Australian School of Petroleum

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https://hdl.handle.net/2440/84916
This collection contains Honours, Masters and Ph.D by coursework theses from University of Adelaide postgraduate students within the Australian School of Petroleum. The material has been approved as making a significant contribution to knowledge.

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Browsing Australian School of Petroleum by Advisors "Bunch, Mark"

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    A 3-D seismic interpretation of the Palaeo-Fluvial geomorphology of the off-shore Gippsland Basin utilising seismic attibutes
    (2015) Neden, Luke; Bunch, Mark; Australian School of Petroleum
    The stratigraphy of the offshore Gippsland Basin exhibits extensive channelization features which developed during periods of lowstand that lowered base level causing incision and sediment bypass. These features are well documented at shallow depths but deeper in the stratigraphy the extent and geometry are less well defined. Traditional structural traps in the basin are becoming depleted and these features represent possible new targets. Equally their presence where down-cut into sealing lithologies represent a risk to the seal integrity/capacity overlying potential reservoirs concerned with CO2 storage. Seismic attributes, specifically coherence (variance) and sweetness, are co-rendered and mapped on stratal slices of the Gippsland Megasurvey 3D seismic dataset to enhance seismic images and establish the extent and geometry of channelisation in the offshore Gippsland Basin. These findings may help to identify new targets and determine potential for greenhouse gas storage, as well as helping to account for seismic anomalies that have been responsible for the misplacement of drilling targets in the past.
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    Characterisation of carbonate cemented zones in the Paaratte Formation of the Victorian Otway Basin and Bass Megasequence of the Bass Basin using wireline log data
    (2014) Armener, Kapila J.M.; Daniel, Richard Francis; Bunch, Mark; Australian School of Petroleum
    The identification and modelling of carbonate cemented zones represents one of the many challenges facing the world leading Carbon Capture and Storage (CCS) CO2CRC Otway Project in Victoria. Carbonate cemented zones are low permeability dolomite-dominated zones that form at the meteoric-saline water interface within winnowed tidal bar sandstones deposited in deltaic-marginal marine environments. Successful identification of these zones from wireline log data requires the creation of empirical tools that combine statistical analysis with geological interpretation. The Mean-Probability Log and the Vshale Facies Log are two empirical tools that, when combined, can successfully identify carbonate cemented zones from well log data. The Mean-Probability Log is derived from available well data contained at CRC-2 which includes the CCA_20 log (Elemental Capture Spectroscopy) and CarbCmnt log (carbonate cemented zones prediction log). These logs, combined with conventional raw and derived logs (Gamma, Sonic, Neutron, Density, Shallow Resistivity, Deep Resistivity, and Ratio) were used to create binned distributions required for a probability distribution model. Probability values from the model were incorporated into individual carbonate cement predictions logs for each of the raw and derived logs. An average of these logs resulted in the creation of a carbonate cemented prediction Mean-Probability Log. Flexibility of the Mean-Probability Log revealed only a variance of 13 samples when compared to Mean-Probability Logs lacking one of the key logs (e.g. Gamma). Calculation of a statistically derived cutoff was incorporated using the mode, standard deviation and a fixed spread (variance). Creation of a Vshale Facies Log was undertaken to assist accuracy of the Mean-Probability Log in predicting carbonate cemented zones within winnowed sandstones. The facies component of the log was derived from reclassification of an existing core-derived facies log used at CRC-2, whilst the clay-content (Vcl) of the log was derived from an existing Petrolog algorithm used in the Darling Basin of NSW. A cutoff value for CRC-2 (Vcl value of 0.6) was established for sandstones that are hosts for known carbonate cemented zones. Both the Mean-Probability Log and the Vshale Facies Log were successfully applied to both selected Otway Basin (onshore and offshore) and Bass Basin wells. Carbonate cemented zone analysis revealed a total of 126 carbonate cemented zones in onshore Otway Basin, 53 in offshore Otway Basin, and 7 in the Bass Basin. Interpretation of carbonate cemented zone results revealed a decrease in thickness and increase in clay-content from the Port Campbell Embayment to Shipwreck Trough in the Otway Basin, and a localised accumulation along the Pelican and Dondu Troughs within the Bass Basin.
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    Detecting the occurrence of dolomite cemented zones in the Otway Gippsland Basins
    (2014) Al-Shukaili, Amira; Bunch, Mark; Daniel, Richard Francis; Australian School of Petroleum
    Dolomite cemented zones have been recognized in both Otway and Gipssland Basins. These cemented zones have significant effects on the reservoir performance as they can degrade or enhance reservoir sweep. The CO2CRC CO₂ sequestration project in Otway Basin may be affected by these carbonate cemented zones, where it has been detected in CRC-2 and CRC-1. Therefore, the aim of this project is to generate an empirical model using well log data to detect the dolomite cemented zones in the Otway and Gippsland Basins. To achieve this goal, log data have been analyzed to firstly create a motif of cemented zones in the on-shore lower Paaratte Formation of Otway Basin. Then, verify cemented zones in the Casino Field of the Shipwreck Trough (offshore Paaratte Formation). As a result, the dolomitisation interval motifs will be generated from Paaratte Formation of Otway Basin and will be used to detect the cemented zones in the Gippsland basin.
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    A regional study of the Toro and Imburu Formation aquifers in the Papuan Basin, Papua New Guinea.
    (2014) Hopwood, Blair; Bunch, Mark; Australian School of Petroleum
    This study represents a regional review of the Toro and Imburu Formation aquifers in the fold belt and foreland regions of the Papuan Basin, Papua New Guinea (PNG). This study extends previous Toro aquifer studies in the Papuan Basin (Eisenberg 1993; Eisenberg et al., 1994; Kotaka 1996). A comprehensive data set was assembled containing all currently available well formation fluid pressure, salinity and temperature data. These data were used to calculate hydraulic potential (Hw) values, which were subsequently used to generate a regional potentiometric map for the Toro Sandstone reservoir and semi-regional maps for the Digimu, Hedinia and Iagifu Sandstone reservoirs of the Imburu Formation. The Toro potentiometric surface map generated in this study is consistent with an extensive hydrodynamic Toro aquifer system existing in the Papuan Basin Fold Belt. The Toro aquifer likely flows northwest to southeast parallel to the fold belt, from the Lavani Valley Toro outcrop (likely recharge region) in the Highlands, through to the Kutubu Complex, potentially via Hides, (possibly Angore) and the Mananda/South East Mananda Fields. The evidence for Toro aquifer hydrodynamic flow is strongest through the Kutubu Complex of fields, with water flow, entering via Agogo and exiting the fold belt, at the southern end of the Usano Field into the foreland of the basin. However, it should be noted that gas water contacts (GWCs) for Hides and Angore Fields are not yet available. These have been estimated in this study from Hides and Angore gas pressure gradient intersections with water pressure gradients identified from nearby wells (Lavani-1 and Egele-1). Therefore it is not currently possible to unequivocally identify a connected Toro aquifer system between Lavani Valley, (possibly Angore) and Hides. Nevertheless, the Lavani Valley-Hides-Mananda/South East Mananda system (LV-H-M/SEM) represents the most likely flow path for a Toro hydrodynamic aquifer model in the fold belt. Evidence for hydrodynamic Toro aquifer flow was identified in the opposite direction, in a southeast to northwest direction, in the South East Hedinia Field. Significant compartmentalisation of the Toro reservoir was identified in several Hinterland Fields and anticline structures (Egele, Angore, Moran, and Paua Fields along with the Kutubu and Makas Anticlines) and in the southeast region of the central fold belt (Gobe/South East Gobe Fields). Likely Toro aquifer flow exit points from fold belt into foreland were identified at the southern end of Usano at Iorogabaui-1 and at southern end of South East Mananada Field at Libano-1 involving the Bosavi Lineament. Possible northwest to southeast Toro aquifer flow was identified in the foreland region of the basin from the Stanley Field in the northwest to the sea in the southeast. The Komewu and Darai Fault systems appear to operate as barriers to northeast to southwest Toro aquifer flow in the foreland. Considerably less data were obtained in this study for the Digimu, Hedinia, Iagifu Sandstone reservoir aquifers compared to the Toro reservoir unit. However, key findings include; (1) for the Digimu Sandstone, hydrostatic and compartmentalised aquifer behaviour in the Agogo, Hedinia/Iagifu and Moran Fields, (2) for the Hedinia Sandstone, hydrodynamic aquifer behaviour in the Hedinia/Iagifu and South East Hedinia Fields and (3) for the Iagifu Sandstone, hydrodynamic aquifer behavior in the Hedinia/Iagifu Fields, a significant Hw step between the Agogo and Hedinia/Iagifu Fields (not seen with any of the other reservoir sandstones) and a compartmentalised aquifer in the Gobe/South East Gobe Fields (where it acts as the main hydrocarbon reservoir). The updated regional data and potentiometric maps generated in this study will assist subregional and field scale modelling of the Toro and Imburu Formation aquifers, future hydrodynamic trapping studies and provide increased confidence for hydrocarbon reserve determination in the Papuan Basin Fields.