Moyra Wilson - Academia.edu (original) (raw)
Papers by Moyra Wilson
ASEG Extended Abstracts, 2019
Logging data are measurements of physical properties of the formation surrounding a borehole, acq... more Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.
In order to investigate the effect that rock texture and fracturing has on the petrophysical prop... more In order to investigate the effect that rock texture and fracturing has on the petrophysical properties of carbonates, an outcrop study has been designed to record facies, degree of diagenesis, style and amount of faulting and fracturing, and sampling to obtain porosity, permeability, Vp and Vs measurements in the laboratory. Oligo-Miocene carbonates cropping out on the island of Malta in the Mediterranean, were chosen because of their geological simplicity and limited degree of diagenesis. In this way it is hoped that the effects of initial facies on the pore systems and the faulting and fracture style and intensity can be identified and measured at outcrop and, using Effective Medium Theory, predicted in the subsurface.
Proc. Indonesian petrol. Assoc., 39th Ann. Conv.
Oligocene carbonate plays in the Upper Kutai Basin are under-explored, with exploration historica... more Oligocene carbonate plays in the Upper Kutai Basin are under-explored, with exploration historically focusing on the Miocene deltaic and turbidite plays. These carbonates mainly consist of the Berai Formation which outcrops along the southern basin margin, and is seismically imaged in the subsurface, forming on isolated basement highs and large platform areas.
The depositional and diagenetic controls on carbonate platform evolution are notoriously heteroge... more The depositional and diagenetic controls on carbonate platform evolution are notoriously heterogeneous and difficult to determine from standard subsurface wireline logging techniques. Here, a combined borehole image (FMI-Fullbore Formation MicroImager), and petrographic study allowed evaluation of depositional and diagenetic trends across an Australasian subsurface buildup that is a major recent gas discovery. The Elk and Antelope gas fields are hosted in Tertiary reefal, platformal and associated deepwater carbonates in the present day foothills region of the Fold and Thrust Belt in the Gulf Province of Papua New Guinea. A full suite of FMI logs (> 2800 m), and 292 thin sections (mainly from sidewall cores and cuttings) from both platform flank and shallow water deposits were evaluated during this study. Despite the obvious scale differences between the datasets there was some correlation between the independent petrography and FMI studies for: a) picking major facies boundaries, and b) interpretation of depositional environments, the latter particularly for slope and deep water deposits. However, thin section petrography proved critical in understanding primary depositional textures and secondary alteration features through the shallow-water carbonates where complex diagenetic overprinting had strongly impacted original fabric, and/or in regions affected by "gas smearing". The petrographic study allowed more detailed examination of diagenesis and its impact on rock fabric (which links to the FMI textures). Component analysis and depositional textures identified in thin section are good indicators of original depositional environment. Full FMI coverage allowed textural definition on a dm/m scale, identification and characterisation of vertical changes, and likely largescale variations in depositional environments and sequences. It was clear from combining the results of the two studies that diagenesis as well as depositional fabric had a strong impact on resultant FMI facies. The diagenetic overprinting would have been difficult to extract from the FMI data without the benefit of the petrographic work. This study shows the merits of selective petrographic analysis to calibrate the quality of facies interpretation from FMI images, and proved critical for enhancing and in places revising initial FMI interpretations.
Proc. Indon Petrol. Assoc., 25th Ann. Conv.
Proc. Indon Petrol. Assoc., 32nd Ann. Conv.
Proc. Indon Petrol. Assoc., 33rd Ann. Conv.
Proc. Indon Petrol. Assoc., 32nd Ann. Conv.
The APPEA Journal
There are limited studies characterising the Willespie Formation, a Permian tight gas sandstone i... more There are limited studies characterising the Willespie Formation, a Permian tight gas sandstone in the southern Perth Basin of Western Australia. Consequently, the main factors controlling the reservoir quality, lateral reservoir connectivity and fluid flow mechanism remain unknown. Available data from five Whicher Range wells—including wireline logs, seismic, core data, well reports and petrographic data—were studied to define the syn-depositional and post-depositional events affecting the reservoir rock quality. Based on analysis of the aforementioned data, the Willespie Formation is interpreted to have been deposited under predominantly fluvial conditions in an ancient rift basin of continental origin with no marine influence. The sedimentary environments were laterally varied, as inferred from discontinuous facies formed by meandering channels, crevasse splay and flood plain settings that were mainly controlled by the Permian tectonic setting. Extensive compaction due to ductile...
Geological Society, London, Special Publications, 2014
ASEG Extended Abstracts, 2019
Logging data are measurements of physical properties of the formation surrounding a borehole, acq... more Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.
In order to investigate the effect that rock texture and fracturing has on the petrophysical prop... more In order to investigate the effect that rock texture and fracturing has on the petrophysical properties of carbonates, an outcrop study has been designed to record facies, degree of diagenesis, style and amount of faulting and fracturing, and sampling to obtain porosity, permeability, Vp and Vs measurements in the laboratory. Oligo-Miocene carbonates cropping out on the island of Malta in the Mediterranean, were chosen because of their geological simplicity and limited degree of diagenesis. In this way it is hoped that the effects of initial facies on the pore systems and the faulting and fracture style and intensity can be identified and measured at outcrop and, using Effective Medium Theory, predicted in the subsurface.
Proc. Indonesian petrol. Assoc., 39th Ann. Conv.
Oligocene carbonate plays in the Upper Kutai Basin are under-explored, with exploration historica... more Oligocene carbonate plays in the Upper Kutai Basin are under-explored, with exploration historically focusing on the Miocene deltaic and turbidite plays. These carbonates mainly consist of the Berai Formation which outcrops along the southern basin margin, and is seismically imaged in the subsurface, forming on isolated basement highs and large platform areas.
The depositional and diagenetic controls on carbonate platform evolution are notoriously heteroge... more The depositional and diagenetic controls on carbonate platform evolution are notoriously heterogeneous and difficult to determine from standard subsurface wireline logging techniques. Here, a combined borehole image (FMI-Fullbore Formation MicroImager), and petrographic study allowed evaluation of depositional and diagenetic trends across an Australasian subsurface buildup that is a major recent gas discovery. The Elk and Antelope gas fields are hosted in Tertiary reefal, platformal and associated deepwater carbonates in the present day foothills region of the Fold and Thrust Belt in the Gulf Province of Papua New Guinea. A full suite of FMI logs (> 2800 m), and 292 thin sections (mainly from sidewall cores and cuttings) from both platform flank and shallow water deposits were evaluated during this study. Despite the obvious scale differences between the datasets there was some correlation between the independent petrography and FMI studies for: a) picking major facies boundaries, and b) interpretation of depositional environments, the latter particularly for slope and deep water deposits. However, thin section petrography proved critical in understanding primary depositional textures and secondary alteration features through the shallow-water carbonates where complex diagenetic overprinting had strongly impacted original fabric, and/or in regions affected by "gas smearing". The petrographic study allowed more detailed examination of diagenesis and its impact on rock fabric (which links to the FMI textures). Component analysis and depositional textures identified in thin section are good indicators of original depositional environment. Full FMI coverage allowed textural definition on a dm/m scale, identification and characterisation of vertical changes, and likely largescale variations in depositional environments and sequences. It was clear from combining the results of the two studies that diagenesis as well as depositional fabric had a strong impact on resultant FMI facies. The diagenetic overprinting would have been difficult to extract from the FMI data without the benefit of the petrographic work. This study shows the merits of selective petrographic analysis to calibrate the quality of facies interpretation from FMI images, and proved critical for enhancing and in places revising initial FMI interpretations.
Proc. Indon Petrol. Assoc., 25th Ann. Conv.
Proc. Indon Petrol. Assoc., 32nd Ann. Conv.
Proc. Indon Petrol. Assoc., 33rd Ann. Conv.
Proc. Indon Petrol. Assoc., 32nd Ann. Conv.
The APPEA Journal
There are limited studies characterising the Willespie Formation, a Permian tight gas sandstone i... more There are limited studies characterising the Willespie Formation, a Permian tight gas sandstone in the southern Perth Basin of Western Australia. Consequently, the main factors controlling the reservoir quality, lateral reservoir connectivity and fluid flow mechanism remain unknown. Available data from five Whicher Range wells—including wireline logs, seismic, core data, well reports and petrographic data—were studied to define the syn-depositional and post-depositional events affecting the reservoir rock quality. Based on analysis of the aforementioned data, the Willespie Formation is interpreted to have been deposited under predominantly fluvial conditions in an ancient rift basin of continental origin with no marine influence. The sedimentary environments were laterally varied, as inferred from discontinuous facies formed by meandering channels, crevasse splay and flood plain settings that were mainly controlled by the Permian tectonic setting. Extensive compaction due to ductile...
Geological Society, London, Special Publications, 2014