bluuebunny/crossref_metadata_2025 huggingface dataset:
LIBRARY INFORMATION SERVICES FOR EXPLORATION COMPANIES
Authors: Keenan Marita D. , Lapworth Patricia B.
Published: August 2017

The increased pace of scientific research and technological development since the Second World War has resulted in an "explosion" in the amount of information being produced in scientific and technical fields. It has been calculated that the published literature of these fields doubles every ten years. Most industries have been affected by this and the petroleum exploration industry is no exception. Exploration companies are prolific producers of information, particularly that resulting from their field operations.The information needs of the management and technical staff of exploration companies cover a very wide field of diverse material, which includes legal, financial, economic, industrial and statistical material, as well as geological and geophysical data and its interpretation. Relevant external material includes information on exploration methods and equipment, laws and regulations governing exploration in Australia, and the status and activities of competitors in the industry. All this comes from many and varied sources, and may be in conventional forms (books, journals, maps, etc) or in forms peculiar to the exploration industry itself (e.g. seismic sections and well logs). Internal information is even more complex in content and form, comprising field data of all kinds, reports, maps and diagrams, seismic sections and records, well logs, aerial photographs, and many other items.The difficulties presented by such a mass of varied and complex material are best overcome by the establishment of a "special library" in the charge of a professional librarian. A "special library" is one serving a specialist clientele and covering a particular field of knowledge. Professional librarians - or information officers - have been trained to gather, index, store, retrieve and disseminate information of all kinds; these tasks comprise the routine work of a special library. They are performed by adapting the standardised guidelines of librarianship to suit the specialised nature of the industry being served. Librarians are also trained in such tasks as literature research and compilation of information dossiers.The establishment of a special library under a qualified librarian provides an exploration company with:a centre for the integration of all kinds of information material; andan active information service.It thus enables a company to make the maximum use of all available information which may be relevant to its purposes.
ENERGY, ENVIRONMENT AND CONSERVATION—AUSTRALIAN CASE HISTORIES AND THEIR IMPLICATIONS FOR THE FUTURE
Authors: Brown Graham A.
Published: August 2017

Five recent case histories of environmental concern over proposed projects involving energy resources in Australia are reviewed.Queensland: The Great Barrier Reef Royal Commission, involving proposed exploration offshore for hydrocarbons;New South Wales: The Clutha Controversy, involving proposed transport and loading facilities to export coal;Victoria: The Port Phillip Bay gas pipeline;Tasmania: Lake Pedder, involving a proposal to flood the lake for the production of hydro electric power;Northern Territory: The Top End National Park, involving proposals to exploit newly discovered uranium resources.The social and legal implications of these activities are discussed, with particular emphasis on the possibility of future laws being enacted to conserve Australia's resources and environment. Special reference is made to the energy industry in general and petroleum in particular.
DRILLING IN OVERPRESSURED FORMATIONS IN AUSTRALIA AND PAPUA NEW GUINEA
Authors: Lepine F. H. , White J. A. W.
Published: August 2017

The accepted definition of an overpressured formation is one in which the pressure of the formation fluid is in excess of the theoretical hydrostatic pressure of the natural formation water if the formation water extended to surface. For the purposes of this paper, formations which have a pressure in excess of that corresponding to a gradient of 0.47 psi/ft from the surface to the depth of the formation are considered overpressured; this corresponds to the gradient of saturated saltwater. It is not necessary for a large reservoir to exist before drilling problems can be occasioned by abnormally pressured formations.Various means of determining the presence of overpressured formations exist and these formations have been encountered in many Australian basins including the Papuan Basin, the Bowen Basin, the offshore portion of the Carnarvon Basin, the Bonaparte Gulf Basin and in the Perth Basin. The usual means of combating abnormal pressures are by addition of barytes to the mud, by back pressure drilling or by allowing the formation pressure to partially deplete. This last alternative is only practical in low volume "shale-gas" occurrences. In the offshore Papuan Basin, a modified form of back pressure drilling known as the floating mud-cap technique was used for a productive reservoir containing a lengthy gas column.
THE STRUCTURE OF FOOTHILLS SOUTH OF THE KUBOR RANGE, PAPUA NEW GUINEA
Authors: Findlay A. L.
Published: August 2017

The Kubor Range, which trends northwest-southeast and has some peaks of over 4000 m, is composed predominantly of Permian granodiorite, intruding Palaeozoic metamorphic rocks. The part of the Papuan basin to the south is aligned in the same direction; in it there are up to 7000 m of Mesozoic sediments and 2000 m of Tertiary sediments. The Mesozoic sequence contains two incompetent units, the Jurassic Mari! Shale and the Upper Cretaceous Chim Formation; these are separated by the more rigid Kondaku Tuff in the north and the Kerabi Formation further south. The lower part of the Tertiary sequence grades from shelf facies Darai Limestone in the south to the terrigenous clastics of the basinal Aure Group in the north; both are overlain by terrigenous clastics of the Orubadi Formation.Most of the structural features were caused by gravity sliding from the north down the basinward slope of the Kubor Granodiorite during the Pliocene. This sliding occurred within the incompetent units in the Mesozoic sequence, namely in the Maril Shale and Chim Formation. The latter is present only in the north. Movement occurred there within both units and synclinal klippen of Tertiary rocks survive. These lie discordantly on underlying structures caused by movement within the Maril Shale. To the south, sliding within the Marti Shale has given rise to imbricate structures at the surface; these are replaced further south by asymmetrical anticlines separated by thrust planes.
EVOLUTION OF THE MESOZOIC SEDIMENTARY BASINS ON THE EAST COAST OF INDIA
Authors: Sastri V. V. , Raju A. T. R. , Sinha R. N. , Venkatachala B. S.
Published: August 2017

The stratigraphy, structure, and tectonics of the Cauvery, Godavari-Krishna, Palar, and Mahanadi Basins located on the east coast of India are considered on the basis of up-to-date surface and subsurface data with particular reference to their evolution during the Mesozoic Era.The sediments exposed in the respective basins are limited to their western and northern borders and represent a relatively smaller stratigraphic interval as compared to the sequence known to be present in the subsurface.Each of these basins is bordered to the west by down-to-the-basin faults. The structural style and recognisable regional trends of the respective basins parallel those of the Eastern Ghats which were largely responsible for their evolution during the Jurassic period. The basin morphology during Late Jurassic comprised horsts and grabens formed due to tensional forces leading to basin subsidence with localised uplifts. The close of the Mesozoic was marked by a regional easterly regression and basinal tilt and an almost complete cessation of horst and graben development and the formation of an essentially monoclinal post-Mesozoic sedimentary cover.A close similarity between the Mesozoic sedimentary basins on the east coast of India and those on the west coast of Australia is marked inasmuch as their tectonic setting, structural style, lithologic suites and faunal and palynological assemblages are concerned. The study broadly indicates that during the Late Jurassic-Early Cretaceous period the basins on the east coast of India were bordered by land masses similar to those postulated to the west of the West Australian basins.
THE STATUS OF GEOPHYSICAL KNOWLEDGE IN THE EAST COAST AND EASTERN BASINS OF INDIA
Authors: Ramakotaiah G. , Avasthi D. N.
Published: August 2017

The major problem in geophysical exploration for hydrocarbons in the east coast basins of India (Mahandi, Krishna-Godavari, Palar and Cauvery Basins) is to obtain persistent and correlatable reflection seismic data from prospective zones at depth. From the geological and well data a considerable thickness of pre-Tertiary and Tertiary sediments is known to be present in these basins. As these areas are covered with a blanket of alluvium, the basin configuration and sub-surface structural features are to be inferred from geophysical data. Although gravity, magnetic and refraction surveys have broadly outlined the basin configuration, suitable seismic reflection techniques are yet to be evolved for detailed mapping of the structures. Experiments using offset spreads and geophone grouping parameters derived from noise studies have yielded encouraging results in a limited area of the Cauvery basin.The problems of the eastern basins (Assam, Tripura and Bengal) are varied in nature. The structures in the shelf area of Assam, have been successfully mapped using reflection seismograph, but the tectonic complexity of sub-thrust regions of the Naga Hills and the steeply folded belts of Tripura present formidable logistics and technical problems for delineating the sub-surface features. Some theoretical studies have been made for developing field techniques to improve the signal-to-noise ratio in these areas.The problem in the Bengal basin is the absence of continuous and correlatable reflection events from the prospective Mio-Pliocene section. The use of digital data acquisition and processing techniques has not substantially improved data quality from this section to date.
GEOLOGIC HISTORY OF THE BASS BASIN
Authors: Robinson V. A.
Published: August 2017

The Bass Basin is located offshore between the southern coast of Victoria and the northern coast of Tasmania. It is bounded on the west by King Island and on the east by Flinders Island and the Bassian Rise. Water depths throughout the basin rarely exceed 270 feet (82 metres) and the area has been actively explored for hydrocarbons since 1963.The oldest sedimentary rocks encountered whilst drilling are Early Cretaceous, but the greatest volume of sediment was deposited during the Tertiary. Lithologies vary from continental sandstone, siltstone, shale, and coal in the older, non-marine Cretaceous to Middle Eocene section to limestone, marl, mudstone, and shale in the younger, marine Late Eocene to Recent section. Drilling and seismic data indicate that there was a considerable amount of volcanic activity in the Bass Basin throughout its history.Three distinctively different structural provinces can be recognised in the basin. These provinces are referred to as- a) southeastern area, b) central area, and c) northwestern area.The southeastern area exhibits the earliest structural growth (Early Cretaceous) whereas the structural growth in the central and northwestern areas occurred in Early and Late Tertiary respectively. Structural style also varies from tilted fault blocks with thousands of feet of vertical displacement in the southeastern area, to low relief, small anticlinal folds and minor faults in the northwestern area. Most of the prominent structural trends are oriented in a northwest-southeast direction which is parallel or sub-parallel to the present basin axis.Seismic and E-log correlations within the non-marine Cretaceous and Lower Tertiary section are extremely difficult and palynology is used to differentiate time-rock units. Five separate zones are identifiable within the Eocene and Paleocene, and the Cretaceous has been sub-divided into ten zones which can be related to the time-rock units in the adjacent Otway and Gippsland Basins.Non-commercial accumulations of hydrocarbons have been found in three different structural features: Pelican, Cormorant and Bass −3. These accumulations are from within the Lower Tertiary non-marine sequence known as the Eastern View Group.
Salt and Diapiric Anomalies in the Southeast Bonaparte Gulf Basin
Authors: Edgerley D. W. , Crist R. P.
Published: August 2017

The Southeast Bonaparte Gulf Basin comprises a Phanerozoic sedimentary sequence bordered by Precambrian rocks of the Kimberley, Sturt and Darwin Blocks. This portion of the basin developed as a subsiding graben, in which the flanks are separated from the central collapsed area by terraces that foundered to intermediate depths. Geophysical data acquired in the area since 1965 suggest the existence of large quantities of evaporites in the basin. Wells drilled in the area have confirmed the seismic evaluation. These evaporites were initially deposited across existing terraces and basinal areas prior to the later Devonian. Salt and diapiric structures of various types are widely distributed within the basin. The origin and growth of most of these structures is associated with epeirogenic movements along faults that demarcate the major structural elements of the basin.
THE ENERGY BALANCE IN WESTERN AUSTRALIA
Authors: Lofting M. J. W. , Richardson A. H.
Published: August 2017

Western Australia's internal energy demand is projected to grow more than six times from 1975 until the year 2000. Demand has been divided into transport and non transport sectors in the context of existing known sources of supply (coal, oil, natural gas, natural gas liquids).Overall, comparing Western Australia's known energy reserves with estimated demand until the end of the century there is a surplus of total energy: natural gas and coal are in excess and there is a critical shortage of liquid fuels, and in particular fuel oil. The shortfall may be reduced by increasing gas production in order to recover the associated liquids.Known small oil reserves with doubtful economics could further reduce the deficit, but the most reliable method of filling the gap is, however, to find new oil reserves. Exploration prospects are thought to be sufficiently good in Western Australia to fill the gap provided incentive is given by government, but a period of shortage in the immediate future cannot be avoided. The crude expected to be discovered will be light and it is predicted that if large reserves are found it will be necessary to export light products to other States, and import heavy products from overseas to supply the necessary distillate for transportation and rising demand for duel oil in sectors where gas will not penetrate.
THE DRILLING OF PALM VALLEY –2 WELL, AMADEUS BASIN, NORTHERN TERRITORY, USING AIR AS THE CIRCULATING MEDIUM
Authors: Dumbrell K.
Published: August 2017

Magellan Petroleum (N.T.) Pty Ltd's Palm Valley -2 was spudded in on 21st December 1969 and reached total depth of 6559 feet on 2nd February 1970. The well was completed as a gas well after flowing at the rate of 69.7 MMCF per day during testing.Hole and casing sizes were: 26 in. (20 in.) 31 ft; 17½ in. (13⅜ in.) 431 ft; 12¼ in. (9⅝ in.) 4225 ft; 8½ in. (7 in.) 6057 ft. The rig used was a National 100 and in addition to 6 in. O.D. and 8 in. O.D. drill collars 3 x 11 in O.D. and 6 x 9¼ in. O.D. were run for drilling down to 4225 feet.Compressed air was used as the circulating medium. The air equipment major components comprised: -2 Ingersoll Rand 1500 cfm primary compressors1 Ingersoll Rand 1500 psi booster compressor1 12 in.−3000 psi Shaffer rotating BOP.15 Rock bits were used in the drilling of Palm Valley −2. Substantial water was encountered while drilling through the Mereeinie Sandstone which is a major aquifer of the region.The 7 in. casing was set at 6057 ft and drilling below this point to total depth (6559 ft) was carried out with 2⅞ in. production tubing, 4¾ in. drill collars in conjunction with OTIS N nipple, XO sliding-door sleeve and X landing nipple. This string was used as a combination drill out/production assembly and was left in the hole as a completion string after removing the sliding sleeve with the wire line. A Cameron LDO 2⅞ in. control head was installed prior to drilling out the 7 in. shoe.The use of air as a circulating medium on Palm Valley −2 clearly demonstrated the economic and operational advantages of this drilling method. There are undoubtedly other favourable geological areas in Australia where this drilling and completion procedure could be adopted to great advantage.
THE DIPMETER USED TO RECOGNISE DEPOSITIONAL ENVIRONMENT
Authors: Shields C. , Gahan M. J.
Published: August 2017

Historically the major application of dipmeters has been towards the derivation of dip in formations penetrated by the borehole. This preoccupation has led to the development of computer programmes which ignore characteristic qualities of the dipmeter data. By computing numerical values for the qualities of (a) Dip pattern, (b) Nature of stratification, (c) Strata thickness, (d) Contrast between strata, (e) Formation hardness (hole diameter), (f) Hole eccentricity (directional homogeneity). (g) Resistivity anisotropy, each correlation can be classified as belonging to a definite numerical group.Applying similar values to measured parameters of carefully documented geological sections representative of different sedimentary environments shows that similar numerical grouping can be recognised: hence, the environment should be revealed by the correlation grouping. Also, as horizontally-layered strata are infrequent in the geological cross-section, the dipmeter may not be an ideal tool for the measurement of regional dip.If the dipmeter is accepted mainly as a tool for recognition of depositional environment and palaeocurrent direction, then a more appropriate correlation curve than of the micro-resistivity should be selected. The requirements of the geologist should spur the development of the necessary computer programmes and field equipment to improve resolution in the borehole, presentation of the dipmeter survey, and provide additional stratigraphic information.
SOME COMPUTING TECHNIQUES FOR STORAGE, RETRIEVAL AND INTERPRETATION OF GRAVIMETRIC DATA
Authors: Morony G.
Published: August 2017

Gravity coverage of South Australia, with stations on a grid of approximately 7 km, is almost complete. A project aimed at computer-storage, retrieval and utilization of these data has been under-way within the Geophysics Division of the South Australian Department of Mines for two years.The storage and retrieval system has been adapted from one developed for gravity data by the Bureau of Mineral Resources. Two data files have been established using this system. The first contains all data from individual surveys stored as a retrievable block on the file. The second contains all gravity data recorded on each 1:250,000 scale published map sheet within the State.Experimental analysis of digitized gravity data from the Great Artesian Basin in South Australia has been undertaken using standard anomaly-separation techniques. A published set of grid operators has been used as the coefficients for each analysis. These coefficients, which are designed for upward and downward continuation and long and short wavelength filtering of potential fields, have each been applied to the test data with various grid spacings. Computer presentation of results allows quick evaluation and comparison of each operator set. Results obtained are suitable for qualitative examination and in the examples chosen indicate limits of intracratonic basins and some detail within them. The nature of this information depends on the grid spacing and operator used. Large amplitude anomalies which cover a considerable area and are due to basement features become more apparent than on the Bouguer anomaly data. An estimate of depth to major density discontinuities has been obtained.Future aims of the project are: (i) processing of raw data files to prepare and update integrated Bouguer anomaly maps using more accurate density information for the Bouguer correction, and (ii) preparation of processed maps on a statewide basis to aid interpretation of the tectonic and basin framework of the State of South Australia.
AN EXPERIMENT IN SOIL GEOCHEMICAL PROSPECTING FOR PETROLEUM, DELLA GAS FIELD, COOPER BASIN
Authors: Devine S. B. , Sears H. W.
Published: August 2017

The aim of the experiment was to test the method of prospecting for petroleum by soil geochemical analysis of hydrocarbons and, in particular, its possible application in the Cooper Basin. Some 379 samples were taken in traverses across the Della Gas Field and a nearby, undrilled anticlinal structure. The samples were taken from a depth of 5 m at a spacing of 5 per mile (approximately 1 every 300 m). Hydrocarbons were extracted with 2N HCI and analysed by gas chromatography. Some modifications to the published analytical techniques had to be made to overcome the prbblem of traces of organic compounds present in local waters and reagents.Arithmetic mean values analysed for the Della Gas Field were: acid soluble material, 8.62 per cent; ethane, 1.33 ppm; propane, 0.77 ppm; butane, 0.62 ppm; pentane, 0.84 ppm. In plots of, firstly, the sum of ethane, propane, butane and pentane and secondly that sum normalized to the amount of acid soluble material, anomalous areas containing only a few sample points occur above and near the Della Field, and the undrilled structure.There is only low statistical correlation between the amount of acid soluble material and the hydrocarbon content of the soils. The hydrocarbon content of the soils may possibly be associated with diagenetic gypsum and calcite and possibly smectite (?mixed layer clay) but the evidence is inconclusive. The soil hydrocarbon content shows some tendency to correlate with the finer grain sizes. The anomalies appear to bear no relation to the vegetation. A radiometric survey with a gamma ray spectrometer showed little variation of values and no relation to the geochemistry nor the outline of the Della Gas Field.The experiment has shown that significant variations in hydrocarbon content of the soils can be analysed in the Cooper Basin and apparent anomalous zones can be outlined. The anomalous zones may be related to the Della Gas Field.
COMPUTER-GENERATED DISPLAYS IN THE STUDY OF A PRODUCING RESERVOIR
Authors: Wells T. N.
Published: August 2017

Since the Barrow Island oil field was discovered in 1964, over 500 production, injection, and water source wells have been drilled through the principal producing reservoir, the Windalia Sand. With the initial interpretation of logs and core data, and the subsequent recording of production/injection rates and pressure measurements, a large volume of disparate but related data has been accumulated-well evaluations, correlation sheets, porosity and saturation data and fluid production/injection histories.In late 1972, behaviour of the water-flood indicated the need for additional geological analysis of the Windalia Pool and a subsequent production review and re-assessment of the water-flood programme as a control for future production from the reservoir.Given limited time and a large mass of data to be reworked and re-evaluated, it was evident that detailed analyses would not be possible without the use of some automatic data processing system to produce the many pre-requisite displays. WAPET's Computer Services Division was called in and a set of computer programs was developed for generating a wide range of maps, cross sections, and performance graphs. All of these provide simple but powerful display-definition procedures to give extensive user control over the scope, content and presentation of a display. Specified data items for a group of wells are easily referenced and operated upon mathematically and logically to produce a number of different displays, e.g., an isopach or water cut map, a stratigraphic cross-section, a series of porosity bar charts, or a series of production performance curves or cross-plots.The programs were used extensively in the two reservoir studies, and proved to be of great assistance. The power, flexibility, and ease of use of the programs allowed the examination of a large volume of data in a short time, resulting in a much more objective analysis than would have been possible using traditional manual techniques of display preparation.
CONCESSIONAL AND CORPORATE AVENUES FOR OIL EXPLORATION IN AUSTRALIA AND THE LEGISLATIVE CONSTRAINT
Authors: Spicer J. R.
Published: August 2017

When an explorer decides he wishes to participate in exploration in Australia there are three elements which will affect his fortune over and above technical considerations. These are (a) the concessional avenue open to him, (b) the corporate avenue open to him, and (c) the legislative constraints.The traditional concessional avenue in the off-shore environment has been by gaining rights under the Submerged Lands Acts. This legislation has been enacted by both the Commonwealth and State Governments in mirror-image fashion for the Adjacent Area lying offshore from each State. In the onshore environment the different States have their own discrete legislative regimes by which they govern exploration and development rights.As a general concept title to petroleum is vested in the Crown.The corporate avenues by which the explorer enters into a relationship, either directly with Government or with some other company which has a relationship directly with Government, are as follows:An explorer individually may be a concession holder;a company may be a concession holder;a joint-stock company may be a concession holder;a partnership may be a concession holder;a joint-venture may be a concession holder;a company may enter into a farm-in/farm-out or "Exploration and Participation Agreement" with a concession holder;a company may hold an over-riding royalty secured by a concession holder;a company may have a carried interest secured by a concession holder;there may be a take-over of company shares.The traditional concessional and corporate avenues are affected by certain statutory enactments of the Commonwealth of Australia. This legislation comprises the Petroleum and Minerals Authority Act, the Foreign Take-overs Act, the Seas and Submerged Lands Act, the Restrictive Trade Practices Act, and the legislation relating to Customs and Reserve Bank regulation. The relationship of these Acts to the Australian Constitution is examined.
EXPLORATION AND ITS RESPONSE TO DIVERGENT INFLUENCES
Authors: Maxwell W. G. H.
Published: August 2017

Petroleum exploration in Australia has evolved through three distinct phases and is now entering a fourth. It began with the wild, speculative flurries that culminated in drilling on the Coorong, South Australia in 1892, it was revived by the accidental discovery of gas near Roma at the turn of the century leading to the oil boom from 1926 to 1933, and it reached its peak in 1962-72 in the third phase, after which exploration activity has gone into decline. Examination of the economic, political and social background to the industry reveals that, on the national scene, political events rather than economic and social trends have had greater impact on the fluctuating course of its development. International influences also appear, in many instances, to be of greater significance than domestic factors. Much time and effort have been devoted by industry, government and academics to the analysis of economic, political and social influences on Australia's petroleum exploration but it is quite obvious that the basic determinant Is still the oft-forgotten geologic-technological factor. The condition of the domestic industry depends primarily on the potential of Australia's sedimentary basins and the quality of the technology used to explore them. In the long term, all other influences are temporary in their impact and subordinate in their ultimate effect.
PETROLEUM RESOURCES OF OFFSHORE SOUTHEASTERN AUSTRALIA
Authors: McPhee Ian
Published: August 2017

THE GIPPSLAND Basin is established as a prolific producer of oil and gas from a number of giant fields and other major discoveries are yet to be developed. Further discoveries can be expected in this petroliferous basin which has good future exploration potential. The Bass Basin has been disappointing as commercial discoveries have eluded the explorers. However source and reservoir rocks are present and the basin has future promise if the key to the nature of accumulations can be found. The Otway and Great Australian Bight Basins cover a vast area and include very thick potential source formations and good reservoir facies. Thick sedimentary sequences in the deep basin have been little explored and no significant shows encountered. The basins have potential but there are exploration difficulties to be overcome before full potential can be understood.
PETROLEUM POTENTIAL OF NORTHERN AUSTRALIA
Authors: Wise James C.
Published: August 2017

Sedimentary basins off the northern Australian Coast have been a target of moderate exploration in recent years. Thirty-six offshore wells have been drilled. Over one-third of these have tested hydrocarbons, but to date no commercial fields have been discovered. As a result, large areas may now be downgraded; however, the existence of major accumulations remains a real possibility. Because so many of the structures have been tested, any giant field discovered will more likely be stratigraphically entrapped.
AN EMPIRICAL APPROACH TO THE DETERMINATION OF POROSITY, SHALE PERCENTAGE, AND PERMEABILITY OF PERMIAN SANDSTONES IN THE COOPER BASIN, SOUTH AUSTRALIA
Authors: Porter C. R.
Published: August 2017

Because of the limited yet adequate logging program run in Cooper Basin wells, porosity has been the most difficult parameter to calculate on a zone-by-zone basis. Empirically derived porosities from a gamma-ray (GK)-sonie (Δt) cross-plot show good agreement with core values of porosity. Furthermore shale percentages calculated from these porosities are in good agreement with shale values derived from crossplot techniques involving sonic, density and neutron log response parameters. An approximation of permeability may also be derived from a further simplified chart.
NON-STANDARD GRAVITY ANOMALIES OVER SEDIMENTARY STRUCTURES
Authors: Flavelle A. J. , Anfiloff W.
Published: August 2017

Calculations of the gravity effect of sedimentary structures can now be easily and rapidly made using digital computers. When density variations are normal, they generate gravity profiles which are easily predictable. However, if the general rule regarding increase of density with depth is not fulfilled then anomaly variations can be unexpected. The standard profile for a fault is a change in Bouguer anomaly level, but in some circumstances it can be marked by a positive (or negative) anomaly and no overall change in level. The rather unexpected type of gravity anomaly generated from fairly standard geological sections emphasises the need to carry out modelling calculations based on the known or suspected geology.A gravity anomaly across the boundary between the Galilee and Drummond Basins in central Queensland is analysed. Part of the structure has been determined seismically, and a thickening sedimentary sequence appears to have caused a reverse density contrast with the basement resulting in a positive gravity anomaly. However, the flank of this anomaly has been affected by the negative contribution of a granite body, resulting in a displaced gradient, a minor low which is also displaced, and another minor high and low which could be mistakenly attributed to near-surface structure. A further complication is that a topographic feature occurs at this point of interaction, strongly affecting the multiple density Bouguer profiles, and thus the interpretation. The successful interpretation of this type of situation requires accurate gravity data, its accurate positioning relative to the seismic section, and gravity modelling facilities which allow a rapid trial-and-error approach to modelling.
PETROLEUM, POLITICS AND PRIVATE ENTERPRISE
Authors: Jamieson P.N.
Published: August 2017

For too long in Australia politics and free enterprise have maintained in the main a stance of mutual exclusivity, thereby almost guaranteeing the violent ructions in our economy and society we have seen over the past three years as a result of a change in government. This would appear to be due primarily to a lack of concern and understanding on the part of both the private and government sectors in one another's problems, needs, and aspirations. This gives rise to needless hesitation and lack of confidence in planning investment and development policies. Perhaps nowhere is this better exemplified than in the petroleum and minerals sector where uncertainties as a result of ad hoc and sometimes incomprehensible governmental policy decisions have had extremely deleterious consequences on individual companies, the resources industry, and Australia.There has been and there still is a communications gap between those in private enterprise who aspire to create and expand profits which in turn can be allocated to employee and shareholder benefits and new investment, and those in government who have the responsibility of ensuring that the nation develops economically in such a way as to benefit all Australians to the maximum extent possible. That gap must be closed and remain closed if we are to avoid the upheavals of the past.
THE STRUCTURE OF THE NATURALISTE PLATEAU AND TROUGH
Authors: Jongsma Derk , Petkovic Peter
Published: August 2017

The Naturaliste Plateau is a broad, relatively flat feature lying at a depth below sea level of around 2500 m off the continental margin of southwest Australia. A northerly trending trough with water depths of 3000 to 4000 m separates the Plateau from the continental shelf. Reflection seismic profiles over the Plateau reveal 500 to 1000 m thicknesses of post-Neocomian sediments on the Plateau and up to 2000 m thicknesses in the Trough. An erosional unconformity which is thought to be of Neocomian age separates folded, faulted sediments and intruded metamorphic and igneous basement from the overlying sediments. Deep sea drilling has shown the upper section as being composed of deep-sea clays and oozes. Several hiatuses occur in this upper section.Magnetic anomalies over the Plateau are intense and have magnitudes of up to 850 nT. The anomalies are much more subdued over the Trough. Depths to the bodies causing the magnetic anomalies are estimated to be between zero and three km below the Neocomian unconformity. The gravity field over the Plateau indicates that the crust is of intermediate thickness. A phase of rifting in the Early Cretaceous gave rise to a gently sloping northern margin, whereas rifting in the Eocene produced a steep, faulted, southern margin. The Plateau appears to have been at its present depths since the Early Cretaceous. Prospectivity for petroleum over the Plateau and Trough is poor.
QUEENSLAND PLATEAU AND CORAL SEA BASIN STRATIGRAPHY, STRUCTURE AND TECTONICS
Authors: Taylor Lloyd , Falvey David
Published: August 2017

Seafloor spreading in the Coral Sea Basin is dated by Deep Sea Drilling Project Site 287 as Early Eocene (51 my bp). This requires normal rifting and breakup of an extended Australian continent including the Queensland. Papuan and Louisiade Plateaus as well as the Cretaceous portions of East Papua. A reconstruction based on continental and plateau margin physiography and Papua-New Guinea geology points to a pole of relative opening at lat. 11.3° S., long. 141.3° E. This results in left-lateral transform motion along the Moresby Trough and Bismarck-Lagaip Fault Zones through breakup, plus the deformation of the Owen Stanley sediment pile, and emplacement of the Papuan Ultramafic Belt.Following initiation of sea-floor spreading, subsidence commenced at what are now the marginal plateaus bordering the Coral Sea Basin. A widespread unconformity spanning the late Eocene-mid Ollgocene can be recognised on all plateaus as well as in the basin proper. This is attributed to the commencement of a significant equatorial circulation pattern in the deepening basin and over the subsided plateaus. Stabilisation of this equatorial circulation pattern permitted coral reef development on residual basement highs on the marginal plateaus and eventually) on the subsiding Queensland continental shelf and Papuan stable platform areas in the late Oligocene-early Miocene.On the basis of seismic refraction and gravity evidence, rift valley sequences up to 3 km thick are inferred beneath the Queensland and Townsville Troughs and bordering the Queensland and Papuan Plateaus. Though seismic refraction data are lacking, similar sequences are also inferred beneath parts of the Eastern and Marion Plateaus. Bligh Trough and Louisiade Rise. The age of this pre-breakup rifting is suggested to be mid Cretaceous-Palaeocene although direct evidence is absent.Gravity modelling over the Queensland Trough, Plateau and Coral Sea Basin supports the interpretation from seismic reflection and refraction data. Continental crustal structure with a deep metamorphic layer is indicated for the Queensland Trough and Plateau with a depth to the Moho of 22-28 km. The continental/ocean crust transition occurs towards the base of the continental slope at a water depth of up to 4.5 km along the Queensland Plateau. Crust beneath the Coral Sea abyssal plain is oceanic with a depth to mantle of 11-13 km.
THE SPECIAL ROLE OF STABLE ISOTOPES IN ASSESSING HYDROCARBON OCCURRENCES
Authors: Smith J. W. , Gould K. W. , Rigby D.
Published: August 2017

13C/12C measurements on carbonates associated with crude oils reveal that, although much of this carbonate may represent primary marine deposition, frequently the carbonate has resulted from a secondary biological oxidation of the crude oil itself. Complete utilization of the oil, major changes in the chemical composition of residual oil, or severe reduction of reservoir porosities may eventuate.Where carbonates occur with coals, isotopic evidence shows that any primary siderite arises as a result of early fermentation processes. However, the final isotopic composition of secondary calcite appears to depend on the establishment of isotopic equilibration between carbon dioxide and methane within the coal seam. Biogenic carbonates isotopically similar to those resulting from the oxidation of crude oils have not been commonly detected in coal.Variations in the D and 13C contents of components of plants are well established. Invariably, the lipids are most enriched in both the 'lighter' isotopes. Since the lipids are regarded as being a major source of liquid hydrocarbons, isotopic measurements promise to afford a valuable additional method for following hydrocarbon genesis. Early isotopic data from Victorian brown coals and Bass Strait crudes illustrate that isotopic differences generated during plant growth remain well preserved; however, coal extracts and crude oils appear to be isotopically dissimilar.
A SEISMIC SURVEY IN THE COOPER BASIN IN QUEENSLAND
Authors: King David , Falvey Margaret
Published: August 2017

Seismic reflection and refraction surveys in the Queensland sector of the Cooper Basin have commonly been impaired by strongly reflecting Permian coal measures and irregular near-surface duricrust. Penetration problems have consequently frustrated attempts to delineate the thickness of the assumed-prospective Permian section. The problem is well illustrated in and around Authority To Prospect No. 219P, where extensive seismic exploration has been unable to establish whether the thin Permian section, intersected in the various wells on structural highs, thickens substantially on the associated flanks. The Clifton seismic survey commissioned by the University of Sydney has exploited multifold CDP profiling using an array of shallow explosive sources, in combination with high fidelity digital recording and processing, to provide effective penetration in an area to the west of Alliance Oil Development N.L. Thunda I well.The Clifton data reveal an unconformity beneath the Permian "P" horizon near the Thunda well: the unconformity dies out off-structure It is probable that thickening of a Devonian-Lower Carboniferous section is chiefly responsible for the accumulation of sediments evident in both seismic and gravity data between the Thunda and Galway structures. A combined interpretation of gravity and seismic data indicates a complex pattern of faulting not previously delineated. Two dimensional modelling indicates that the gravity field comprises significant components from structure within the sediments, from the sediment-basement interface, and from isostatic compensation at the Moho.Deep crustal reflections were successfully recorded in the Clifton survey using source charges of only 5 x 4.5 k. An event at 11-12 secs is identified as a reflection from a laminated-type Moho transition zone near a depth of 33 km.
APPLICATION OF SEMI-AUTOMATED AND INTERACTIVE MAGNETIC INTERPRETATION TECHNIQUES IN PETROLEUM EXPLORATION
Authors: Whiteley Robert J. , Long Barry F. , Pratt David A.
Published: August 2017

The magnetic method is used at many stages of a modern petroleum exploration program. Effective interpretation techniques are required to extract maximum geological information from magnetic data. Those techniques which provide the greatest flexibility and make full use of the talents of experienced interpreters are generally of a semi-automated and interactive nature.There are several practical methods for semi-automated quantitative magnetic interpretation in sedimentary basins. Initial interpretation can be achieved by automatic calculation of characteristic anomaly parameters continuously along original or processed magnetic data profiles. Detailed interpretation of more subtle magnetic features can then follow by theoretical anomaly comparison with field anomalies using interactive portfolio modelling or by direct computation.Examples of the use of these semi-automated techniques in the interpretation of basement and intra-sedimentary magnetic anomalies show that combined magnetic and seismic interpretations can provide considerable insight into the structural processes which have operated in a sedimentary basin.
PREDICTION OF RESERVES AND PRODUCTION PERFORMANCE BY SIMULATION: HALIBUT FIELD
Authors: Taylor F.
Published: August 2017

Production from Halibut began in 1970 and after seven years 44.7 megatonnes (354 million barrels) of oil have been produced from initial Halibut reserves estimated at 82.1 megatonnes (653 million barrels). Thus the field is 54% depleted and approaching the point where oil production rates will start to decline rapidly due to increasing production of formation water. The accurate prediction of this decline point in time is of critical importance in scheduling the installation of artificial lift facilities. As a result of a 1974 reservoir engineering study, which formed part of the basis for a 53% increase in estimated Halibut reserves, predictions of near term performance have proved to be reasonably accurate and substantiated a decision in 1974 to program installation of artificial lift facilities for a 1978 start-up.A significant part of the 1974 study was the comparison of reservoir performance data obtained through regular reservoir surveillance and specialized well testing programs with predictions of reservoir performance from a three-dimensional, two-phase simulation model of the field. Reservoir description parameters used in the model were varied until its performance matched actual history for the period in hand. In achieving a history match, the model was adjusted: firstly, to reflect permeabilities estimated by in situ pressure build-up and pulse tests (these values being more than twice as high as those measured in recovered core material); secondly, to simulate restricted areas of vertical communication as defined by pulse testing between different sand units; and thirdly, to match water contact rises indicated by TDT logging. Once the model was calibrated by this method it was used to predict field performance over the whole life of the field and to schedule and size additional production facility needs.Since completion of the study, two years of additional reservoir behaviour history have become available. Performance predictions made after achieving a satisfactory history match have been in good agreement with actual performance over the past two years and work is well along on facilities design and implementation.
THE CAROLINE CARBON DIOXIDE FIELD AND ASSOCIATED CARBON DIOXIDE OCCURRENCES, GAMBIER EMBAYMENT, SOUTH AUSTRALIA
Authors: Mulready Jack
Published: August 2017

Subsurface occurrences of high purity carbon dioxide are comparatively rare although widespread geographically. Within the Gambier embayment of the Otway Basin two substantial examples of carbon dioxide entrapment have been encountered, at Kalangadoo No. 1 with 147 tonnes/day (2.8 mmcf/day) and Caroline No. 1 with 142 tonnes/day (2.7 mmcf/day). Australia's only commercial production of subsurface CO2 is the Alliance Caroline well which produces at an annual rate of around 15 000 tonnes (0.3 BCF) per annum of liquid CO2. Treatment is limited to removal of the 1% hydrocarbon content of the well-head stream by simple fractionation.At Kalangadoo No. 1 the CO2 is found in steeply dipping (?) Palaeozoic arenaceous sediments (unconformity trap), with porosity coming from secondary fractures. By contrast, at Caroline No. 1 the host sediments are sands of the Cretaceous Waarre Formation (fault trap) with primary porosity.Throughout the world several diverse sources of subsurface C02 have been established. The most significant occurrences are in regions with vulcanism in close proximity to carbonate sediments. These show a random distribution with regard to age and nature of host sediments. Isotopic studies (for both carbon and oxygen) have been employed in an attempt to further clarify the source of subsurface CO2 at the Caroline Field. Although not conclusive the evidence to date suggests that a volcanic origin would seem the most likely.
EARLY SUBSEA PRODUCTION SYSTEM
Authors: Bilderbeek B. H. van
Published: August 2017

As a result of the high capital expenditure and construction time required for fixed platform type off-shore production, Vetco has investigated methods for early subsea production, utilising floating platforms. Several systems have been developed which offer flexibility when considering field size, geometry, water depth, etc.The "Modular Template System" is applicable where up to eight wells are to be completed. The modular approach of this system offers the user a system which requires relatively low initial capital investment. The basic template structure accommodates only two wells and is, therefore, not significantly larger in size than a conventional drilling base.The "Multi-Well (unitised) Template System" employs a one piece template structure which car. accommodate up to eleven wells. This substantial template requires only a first time installation and is recommended for use in situations where the total well requirement has been predeterminedAs a third alternative, a "Satellite Well System" has been developed which has individual satellite wells located strategically throughout the field. Flowlines from these wells converge to a central riser manifold.The Vetco "Early Subsea Production System" transports the production fluid from the template/riser manifold to the floating platform through an individual flowline riser system. The simplicity of this approach provides reliability as well as ultimate well control.Several options have been developed to allow use of the "Early Subsea Production Systems" in those situations where gas injection, water injection, gas lift and/or TFL serviceability are required.The Vetco "Early Subsea Production Systems" are solutions for the recovery of hydrocarbons from fields located in water depths which allow the use of standard guideline techniques.With drilling operations being conducted in ever deeper waters, a separate design study has been conducted to adapt the "Early Subsea Production Systems" to deep water applications.