bluuebunny/crossref_metadata_2025 huggingface dataset:
AUSTRALIAN OFFSHORE DRILLING: PAST, PRESENT AND FUTURE
Authors: White J. A. W.
Published: August 2017

The Australian offshore drilling industry is now ten years old. In late 1964 the Global Marine drill-ship "Glomar III" spudded Esso's Gippsland Shelf No. 1 (later re-named Barra-conta-1); the discovery well of the Barracouta gas field. Fourteen other mobile offshore rigs have drilled wells in Australian waters, including one jack-up, four semi-submersibles and two drill-barges. Five production platforms have been built and now supply Australia with a large proportion of her oil requirements.Water depths have ranged from 8 m (Ripple Shoals No. 1) to 388 metres (East Mermaid No. 1) and distances offshore from the mainland from 5 km (Golden Beach No. 1/1A) to 400 km (Troubadour No. 1). Wells have been drilled to depths of over 4,500 metres.Several new techniques have been introduced including turret mooring (Discoverer II), foam drilling (Glomar Tasman) and dynamic positioning (Sedco 445). New drilling vessels under construction in Australia will provide additional offshore drilling capacity.For the future we can expect to see larger drill-ships and semi-submersibles which will be able to continue drilling operations in adverse weather conditions. Dynamic positioning and improved conventional anchoring systems will enable the deeper waters to be explored. New equipment and techniques will probably include buoyant marine risers, sub-sea mud discharge pumps and electro-hydraulic preventer actuated systems.
FUTURE OF SYNTHETIC LIQUID HYDROCARBONS IN AUSTRALIA
Authors: Keith G. N.
Published: August 2017

Australia's currently known reserves of fossil fuel indicate that we have 250 years supply of black coal at current production rates, 400 years of brown coal, 170 years of natural gas, but only 16 years of crude oil (20 years if natural gas liquids figures are included). While we are presently supplying about 65% of our liquid hydrocarbon requirements, this will drop to about 10% by 1990 unless significant new discoveries are made. While it may be technically possible to replace the petroleum based industrial fuels with either coal or natural gas, there is no currently developed alternative for transport fuels. If Australia wishes to pursue the objective of energy self-sufficiency, then these transport fuels produced from indigenous crude, even with the maximum of secondary processing, will have to be supplemented with synthetic fuels made from coal, natural gas or L.P.G.There is considerable activity world wide in perfecting the technology of coal liquefaction, but it seems certain that the process will be highly capital intensive and there will need to be some guaranteed minimum price for the products to protect the venture from fluctuations in the world price of natural crude oil.Converting LPG to gasoline is technically feasible but whether it is sound from an economic standpoint or whether it is justified when considering conservation of energy is a matter for debate.Natural gas can be converted to gasoline but again with a relatively low efficiency of energy conservation. However, it could be attractive where gas is available far in excess of conventional demands and can be supplied to the process at a reasonable price.
THE REGIONAL GEOLOGY OF THE EXMOUTH PLATEAU
Authors: Willcox J.B. , Exon N.F.
Published: August 2017

The Exmouth Plateau and adjacent continental slopes cover 300 000 km 2 beyond the Northwest Shelf, in water depths ranging from 800 to 5000 m. The regional geology has been interpreted from 18 000 km of seismic reflection profiles, and ties to exploration wells.The plateau is formed over a major arch and syncline. These structures parallel the Rankin Platform and lie 250 and 100 km respectively to the northwest of it. The dominant structural grain is northeasterly, but easterly and southeasterly cross-trends occur along the northern and southwestern margins respectively. Extensive normal faulting affects the pre-Cretaceous sequence.Basement is overlain by up to 10 000 m of Phanerozoic strata, about half of which probably comprises shallow marine and terrestrial sediments of Silurian to Permian age. As much as 4 000 m of Triassic shallow marine to fluvial sediments overlie the Palaeozoic. The Triassic surface is uneven, extensively block-faulted, and unconformably overlain by up to 2 000 m of Middle Jurassic to Neocomian deltaic sediments. An average of 200 m of mid-Cretaceous shallow marine clastic sediments overlies the Neocomian, and are in turn unconformably overlain by a carbonate sequence of Santonian to Recent age containing two major hiatuses and averaging 700 m thick.The period of block-faulting preceded formation of a northeasterly-trending spreading-centre in the Late Jurassic, which separated the area from the adjacent part of Gondwanaland to the west. An associated easterly-trending transcurrent fault probably formed the northern margin of the Exmouth Plateau. In the Late Cretaceous the area southwest of the plateau collapsed rapidly along a northwesterly-trending fault. Gradual subsidence of the plateau took place throughout the Cainozoic and, at the northern margin, collapse along old easterly trending fault-lines gave rise to grabens south of marginal sub-plateaux. Late Cainozoic warping formed the Exmouth Plateau Arch.Petroleum source rocks, especially Palaeozoic to Neocomian shales and siltstones, and reservoir rocks, especially Triassic and Neocomian sandstones, appear to exist in the Exmouth Plateau area. The depth of burial has probably been adequate to form hydrocarbons from pre-Cretaceous source rocks. Numerous fault traps in Triassic sediments, analogous to those of the Rankin Platform, appear to exist. Other likely petroleum targets are stratigraphic traps in the Jurassic—Neocomian deltaic sequence.
DEPOSITIONAL ENVIRONMENTS AND GEOTECTONIC FRAMEWORK: SOUTHERN AUSTRALIAN CONTINENTAL MARGIN
Authors: Deighton I. , Falvey D.A. , Taylor D.J.
Published: August 2017

Three principal phases occurred in the development of the basins of the southern Australian continental margin: epi-continental, marginal continental and oceanic. These correspond generally to the phases of margin development proposed by Falvey (1974): pre-rift, rift valley, and post-breakup; but tectonic and depositional transitions are not necessarily contemporaneous.Prior to the Upper Cretaceous, the region of the present day southern Australian margin lay well within the Eastern Gondwanaland continent, essentially barred from deep ocean basins. During the Upper Cretaceous the series of epicontinental basins was increasingly subjected to marine breakthroughs. Thus marine ingressive horizons were deposited along an incipient rift valley between the primitive Indian Ocean and Tasman Sea. Rift valley subsidence, possibly related to deep crustal metamorphism, was most significant on the flanks of the rift zone. Further marine influence during the Paleocene ('infra-breakup') and early Eocene corresponded to the onset of seafloor spreading between Australia and Antarctica. The neo-breakup phase is dominated by shelf and plateau subsidence and spreading ridge development, with topography influencing ocean current. The changing palaeogeography can be accurately illustrated by computer-derived reconstructions based on quantitative sea-floor spreading data. Quantitative thermal uplift/subsidence models can be used to estimate post-breakup water depth of the subsiding ocean basin and the continental margin. A complex pattern of transgressive continental deposition and submarine erosion diminished with the gradual widening of the Southern Ocean and the establishment of circumpolar ocean current paths. Oceanic basins dominated the margin through the Neogene.
SOME CONCEPTS OF SEISMIC STRATIGRAPHY WITH APPLICATION TO THE GIPPSLAND BASIN
Authors: Steele R.J.
Published: August 2017

One approach to the problem of extracting stratigraphic information from seismic data is through the concept of sequences which are defined as time-stratigraphic units that are bounded by unconformities or their correlative conformities. These sequences are distinct depositional units that may be thought of as the building blocks of sedimentary basins. Sequence boundaries can be recognized on good quality seismic data by offlapping, onlapping and truncated patterns of cycle terminations. These sequence boundaries can be mapped to determine the configuration and lateral extent of each sequence and to provide a time-stratigraphic framework for analysing a basin. In addition, the logical lateral variations of environment and lithofacies that may be expected within each sequence provide a basis for rational extrapolation of lithological trends beyond the well control.Seismic sequences can also be used to recognize and measure relative sea level fluctuations. The amount of coastal onlap shown by sequences can be used to measure the magnitude and timing of relative sea level rises, and similarly, basinward shifts in deposition across sequence boundaries can be used to document sea level falls. Using these principles, graphs can be constructed that show detailed relative sea level fluctuations within a basin as a function of geological time.A relative sea level chart has been constructed for the Gippsland Basin by integrating seismic sequences with palaeontological data. When the Gippsland chart is compared with high resolution charts derived from seismic sequences in other areas it is found that many synchronous sea level fluctuations occur in widely spaced basins. These synchronous fluctuations are considered to be due to eustatic variations which contrast with other fluctuations that result from local tectonic movements.As detailed relative sea level charts from many areas become available a more complete picture of ecstatic variations should emerge. Such a eustatic framework should assist in inter-regional correlations and also allow the geologist to distinguish between the effects of local tectonism and world-wide sea level changes.
THE GEOLOGICAL EXPRESSION OF EUSTACY IN THE EARLY TERTIARY OF THE GIPPSLAND BASIN
Authors: Partridge A. D.
Published: August 2017

In the non-marine to marginal marine environments of the Latrobe Group, distinct sedimentary sequences are recognised on seismic records and these sequences are often expressed in wells by palynological zones, changes in E-log character and lithology.The succession of sequences represents variations in sea level, many of which are interpreted aseustatic. Eustatic falls are represented by unconformities and channel formation along the seaward margin and by hiatuses (frequently with dolomite cementation of underlying sands) landward in deltaic and non-marine sections. Eustatic rises are represented by dinoflagellate ingressions over truncated surfaces at sequence boundaries, followed by outbuilding of deltaic environments at the stillstand towards the end of each cycle.During the Paleocene and Eocene very little sediment was deposited beyond the limits of the marginal marine environments except within channels where the Flounder and Turrum Formations are found. In this time interval they was an overall landward encroachment of successive sequences reflecting an overall sea level rise. The interaction of rising sea level and limited deposition beyond the marginal marine edge meant that successive sequences became more restricted seaward such that within the marine environment the area of non-deposition increased. The surface thus defined, modified locally by channel erosion, constitutes the unconformity at the top of the Latrobe Group. This unconformity surface was preserved when deposition of fine-grained open marine sediments of the Lakes Entrance Formation commenced in the Oligocene.In the Tasman Sea a succession of terrigenous silts and clays present in the Deep Sea Drilling Project (DSDP) Site 283 can be correlated with periods when fine-grained sediments bypassed the Gippsland shelf. The stratigraphy of this site can be interpreted as a record of availability of sediment from the southeastern Australian continental shelf. The times of commencement and termination of stratigraphic units and disconformities at Site 283 correlate with timing of eustatic cycles. Thus the stratigraphy of Site 283 is a record, as is the Latrobe Group, of how eustacy interacts with basin morphology to modify distribution of sediments.
TUBINGLESS COMPLETIONS IN THE SURAT BASIN
Authors: Delbaere M. A.
Published: August 2017

Oilfield operators have always looked for ways of reducing the costs of oil and gas development projects and especially when investment costs were critical to project economics. Tubingless completions have evolved over the last 30 years in North America to fill the need for reduced investment costs particularly in the case of fields with either limited reserves or limited profitability.Tubingless completions basically utilise small diameter tubulars to function as both production casing and flowstring. The tubulars are cemented in the borehole, not to be removed or recovered until the field is depleted and/or the well abandoned. The technique is limited in application to those fields with no corrosion or wax or hydrate problems and with a limited requirement for reservoir stimulation and workovers. The greater the number of operations performed within the tubingless well bore the greater the risk of losing the well.The main benefits of tubingless completions are as follows:Reduction in development well completion costs.Marginally productive hydrocarbon zones can be completed and tested.Completion of individual gas zones of multi-pay wells within their own permanently segregated flowstrings at much lower capital and operating costs.The experience this far with Kincora gas field development wells indicates the tubingless completion method to be completely feasible for gas wells drilled in the Surat Basin and possibly in other areas of Australia.
OIL AND THE ENVIRONMENT - CALIFORNIA CASE STUDY
Authors: Barnett D. W.
Published: August 2017

USA environmentalists have tended to oppose all new energy developments. Their efforts may be counterproductive because opposition to, say, offshore oil directly leads to the continued use of other energy sources that may have a higher social cost. Rather than attempting to eliminate all pollution from energy production, which would be prohibitively expensive, one should minimize the social cost of energy production for the given demand.Linear programming is used to rank various oils (California State and Outer Continental Shelf (OCS), Gulf of Alaska, Prudhoe Bay, Athabasca tar sands, oil shale and certain foreign crudes) in terms of their social desirability. The objective is to minimize the cost of supplying the California market, subject to resource, sulphur and oil spill constraints.Social desirability is indicated by the inclusion of the oil in the optimal solution and the size of the associated shadow price. The larger the shadow price, the greater the benefits of increased production. The more negative, the greater the cost associated with forcing consumption of that fuel. The environmental shadow prices indicate the size of the trade-off between a particular environmental standard and minimum cost. The trade-offs can be surprisingly large. Any reasonable spill standard can be achieved by changing the development pattern. Generally, the further offshore, the smaller is the environmental degradation, but the more expensive is the oil. Foreign oils can be economically and environmentally inferior to domestic oils. Crude from the California OCS, San Joaquin Valley and Prudhoe Bay appears a valuable resource, while the Gulf of Alaska, synthetic and foreign crudes appear marginal to submarginal.The methodology could be readily adapted to the Australian scene.
THE AUSTRALIAN OIL REFINING INDUSTRY OUTLOOK
Authors: Newman F. P.
Published: August 2017

The Australian refining industry began with the establishment of two small refineries in the mid-1920s. However, it was not until the mid-1950s, after the construction of four large new refineries, that this industry emerged as an important factor in meeting the domestic demand for petroleum products. The refining companies are now able to meet about 90% of Australia's demand for refined petroleum products. This efficient industry provides a wide range of products of varying quality specifications.Existing and probable new government regulations relating to lead in motor spirit and to the level of emissions from refinery plant will necessitate a high level of investment in refinery plant. In the near future, our crude supply pattern is likely to become more dependent on Middle Eastern sources whilst the domestic market for refined products is trending towards a whiter barrel. Major capital investment in refinery plant will be required to adjust to these influences.A major problem facing the Australian oil industry is its recent low profitability. Reduced cash flows constrain the ability of the refining industry to undertake new investment.Actions by the OPEC countries have reduced the degree of vertical integration in the international oil industry and thereby reduced the profit earned on the extraction and sale of crude. Therefore the ability and the need for the major companies to support downstream operations as an aid to the sale of crude has also been reduced. The Australian oil refining and distribution industry must compete for investment funds with other companies in the international oil industry. Its current low return on funds and its debt gearing, already comparatively high by international standards, means that profitability must be restored before substantial new investment can be prudently undertaken.
SANDSTONE RESERVOIR GEOMETRY OF NON-MARINE SEDIMENTS IN THE TOOLACHEE GAS FIELD
Authors: Devine S. Bevan , Gatehouse Colin G.
Published: August 2017

The concept of Genetic Increments of Strata (GIS) has been applied to correlations of the non-marine rocks of the Early Permian Patchawarra Formation of the Cooper Basin. Boundaries of GIS in the non-marine rocks are related to a dynamic model of non-marine deposition in which discrete sandstone bodies result from channel activity.In the 9 wells in the Toolachee Gas Field area of about 150 sq. miles, log correlations based on these principles determined eight major sandstone bodies, six of which hold gas reserves. The sandstone bodies are elongate and sinuous. They have cross-sectional dimensions of about 5 miles wide by up to 60 ft thick. Faulting and differential compaction have influenced the locations of the axes of the channel sandstone bodies.The value of mapping the geometry of the channel sandstones in the Cooper Basin lies in establishing a possible trapping mechanism which is independent of structural closure and which requires only a structural dip nonperpendicular to the channel sandstone direction; and providing a geologic basis for gas reserve estimates, the positioning of future appraisal and development wells and the prediction of field extensions and nearby new fields.An estimate of the proven-probable gas in place in the Toolachee Gas Field (560 BCF) based on the channel sandstone mapping is comparable with estimates based on lumping all pay intervals together in each well and drawing geometric pay isoliths. Estimates of possible reserves are increased by the mapping because of the introduction of the trapping mechanism of sandstone margins. The Toolachee Field has the potential to be perhaps doubled in size.
PATTERNS OF DIAGENESIS IN SOME AUSTRALIAN SEDIMENTARY BASINS
Authors: Shibaoka M. , Bennett A. J. R.
Published: August 2017

Three characteristic types of Australian sedimentary basins can be recognized on the basis of depth-reflectance curves. These may be designated as the Cooper, Sydney, and Gippsland Basin types. Characteristic depth-reflectance curves allow an assessment of the depositional and tectonic histories of sedimentary basins to be made. If the geological history and especially the stratigraphy of a basin is well known, it is possible to estimate the maturity which coal or kerogen would have attained at any past or present time. This maturity would be expressed by particular reflectance values of vitrinite. By making actual measurements of vitrinite and kerogen reflectance, the model of maturation can be tested. In this way it has been possible, for a number of basins, to estimate the geological period in which liquid hydrocarbons were generated and the rate at which the maturation process proceeded. The formation of an accumulation of oil is a matter of balance between the supply and loss of oil to and from traps, as well as persistence of traps and migration paths through geological time. The lapse of time after oil generation and the rate of generation are thus most important. The above-mentioned three types of sedimentary basins differ in these respects. Reflectance data can therefore be used not only to estimate the present state of organic maturity, but also in conjunction with the history of sedimentation in the basin, to interpret hydrocarbon generation activity in geological time.
HYDROCARBON POTENTIAL OF THE NORTH WANGANUI BASIN, NEW ZEALAND
Authors: McQuillan H.
Published: August 2017

The proximity of the North Wanganui Basin to the onshore Kapuni and offshore Maui gas/condensate fields of the adjacent Taranaki Basin has attracted the interest of oil companies for some time. Exploration during the late 1950's and early 1960's delineated several prospective traps. Some of these were subsequently drilled and, apart from minor gas indications, were dry holes. Data from the sixteen wells drilled are on open file and these together with other available information are incorporated in a series of maps representing stages in the evolution of the basin.The sedimentary history of the North Wanganui Basin began early in the Oligocene when a shallow north to south marine transgression saw the infilling of structurally defined northeast-southwest trending depressions in the folded Mesozoic basement. As the relief of the peripheral landmass was reduced the former basin irregularities were smoothed out and the way was paved for the spread of carbonate rich seas from which a suite of carbonate grainstones and packstones was deposited during the middle Oligocene. Late Oligocene time saw the renewed influx of clastic sediments as movements on the dominant wrench fault basement structure brought revived relief to areas of sediment supply. At that time the southern margin of the basin possibly merged westwards with the Taranaki Basin. Punctuated by periods of vulcanicity centred west of the present coastline, a thick sequence of mud, silt and sand, dominantly marine but locally including terrestrial coal measures, makes up the Miocene succession. Sedimentation controlled by growth faulting is characteristic, and the east-west barrier of the Pipiriki High persisted in restricting the southern extension of the basin during that time. The Miocene closed with a tilting movement hinged on the Pipiriki High such that subsequent Pliocene and Pleistocene sedimentation followed a south-east migrating depocentre in the quite separate South Wanganui Basin.Hydrocarbon indications in the basin itself are few. The presence there of potential reservoir and source rocks in addition to the proven production in the adjacent Taranaki Basin are reason for some optimism in the further evaluation of the hydrocarbon prospects of the North Wanganui Basin.
AN ANALYSIS OF THE PRODUCTION PERFORMANCE OF THE WINDALIA SAND RESERVOIR OF THE BARROW ISLAND OIL FIELD
Authors: Williams C. T.
Published: August 2017

The Windalia Sand is a high porosity, low permeability oil reservoir. Currently 454 wells penetrate the unit for production or water injection operations, and are drilled on a north-south, east-west 16 ha (40 ac.) spacing. Early production performance data indicated a trend of water break-through into wells located east and west of water injection wells in an inverted nine-spot pattern. This early trend has continued and the east- west break-through has become more widespread with time. It was recognised that it could be possible to improve the performance of the waterflood if the factors causing the phenomenon were able to be identified. A detailed geological review of well data was initiated to investigate causes and possible controls of the phenomenon and to determine if oil recovery could be improved. This work was augmented by an engineering study of production data. Subsequently, a computer model was developed to investigate the simulated effects of changes to well patterns on the field's production performance.The geological review determined that the reservoir contains significant local and transitional irregularities (or inhomogeneities). The mapping of a number of reservoir parameters has shown there are genetic patterns or trends and these are postulated as being at least partial controls of preferential direction of fluid movement.Previously the reservoir had been regarded as being a more uniform "layer-cake" sand. Well completion practices and timing together with production and injection methods are thought to have accentuated the latent genetic controls. Imposed pressure parting has been postulated, on engineering premises, as a control of fluid movement. The modelling study used the notion of anisotropic permeability in attempting to history-match production performances.Because of the reservoir size and anisotropy it was impractical to model the entire field. Selected type areas within the reservoir were studied. Good history-matching of various well types (based on location within a pattern) was possible. Predictions of production performance can be made for various simulated pattern changes allowing feasibility studies to be made of possible conversion programs.East-west producing wells are being converted to injectors as they water out. This program has converted part of the reservoir to a line-drive injection configuration and improved performance in these areas is evident.
FINANCING THE DEVELOPMENT OF AUSTRALIA'S PETROLEUM AND MINERAL INDUSTRIES
Authors: Hamley B. L.
Published: August 2017

Recent collation by the Bank indicates a high level of development expenditure will be necessary over the next five years with peaks in the cycle in 1979 and 1980.By an analysis of historical capital flows, overseas capital, borrowings in particular, will be necessary in increasing amounts. Whilst the traditional sources of capital will be used, direct borrowing from OPEC sources could be utilized, probably using the Australian banking system as the appropriate channel.Whilst the resumption of a strong capital inflow will be necessary, excessive growth in the money supply from this source will be moderated by a rise in imports of capital goods for the mining industry. Original research by the National Bank of Australasia Ltd entitled the "Degree of Competitiveness Indices" shows, by an index of exchange rates and inflation rates of our major trading partners, how Australia stands in relation to world markets.Devaluation and fiscal incentives should result in an upturn in the rate of capital formation in the mining industry in future years. This paper is in general agreement with the Government's policy towards foreign investment in Australia with one important qualification in that it is better to develop resources, even with overseas ownership, rather than leave them idle.
THE PETROLEUM GEOLOGY OF THE OUTER DAMPIER SUB-BASIN
Authors: Crostella A. , Chaney M. A.
Published: August 2017

The Dampier Sub-basin represents the northern part of a depositional downwarp along the Western Australian coast within the greater Carnarvon Basin. The sub-basin can be separated into an inner and outer section by the depositional Lewis Trough, which drilling and seismic results indicate to have been active since at least earliest Jurassic times.The Dampier Sub-basin originated as an intracratonic depocentre at the end of the Carboniferous and has developed progressively into a marginal basin at the present day. The oldest sediments penetrated to date in the outer area are fluviatile Upper Triassic clastics. Well data have shown that sedimentation continued without a break from the Late Triassic until the late Middle Jurassic, with gradually increasing marine influences. This phase of deposition was terminated by uplift in the Early Callovian, resulting in the emergence of various parts of the basin. These areas were transgressed at different stages, but by the late Early Cretaceous a marine environment was firmly established over the whole region.Eleven hydrocarbon accumulations have been discovered to date in the Outer Dampier Sub-basin where the primary hydrocarbon generating section is believed to consist of pre- Upper Cretaceous shales, particularly in the Lewis Trough. The feature of major relevance to the petroleum geology is the Rankin Platform where the main discoveries occur in Triassic to Lower Jurassic reservoirs. Trapping is provided primarily by the drape and differential compaction of Cretaceous shales over the pre-tectonic horsts, but the water level in individual fields appears to depend on a combination of both drape and fault trapping. In the Angel Field, on the Madeleine Trend, hydrocarbons occur in Tithonian sands within a fold structure sealed by conformable Cretaceous shales.
EARLY PERMIAN DEPOSITIONAL ENVIRONMENTS, SOUTHERN SYDNEY BASIN
Authors: Ramli Nik , Crook Keith A. W.
Published: August 2017

Seven major lithofacies are present in the Lower Permian sediments of the Jervis Bay area (southern Sydney Basin). These facies, which are areally extensive, are members of the Pebbly Beach Formation (facies A), the overlying Snapper Point Formation (facies B-F) and the Wandrawandian Siltstone (facies G).Facies A to D represent a regressive shoreface succession which passes upwards into lagoonal and marsh sediments. They were deposited during the Snapper Point regression. Currents were predominantly long-shore with rip and onshore and offshore storm current components.Facies E to F constitute a regressive (i.e. shoaling upwards) spit profile which Accreted by longshore progradation during the early stages of the Wandrawandian transgression. They form the upper part of the Snapper Point Formation.Facies G comprises sandy muds of the Wandrawandian Siltstone which were deposited in a marine embayment at temperatures below 0°C as evidenced by glendonites (pseudomorphs after thenardite). The muds represent the culmination of the Wandrawandian transgression which followed upon the disruption of sediment supply to the spits and their consequent inundation.This depositional history resolves earlier conflicting interpretations of this part of the southern Sydney Basin sequence. It provides a better understanding of the origin of the Snapper Point Formation, which has been a common target for onshore petroleum exploration drilling.
THE STATUS OF HYDROCARBON EXPLORATION, OFFSHORE NORTHEASTERN AUSTRALIA AND THE GULF OF PAPUA
Authors: Sabitay A.
Published: August 2017

Since 1969, geophysical exploration and drilling in the offshore area of northeastern Australia has been at a virtual standstill. In the Gulf of Papua, progress recommenced in late 1973 when Papua New Guinea gained control of its mineral resources. Exploration has been curtailed by the formation of a Royal Commission to study possible adverse effects on the Great Barrier Reef due to oil exploration. The findings of the Royal Commission were delivered on 30th October 1974. Generally considered, the Commission concluded that risks of hydrocarbon spills were small enough and hazards from such spills not detrimental enough (except for dispersants and sinking agents) that drilling in selected areas should take place after improving safety precautions.The Great Barrier Reef National Park Act came into effect on 20th June 1975. Provision is made in the act for allowing or forbidding the recovery of minerals in particular zones of the Great Barrier Reef region. To date neither the zones nor the regulations governing exploration under the Act have been proclaimed.Nine distinct areas of sedimentation having hydrocarbon potential are recognized in the area. These are, in order of interest: the Gulf of Papua, the Maryborough and Capricorn Basins, the Halifax, Laura and Hillsborough Basins, the Queensland Plateau, the Marion Plateau and, lastly the Styx Basin. In these areas, potential hydrocarbon production is indicated by Pasca No. A1 and Uramu No. 1A in the Gulf of Papua, and onshore at Barikewa No. 1, Lehi No. 1, Kuru No. 1, Bwata No. 1 and Puri No. 1. One of three exploration wells in the onshore Maryborough Basin had significant gas shows.
PROTEROZOIC, PERMO-CARBONIFEROUS AND PLEISTOCENE GLACIAL CYCLES AND CYCLIC SEDIMENTATION IN RELATION TO OIL SEARCH
Authors: Sprigg R. C.
Published: August 2017

The Australian Upper Proterozoic, Permo-Carboniferous and Pleistocene glacial epochs were each notable for well -developed examples of glacially-induced, cyclical sedimentation. The Pennsylvanian (Upper Carboniferous) of North America was similarly characterized by cyclothems of probably related origin. Both the foregoing Pennsylvanian and the Australian Permain contain much of the world's coal. Both are significant sources also of hydrocarbons and constitute some of the more prolific hydrocarbon resources on both continents.Around the world, Quaternary sea-floor and terrestrial sedimentary sequences reveal increasing evidence of comparable climatic fluctuations and related sea-level influenced sedimentary deposition. Such fluctuations relate primarily to alternate waxing and waning of contemporary continental ice sheets. Astronomic cycles influenced principally by the varying obliquity of the ecliptic (earth's axial tilt), and the precession of the equinoxes, appear to offer primary climatic controls. Milankovitch -type astronomic radiation cycles almost certainly apply.Prominent sedimentary cycles characterising parts of the Australian Quaternary succession relate directly to repetitive climatic and sea-level changes. In turn, these are related back to Permo-Carboniferous sedimentary deposition as it influenced coal formation, the development of hydrocarbon source rock and a range of sand reservoirs as they bear on oil exploration.
THE TECTONIC DEVELOPMENT OF TIMOR: A NEW MODEL AND ITS IMPLICATIONS FOR PETROLEUM EXPLORATION
Authors: Chamalaun F. H. , Grady A. E.
Published: August 2017

It is argued that the two current tectonic models for Timor, namely the overthrust model and imbrication model do not adequately explain some recent observations, such as the continuity of the Australian continental crust underneath Timor, the lack of field evidence for pervasive imbrication or large scale horizontal thrusting, the absence of convincing evidence for allochthonous masses and the 'palaeomagnetic similarity between the Permian of Timor and Australia. An alternative model is developed in which the continental margin of Australia, when reaching the subduction zone, is decoupled from the down-going slab and, as a result of isotatic rebound, is weakly imbricated. Material transfer across the plate margin is limited to surficial olistostrome mass transport, which could have caused some thrust faulting in the younger Tertiary basins in the south. This model presents a simpler structural geometry and predicts continuity with the Sahul Shelf.
GOLDEN BEACH: A BRIGHT SPOT
Authors: Mariow R. B.
Published: August 2017

The Golden Beach closed anticlinal structure lies five kilometres offshore in the Gippsland Basin. Golden Beach 1A was drilled in 1967 near the crest of the structure and intersected a gas column of 19 m (63 feet) at the top of the Latrobe Group (Late Eocene) where most of the hydrocarbon accumulations in the Gippsland Basin have been found. The gas-water contact lies at a depth of 652 m (2139 feet) below sea level.On seismic data recorded over the structure, a high amplitude flat-lying event was interpreted as a bright 'flat spot' at the gas-water contact. Reprocessing of the seismic data enhanced the bright spot effect and enabled the areal extent of the gas zone to be mapped. The presence of the gas also leads to a polarity reversal of the top of the Latrobe Group seismic reflector over the gas accumulation.Seismic data from other structures containing hydrocarbons in the Gippsland Basin support the concept that bright spots and flat spots are more likely to be associated with gas than with oil accumulations, and that the observed bright spot effect decreases with increasing depth.
THREE-DIMENSIONAL DATA COLLECTION AND PROCESSING
Authors: Selby E. G.
Published: August 2017

There are many limitations in the ultimate accuracy of a conventional two dimensional seismic survey. One of the most important of these is that, in general, a prospect is not a two dimensional model but a three dimensional one. For a complete interpretation of a prospect area the final result should be a migrated time or depth map. With limited sampling (a seismic grid typically consists of loops with dimensions at least 1 km by 1 km) it is necessary to interpolate grid points to allow map migration and this method has inherent inaccuracies.The three dimensional seismic exploration technique is designed to provide a sufficiently close sampled grid of seismic traces, typically with a line and depth point spacing as close as 50-100 m, to allow the seismic data itself to be migrated three dimensionally. This allows the interpreter to work with migrated seismic sections and to contour directly the migrated map.Several techniques exist to allow practical and economic collection of seismic data to provide this close sampling. These techniques can be adapted to various terrain and cultural conditions.The main advantages of three dimensional data collection are correct imaging of the seismic information giving true vertical reflection time sections and improved signal-to-noise ratio due to the increased fold inherent in the three dimensional migration process. The additional advantage to the interpreter is that the data has a sampling which gives a line intersection at each depth point in the prospect.
PREDICTION OF CONDENSATE FLOW RATES IN LARGE DIAMETER HIGH PRESSURE WET GAS PIPELINES
Authors: Cunliffe R. S.
Published: August 2017

Esso Australia Ltd. operates two offshore gas platforms for Esso Exploration and Production Australia Inc. and Hematite Petroleum Pty. Ltd. in the Gippsland Basin. Gas and condensate from the Marlin platform flow to the gas plant near Sale, Victoria through a 67 mile, 20 inch pipeline. Gas and condensate from the Barracouta platform flow to the plant through a 30 mile, 18 inch pipeline. Average flowing pressure is 1300 psig. Condensate: gas ratios are 65 bbl/MMscf for Marlin and 15 bbl/MMscf for Barracouta.As these platforms are the only source of supply for the city of Melbourne, gas rates are changed to match gas demand. Changes in gas rate are accompanied by changes in condensate flow. From consideration of liquid holdup and liquid residence time, a method of predicting the condensate flow rate resulting from gas rate change was developed.A controlled run was made to test the prediction. After holding the Marlin gas rate steady at 150 MMscfd for 50 hours to reach equilibrium holdup conditions, the rate was increased to 250 MMscfd and held at this rate for 26 hours to reach equilibrium conditions again. The condensate flow rate out of the pipeline was monitored continually.The Marlin pipeline test demonstrated that changes in condensate flow rate resulting from changes in gas rate in high pressure wet gas pipelines can be predicted within 15 per cent of actual rates using liquid holdup and liquid residence time as input data. In the absence of holdup data from pipeline pigging, Eaton's correlation will provide good values for holdup for wet gas pipelines with operating pressure up to 1500 psig and which traverse relatively flat topography.This work has application in the sizing of liquid surge capacity required to receive condensate from high pressure wet gas pipelines. In many cases, investment in slug catcher facilities can be greatly reduced without risk of overfilling with liquid.
THE APPLICATION OF THE HIGH RESOLUTION HEWLETT-PACKARD QUARTZ CRYSTAL PRESSURE GAUGE TO FORMATION EVALUATION IN THE GIPPSLAND BASIN
Authors: Pinczewski W. Val
Published: August 2017

Over the period 1974-1977 Esso Australia Limited has conducted 35 pressure build-up tests, 24 well-to-well pulse tests, and 45 formation interval tests (using the Schlumberger FIT tool) in various parts of the Gippsland Basin. The primary pressure sensing device in all of these tests was the Hewlett- Packard quartz crystal pressure gauge. The pressure build-up tests were performed in both oil and gas wells whilst pulse testing has to date been limited to oil reservoirs. The formation interval tests carried out on offshore exploration and evaluation wells have tested both oil and water zones.Although the overall experience has been that the gauge performs satisfactorily we have found that several precautions, relating both to the operation of the gauge and interpretation of the response, must be exercised in order to arrive at meaningful interpretations of reservoir parameters. Although the gauge is temperature compensated it requires a period of 20 minutes to reach temperature equilibrium during which time the gauge response varies significantly. Additionally, the high resolution of significant extraneous effects associated both with the wellbore and the reservoir, mask the pressure transient data and make interpretation difficult.When adequate precautions are taken the gauge is highly effective in determining reservoir transmissibility (kh/p), reservoir storage (och), continuity between wells and reservoir zones, and for determining fluid gradients in exploration and evaluation wells which penetrate the high permeability sands characteristic of the Gippsland Basin.
NORTH WEST SHELF GAS: EFFECT ON WESTERN AUSTRALIA'S FUEL ECONOMY
Authors: Saunders D. W.
Published: August 2017

Despite its small population, Western Australia is a big energy user, as a result of large mining and mineral processing projects and long distances involved in travel. The per capita use of primary energy in Western Australia in 1975/76 was 226 gigajoules, compared with 204 gigajoules per head for Australia as a whole.Total primary energy demand in Western Australia is expected to increase by 77 per cent from 292 × 1015 joules in 1977 to 517 × 1015 joules in 1987.Fuels used directly for mining and mineral processing operations dominate energy demand. Total amounts of mining and mineral processing fuels (including input to power stations which form part of mining projects) represented 39 per cent of total primary energy demand in 1977, and are expected to increase to 43 per cent in 1986/87.Residential, commercial and industrial reticulated gas represents only a small part of the State's energy needs. However, it is an important component in both social and economic terms. At the present time, demand for gas for industrial purposes is in excess of supply and sales to industrial customers are restricted. The demand for gas will continue to exceed supply from the small Dongara Field until North West Shelf gas becomes available in 1984.In 1977 Western Australia depended on oil for 70 per cent of its primary energy needs. This proportion is expected to decline to 44 per cent in 1987. Over the same time period the share of the total market supplied by gas is expected to increase from 11 per cent to 29 per cent.The suppliers of petroleum products in Western Australia, and particularly the Kwinana refinery, will need to prepare for a major change in product demand after the proposed introduction of North West Shelf gas in 1984. Requirements for heavy furnace oil will decline, whilst it is anticipated that the demand for the lighter distillate and motor spirit will continue to increase.
A HISTORY OF OFFSHORE DRILLING
Authors: Jackson A.G.
Published: August 2017

The offshore drilling industry was born of economic necessity and developed according to the needs of oil exploration operators. From a modest start in 6m of water in 1949, offshore drilling has grown to a fleet of 373 competitive mobile drilling units some of which have the capability to drill in excess of 900m of water. During the process, four types of mobile drilling rigs evolved, each with its own share of the total rig market: submersible, jackup, drillship or barge and semisubmersible. Characteristically, during the growth period, the Industry has periodically over-built and suffered the consequences of rig surplus. From its start in the U.S. Gulf of Mexico, offshore drilling has spread out to encompass every area of the world. The design of rigs has been influenced by economic demand, physical environment, experience, regulatory requirements and technical developments in the drilling industry. Rig construction costs have dramatically increased from 2 million U.S. Dollars, in earliest times, to 20 - 70 million U.S. Dollars now. Personnel who man the rigs were trained from the area of operations with the initial cadre from the United States Gulf of Mexico. Government influence has been profound in determining the level of offshore activity through the control of prices, lease sales, the tax level, environmental measures, and protectionist policies. As long as the oil and gas price remains competitive with other energy sources and the present determination to diversify the petroleum source is maintained, growth of the industry will continue. The form of this growth will be governed by economic and political circumstances and the physical environment in the areas in which economically recoverable hydrocarbons are found.
TRAPPING MECHANISMS AND THE HYDROCARBON POTENTIAL OF THE EXMOUTH PLATEAU, WESTERN AUSTRALIA
Authors: Wright A. J. , Wheatley T. J.
Published: August 2017

An interpretation of the structural configuration and hydrocarbon potential of the Exmouth Plateau has been made utilizing the results of G.S.I's 1976 Scientific Investigation (No. 10 S.L.).Seismic sections suggest sediments down to at least four seconds (two way time) below the sea floor. A prominent regional unconformity separates faulted and dipping sediments from generally flat overlying beds.Eight horizons of apparent regional importance were picked and correlated to existing well control.Structure maps were prepared for the regional unconformity and three overlying horizons, including the interpreted top of the Barrow Group. Mapping showed the main potential hydrocarbon traps to be large fault block features associated with the regional culmination of the unconformity event, and broad anticlinal drapes at top Barrow Group level. Geological interpretation suggests that the fault blocks consist of late Middle to Upper Triassic sediments, probably sandstone and shale. These sandstones could be potential reservoirs for hydrocarbons generated at depth. Seismic evidence of hydrocarbon generation includes a probable gas chimney associated with the western bounding fault of the highest fault block.The present sea floor topographic high of the Exmouth Plateau is coincident with the large drape structure embracing a foresetting package within the Barrow Group. Velocity studies over the Plateau suggest a probable lack of sand in the upper part of the Barrow Group section. Sourcing of sands in the lower part is envisaged as originating from sediments in older, underlying fault blocks. The Triassic fault blocks are considered to have the higher potential for oil reserves, but recoverable volumes are not likely to be in the 'giant' category (500 million barrels).