bluuebunny/crossref_metadata_2025 huggingface dataset:
THE VALUE OF INTEGRATING BOREHOLE RESISTIVITY IMAGES WITH GEOLOGICAL DATA: RELEVANCE TO HYDROCARBON EXPLORATION
Authors: Messent B. E. J. , Yacopetti C.M.
Published: August 2017

This paper outlines the contribution borehole resistivity images can make in a frontier exploration program when they are integrated with all available geological data. Specific examples are given from the Duntroon Basin.Dipmeter data and borehole resistivity images can be used to validate seismic structural interpretations. An example is given to show the comparison in interpretation of the different methods.Faults are identified on the borehole images and in addition, qualitative assessment of sealing potential can be made by determining the occurrence and extent of mineralisation. In Greenly-1 the hydrocarbon shows, which are interpreted as migrated hydrocarbons, are found In close proximity to faults identified on borehole images. It is postulated that the faults acted as a conduit for the migrating hydrocarbons. However, these fault planes are now mineralised and interpreted to be sealing. This interpretation is supported by the presence of isolated, over-pressured sandstones.Resistivity images readily identify the orientation of present day horizontal stresses with its implications for fault-trap integrity. However, this is not deemed to be an issue in the Duntroon Basin as there is evidence that at least some of the faults are sealing. Borehole images can also be used to assess caprock integrity by determining the presence or absence of fractures.Within potential reservoir units, borehole resistivity images assist in the interpretation of depositional environments, reservoir geometries and post-depositional changes which affect reservoir quality.Borehole resistivity images provide qualitative interpretations of permeability. It is therefore possible to use the images in the selection of pre-test seats and sampling points in poor quality boreholes or low permeability reservoirs.
CROSS-SECTION BALANCING AND THERMOCHRONOLOGICAL ANALYSIS OF THE MESOZOIC DEVELOPMENT OF THE EASTERN OTWAY BASIN
Authors: Cooper G.T. , Hill K.C.
Published: August 2017

Recent advances in cross-section balancing software have simplified the application of basic geometric constraints to the analysis of basin development. Geometric analysis of field and seismic data allows the user to verify initial interpretations and also elucidates important information about the structural evolution of a basin. Principally, computerised balancing and restoration of cross-sections assists in constraining:the amount of crustal extension;trap geometries, particularly fault geometries through time;the geometry of key horizons at any time, revealing basin morphology and migration paths;the time and amount of maximum burial and hence hydrocarbon migration; andthe likely mechanisms involved in basin evolution. In turn, these parameters can be used to further assess hydrocarbon prospectivity by providing useful data for lithospheric modelling.This study utilises 2D cross-section balancing software (Geosec™) to decompact, balance and restore a series of regional onshore-offshore cross-sections based on both reflection seismic data in the Torquay Embayment and field mapping in the Otway Ranges. The thickness of eroded strata has been constrained by Apatite Fission Track and Vitrinite Reflectance analyses. The resulting section restoration suggests that the eastern Otway Basin experienced extension of 26 per cent in the Early Cretaceous and that the Otway Ranges were subjected to −8 per cent shortening during mid-Cretaceous inversion and −4 per cent shortening during Mio-Pliocene inversion.The structural style of the Otway Ranges and Torquay Embayment is typified by steep, relatively planar, en echelon, N and NE-dipping Early Cretaceous extension faults that were subsequently inverted and eroded during the Cenomanian and Mio-Pliocene. The structural style of the region shows strong similarities with oblique- rift analogue models suggesting that the extensional history of the region was strongly controlled by prevailing basement fabric.Lower Cretaceous source rocks in the eastern Otway Basin reached maximum maturity prior to mid-Cretaceous inversion with the exception of parts of the Torquay Embayment which may not have experienced significant uplift and erosion at this time. The lack of subsidence in the eastern Otway Basin prevented the deposition of significant amounts of Upper Cretaceous sediments which are proven reservoirs in the western Otway Basin and Gippsland Basin. Subsequent Tertiary burial was insufficient, in most regions, to allow the source rocks re-enter the oil generation window.
CARBON ISOTOPES, KEROGEN TYPES AND THE PERMIAN-TRIASSIC BOUNDARY IN AUSTRALIA: IMPLICATIONS FOR EXPLORATION
Authors: Foster C.B. , Logan G.A. , Summons R.E. , Gorter J.D. , Edwards D.S.
Published: August 2017

A global stratotype section for the boundary between the Permian and Triassic Systems is yet to be agreed internationally. However, in many parts of the world, there is evidence of massive extinction of marine fauna at or near the P-T boundary. In the absence of marine fauna, as is the case in most of Australia, changes in plant microfossils, in carbon isotopic signatures, and radiometric dates using SHRIMP, have been used to mark the boundary. The leading questions which arise from this are whether these events are synchronous and how they affect exploration.In eastern Australia, the top of the coal measures has been used as the top of the Permian, although presently only plant microfossils can be used to determine if the youngest seam is present. This has important economic consequences for determination of volumes of effective source rock and for estimates of coal-bed methane. It has been suggested that changes in the carbon isotopic signatures (δ13C) of either organic matter (δ13Corg) or carbonates (δ13Ccarb) can be used to delimit the P-T boundary. From studies of (δ13Ccarb data, Scholle (1995) concluded that 'the establishment of a secular variation curve which has enough detail and reliability to be used as a chemostratigraphic tool still lies in the future'. We concur, and demonstrate for organic carbon that, while there is evidence for secular change, the 13C signature is complicated and overprinted by contributions from different parent plant types; wood-dominated organics are typically −24 %o, while non-woody matter is significantly lighter (−30 %o). There is no simple relationship of δ13Corg to geological age. The consistency of our data, from both the east and west of Australia, allows us to construct a model to predict probable depositional and organic facies using either carbon isotopes (from kerogen or oil) or quantitative estimates of organic matter from standard palynlogical slides. This offers a novel and usefl predictive tool for hydrocarbon exploration.
ELEVATED MID-CRETACEOUS PALAEOTEMPERATURES IN THE WESTERN OTWAY BASIN: CONSEQUENCES FOR HYDROCARBON GENERATION MODELS
Authors: Mitchell M.M.
Published: August 2017

The Otway Basin formed during the Mesozoic separation of Antarctica and Australia. A study of apatite fission track (FT) analysis and vitrinite reflectance (VR) data from borehole samples in the western Otway Basin was initiated to elucidate some of the thermal and structural complexities of this region.Interpretation of results suggest that some areas experienced regionally elevated palaeotemperatures, however, much of the region is at present-day maximum temperatures. Where cooling from maximum palaeotemperatures is observed, the timing may be grouped over three main intervals as follows; mid-Cretaceous, Late Cretaceous to Early Tertiary, and Tertiary. Cooling was facilitated by a decline in geothermal gradient, uplift and erosion, or both. Evidence for a decline in geothermal gradient from values >55°C/km in the mid- Cretaceous is recognised in several wells. Elevated mid- Cretaceous palaeogeothermal gradients (50−60°C/km) have been reported for the eastern Otway Basin, suggesting that these high temperatures were a regional phenomena. Cooling by uplift and erosion at this time was minimal throughout the western Otway Basin in contrast to the kilometre scale uplift and erosion reported for the eastern Otway Basin and adjacent basement inland of this section of the rift.The relative early maturation of the Otway Supergroup during mid-Cretaceous regionally elevated geothermal gradients, and subsequent basin restructuring, are key factors affecting hydrocarbon preservation in the western Otway Basin. Strategies for identification of prospective areas include identification of regions that have remained at moderate temperatures during the Early Cretaceous, and have not undergone burial under a thick Upper Cretaceous to Tertiary section.
THE NATIONAL THIRD PARTY ACCESS CODE FOR NATURAL GAS PIPELINE SYSTEMS
Authors: Radford G.
Published: August 2017

The National Third Party Access Code for Natural Gas Pipeline Systems is a result of February 1994 recommendations made by the Council of Australian Governments. The Code establishes a third party access regime which, when implemented, will apply to gas transmission pipelines and gas distribution systems.This paper provides an overview of the Third Party Access Code. It examines the scope of the Code; the procedure by which the Code is made to apply to new pipelines; the content of access arrangements required under the Code; and the provisions for third party access and dispute resolution. The paper also notes various miscellaneous provisions in the Access Code which address issues such as ring-fencing of pipeline services and the prohibitions on hindering access.The paper concludes with some practical guidance on steps the gas industry can take in response to the Access Code. These steps are suggested from the perspective of existing and prospective pipeline operators and owners, as well as from the perspective of pipeline users and prospective pipeline users.
THE THEVENARD ISLAND SAFETY CASE- APPROACHES USED TO DEVELOP AND IMPLEMENT A SAFETY CASE FOR AN EXISTING FACILITY
Authors: Charko B.W.
Published: August 2017

As a proactive step in the management of Health and Safety, WAPET as operator on behalf of its Joint Venture Participants, considered it good practice to develop a Safety Case for the onshore component of the Thevenard Island facilities and operations along with the legislated offshore requirement. The development of the Safety Case utilised a process which incorporated qualitative assessment of risk, quantification of key risks and assurance that risks were as low as reasonably practicable. For this existing facility, the process clarified the quality of the existing hazard controls and provided an opportunity to make significant improvements.The process used ensured a high degree of employee and Regulator involvement throughout the Facility Description, Safety Management System and Formal Safety Assessment components of the Safety Case. This has achieved a high degree of awareness among the operations staff of risk management techniques. These techniques are now being applied routinely in the management of the operation.
PREPARATION AND IMPLEMENTATION OF A SAFETY MANAGEMENT SYSTEM IN BHPP
Authors: Hunter P.C.
Published: August 2017

BHP is a leading global resources company which comprises four main business groups: BHP Copper, BHP Minerals, BHP Steel and BHP Petroleum. BHP Petroleum (BHPP) global operations are divided into four Regions and Australia/Asia Region is responsible for exploration, production, field development and joint ventures in the Asia-Pacific region. In Australia, the Company's largest producing assets are its shares of the Gippsland oil and gas fields in Bass Strait and the North West Shelf project in Western Australia.BHPP operates three Floating Production, Storage and Offloading (FPSO) vessels-Jabiru Venture, Challis Venture and Skua Venture-in the Timor Sea and one FPSO, the Griffin Venture, in the Southern Carnarvon Basin. Stabilised oil is offloaded from all four FPSOs by means of a floating hose to a shuttle tanker. Gas from the Griffin Venture is compressed and transferred through a submarine pipeline to an onshore gas treatment plant.BHPP's Asian production comes from the Dai Hung oil field offshore Vietnam where BHPP is the operator and from Kutubu in Papua New Guinea.In Melbourne, BHPP operates a Methanol Research Plant and produced Australia's first commercial quantities of methanol in October 1994.BHPP is an extremely active offshore oil and gas explorer and has interests in a number of permits and blocks in the Australian-Indonesian Zone of Co-operation.This paper discusses BHPP's approach to safety management, both for its worldwide operations and specifically in Australia/Asia Region. It explains how BHPP's worldwide safety management model takes regional regulatory variations into account. It shows, specifically, how this has been done in Australia/Asia Region using what BHPP considers to be a best practice approach.The paper describes how BHPP Australia/Asia Region benchmarked its performance against other operators in Australia and the North Sea. It explains how the findings of the benchmarking study were used to plan the preparation of a safety management system (SMS). The structure of the SMS is described along with the legal requirements in Australia.The paper concludes that implementation of the SMS is progressing according to plan and points out that safety cases for the FPSOs have been submitted to the Regulators. Implementation of the SMS and the drive for world class safety standards is having a substantial effect and safety performance is improving. One measure of safety performance, the Lost Time Injury Frequency Rate (LTIFR) is down from around 15 at the end of 1994 to under 3 in December 1996.
ESSO AUSTRALIA'S APPROACH TO SAFETY MANAGEMENT
Authors: Smith M.G.
Published: August 2017

Esso Australia Ltd.'s current company-wide safety initiatives are aimed at challenging all employees and contractors to think about steps they can take to help move towards an injury-free workplace.The development and practical application of a number of occupational safety initiatives have contributed towards Esso employees achieving a period approaching 13 million workhours (nearly five years) without a Lost Time Injury (LTI) and which also assisted Esso's contractor workforce to achieve a period of more than 3 million work hours LTI free w hile performing exploration, heavy construction, drilling, production and maintenance operations.Esso produces 32 million litres of crude oil per day and up to 25 million cubic metres of gas per day from 18 Bass Strait platforms, and two onshore oil/gas facilities on behalf of the Esso/BHP Petroleum joint venture (Fig 1). More than 1200 employees and 800–1,000 contractors are involved in operations involving a high level of production drilling and construction activity.This level of safety performance has been achieved through the unwavering commitment and dedication from all levels in the organisation to create a safety culture which is genuinely accepted by employees and contractors as one of their primary core personal values.The framework for Esso's safety management is Esso's 'Operations Integrity Management System' (OIMS). This requires that all operations adopt a structured approach to safety management with particular emphasis on risk management including continuously looking for opportunities to improve safety management processes.We have been active in developing and refining innovative personal and work group risk management tools (Steback 5x5 and Task Analyss). These tolsare designed to promote increased levels of shop floor involvement in identifying and addressing safety issues, improving first line supervisor involvement and safety skills, and nurturing a '24-hour' safety culture which extends beyond the workplace into the home and family environment. The combined effect of these initiatives is helping create a mindset that n level of injury (not even first aid) is acceptable regardless of the activity being undertaken. It promotes the expectation that everyone approaches their daily work with the mindset that 'all injuries are preventable!'
LOCAL INDUSTRY PARTICIPATION-OPPORTUNITIES AND CHALLENGES
Authors: Sashegyi W.S.
Published: August 2017

The current high level of activity in the resources sector within Western Australia offers opportunities for local industry to participate in a wide range of major construction, manufacturing and service opportunities. At the same time, however, local industry has again been expressing concern about their involvement in these projects.Challenges arise from the rapid technological change occurring within the petroleum industry, the availability of skilled labour, the increasing size and complexity of tender packages and the move to modularisation, the availability of the necessary industrial infrastructure and changes in purchasing practices. On the other hand project developers remain dependent on local industry to assure through-life project support.There is a need for the upgrading of infrastructure and the development of a fully integrated heavy engineering facility based in Western Australia. The Jervoise Bay/Henderson Industrial Estate has been identified as the most suitable base for such activity. The opportunity also exists for the establishment of an Indian Ocean based gas turbine overhaul and refurbishment facility.The challenge for the petroleum industry is to foster Australian industry involvement. The opportunity is to thereby strengthen through life support for projects. For its part, Australian industry must be able to meet specification, quality, price and delivery criteria.In today's procurement environment, addressing the challenges facing local industry participation and capitalising on the available opportunities requires the cooperation of the complete purchasing chain. Project proponents, however, still play a pre-eminent role in ensuring the necessary cooperation and the early involvement of local industry at all levels of that purchasing chain.
WATER MIST AS AN ALTERNATIVE TO HALON
Authors: Bon R.A. , Castles D.K.
Published: August 2017

Halon is being removed from all Esso facilities in accordance with Victorian Environment Protection Legislation for the control of ozone depleting substances. The phasing out of halon as a fire protection system required critical evaluation of available alternatives for protection of turbine machinery and switchgear rooms.Esso Australia Ltd., having evaluated and tested a range of available halon replacement systems, has selected a European manufactured water mist as the preferred alternative for fire protection of turbine machinery enclosures. The system selected required significant modifications from the vendor's standard configuration in order for it to be applied to the offshore environment, be accepted by turbine Original Equipment Manufacturers and achieve independent third party certification. Water mist cannot be applied in all situations to replace halon, with an inert gaseous agent required for the protection of switchgear rooms and for flare snuffing.This paper discusses the issues associated with the selection and installation of this new technology and the lessons learnt. It also discusses issues associated with the evaluation, testing, design and installation of over 80 systems on 14 offshore platforms and two onshore plants.
ENVIRONMENTAL RISK MANAGEMENT: A PROPOSED SCHEME
Authors: Goff H.B. , Steedman R.K.
Published: August 2017

Environmental risk assessment is becoming an increasingly important factor in the assessment process for new projects. The oil and gas industry is familiar with assessing and managing risks from a wide range of sources. In particular, risk assessment and management is fundamental to the evaluation and implementation of Safety cases. Risk assessment is essential in valuing exploration acreage. Various industry and government risk management standards and criteria have been developed for public and occupational health and safety.This paper examines the extension of these approaches to environmental risk management for the offshore oil and gas industry and proposes a conceptual management scheme.We regard risk as the probability of an event occurring and the consequences of that event. The risk is classified into four categories, namely:primary risk, which relates to the mechanical oilfield equipment;secondary risk, which relates to the natural transport processes. For example dispersion of oil in the water column and surrounding sea;the tertiary risk, which relates to the impact on some defined part of the physical, biological or social environment; andthe quaternary risk, which relates to the recovery of the environment from any impact.Generally the methods of quantitatively analysing primary and secondary risks are well known, while there remains considerable uncertainty surrounding the tertiary and quaternary risk and they are at best qualitative only. An example of the method is applied to coral reef and other sensitive areas which may be at risk from oil spills.This risk management scheme should assist both operators and regulators in considering complex environmental problems which have an inherent uncertainty. It also proves a systematic approach on which sound environmental decisions can be taken and further research and analysis based. Perceived risk is recognised, but the management of this particular issue is not dealt with.
MONITORING OCEAN CONCENTRATIONS OF AROMATIC HYDROCARBONS FROM PRODUCED FORMATION WATER DISCHARGES TO BASS STRAIT, AUSTRALIA
Authors: Terrens G.W. , Tait R.D.
Published: August 2017

Previous assessment of dispersion modelling, toxicity testing, and characterisation of produced formation water (PFW) discharges into Bass Strait indicated a very low environmental risk from PFW to the marine environment. Peak PFW concentrations can exceed the effect levels (ECs0 or LC50) measured in 24-96 hr laboratory toxicity tests only within distances of tens of metres from the discharge point. In this assessment, the field monitoring of aromatic hydrocarbons in the water column (which are in low concentrations in PFW) was undertaken to directly assess dispersion and predicted fate mechanisms.Very low concentrations of both light and heavier aromatic hydrocarbons are likely in any PFW discharge. A high volume absorption sampler was deployed 20 m from the discharge point to continuously sample ocean concentrations of aromatic hydrocarbons for up to one week, providing large volume (1,000 L) water samples. Gas Chromatography/Mass Spectrometry (GCMS) was used to measure aromatic hydrocarbon concentrations.The concentrations measured with the ocean sampling device provide time integrated samples over approximately one week, and the results showed that the ratio of discharge concentration to ocean concentration was approximately 20,000:1.Compared to dispersion modelling predictions, the ocean sampler indicates lower environmental risk. This is because dispersion modelling predicts ocean concentrations within the plume whereas the sampler is measuring concentrations at a fixed point over the long term and is exposed to the plume only intermittently, similar to a sessile marine organism. Therefore the ocean concentrations provided by the large volume sampler are more representative of longer term ocean concentrations which can be experienced by marine organisms.Further assessment of prevailing operational and oceanographic conditions in Bass Strait suggests that there does not appear to be a water column accumulation of PFW aromatic hydrocarbons adjacent to the discharge.
MULTIPLE ELIMINATION USING WAVEFIELD TRANSFORMATIONS OFF THE COAST OF WESTERN AUSTRALIA
Authors: Lamont M.G. , Uren N.F.
Published: August 2017

There are two principle reasons why water bottom multiples off the coast of Western Australia can be very difficult to attenuate:A strongly reflective sea floor (often caused by shallow carbonates) gives multiples large amplitudes compared with the primary events they overlay.A widely occurring velocity inversion, beneath the carbonates, causes multiples and primaries to have similar moveouts.A range of processes are commercially available to attenuate multiples, including FK Demultiple, Radon Demultiple, and Predictive Deconvolution. These methods can be very successful under the right conditions. Two dimensional autoconvolution methods, although very promising, still have drawbacks and are extremely computationally expensive.Two new wavefield transformations, Multiple MoveOut (MMO) and IsoStretch Radial Trace (ISR), have been developed to precondition data prior to the removal of surface related multiples by existing techniques. These form the basis of a new multiple attenuating procedure.MMO shifts the data so that the simple water bottom multiples become periodic with the primary event. Water bottom pegleg multiples become approximately periodic.ISR interpolates oblique traces of constant stretch which also approximately map constant angles of incidence on the sea floor. The water bottom primary and multiple events form stationary time series after ISR. They are then amenable to removal by Event Prediction (one dimensional autoconvolution) or Predictive Deconvolution.The results of the new procedure are demonstrated on field data from off-shore Western Australia. It is shown to be more effective at removing both simple and pegleg water bottom multiples than traditional techniques. Finally, it is not computer intensive and does not require velocity analysis prior to its application (besides estimate of water velocity).
STRATIGRAPHY OF THE SOUTHERN SAHUL PLATFORM
Authors: Labutis V.R. , Ruddock A.D. , alcraft A.P. C
Published: August 2017

This study of the southern Sahul Platform area in the Zone of Cooperation is based on the identification of depositional sequences, their distribution and relationship to structuring events in order to predict the locations of favourable combinations of source, seal and reservoir facies with increased confidence. A sequence stratigraphic approach integrating well logs, palynology and seismic data was used to identify and map significant seismic horizons such as the Aptian and Tithonian unconformities.Early to Middle Jurassic sediments were deposited in a broad, northeast-southwest oriented sag basin with a northeastward sediment transport direction. Depositional environments range from non-marine to marginal marine in the Plover Formation to the shallow marine sediments of the Elang Formation. The Elang Formation, comprising two depositional sequences, represents the last of the sediments deposited before the Breakup Unconformity. These formations comprise the dominant reservoir facies, containing a number of oil and gas discoveries. Porosity degradation occurs in Jurassic reservoirs below 3,360 m.The Callovian Breakup Unconformity resulted in the initiation of the narrow, confined depocentres of the Sahul Syncline, Malita Graben and a series of east-west troughs. The Sahul Platform and Londonderry High comprise the flanks of these depocentres but were originally located within the depocentre of the Early to Middle Jurassic sag basin. The Flamingo Syncline is a younger feature developed in the Albian.Late Jurassic and Early Cretaceous sediments are confined mainly to the Sahul Syncline and Malita Graben and are absent or represented by thin, condensed sections on the flanking highs. The condensed sections on horst blocks are a result of sediment bypass rather than considerable erosion. Reservoir facies of Tithonian-Berriasian age are interpreted to occur within east-west troughs constituting another reservoir section apart from the Bathonian-Callovian sediments. Wells distant from the Sahul Syncline and Malita Graben, have encountered hydrocarbons, indicating that the area contains mature source rocks, capable of charging traps away from the immediate vicinity of the depocentres.
THREE-DIMENSIONAL FORWARD STRATIGRAPHIC MODELLING OF EARLY CRETACEOUS SEDIMENTATION ON THE LEVEQUE AND YAMPI SHELVES, BROWSE BASIN
Authors: Griffiths C.M. , Paraschivoiu E.
Published: August 2017

Early Cretaceous clastic sedimentation on the Leveque and Yampi Shelf areas of the Browse Basin has been brought sharply into focus recently as a result of exploration success at Gwydion and Cornea. The changing nature of clastic sedimentation patterns in the shallow-to-deep marine environments during C. delicata to upper S. areolata times is of increasing exploration interest. This study was designed to address the following questions:
Could the conceptual geological model discussed by Spry and Ward (1997) generate potential reservoir sands in the region from Leveque-1 to Yampi-1?What would be the geometry and depositional environment of such sands?SEDSIM is a three-dimensional stratigraphic forward modelling program developed at Stanford University. The program models sediment erosion, transport, and deposition, and predicts clastic sediment distribution on a given bathymetric surface. SEDSIM was used to simulate one million years of deposition on the Leveque and Yampi Shelves from approximately 145 Ma. The model illustrates the use of 3D stratigraphic forward modelling in illustrating and testing stratigraphic play fairway concepts and the development of sedimentation patterns. Reprocessed seismic data from Seismic Australia were used together with a depth-converted near Base Cretaceous surface provided by Woodside Offshore Petroleum. Input data include; a high resolution relative sea-level curve, an understanding of wind and wave directions throughout the modelled period, tectonic movements throughout the modelled area, the nature of the underlying strata, sediment input points, and grain-size distributions. The simulation clearly shows the development of linear shelfal sands on the C. delicata flooding surface during the following regression. Further work will extend the study to early M. australis times.
DEVELOPMENT AND PETROLEUM RESOURCE EVALUATION OF THE BOWEN, GUNNEDAH AND SURAT BASINS, EASTERN AUSTRALIA
Authors: Korsch J. , Boreham C.J. , Totterdell J.M. , Shaw R.D. , Nicoll M.G.
Published: August 2017

The Early Permian to Middle Triassic Bowen and Gunnedah basins and the Early Jurassic to Early Cretaceous Surat Basin in eastern Australia developed in response to a series of interplate and intraplate tectonic events located to the east of the basin system. The initial event was extensional and stretched the continental crust to form a significant Early Permian East Australian Rift System. The most important of the rift-related features are a series of half graben that form the Denison Trough, now the site of several commercial gas fields. Several contractional events from the mid-Permian to the Middle Triassic are associated with the development of a foreland fold and thrust belt in the New England Orogen. This caused a foreland loading phase of subsidence in the Bowen and Gunnedah basins. Thick coal measures deposited towards the end of the Permian are the most important hydrocarbon source rocks in these basins. The development of the Surat Basin marked a major change in the subsidence and sedimentation patterns. It was only towards the end of this subsidence that sufficient burial was achieved to put the source rocks over much of the basin into the oil window. Based on an evaluation of the undiscovered hydrocarbon resources for the Bowen and Surat basins in southern Queensland, our estimates of the yields of hydrocarbons suggest that significant volumes of hydrocarbons have been produced in the basins. The bulk of the hydrocarbons were generated after 140 Ma and most of the generation occurred in the late Early Cretaceous. Because the estimated volume of the hydrocarbons generated far exceeds the volume of discovered hydrocarbons, preservation of accumulations may be the main risk factor. The yield analysis, by demonstrating the potentially large quantities of hydrocarbons available, should act as a stimulus to exploration initiatives, particularly in the search for stratigraphic traps.
A RE-ASSESSMENT OF THE PETROLEUM POTENTIAL OF THE DARLING BASIN: A DISCOVERY 2000 INITIATIVE
Authors: Alder J.D. , Bembrick C. , Hartung-Kagi B. , Mullard B. , Pratt D.A. , Scott J. , Shaw R.D.
Published: August 2017

New data, including regional high resolution aeromagnet ic coverage, acquired by the New South Wales Department of Mineral Resources (DMR) as part of its Discovery 2000 Initiative, have provided the first opportunity for a comprehensive review of the regional framework of the Darling Basin. Covering an area of 90,000 km2 in central western NSW, the Darling Basin contains over 8,000 m of mainly Palaeozoic sediments. With only 17 petroleum wells drilled in the basin, mostly during the 1960s and 1970s, and some 1,550 km of modern multifold seismic coverage, the Darling Basin represents one of the major frontier basinal regions of onshore Australia.The initial phase of petroleum exploration was discouraged by the lack of shows, the likelihood of gas-prone source rocks and presence of a thick, red-bed dominated, organically lean, Late Devonian sequence. Renewed interest in the Darling Basin's prospectivity followed from favourable, albeit superficial, comparisons between the Darling Basin and Queensland's Adavale Basin, where commercial gas is produced at the Gilmore Gas Field. Additionally, as part of some $15 million expenditure by the DMR on acquiring new and reassessing old data from the Darling Basin, new geochemical analyses of extracts collected from core holes and out-crop suggest the presence of at least one active Palaeozoic petroleum system. This system has been responsible for generating oil and possibly substantial quantities of gas found dissolved within artesian waters in the overlying shallow Mesozoic sequences.
SEQUENCE STRATIGRAPHY AND HYDROCARBON PROSPECTIVITY OF THE CAMPANIAN TO EOCENE SUCCESSION, NORTHERN BONAPARTE BASIN, AUSTRALIA
Authors: Mclntyre C.L. , Stickland P.J.
Published: August 2017

The Campanian to Eocene succession of the Northern Bonaparte Basin contains a number of siliciclastic reservoirs which provide alternative targets to the Callovian structural plays that have dominated exploration to date. The succession is part of the Passive Margin Megasequence which extends from the Aptian to the Pliocene, and is traditionally subdivided into the Turnstone, Johnson and Grebe Formations.Prograding deltaics of the Turnstone Formation swamped an incipient Early-Campanian carbonate ramp following a second-order sequence-boundary. Five third-order sequences are recognised within the Turnstone Formation, each dominated by Lowstand (shelf-margin wedge) and Highstand Systems Tract components. A coeval basinal carbonate system resulted in the deposition of marls and lutites distal of the clastic deltaics. In the Early Paleocene, drowning of the clastic system led to the establishment of a productive carbonate ramp. Rare lowstand siliciclastic reservoirs are developed within carbonate-dominated prograding complexes, as incised valley-fill, and possibly within prominent slope canyons. In the Late Paleocene, a third-order transgression drowned the carbonate system. The Early Eocene Grebe sandstones were then deposited as a second-order lowstand package upon a prominent sequence-boundary. Subsequent flooding of the siliciclastic system resulted in the re-establishment of the prograding carbonate ramp system.The morphology of the passive-margin was strongly influenced by the interplay between sediment-supply and subsidence. The predominantly ramp-like geometry of the margin promoted the development of numerous shallow-marine lowstand reservoirs. The hydrocarbon prospectivity of each of these reservoirs is primarily controlled by the magnitude of the subsequent flooding events: Only the largest transgressions resulted in sufficient reduction of depositional energy to isolate the lowstand siliciclastics.Vertical migration remains the critical risk for all passive margin plays, as the reservoirs are separated from the Late Jurassic and Early Cretaceous source kitchens by up to one kilometre of claystone dominated sequences. None-the-less, the widespread occurrence of shallow hydrocarbon shows in the greater Bonaparte Basin indicates that Neogene faulting does provide locally valid migration pathways into post-rift reservoirs.
NEOGENE TECTONICS, GREATER TIMOR SEA, OFFSHORE AUSTRALIA: IMPLICATIONS FOR TRAP RISK
Authors: Shuster M.W. , Eaton S. , Wakefield L.L. , Kloosterman H.J.
Published: August 2017

The present day tectonic configuration of the Timor Sea area is the product of multiple phases of deformation occurring from the Proterozoic to the Holocene. Each major phase of deformation has produced structural hydrocarbon traps, which, in many cases, have subsequently undergone considerable reactivation, and in some cases, breaching. The last phase of tectonism affecting the region is the Neogene collision of the Australian and SE Asian Plates in the Banda Arc region. Although its importance in trap modification and integrity has been acknowledged, a cohesive tectonic model integrating observations that cross the international border has been lacking. The observed Neogene structural deformation and subsidence/uplift trends of the Australian shelf in the Greater Timor Sea can be explained by a combination of strike-slip faulting and flexure as the result of oblique convergence and partial subduction of the Indo-Australian Plate under the Southeast Asian plate. Neogene subsidence and deformation of the Cartier Trough and Malita Graben are interpreted to be the result of rhomb graben (i.e. pull-apart) basin development associated with sinistral shear and reactivation of relict rift structures. These basins developed along 'releasing bends' on the west-northwestward dipping flanks of rigid basement highs. Conversely, in areas where existing basement structure trends define 'confining bends' (e.g. southeast-eastward dipping flanks of basement high features), older rift structures have been reactivated transpressionally, in some cases resulting in large-scale inversion. The present day bathymetry suggests that these rhomb-grabens are currently active. In addition to the wrench-related deformation associated with oblique plate convergence and partial subduction, the Australian shelf has undergone flexure resulting in extension. It is proposed that the Neogene palaeo-and the present day stress fields of the Australian shelf reflect the combination of shear stresses related to wrenching and the tensional stresses related to flexure as the Australian Plate is obliquely subducted. Understanding of this modus operandi has direct bearing to hydrocarbon exploration as areas of structural risk (i.e. structures prone to trap breaching) can be delineated. In general trap breaching risk is lower in areas lying away from the shelf margin and away from 'releasing bends' along shear zones.
PREDICTION OF CARBONATE RESERVOIRS AND TRAPS BY APPLYING SEQUENCE STRATIGRAPHY IN THE EASTERN WARBURTON BASIN, SOUTH AUSTRALIA
Authors: Sun X.W.
Published: August 2017

The Early Palaeozoic eastern Warburton Basin unconformably underlies the Cooper and Eromanga Basins. Four seismic sequence sets (I−IV) are interpreted. Among them, sequence set II is subdivided into four Cambro-Ordovician depositional sequences. Sequence 1, the oldest, is a shallow shelf deposit that occurs only in the Gidgealpa area. Sequences 2 and 3 were deposited in a wider area; from west to east, environments varyied from deep siliciclastic ramp, carbonate inner-shelf, peritidal, shelf edge, and slope-to-basin. Their seismic reflection configurations are high-amplitude, regionally parallel-continuous, layered patterns, locally mounded geometry, as well as divergent-fill patterns. Sequence 4, the youngest, was deposited in a mixed siliciclastic and carbonate, storm-dominate shelf. Its seismic reflection configurations are moderate amplitude, parallel-layered patterns, decreasing in amplitude upwards.Boundaries between the four sequences generated good secondary porosity in the carbonates. Karst development is interpreted to have generated much of this porosity in shelf and peritidal carbonates, and carbonate build-ups. Shoal-water sandy limestone and calcareous sandstone of Sequence 4 may be other potential reservoir rocks. Potential source rocks comprise mudstone and shale of slope and basin lithofacies. There are two kinds of stratigraphic trap. One is in Sequences 2 and 3, associated with high-relief carbonate build-ups encased in lagoonal mudstone and shelf edge sealed by transgressive siltstone and shale. The other is a transgressive marine shale enclosing porous dolostone of the karstified Sequence 1. In addition, petroleum may have migrated from Permian source rocks of the Cooper Basin to karstified carbonate reservoirs of the Warburton Basin at unconformities.
CHARACTERISING THE FULL STRESS TENSOR BASED ON OBSERVATIONS OF DRILLING-INDUCED WELLBORE FAILURES IN VERTICAL AND INCLINED BOREHOLES LEADING TO IMPROVED WELLBORE STABILITY AND PERMEABILITY PREDICTION
Authors: Barton C.A. , Castillo D.A. , Moos D. , Peska P. , Zoback M.D.
Published: August 2017

To minimise wellbore failures in unstable environments, knowledge of the complete stress tensor is crucial to designing optimally-stable borehole trajectories, selecting suitable mud weights, and determining appropriate casing points. Understanding how the in situ stress field interacts with the drilling and production of a well enables one to design for maximum stability and to facilitate intersecting the greatest population of hydraulically-conductive fractures for efficient production. Knowledge of the in situ stress field is also important to reduce uncertainties in sand production prediction to allow more aggressive completion designs and production schedules.A new interactive software system, Stress and Failure of Inclined Boreholes (SFIB) (Peska and Zoback, 1995a) is used to demonstrate how observations of drilling-induced compressive and tensile wellbore failures from acoustic and electrical images in vertical and inclined boreholes can be integrated with routinely-collected drilling data (leak-off and drill stem tests) to construct a well-constrained stress tensor. These techniques can also exploit wellbore image data to constrain in situ rock strength in vertical and inclined wells. This paper illustrates how to apply this knowledge to limit wellbore instability, design optimally stable wellbores, develop constraints that help mitigate problems associated with sand production, and optimise productivity of fractured reservoirs.In addition to mapping drilling-induced wellbore features, image data can also be used to determine the distribution, orientation, and apparent aperture of natural fractures and fault systems. With knowledge of the orientations and magnitudes of the in situ stresses it is possible to identify the subset of fractures that are likely to be hydraulically conductive.Examples of recent applications in the North Sea, Gulf of Mexico, California, and Puerto Rico illustrating how this integrated approach can be used in a variety of tectonic settings.
STRATEGIC APPLICATIONS OF LIFE CYCLE COSTING: OPERATIONS BUSINESS PLANNING
Authors: Evans R.M. , Thompson D.M.
Published: August 2017

This paper briefly examines the business environment and challenges facing the Upstream (E&P) Sector. It suggests that operational phase risks, which undermine a venture's economic success, have traditionally been understated and inadequately defined. This, in turn, has tended to shape a (reactive) problem solving culture vis-vis a (proactive) management of risk culture in the Industry. Failures of ventures to deliver the expected return on the capital investment have been an unwelcome result.Operations Business Planning (OBP) is a technique which encourages the venture to move into proactive modus operandi. It achieves this through systematically integrating a venture's assets, activities, resources, costs and employee knowledge into a practical dynamic model. This model can be used to constantly challenge the acceptability of the venture's performance and to proactively re-shape its strategies and tactics to successfully exploit the varying business climates it faces in its life.Examples are cited to demonstrate the success of OBP's application and the benefits achieved.
COMPETING WITH THE AGGREGATORS: SOME ISSUES WITH THE NATIONAL THIRD PARTY ACCESS CODE
Authors: Radford G.
Published: August 2017

Broadly stated, the objective of the National Third Party Access Code for Natural Gas Pipeline Systems is to promote competition in natural gas markets. For the National Access Code to achieve this objective in a meaningful way, it must allow prospective gas suppliers to gain ready access to pipeline systems.This paper considers two particular aspects of the National Access Code which may cause difficulties for new gas suppliers who wish to compete with incumbent gas aggregators. The first issue relates to the ease with which a new gas supplier can identify what spare capacity is available in a pipeline. The second issue is what type of capacity a new gas supplier can hope to obtain.
SURVEYS OF OIL SPILL INCIDENTS AFFECTING
MANGROVE HABITAT IN AUSTRALIA: A PRELIMINARY ASSESSMENT OF INCIDENTS, IMPACTS ON MANGROVES, AND RECOVERY OF DEFORESTED AREAS
Authors: Duke N.C. , Ellison J.C. , Burns K.A.
Published: August 2017

Over the past three decades, nine notable oil spills affected mangrove habitat in Australia. Six were the result of shipping incidents, and three others were land-based incidents. There were two incidents in the 1970s, three in the 1980s, and four in the 1990s. Types of oil released changed from crude oils in the 1970s to fuel and diesel oils in the 1990s. The total volume of oil released into Australian waters in mangrove-related incidents since 1970 was around 5,000 tonnes. Dispersants were used in the four major incidents involving shipping. Hydrocarbon in sediments generally decreased rapidly after spillage, leaving unrecognisable trace residual fractions in most locations after several years.At least 220 ha of mangroves were oiled in Australia since 1970, and around 13 ha were killed. The extent of oiling depended largely on the amount of oil released. The area of deforestation however, depended on the type of oil with the greatest areas killed by crude oils and diesel, and lesser damage caused by fuel oils. Recovery of deforested sites depended chiefly on site exposure. Sites of greatest exposure experienced both rapid and slow recovery, and sometimes rapid decline. In exposed locations, sediment flushing appeared important in stimulating recovery, while greater exposure also allowed premature destruction of growing plants by strong seas and storms. Based on estimates of total above-ground biomass, mean rates of recovery matched those observed in Panama, and full biomass recovery of areas deforested by oil spills might take around 36 years on average, with 50 per cent recovery after 20 years.