b'AEGC 2023Short abstractstectonics (subsidence/uplift) and eustasy, with variation inchanging pressure in psi from the well data, showing that our sediment supply, impacts deep-water sand delivery. Withinquantitative results are credible.this study clinothems are used to establish quantitative and statistical relationships between the shelf-margin architecture, palaeoshoreline processes, and deep-water system types (i.e.,Observation of vibroseis signature repeatability at the quantitative 3D seismic stratigraphy). In the Bight Basin on thesingle location.southern margin of Australia, the Hammerhead shelf margin prograded during the Late Cretaceous, following continentalValeriya Shulakova 1, Konstantin Tertyshnikov2, Pavel Shashkin2, rifting from Antarctica. This understudied interval offers anYevhen Kovalyshen1 and Roman Pevzner2opportunity to investigate controls on shelf-margin evolution1 CSIRO during the early post-rift phase. All available data (2D seismic2 Curtin Universitydata, 3D seismic data and well data) from the Ceduna Sub-basin have been integrated to investigate the controls on shelf-marginSource repeatability is one of the most important factors for architecture and factors affecting sediment delivery to deep- time-lapse seismic surveys or any survey that implies further water. Quantitative analyses of clinoform geometry are usedseismic amplitude analysis. The use of a distributes acoustic to calculate several parameters at 3rd order and 4th5th ordersensing (DAS) technology in downhole seismic measurements scales. Sixteen 3rd order seismic sequences and 28 4th5thallows observation of a far field signature of a single source order clinothems with an average duration of ~78 kyrs arelocation for the entire depth of the well with fibre-optic cable recognised. Four discrete phases of Hammerhead shelf-marginproviding high-density sampling of the seismic wavefield.evolution are identified with lateral variations in sediment supply proposed to be the main driver of shelf-margin variability. ThisIn order to analyse changes in a source signature we conducted interpretation suggests that after a major flooding event, the A/Sthe following field experiment. The seismic data were acquired ratio increased throughout the evolution of the Hammerheadin a vertical 900-m deep well using DAS system at the Curtin NGL shelf-margin, with a rapid decline in sediment supply in thetraining well in Perth, Western Australia. The fibre-optic cable in Maastrichtian causing backstepping of the shelf-edge. At higherthe well was connected to iDAS (Silixa) interrogator. The seismic resolution, fluvial-dominated coastlines are typically associatedwaves were generated by 26,000 lbs. vibroseis source placed 160 with steeper slope gradients and longer turbidite run-outm away from the well head and remained at the same location distance than wave-dominated coastlines in this depositonalduring the experiment. The vibe was set to produce 6-150 system. Results of this research may be applied to other basinsHz sweep signal of 24 s length with 0.5 s cosine tapers and 6s worldwide developed in similar tectonic and climatic settings. listening time. The peak force was set to 70%. We recorded several sets of 32 consecutive sweeps with variable time interval between the series (from 15 minutes to several hours).Monitoring of the producing reservoir pressure and saturation changes using extended elastic impedanceWe observe significant instability between the source signature both within the same sweep set and between the sets. In general, from time-lapse seismic data: enfield field, NW Australia. similarity between the records is decreasing with the increase of Sergey Shevchenko 1 Wayne Pennington2 the time lag between their acquisitions. In this presentation, we discuss magnitude of these changes and the potential causes.1 SIS-Exploration 2 Michigan Technological University, HoughtonThe nature of the Carpentaria Conductivity AnomalyThe Extended Elastic Impedance (EEI) concept has been used by the oil industry primarily for lithology and fluid prediction.Janelle Simpson and Dominic BrownWe present a method of reservoir monitoring that calculatesGeological Survey of Queenslandchanges in pressure and saturation in a producing reservoir by applying EEI to time-lapse seismic data. The method usesThe Carpentaria Conductivity Anomaly (CCA) is a significant time-lapse seismic difference data rotated to specific EEI conductivity anomaly in Queensland extending from the Gulf of angles which are optimised for the changes expected in aCarpentaria through to the Simpson Desert. The broad nature of given reservoir. One angle is found to be appropriate to identifythe CCA suggests an origin rooted in tectonic scale processes. The predicted changes in saturation, using fluid-substitution models,CCA is on the eastern edge of the Mount Isa Province, coincident while the other angle is found from rock-physics assumptions orwith the Gidyea Structure which marks the contact between laboratory measurements of fluid-pressure changes. the subsurface Numil terrane and the Mount Isa terrane. The endowment of copper within reach of the CCA is significant, Iron Our technique is tested using time-lapse seismic data for theOxide Copper Gold deposits hosted in the Eastern Succession are Enfield oil field, in the North West Shelf, Australia, with estimatesclustered in a belt within the hanging wall to the Gidyea Structure.of optimal EEI rotation anglesbased on log data and Biot-Gassmann modelling for the fluid changes, and on rock physicsThe Cloncurry and Cloncurry Extension MT surveys were carried models fit to measurements made on core samples for theout between 2016-2021 and collected 996 sites on a 2 km pressure changes. Seismic reflectivity and inversion domainsgrid. These data are located across the location of the Gidyea were used for comparison and analysis of the final rotatedStructure, mainly within the hanging wall. Three-dimensional volumes. We have chosen three polygons within the producingMT inversions were carried out on the full data array using field where we tested our model quantitatively. In the caseModEM on the NCI supercomputing infrastructure. Inversion study, the method successfully predicted the areas wheremodels contain a prominent linear conductor to the east of changes in pressure and/or saturation were expected, and did athe Gidyea Structure, several pipe-like conductors within the good job of separating the two properties. Our final calculatedresistive Mount Isa crust, and a belt of elevated conductivity pressure maps were successfully tested with two areas ofassociated with the Quamby Fault in the west. The conductivity 139 PREVIEW FEBRUARY 2023'