Full List of Geotrack Thermal History Studies with detailed well/sample listing
A fundamental issue concerning prospectivity in the region is the timing of active hydrocarbon generation from potential Devonian and Cambrian source rocks in the region. As an example - previous work in the region around Parcels 1 and 2 has suggested that the Devonian section reached peak maturity after Cretaceous time – i.e., in this case, there would be no break in the downhole maturity trend at the sub-Cretaceous unconformity. Our new integrated AFTA and VR results clearly shows this model is incorrect, and was likely to have been constructed by falsely attributing caved Cretaceous organic matter to an in-situ Devonian population. The new mini-well series also provides previously unavailable and direct control on the timing and magnitude of maturation levels of potential Cretaceous source rocks in the region. Such data and conclusions are essential for targeting commercial discoveries.
Apatite fission track analysis (AFTA®), combined with VR (vitrinite reflectance) data, has been used to directly measure the timing, intensity and regional variation of multiple paleo-thermal events across northern Alaska in this study. AFTA provides direct measurement of the timing and magnitude of the paleo-thermal episodes responsible for maturity development and hydrocarbon generation, while VR data also provide control on the maximum paleotemperature. The paleotemperature estimates derived from AFTA and VR also provide quantitative constraints on paleogeothermal gradients, paleo-heat flow and amounts of section removed during exhumation.
Despite significant exploration success in the last five years along the West African margin, the margin remains under-explored and basic questions about the petroleum systems remain unanswered. Key questions relate to the unroofing (or uplift) history and the corresponding thermal history of the margin, in relation to its effect on hydrocarbon maturation history, and sources and distribution of reservoirs. This study is designed to answer those key questions on a broad regional basis by providing a comprehensive thermal history framework and exhumation history for the margin from Gabon to Namibia. Samples from wells in the offshore region, and from both wells and outcrops onshore will be included in this vast regional study
Northern Carnarvon Basin Research Study
A new study designed to investigate the timing, magnitude and extent of paleo-thermal effects, and to provide an independent assessment of maturity levels, using AFTA®
Analysis of ~30 new AFTA® (apatite fission track analysis) samples from 13-15 wells will be the basis for evaluating variation in thermal, tectonic and maturation histories throughout the Carnarvon Basin. Using the latest AFTA® and THR™ (thermal history reconstruction) technologies, this regional study (the first of its kind for this area), will delineate the timing and extent of paleo-thermal effects in each study well, plus provide an independent test of maturity levels in Mesozoic source rocks. Integration of the new AFTA results with existing VR and FAMM data will arm explorationists with an independently-generated thermal and maturation history framework, which can later be used to constrain more detailed basin models, and thus help identify which play-types are best targeted in different parts of the Carnarvon Basin.
- Great Australian Bight
- The proposed study incorporates new AFTA® and vitrinite reflectance results to provide a constrained thermal history framework for understanding the structural, source rock maturation and hydrocarbon generation histories of the Great Australian Bight Basin, including the Duntroon Basin and Polda Trough.
- Papua New Guinea
This study program is designed to answer specific exploration questions that have long confronted explorationists working the Papuan Basin, PNG. Fundamental exploration issues in the Fold Belt and Foreland of PNG remain unresolved. These include:
- Agreement on a unified tectono-stratigraphic framework for the Papuan Basin encompassing both Foreland and Fold Belt regions.
- The relative effects (structural and thermal) of major tectonic events in the region.
- Establishment of accurate thermal histories across the basin.
- Evaluation of generation and charge history including local variances.
- Determination of the type (oil versus gas) and relative volumes of hydrocarbons generated.
- Effect of uplift, erosion and fresh water influx on hydrocarbon accumulations.
The study objectives rely on the combined expertise and experience of Keiraville Konsultants (experts in source rock characteristics and maturity), Geotrack International (experts in measured thermal history), and PetroConsult (experts in 2-D basin modelling). The project is designed to provide constraints on the issues outlined above, and only when taken together, will they allow a better understanding of petroleum systems in the Papuan Basin. Such a project, bringing together world experts in their own field to answer fundamental unresolved questions in PNG, has not been attempted previously.
- Offshore Canning Basin
Exploration activity in the onshore Canning Basin has revealed numerous small hydrocarbon accumulations generated from Paleozoic source rocks. Previous thermal history studies carried out in this region in connection with hydrocarbon and mineral (MVT) exploration have revealed a series of episodes of heating and cooling, particularly in Triassic-Jurassic and Devonian times. Because of variation in the magnitude of these episodes across the basin, the time at which source rocks reached maximum maturity levels, and hence the timing of peak hydrocarbon generation, shows significant variation across the onshore region.
The relative significance and influence of these events on hydrocarbon generation and migration in the offshore region are not well understood, but are sure to exert a critical control on regional hydrocarbon prospectivity. A rigorous assessment of the thermal history, with particular emphasis on the timing of maturity development, is therefore a vital part of prospect evaluation in this region.
- Londonderry High
The Londonderry High, situated centrally to the main producing fields of the Timor Sea (including Challis, Elang and Petrel), is now a focal point of renewed exploration activity. The area has two-fold potential in that it may have been charged by migrating oil generated at the flanks of the High from Jurassic and Early Cretaceous source rocks, or by local generation from Permian source rocks. Either way, the thermal and burial/uplift history of this platform area is crucial to the understanding of the region's hydrocarbon prospectivity.
In this study, THRTM (Thermal History Reconstruction) will be employed to determine the timing and magnitude of maximum paleotemperatures, assess the maturation levels of key source rock units, directly determine paleogeothermal gradients, and estimate section removed by uplift and erosion. These issues are vital to to a rigorous assessment of the hydrocarbon potential of the Londonderry High, and are addressed by direct and quantitative assessment of the thermal history using new AFTA and VR results.
- Southern Bonaparte Basin
The Southern Bonaparte Basin report describes the results of a non-exclusive study in which Apatite Fission Track Analysis (AFTA®) and Vitrinite Reflectance (VR) are used to identify, characterise and quantify the major episodes of heating and cooling which have affected the southern Bonaparte Basin, including onshore regions. New information is used to reconstruct a thermal history framework from which the burial and uplift, and hydrocarbon generation history can be understood. This report complements and extends a previous non-exclusive study of the Bonaparte Basin (Geotrack Report #337) carried out by Geotrack International in 1992. Wells covered by this study include Berkley-1, Tern-1, Penguin-1, Petrel-2, Flat Top-1, Barnett-1, Lacrosse-1 and Keep River-1.
- Browse Basin
Exploration activity in the Browse Basin began in 1963, with interest increasing significantly in the past five years owing to recent drilling success in the region. The Browse Basin is believed to have experienced a complex geological history consisting of several episodes of heating related to Paleozoic and Mesozoic rifting, pre- and post-breakup volcanism, possible Triassic and Miocene inversion, and tectonics related to salt movement. The relative significance and influence of these events on hydrocarbon generation and migration are not well understood and this project aims to resolve these problems by direct assessment of the timing and magnitude of paleo-thermal effects in the Carboniferous to Tertiary section. A rigorous assessment of the thermal history, the timing of maturity development, and the reliability of existing VR data is a vital part of prospect evaluation in this region.
- Torquay Basin
The Torquay Sub-Basin study area covers V99-1 in that part of the Otway Basin offshore from Geelong to Cape Otway. The Early Cretaceous section in the Otway Basin contains proven oil and gas source intervals but the lack of hydrocarbon indications in the three wells drilled in the Torquay Sub-Basin to date has resulted in a pessimistic prognosis for commercial success. However, the complicated tectonic history of the region and its profound influence on the thermal history of potential source horizons has not been fully considered in past programs, and hence the hydrocarbon maturation and generation history is poorly understood. Application of AFTA and VR data has allowed a complex thermal history to be unravelled, including the identification and quantification of key episodes of heating in the Mesozoic and Tertiary. These measured constraints are critical to the understanding of maturation and the timing of episodes of hydrocarbon generation relative to structural development.
- Gippsland Basin - AREA V99-2
The offshore Gippsland Basin has been a major producer of oil and gas but as exploration in the Basin has matured operators are focussing on the potential of the infra-Latrobe Siliclastics and Golden Beach Subgroup sequences. Area V99-2 lies adjacent to the major Kingfish Oilfield and covers part of the Central Deep of the basin. Two wells in the area discovered oil and gas condensate in the basal Latrobe Siliclastics and Golden Beach Subgroup sandstones, although the discoveries are considered to be uneconomic. In this study the hydrocarbon potential and generation history of these units will be investigated, particularly in relation to the Oligocene to mid-Miocene compressional phase which was largely responsible for the structural traps within the basin.
This study includes analysis of wells within the release block and adjacent regions. The conclusions are based on re-interpreted and enhanced AFTA and VR data for the Anemone-1(1A) and Angler-1 wells, together with data from Archer-1, Mudskipper-1, Hermes-1, Moray-1, Helios-1, Ayu-1 and a key pseudo well.
- Onshore Otway
Geotrack's new onshore Otway Basin study will provide a constrained thermal history framework to improve the understanding of source rock maturation and structural evolution of that part of the onshore Otway Basin pertaining to VIC/O99(01) and (02). The study builds on over 20 years experience in assessment of the tectonic, thermal and structural development of the Otway Basin.
The work program has been specifically designed to address major elements of the thermal and structural history that have an important bearing on the hydrocarbon prospectivity. Key aspects include the magnitude of Early Cretaceous heat flow, timing of major periods of uplift and erosion and thermal history assessments of the currently known hydrocarbon occurrences.
Constrained histories will be provided for all of the hydrocarbon exploration wells and selected deep stratigraphic bores in the two open areas, plus a number of nearby exploration wells that can provide additional insight into the thermal and structural evolution.
- Offshore Namibia
The Offshore Namibia region is largely unexplored, with only six wells drilled outside the Kudu licence. However, many aspects of the geology of the region are favourable for hydrocarbon prospectivity, and the results from the Walvis Basin reveal a Late Tertiary heating pulse that has significantly enhanced maturity levels across the region. An explanation of heating in terms of deeper burial seems most likely, although other explanations may be possible. Results from the Orange Basin, around the Kudu field, show a simpler thermal history in this region, and suggest that in this region all units are presently at their maximum burial depths. Overall, the results of this study suggest considerable potential for oil generation across much of the offshore Namibia region, in contrast to the previously prevailing opinion of this region as largely gas-prone.
- North of Shetlands
The thermal history of the Mesozoic and Tertiary section and its effects on maturity development and oil generation are factors which are critical to the prediction of hydrocarbons on the Atlantic margin north of the Shetland Islands. Geotrack's studies in the West of Shetlands, Rockall Trough and West of Scotland regions have shown that the basins on the Atlantic margin have experienced multiple thermal episodes throughout their histories and have highlighted the importance of knowing which episodes were responsible for maturity, thus providing the basis for understanding the relationship between generation and the timing of trap formation. This work also revealed that contrary to conventional concepts, the Tertiary igneous activity and associated fluid movement has contributed significantly to source rock maturity over wide regions. Investigation of these effects is a key aim of the North of Shetlands project.
- Seychelles
The Seychelles microcontinent covers an area of approximately 300,000 km2 within the western Indian Ocean, an area equivalent to the productive North Sea or the Texas/Louisiana Gulf Coast province. Until the Late Cretaceous, this microcontinent was sandwiched between northern Madagascar and the west coast of India; that is, between two giant tarsand fields and what became the Bombay High Offshore Oil Province. This study (now available) includes new AFTA and VR analyses from offshore wells and onshore localities. Results indicate several episodes of heating, the timing of which is constrained by AFTA. This project provides the most detailed and comprehensive investigation of the thermal history that has yet been attempted in the region.
- Oklahoma
The Southern Oklahoma oil and gas fields are interspersed amongst a complex system of deformed mountain belts, uplifted crystalline basement and enormously thick foreland basins. There are no units throughout most of the region any younger than Pennsylvanian in age and for this reason, conventional studies using the preserved stratigraphy have been unable to answer questions which are fundamental to exploration. With the strategic use of thermal history data, this project will provide practical information about the structure and timing relationships which are essential parameters for modelling oil and gas generation and entrapment in the region.
- Falklands
Thermal history reconstruction is a critical aspect of exploration acreage evaluation. This project has for the first time acquired reconnaissance data on the thermal history of the Falkland Islands region. The report includes a reconstruction of the Paleozoic to Tertiary thermal evolution of the outcrop area, based on interpretation of new AFTA and vitrinite reflectance data. The results are important in the evaluation of the thermo-tectonic evolution of the Islands and to the proper understanding of the petroleum system, providing key constraints for modelling maturity development in potential source rocks and prediction of hydrocarbon generation in the offshore basins.
- Quadrant 53 (UK)
Despite the close proximity to the huge S North Sea gas fields, and the potential for accumulation of hydrocarbons generated from known Carboniferous source rocks, to date most of Quad 53 has been only lightly explored by drilling. The absence of thick Zechstein salts makes the traditional Permian gas reservoir targets potentially more risky than in the areas to the north, but other parts of the section including the Carboniferous remain prospective. The basin margin setting and the potential for hydrocarbon generation over a long period of geological time make proper assessment of thermal history, the timing of maturity development and the timing of major episodes of structuring, uplift and erosion a vital part of prospect evaluation in this region. This thermal history study is now available.
- West of Scotland
Geotrack initiated the West of Scotland project in May 1995 to acquire the thermal history data needed to recognise and characterise the thermal episodes that have affected the region, and assess the development of maturity, hydrocarbon generation and tectonic evolution. The data produced by the project are critical to understanding and predicting oil and gas generation and hence the evaluation of acreage in the area.
- North Irish Sea
The Northern Irish Sea study area covers the southern parts of UK Quadrants 112 and 113 the Isle of Man and its territorial waters. The Carboniferous in this region contains proven oil and gas source intervals but the absence of rocks younger than Triassic over most of the region has meant that their burial and uplift, and hence hydrocarbon maturation and generation history is poorly understood. Application of AFTA and VR data has allowed a complex thermal history to be unravelled, including the identification of several episodes of heating in the Tertiary, Mesozoic and earlier periods of the basin history. These data are critical to the understanding of maturation and the timing of episodes of hydrocarbon generation relative to structural development.
- Timan Pechora
The Timan-Pechora Basin of northern Russia lies along the western margin of the Ural Mountains and forms the northernmost foreland basin developed during the collision of the European and Asian continental plates. The collision commenced in the Early Carboniferous but the exact timing of the basin's structural development is complicated by the presence of a series of north-south trending inverted highs which appear to young from east to west and span the emplacement of the Urals.
The timing and magnitude of maximum paleotemperatures is critical for evaluating the remaining oil potential of each structural domain within the basin and the amounts of uplift and erosion provide a vital component for integrated basin modelling in the region.
- West Siberian Basin
Geotrack International has negotiated an agreement with The Nedra Enterprise, a large Russian exploration company, enabling complete access to core and cuttings samples, well log and seismic data, geological information, from the Tyumen deep well (currently at ~7000m in Triassic). This well penetrates a key stratigraphic section in the deepest part of the basin near the Urengoy supergiant field. The samples and data are now held by Geotrack, including 40 samples of conventional core and cuttings over a 7000 m section. The study in progress will carry out a range of new analyses on the samples and produce an integrated data package and comprehensive interpretation report, including a report on the geological and tectonic setting of the area.
- West of Shetlands
The West of Shetlands region, offshore UK, is an area that has seen significant exploration success in the last few years and several new oil and gas finds have been announced recently. Evaluation of the full potential of this region requires detailed knowledge of the thermal history - critical to the understanding of oil and gas generation history and hence to the proper assessment of hydrocarbon prospectivity. This study promises those constraints.
- Barents Sea
This comprehensive study of the thermal history of the Norwegian Barents Sea region has revealed a complicated tectonic history which has a profound influence on the maturation history of potential source rock horizons. Application of AFTA and VR data has allowed this complex thermal history to be unravelled, including identification and quantification of key episodes of heating and cooling during the Mesozoic and Tertiary.