Index, hence four different permeability models. From the log dependent results, an excellent match to the formation mobility has been achieved despite the reservoir heterogeneity. Furthermore, the outputs showed very encouraging results with the core data, upon which the methodology can be used in uncored wells. The workflow described in this paper shows a new methodology for reservoir characterisation through electric logs. The methodology allows an independent technique for rock typing in the absence of any core data. Regardless of the degree of the reservoir heterogeneity, a high-resolution facies and permeability index can be generated for advanced formation evaluation.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89176314","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}

{"title":"Green’s function retrieval from deterministic seismic wavefield using higher-order cross-correlation","authors":"Yunfeng Chen, E. Saygin","doi":"10.1080/22020586.2019.12072929","DOIUrl":"https://doi.org/10.1080/22020586.2019.12072929","url":null,"abstract":"Summary Seismic interferometry, commonly known as empirical Green’s function retrieval in seismology, has been widely applied to extract the impulse response of Earth. The conventional approach based on cross-correlation of long-term ambient seismic wavefield relies on the simultaneous recording of noise signals at seismic receivers. Recent studies have demonstrated observationally that the correlation of coda of (ambient noise) cross-correlation function (C3) enables the reconstruction of inter-station Green’s function regardless of the operating time (i.e., synchronous or asynchronous) of stations. Here we extend the C3 scheme to a more general framework that involves the correlation of cross-correlation function (C2). This new approach exploits the deterministic energy of the wavefield and is more robust than C3 that may suffer from incoherent coda wave energy due to less ideal (e.g., sparse, noisy, short duration) network configurations. We apply this technique to the recently deployed ALFREX seismic network in southwestern Australia. We show that the Green’s function between asynchronous stations can be robustly recovered using the C2 approach whereas this is not feasible from C3. The proposed technique can effectively bridge the temporal gaps between temporary networks and demonstrate great potential for improving the spatial coverage of data and resolution in seismic imaging of crustal structures.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89324199","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}

{"title":"Which anomaly should I drill? Using spatial statistics to inform exploration in covered IOCG terranes","authors":"L. Katona, A. Fabris","doi":"10.1080/22020586.2019.12073053","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073053","url":null,"abstract":"Summary This contribution presents a method for efficiently classifying geophysical anomalies and identifying regions and features that share characteristics of many known iron-oxide-copper-gold (IOCG) deposits of the Gawler Craton, and can therefore be used in drill target prioritization. Residual Bouguer gravity and reduced-to-pole total magnetic intensity grids over the Gawler Craton were transformed, generating polygon datasets representing populations of locally anomalous gravity and magnetic intensity. Taken as simple anomaly polygons, there are a very large number of features across the Gawler Craton (>39,000 TMI and >10,000 gravity). Superimposing mineral deposits over these features shows a clear spatial correlation between IOCG deposits and occurrences, and anomalies (>90% of deposits within 1,000 m of an anomaly), but leaves thousands of anomalies of varying magnitudes that cannot all be related to IOCG mineralization. Eliminating TMI and gravity anomalies with a separation of more than 1,000 m reduced the search space to ~20,000 TMI features and ~8,500 gravity features. Limiting the search to a statistically derived gravity threshold ≥0.4 mGal gravity anomalies, the exploration space is reduced to 798 gravity features with coincident TMI features within the Olympic Copper-Gold Province. The Anselin Local Morans I method was used to delineate geographic regions based upon spatial clustering of high magnitude anomalies. The spatial distribution and clustering characteristics of the gravity anomalies provide additional information and can be related to differing basement geology and deposit style. Terranes where lithologies and Cu-Au occurrences are commonly magnetite-rich show clustered high-magnitude gravity anomalies, and correlated spatially with the Mount Woods and Moonta domains within the eastern Gawler Craton. Importantly, it was found that the central, and currently most endowed, the Olympic Domain, was distinct in that it was dominated by spatial outliers (discrete high-magnitude density features). These results could be used as a starting point in developing IOCG exploration strategies, due to the high number of additional untested, spatially coincident gravity and magnetic anomalies that warrant further investigation.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88526399","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}

{"title":"Developing the Butcherbird high purity manganese project","authors":"Justin Brown","doi":"10.1080/22020586.2019.12073238","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073238","url":null,"abstract":"Summary Element 25 Limited is developing the Butcherbird High Purity Manganese Project located approximately 130km south of Newman in the Pilbara region of Western Australia. The project hosts Australia’s largest onshore manganese deposit containing 263 Mt grading 10% manganese. The ore occurs as multiple supergene deposits which are the product of weathering of a regionally extensive basal shallow marine manganiferous shale. The resource was defined with a combination of airborne TEM, mapping and drilling. Significant exploration upside remains to expand the known resources. Element 25 is undertaking a Pre-Feasibility on the development of the Butcherbird Project using a hydrometallurgical flowsheet to produce high purity manganese metal and battery grade manganese sulphate. The production of manganese metal using electrowinning requires significant electricity. The project will likely use a combination of gas generation from the goldfields gas pipeline which crosses the project and renewable energy generation using wind and solar. The project will be an Australian first in terms of downstream processing of manganese metal and sulphate.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88974985","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}

{"title":"A multi-disciplinary approach for defining nickel and gold mineral systems; Halls Creek Orogen, Western Australia","authors":"F. Kohanpour, S. Occhipinti, M. Lindsay, W. Gorczyk","doi":"10.1080/22020586.2019.12072939","DOIUrl":"https://doi.org/10.1080/22020586.2019.12072939","url":null,"abstract":"Summary Geodynamic models, geological-geophysical interpretations, and isotope analysis illustrate that there are links between the nickel and gold mineral systems in the Halls Creek Orogen, Western Australia. Whole-rock Nd and Ar-Ar analysis of rocks throughout the region, when compared with the geodynamic models suggest that nickel and gold mineralization in the Halls Creek Orogen can be related to basin development and subsequent basin closure during the convergence of North Australian Craton and Kimberley Craton, respectively. Whole-rock Nd analysis confirmed the input of juvenile melts in the centre of the orogen before the 1835-1805 Ma Halls Creek Orogeny, supporting the upwelling of decompression mantle melts during the basin development. These analyses also revealed the spatial links between nickel and gold mineralization and lithological units with positive εNd values. The results of geodynamic models, geophysical interpretation, and isotopic analysis are used to understand the critical processes in the gold and nickel mineralization, which are presented by predictor maps. The GIS-based knowledge-driven fuzzy method used to integrate the predictor maps and create the prospectivity maps. Herein we show that mafic-ultramafic units prospective for nickel mineralization formed by upwelling of decompression mantle melt during crustal thinning and extension during basin development, and typically consist of the most juvenile magmas in the region. Whereas, gold deposits formed during the compressional regime and basin closure, and are located along a major shear zone separating two terranes. Another critical element that appears to be related to gold prospectivity is the presence of lithologies with a juvenile signature. In contrast to nickel analyses which are closely related to mafic-ultramafic units, the source component seems less influential when attempting to target orogenic gold deposits.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89457817","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}