Program Agenda - Geoscience

Geoscience

Wednesday, May 22, 2024

12:45 PM - 1:45 PM

The Exhibition

Overview

Take the opportunity to meet and network with the minds behind the visual presentations during this session. The Technical & Business Program Visual Presentations can be viewed in the Exhibition Hall during the Australian Energy Producers Conference & Exhibition. All visual presentations, plus their accompanying Peer-reviewed Papers or Extended Abstracts will be included in The Australian Energy Producers Journal (2024) and Supplements.

Presentations

Source rocks of the Birrindudu Basin: perspectives from a new sampling program
Grace Butcher*, Emmanuelle Grosjean & Tehani Palu (Geoscience Australia), Padmasiri Ranasinghe (Energy Resources Consulting), Richard Kempton & Siyumini Perera (CSIRO)
Exploration Potential of Papua New Guinea – Latest MultiClient 3D provides new insight into the Underexplored Papuan Basin over the Papuan and Eastern Plateaus
Tad Choi* (Petroleum Geo-Services Australia), Jens Beenfeldt & Marcin Przywara (Petroleum Geo-services)
From raw seismic data to quantitative interpretation via cloud-based FWI
Henry Debens* (Woodside Energy Ltd)
Petroleum Systems Analysis of the Onshore Otway Basin, South Australia
Casey Edwards* (Source Geoscience), Tim Rady (geomorph), Chris Cubitt, Rob Kirk & Sharon Tiainen (South Australia Department for Energy and Mining)
Chemostratigraphy of the Sherbrook Supersequence – 13 wells from the Offshore Otway Basin
Merrie-Ellen Gunning* & Duy Nguyen (Geoscience Australia), David Riley, Clare Tansell & Giada Bufarale (Chemostrat)
Thermochronological constraints on the tectonic history of the Polda Basin
Simon Holford* (The University of Adelaide), Ian Duddy & Paul Green (Geotrack International Pty Ltd), Richard Hillis, Martyn Stoker (The University of Adelaide)
Development of a novel seismic acquisition system based on fully autonomous ocean bottom nodes
Fabio Mancini* & Ben Hollings (Blue Ocean Seismic Services), Ted Manning (bp), Henry Debens (Woodside Energy Ltd)
Shipwreck and Sherbrook Supersequence Regional Gross Depositional Environments, offshore Otway Basin
Stephen Abbott (Geoscience Australia), Chris Cubitt (South Australia Department for Energy and Mining), George Bernardel, Chris Nicholson* & Duy Nguyen (Geoscience Australia)
The central and southeast offshore Otway Basin well folio
Duy Nguyen (Geoscience Australia), Chris Cubitt (South Australia Department for Energy and Mining), Dianne Edwards, Stephen Abbott & George Bernardel (Geoscience Australia), (Presented by Chris Nicholson* (Geoscience Australia))
Variation of vertical stress in the MacArthur and Beetaloo basins
Rasoul Ranjbarkarami*, Mojtaba Rajabi & Parisa Tavoosiiraj (The University of Queensland)
Real-time Chemostratigraphy at Wellsite; removing drilling uncertainties
David Riley*, Morven Davidson & Tim Pearce (Chemostrat), Alex Fuerst & Jordan Kinsley (Chemostrat Australia)
Evergreening of seismic data to enable carbon storage screening at scale - a case study from the Barrow-Dampier sub basins
Nigel Seymour* (SLB), Paul Phythian (Chevron Australia), Merrie-Ellen Gunning (Geoscience Australia), Kiran Ferguson (SLB), Suyang Chen & Dayang Aini Awang Piut (SLB WTA Malaysia Sdn Bhd)
Unconventional hydrocarbon prospectivity of the Paleoproterozoic Fraynes Formation in Manbulloo S1, Northern Territory
Liuqi Wang*, Adam Bailey, Emmanuelle Grosjean, Tehani Palu, Chris Carson, Lidena Carr, Jade Anderson, Grace Butcher, Chris Southby & Paul Henson (Geoscience Australia)
A speculative ridge within the Kidson Sub-basin – integrated interpretation from geophysical data
Yijie (Alex) Zhan* (Geological Survey of Western Australia)

Speakers

Mrs Grace Butcher

Senior Geospatial Specialit

Geoscience Australia

Source rocks of the Birrindudu Basin: perspectives from a new sampling program

Abstract

The Birrindudu Basin is a region of focus for the second phase of the Geoscience Australia’s Exploring for the Future (EFTF) program (2020–2024). The Paleo to Mesoproterozoic Birrindudu Basin is an underexplored frontier basin located in northwestern Northern Territory and northeastern Western Australia. Interpretation of industry seismic data indicates it contains strata of similar age to the prospective McArthur Basin, South Nicholson region and Mount Isa Province, but remains comparatively poorly understood. Furthermore, much of the age of the stratigraphy of the Birrindudu Basin, particularly the younger stratigraphic units, and regional correlations to the greater McArthur Basin remains provisional and speculative.
A comprehensive suite of analysis has been undertaken on rock samples from 99VRNTGSDD1, 99VRNTGSDD2, ANT003, LBD2, LMDH4, WLMB001B drill holes to help provide an improved understanding of the source rocks, their potential and oil migration in the basin. In total 130 samples were analysed for organic petrology, enabling us to discern the composition of organic matter, assess their relative abundances, and gauge the thermal maturity of the sedimentary organic material by analysing the reflectance of organoclasts. This was complemented by Rock-Eval pyrolysis on 178 samples which aids in evaluating their source rock potential. Finally, 46 samples were analysed with CSIRO’s Grains with Oil Inclusions (GOI™) and frequency of oil inclusion (FOI) methods, which identify ‘hidden’ oil shows and provide an assessment of palaeo-oil saturation. Results show that oil was once present in the basin, demonstrating generation and migration elements of a petroleum system.

Biography

Grace Butcher is a Geologist at Geoscience Australia. She Graduated with a BSc (Hons) in 2010 from the School of Earth and Environment at the University of Leeds. Working with the Onshore Energy Systems team at Geoscience Australia. Grace is currently working on the flagship Exploring for the Future Program in Northern Australia.

Dr Tad Choi

Sales & New Ventures Manager, Asia-pacific

PGS

Exploration Potential of Papua New Guinea – Latest MultiClient 3D provides new insight into the Underexplored Papuan Basin over the Papuan and Eastern Plateaus

Abstract

The Gulf of Papua, part of the regional Papuan Basin is characterized by extensional to passive tectonics from the Triassic to Late Oligocene and collisional tectonics from the Late Oligocene until the present day. The basin has undergone rapid clastic deposition in recent epochs, that covers an extensive carbonate shelf with local bioherms and associated carbonate facies which developed in the Miocene. Underlying the carbonates, an array of deformed and complex rift basins are present, with potential petroleum plays in undifferentiated Mesozoic sediments which onlap basement highs.
The Miocene carbonates are the primary exploration targets, along with Pliocene clastic turbidite sediments in the Gulf of Papua. These were charged by presumably Mesozoic marine – deltaic/terrestrial source rocks that were deposited during the opening of the Coral Sea. The offshore Papuan Basin is underexplored and the onshore Aure Fold Belt and offshore Fly River Platform – Gulf of Papua play types could potentially extend offshore into the Coral Sea area.
New broadband PSDM seismic data covering a part of the Eastern and Papuan Plateaus reveal new insight into the structural development of the region, rift basin geometries, configuration, and association of rift clastics and post-rift carbonates. Internal carbonate features can be observed on the new seismic data set, and new plays and traps established in the yet undifferentiated rift sediments of Mesozoic age are proposed in this study.

Biography

Tad has over 2 decades of experience in the oil and gas industry, working primarily in the Asia-Pacific region. He started his career in 2002 at Woodside Energy, where he spent 10 years in Exploration then he joined PGS as a Principal Geoscientist in Singapore in 2012. He has been with PGS now for nearly 12 years and was based in KL between 2016-2022. He is currently the Sales and New Ventures Manager for Asia-Pacific based in Perth. He holds a Master’s and a PhD degree in geology from Niigata University, Japan.

Dr Henry Debens

Geophysicist

Woodside Energy

From raw seismic data to quantitative interpretation via cloud-based FWI

Abstract

Full-waveform inversion (FWI) has evolved in recent years from a technique for recovering long- to intermediate-wavelength updates of acoustic overburden velocities, as part of a broader model building workflow, to a standalone tool for high-fidelity seismic imaging using raw seismic data – with ever greater resolution and ever more sophisticated physics being sought. In doing so, it has moved notably closer to fulfilling the vision of its original inventors in the late 70s and early 80s.
In this work, several novel approaches to FWI and its deployment are considered. The first of these allows for the estimation of elastic amplitude-versus-angle behaviour while still using an acoustic wave equation, thereby mitigating the significant computational burden associated with elastic FWI. The second allows for the quantification of residual kinematic errors during FWI via the provision of a metric that can be considered comparable to common-image-point gathers. The third allows for robust long-wavelength updates to be generated from raw seismic data in the absence of diving wave energy, providing reliable estimates of velocity at depths equivalent to or greater than the longest offsets available in the data – thereby enabling more-effective imaging with data of limited quality. Finally, it is demonstrated that these approaches can be deployed in a reliable and cost-effective manner via the considered use of public cloud resources, with learnings relevant for most massively parallel scientific applications.
Case studies from several environments around the world are provided for discussion, with a focus on deep- and shallow-water regions offshore Western Australia.

Biography

Henry has been working as a Geophysicist in the Technology & Innovation group at Woodside Energy since 2016, joining Woodside after completing an M.Sci. in geophysics and Ph.D. in petroleum geophysics at Imperial College London. Henry’s work involves all aspects of the seismic data life cycle but chiefly concerns the development and application of novel approaches to seismic imaging and inversion.

Ms Casey Edwards

Managing Director

Source Geoscience

Petroleum Systems Analysis of the Onshore Otway Basin, South Australia

Abstract

An updated Petroleum Systems Model was built for the South Australian portion of the onshore Otway Basin, incorporating new seismic interpretation and detailed seismic stratigraphy along with a recent chemostratigraphy study. The Area of Interest (AOI) for the study included 74 wells, five commercial gas fields and two non-commercial oil occurrences. The Otway Basin is a divergent passive continental margin, divided into northern and southern parts by the northwest trending Tartwaup Hinge. In the South Australian portion of the Onshore Otway Basin, the Penola Trough is the most significant hydrocarbon province to date. A revision of the existing geochemistry database, seismic stratigraphy and source rock model development indicates potential good quality, liquids prone lacustrine source rocks are present in the Jurassic Casterton Formation, (Chemostratigraphy zone S0-P5) and the Early Cretaceous Lower Sawpit Shale, (S1-P1/S1-P2). Poorer quality, gas prone source rocks are likely to be present in the Valanginian Upper Sawpit Shale (S1-P4/S1-P5) and Hauterivian Laira Formation (S1-P6 to S1-P10). 1D well and map based modelling undertaken using the Zetaware software suite suggests the majority of liquid hydrocarbons were generated and expelled from the Lower Sawpit Shale between 126 and 70Ma, with the greatest volume sourced from the Penola and Robe Troughs. Gas and condensate expulsion also took place from the Upper and Lower Sawpit Shale in the Penola and Robe Troughs, with expulsion complete by around 30Ma. Gas is modelled to have been generated and expelled from the Laira Formation in the Tantanoola Trough, between 100Ma and present day.

Biography

Graduating with a BSc in Geology (hons) from UNSW, Casey has over 19 years experience in the oil and gas industry. She began her career in Sydney with Oilsearch, and after relocating to Perth in 2005, spent several years as both a senior and principal geoscientist with the consulting firms ECL Australia and RPS Group. During this time she specialised in petroleum systems analysis (PSA) for conventional and unconventional systems, working for a wide range of clients in basins throughout the world. In 2014 Casey started Source Geoscience Pty Ltd, a consultancy providing tailored technical solutions to petroleum system problems. Projects to date have included PSA, geothermal, unconventional and geologic modelling work in most Australian basins and multiple international basins, for small, medium and large private companies and government organisations.

Ms Merrie-Ellen Gunning

Director

Geoscience Australia

Chemostratigraphy of the Sherbrook Supersequence – 13 wells from the Offshore Otway Basin

Abstract

An elemental chemostratigraphic study of the offshore Otway basin has been undertaken as part of a collaboration between Chemostrat and Geoscience Australia (GA). The main aim of which is to better constrain the sequence boundaries of, and within, the Sherbrook Supersequence.
This comprehensive study includes the elemental analysis of 1185 cuttings samples from the Sherbrook Supersequence (and overlying stratigraphy) in 13 wells, located offshore Otway Basin. Sampling of cuttings for this project was particularly challenging as many of the targeted wells have a paucity of material available for destructive analysis. Lithological and well log interpretation in the basin is often inadequate for constraint of sequence boundaries. Nonetheless the use of Inductively Coupled Plasma-Optical Emission Spectrometry and Mass Spectrometry (ICP-OES and MS) analysis was undertaken to complete a regional elemental chemostratigraphic study of the Sherbrook Supersequence, Otway Basin.
The resultant chemostratigraphic framework, with nomenclature adapted from Forbes et al (2020) comprises of two chemostratigraphic sequences, eight chemostratigraphic packages and seventeen chemostratigraphic units. It is important to note that in some wells the chemostratigraphic correlation differs extensively from the lithostratigraphy, highlighting areas for closer examination.
From the 13 wells analysed at least three, Crayfish-1A, Copa-1 and Breaksea Reef-1, indicate necessary changes to markers for LC2 (base Sherbrook). Additionally, within the Sherbrook Supersequence, there is scope for correlation between wells despite their separation, and seismic ties can now be better constrained.

Biography

Merrie-Ellen Gunning has over 20 years of experience in the Oil and Gas industry where she has performed a diverse range of roles from strategic planning, business development and operations management, to technical roles specialising in geophysics and exploration. Added to this is 5 years of experience in the Aluminium industry across the value chain from extraction, mining bauxite and nepheline, through refining Alumina to smelting. In addition to her extensive knowledge of industry in Australia her experience has included postings to Indonesia, Norway, the US, Russia and Singapore, and overseeing operations across the world. She has an MBA from Melbourne Business School and a Bachelor of Applied Science in Geology. Merrie-Ellen joined Geoscience Australia in August 2015 and has worked on a wide range of prospectivity and CO2 storage projects, leading the Energy Systems Branch throughout 2017 and is currently Director of Offshore Energy Systems.

Prof Simon Holford

SA State Chair of Petroleum Geoscience

The University of Adelaide

Thermochronological constraints on the tectonic history of the Polda Basin

Abstract

The Polda Basin is a narrow (~25 km wide), east-west striking intracontinental basin that extends ~350 km from the onshore Eyre Peninsula in South Australia to the offshore Great Australian Bight and contains up to 5 km of strata, with a thick sequence of Neoproterozic sedimentary and volcanic rocks overlain by unconformably-bound sequences of Carboniferous-Permian, Upper Jurassic and Cenozoic strata. Though the Polda Basin has witnessed limited exploration for hydrocarbons, it is attracting renewed interest due to the potential for underground hydrogen storage in thick halite accumulations in the Neoproterozoic Kilroo Formation, whilst surrounding regions of the Gawler Craton are considered prospective for natural hydrogen. To date however, knowledge of the tectonic history of the Polda Basin, which is critical to assessing its potential role in the energy transition, is limited. This study presents thermal history data (apatite fission track analysis and vitrinite reflectance) from both outcrop samples and onshore and offshore boreholes, which provide insights into the burial and exhumation history of the Polda Basin. Our results indicate that the preserved Upper Jurassic sequence was formerly considerably thicker prior to late Cretaceous exhumation, which may have supplied sediment to the adjacent Ceduna sub-basin. Our results highlight a complex history of Phanerozoic vertical motions in this region, and we consider the implications of the tectonic episodes revealed by our results for the resource and energy storage potential of the Polda Basin.

Biography

Professor Simon Holford is South Australian State Chair of Petroleum Geoscience in the Discipline of Earth Sciences, University of Adelaide. Simon has published ~100 papers on the prospectivity and tectonics of rifted margins, petroleum geomechanics and magmatism in basins. Simon has successfully supervised ~15 PhD students and ~60 Honours and Masters students. Simon has a PhD from the University of Birmingham and a BSc(Hons) from Keele University. Simon has won multiple awards, including Best Paper prizes at APPEA 2012 and AEGC 2019, Best Extended Abstract at APPEA 2021 and the Geological Society of Australia’s Walter Howchin and ES Hills medals.

Dr Fabio Mancini

Chief Geophysicist

Blue Ocean Seismic Services

Development of a novel seismic acquisition system based on fully autonomous ocean bottom nodes

Abstract

It is now established that Ocean Bottom Nodes (OBNs) provide superior seismic data compared to traditional towed streamers, but their deployment is time consuming and expensive. As an alternative, we are developing a novel seismic acquisition system which utilises a fleet of fully autonomous underwater vehicles (AUVs) as ocean bottom nodes. The objective is to eliminate the reliance on remotely operated vehicles (ROVs) or ropes for deployment, making ocean bottom seismic acquisition significantly more efficient and cost-effective.
To succeed, several criteria need to be met, including recording of good geophysical data, system affordability, low power consumption, units’ ability to act autonomously (e.g., steer, land, listen, re-position, surface) and to respond to remote commands (e.g., cease activity, return), a failure recovery protocol, an automated deployment and retrieval mechanism, and system-wide communications.
The ability to record good seismic data was assessed in October 2022, when we performed active-source seismic field trials in the UK. Five AUVs were deployed adjacent to commercial OBNs (all units carried identical geophysical payloads) and a series of 2D lines were acquired at varying orientations. Analysis of the data confirmed that our units achieved satisfactory coupling with the seabed.
The unit’s in-water capabilities were assessed during multiple field trials in 2022 and 2023, offshore UK and Australia. Tests consisted of simulating seismic acquisition cycle (flights, landings, take-offs and repositioning) where it was verified that missions were reliably executed, including landing within 10 meters from pre-planned locations and recording of good quality passive seismic data.

Biography

Fabio Mancini is an experienced geophysicist with a passion for development and deployment of new technologies. He started his career as a processing geophysicist in CGG, before undertaking a PhD at the University of Edinburgh on converted wave imaging. After its completion, Fabio worked for 5 years at Total, first in R&D then in operation, on projects covering both seismic processing and acquisition. He subsequently moved to Hess, where he worked in their Technology team, in charge of Hess seismic activities for the east hemisphere. Fabio then moved to Australia to join Woodside where he covered several roles. During his time as Head of geophysical technology, Fabio and his team worked actively on high frequency Full Waveform Inversion and advanced acquisition solutions. One of these concepts became the basis of the novel Blue Ocean Seismic system. In 2022 Fabio joined Blue Ocean Seismic Services as their Chief Geophysicist.

Mr Chris Nicholson

Basin Analyst

Geoscience Australia

Shipwreck and Sherbrook Supersequence Regional Gross Depositional Environments, offshore Otway Basin

Abstract

The Shipwreck and Sherbrook supersequences (SSs) comprise the upper Cretaceous succession in the Otway Basin and were deposited during an extensional basin phase. The Shipwreck SS hosts gas fields in the Shipwreck Trough. Elsewhere the upper Cretaceous interval is relatively lightly explored, and the deep-water area is an exploration frontier. We present regional gross depositional environment (RGDE) maps for the LC1.1 and LC1.2 sequences of the Shipwreck SS, and the LC2 Sherbrook SS, that enhance the basin-scale tectono-stratigraphic framework. Gross depositional environments (GDEs) were recognised in wireline logs and cores from 37 wells. Integration of the well results with seismic facies mapping yielded Fluvial Plain, Coastal-Deltaic Plain, and Shelf RGDE. The Outer Margin High RGDE, recognized only in seismic profiles, displays igneous characteristics. The Fluvial Plain and Coastal/Deltaic RGDEs are almost entirely restricted to the inboard platform areas and the inner Morum Sub-basin. The mud-prone Shelf RGDE is widespread across the deep-water Morum and Nelson depocentres. The Outer Margin High RGDE occurs outboard of the Nelson Sub-basin. The extent of the Fluvial and Coastal-Deltaic Plain belts progressively increases, imparting a regressive aspect to the succession and indicating sediment supply predominantly from the northwest (Shipwreck SS) and north (Sherbrook SS). The distribution of RGDE was also influenced by growth faulting. Study insights include thick seal (Shelf RGDE) development across the greater Shipwreck Trough, and thick reservoir development in the hanging wall of growth faults. This study will inform area selection for more detailed GDE mapping, and formulation of hydrocarbon and CO2 storage plays.

Biography

Chris Nicholson joined Geoscience Australia in 2004. He is a Structural Geologist and Basin Analysist in the Basin Systems Branch of GA’s Mineral, Energy and Groundwater Division where he works on regional prospectivity studies of Australia’s offshore basins. His current focus is the Otway Basin and prior to that he was Director of the North West Margins Energy Systems team investigating the prospectivity of the Triassic interval across the central NWS. He has previously led and been involved in similar hydrocarbon prospectivity studies and CO2 storage assessments in the Browse Basin and other frontier offshore basins, including the northern Perth, Mentelle and Bight basins and the Vlaming and Bremer sub-basins. Chris graduated with a BSc (Hons) in Geology from the Australian National University in 2000. He is a member of the Petroleum Exploration Society of Australia (PESA) and South East Asia Petroleum Exploration Society (SEAPEX).

Mr Chris Nicholson

Basin Analyst

Geoscience Australia

The central and southeast offshore Otway Basin well folio

Abstract

As a resource to enhance exploration in the offshore Otway basin we have produced a new well folio that extends the scope of a previous release, by including 33 key wells from the central and southeast offshore Otway Basin. Well composite logs constructed for these wells include; interpreted lithology, depositional environment (DE) and gross depositional environment (GDE), petrophysical analyses, organic geochemistry and organic petrology, and updated well markers.
The Otway Basin is a northwest-southeast trending rift basin which spans onshore Victoria and South Australia into the deep-water offshore. The prospective sequences within the basin are largely contained in the Cretaceous and three proven or postulated petroleum systems have been identified. While there is production from the onshore basin and the offshore Shipwreck Trough, most of the basin remains underexplored. This folio covers the areas from Normanby 1 in the central basin, through the Shipwreck Trough and Nelson sub-basin to Whelk 1 in the south.
Additional to the previous work, this folio includes comprehensive depositional environment (DE) and gross depositional environment (GDE) from core. Well markers are also better constrained than previous publications by biostratigraphy. Overall, there is a better understanding of regional correlation across this basin where lithological considerations alone are inadequate to provide understanding. As well as the composites the folio provides the datasets used to construct them.
The new well folio supports Geoscience Australia’s pre-competitive studies on the offshore Otway Basin and is a resource for industry stakeholders undertaking petroleum and CO2 storage prospectivity assessments.

Biography

Mr Rasoul Ranjbarkarami

Student

The University of Queensland

Variation of vertical stress in the MacArthur and Beetaloo basins

Abstract

Over the past few years, the McArthur and Beetaloo basins, which cover ~200,000 km2 of northern central Northern Territory, have been the focus of unconventional hydrocarbon exploration, specifically targeting shale gas and tight gas resources. Vertical stress, which is one of the three principal stresses, is a critical parameter in geomechanical analysis of sedimentary basins and has numerous implications such as fracture gradient, pore pressure prediction, assessing the present-day stress regime, and hydraulic fracturing design. In addition, variations in vertical stress levels yield valuable insights into the tectonic history of an area.
In this study, we examined the variability of vertical stress by employing a systematic analysis of density log and check-shot velocity data obtained from 30 wells located within the MacArthur and Beetaloo basins. Our analysis revealed a substantial range of vertical stress gradients spanning from 20 MPa/km to 27 MPa/km (equivalent to 0.9 Psi/ft – 1.2 psi/ft) across these basins, with an average gradient of 23±0.2 MPa/km. This variability in vertical stress gradients underscores the inadequacy of the commonly assumed 1.0 psi/ft approximation for geomechanical analyses within these particular basins. The origins of such diverse vertical stress gradients can be attributed to several factors. These include localized uplift events, zones of overpressure, lateral changes in sedimentary facies, and diagenetic processes. However, the presence of various rock units, including magmatic intrusions, and a complex history of uplift and erosion appear to be the primary contributors to the variable vertical stress gradients within this region.

Biography

Rasoul Ranjbarkarami is a PhD candidate in Geomechanics at the University of Queensland. He graduated with a MSc in Petroleum Geoscience from University of Tehran (2013). His research interests are petroleum geomechanics, structural geology, and petrophysical evolution of reservoir rock. Rasoul started his career in 2013 by a position as a geologist and spent 8 years working for explorational companies in oil and gas before joining School of Environment in UQ.

Dr David Riley

Stratigraphy Manager

Chemostrat

Real-time Chemostratigraphy at Wellsite; removing drilling uncertainties

Abstract

Real-time chemostratigraphy is a workflow deployed at wellsite to remove exploration uncertainty and support drilling operations. This study presents the chemostratigraphy wellsite workflow in which during-drilling operations support either the placement of casing points (using predefined geochemical markers to target a depth above a specific feature), or aid geosteering. Geosteering is typically employed during the drilling of a horizontal wells and is done to keep the drill within a certain zone or horizon to maximise production.
Wellsite chemostratigraphy has been effectively deployed to wellsite within multiple basins around the globe and has recently been deployed to the Perth Basin. The wellsite workflow starts before the deployment with offset wells are analysed by inductively coupled plasma (ICP) spectroscopy within a laboratory-based setting. This builds the correlation framework and identifies the trends required to carryout the specific task (either core placement, casing point or geosteering). Samples are then analysed by energy dispersive x-ray fluorescence (ED-XRF) units this data is then used to confirm the zonation previously defined can be identified at wellsite using the tool that will be employed onsite and that the selected elements are those less likely to be affected by drilling mud contamination and loss of circulation material (LCM). However, during drilling operation there may be instances where LCM must be added to the drilling muds that may have a detrimental effect on the data quality for certain elements. With a dedicated ICP database behind the wellsite operation, machine learning tools may be employed to “repair” correlation critical elements.

Biography

David Riley completed a MGeol and PhD from the University of Leicester, UK, joined Chemostrat Ltd as a chemostratigrapher in October 2012. Since joining Chemostrat Ltd has worked on stratigraphy and provenance projects from eastern Canada, UK North Sea, Middle East, Southeast Asia, and Australia. In 2022 became Chemostrat Ltd Stratigraphy Manager, providing technical oversight on all chemostratigraphic studies. David is a Fellow of the Geological Society of London.

Mr Nigel Seymour

Asia Geophysics Lead

SLB

Evergreening of seismic data to enable carbon storage screening at scale - a case study from the Barrow-Dampier sub basins

Abstract

The Barrow-Dampier carbon capture and storage (CCS) regional study is an industry collaboration between Geoscience Australia & SLB. A key objective of this study is a focussed reprocessing, depth imaging and merging of 26,150km2 of input legacy seismic data. The regional merge has provided a robust foundational dataset for basin scale CCS screening and play-risk mapping and allowed de-risking of capacity and containment of prospective storage locations.
One of the most intensely explored hydrocarbon basins in Australia, the Northern Carnarvon Basin consists of a series of southwest trending troughs that includes the Barrow and Dampier sub-basins. Oil was first discovered at Barrow Island in 1965 and 3D seismic has since been a key tool in exploration and development of the basin. Evergreening this data is an essential component of the regional CCS screening. A modern broadband reprocessed, depth imaged and merged dataset was delivered to address the following objectives:
1. Detailed earth model for accurate depthing, improved fault imaging and positioning
2. Improved conformance between hydrocarbon bearing intervals and structure
3. Improved imaging through shallow Tertiary carbonate section
4. Broad bandwidth for reservoir characterization
The project was conducted over an accelerated 12-month timeline. The data incorporated into this study included 29 seismic surveys, with vintages from 1991 to 2017. Attention was paid to merging the vintages, ensuring a consistent seismic wavelet, seamless velocity model, and continuous seismic character across survey boundaries. We will discuss the logistical and geophysical challenges, lessons learned and show examples of the regional merge.

Biography

Nigel Seymour is the Asia Geophysics Lead for SLB Exploration Data and has 27 years of experience in seismic data processing and imaging. He is an accomplished Geophysicist and has worked on exploration and development projects around the globe. In his current role he provides geophysical support to the Exploration Data and Geosolutions business lines in Asia region. He recently worked with the Australia SLB team to realize the value of seismic data for regional carbon storage screening. Nigel graduated from the University of Liverpool with a bachelor’s degree in geology and geophysics. He currently lives in Perth, Western Australia.

Dr Liuqi Wang

Well Analyst

Geoscience Australia

Unconventional hydrocarbon prospectivity of the Paleoproterozoic Fraynes Formation in Manbulloo S1, Northern Territory

Abstract

The Palaeoproterozoic Fraynes Formation of the Western McArthur Basin has abundant organic-rich shales, predominantly in the gas windows. As part of Geoscience Australia’s Exploring for the Future (EFTF) program, this study aims to assess the present-day hydrocarbon generating potential and shale gas prospectivity in the Fraynes Formation through the reconstruction of original source-rock generative potential and wireline log interpretation. Both organic and inorganic geochemical properties were collected from well completion reports for the wells Manbulloo S1 and Hidden Valley S2. The petrophysical property testing was conducted by Geoscience Australia.
The original total organic carbon (TOC) content was derived from present day TOC content, transformation ratio and residual carbon factor using the testing results from organic petrology and Rock Eval pyrolysis. The generative potentials of oil and gas were estimated using the original TOC content, hydrogen index and thermal maturity data.
Machine learning methods were used to analyse the well logging and laboratory testing data and interpret TOC content from well logs and conventional petrophysical interpretations. The organic porosity was estimated from the difference between the present day and original hydrogen indexes. Shale total porosity was re-interpreted from bulk density logs by removing the organic matter effect and adding organic porosity. The saturations of water and hydrocarbon were re-interpreted using the updated porosity profiles, formation water resistivity and formation true resistivity logs.
The organic-rich shale intervals in the Fraynes Formation are found to have high unconventional hydrocarbon potential, expanding our knowledge on the unconventional energy resources in the Western McArthur Basin.

Biography

Liuqi Wang is a well analyst at Geoscience Australia working in the Minerals, Energy and Groundwater Division. He received his PhD in petroleum engineering and worked as a research fellow at the University of New South Wales before joining Geoscience Australia. His research interests include petrophysics, static and dynamic reservoir modelling, applied statistics and artificial intelligence. He is a member of PESA and EAGE.

Mr Yijie (Alex) Zhan

Senior Geophysicist

Geological Survey of Western Australia

A speculative ridge within the Kidson Sub-basin – integrated interpretation from geophysical data

Abstract

This paper presents an analysis of the basement geometry and its implications on the Kidson Sub-basin in the southern Canning Basin. Integration of seismic data mostly near the rim of the sub-basin with AEM data across its central portion reveals a NEE-SWW oriented ridge in the Permian, casting a projection for a possible elevated basement in the Ordovician and basement. The proposed ridge effectively separates the Kidson Sub-basin into two distinct parts, providing an explanation for the depositional variations observed in the Nambeet and Goldwyer Formations, as well as the absence of the Willara Formation in the southeastern portion of the sub-basin. The presence of subtle updip trends observed in seismic profiles along the southern flank of the ridge suggests a proximity of the basement high away from the limited seismic coverage.
The ridge is speculative and requires a series of further work to verify its existence, including passive and reflection seismic surveys across the structure. If it is confirmed, it might be a significant feature with far-reaching implications for the petroleum and mineral prospectivity of the Kidson Sub-basin. The hydrocarbon sourced from the Nambeet, Goldwyer and Bongabinni Formations in the NNW depocenter may have migrated via the extension of the Parallel Range Fault and trapped in the footwall block over the ridge. Compared to the structures in the Fitzroy Trough, the traps within the Kidson Sub-basin are expected to maintain reasonable integrity, and have good potential for petroleum accumulation and carbon sequestration in its thick Paleozoic succession.

Biography

Yijie (Alex) Zhan graduated from China University of Geoscience (Beijing) with a B.Sc. in 2005. He has worked on structural interpretation, fracture detection and reservoir modelling in various basins. He published in English and Chinese on seismic interpretation, AEM, azimuthal anisotropy, forward modelling and characterisation of gas-bearing volcanoclastic and conventional reservoirs. He joined the Geological Survey of Western Australia’s Basin and Energy Geoscience group as senior geophysicist in 2011, and is a member of PESA.

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