Chapter 1 An overview of the petroleum geology of the Arctic (original) (raw)
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Geological Society, London, Memoirs, 2011
Over the past 75 years, hydrocarbon exploration of Arctic regions north of the Arctic Circle (66°N) has yielded some 450 discoveries which collectively account for 2.5% of global conventional liquids discovered to date and 15.5% of the world's discovered conventional natural gas. Accumulations occur in rocks ranging from Cambrian to Pleistocene in age but 94% of all Arctic hydrocarbon resources occur in clastic reservoirs of Mesozoic age. Although discoveries have been reported from 15 different basins onshore and offshore Alaska, Canada, Norway and Russia, 75% of all discovered resources are located in the portion of Russia's Western Siberia Basin that lies north of 66°N. Hydrocarbon accumulations discovered in the Arctic region have been generated from nearly 40 different petroleum systems. The main elements of these petroleum systems such as sources, reservoirs and seals are described and the chronology of these depositional events is summarized in two chronologic charts ...
Resources, 2021
The Timan–Pechora oil and gas province (TPP), despite the good geological and geophysical knowledge of its central and southern regions, remains poorly studied in the extreme northwestern part within the north of the Izhma–Pechora depression and the Malozemelsk–Kolguev monocline, and in the extreme northeast within the Predpaikhoisky depression. Assessing the oil and gas potential of the Lower Paleozoic part of the section is urgently required in the northwestern part of the TPP, the productivity of which has been proven at the border and in the more eastern regions of the province (Pechora–Kolva, Khoreyverskaya, Varandei–Adzva regions), that have been evaluated ambiguously. A comprehensive interpretation of the seismic exploration of regional works was carried out, with the wells significantly clarifying the structural basis and the boundaries of the distribution of the main seismic facies’ complexes. The capabilities of potentially oil- and gas-producing strata in the Silurian–Low...
Preliminary Geospatial Analysis of Arctic Ocean Hydrocarbon Resources
2008
Ice over the Arctic Ocean is predicted to become thinner and to cover less area with time (NASA, 2005). The combination of more ice-free waters for exploration and navigation, along with increasing demand for hydrocarbons and improvements in technologies for the discovery and exploitation of new hydrocarbon resources have focused attention on the hydrocarbon potential of the Arctic Basin and its margins. The purpose of this document is to 1) summarize results of a review of published hydrocarbon resources in the Arctic, including both conventional oil and gas and methane hydrates and 2) develop a set of digital maps of the hydrocarbon potential of the Arctic Ocean. These maps can be combined with predictions of ice-free areas to enable estimates of the likely regions and sequence of hydrocarbon production development in the Arctic. In this report, conventional oil and gas resources are explicitly linked with potential gas hydrate resources. This has not been attempted previously and is particularly powerful as the likelihood of gas production from marine gas hydrates increases. Available or planned infrastructure, such as pipelines, combined with the geospatial distribution of hydrocarbons is a very strong determinant of the temporalspatial development of Arctic hydrocarbon resources. Significant unknowns decrease the certainty of predictions for development of hydrocarbon resources. These include: 1) Areas in the Russian Arctic that are poorly mapped, 2) Disputed ownership: primarily the Lomonosov Ridge, 3) Lack of detailed information on gas hydrate distribution, and 4) Technical risk associated with the ability to extract methane gas from gas hydrates. Logistics may control areas of exploration more than hydrocarbon potential. Accessibility, established ownership, and leasing of exploration blocks may trump quality of source rock, reservoir, and size of target. With this in mind, the main areas that are likely to be explored first are the Bering Strait and Chukchi Sea, in spite of the fact that these areas do not have highest potential for future hydrocarbon reserves. Opportunities for improving the mapping and assessment of Arctic hydrocarbon resources include: 1) refining hydrocarbon potential on a basin-by-basin basis, 2) developing more realistic and detailed distribution of gas hydrate, and 3) assessing the likely future scenarios for development of infrastructure and their interaction with hydrocarbon potential. It would also be useful to develop a more sophisticated approach to merging conventional and gas hydrate resource potential that considers the technical uncertainty associated with exploitation of gas hydrate resources. Taken together, additional work in these areas could significantly improve our understanding of the exploitation of Arctic hydrocarbons as ice-free areas increase in the future. iv Key Findings Overall conclusions from this study are as follows: • Geographic areas with the highest hydrocarbon potential are Arctic Alaska, eastern Greenland, the East and West Barents basins in Norway and Russia, and the South Kara/Yamal basins of Russia. • Global interest in Arctic hydrocarbon resources is dynamic, increasing dramatically as global demand for hydrocarbon resources increases. • The Arctic contains ~13% of global undiscovered oil, ~30% of global undiscovered conventional natural gas, and as much as one third of global gas hydrate. • Geospatial analysis of marine Arctic hydrocarbon resources can be linked to progressively icefree areas enabling estimation of possible development areas. • The rate and location of future hydrocarbon exploration activities will depend not only on richness of hydrocarbon potential, Arctic ice, and potential for supporting infrastructure, but also on the opening of areas by various governments for industry exploration.
Petroleum potential in western Sverdrup Basin, Canadian Arctic Archipelago
Bulletin of Canadian Petroleum Geology, 2000
One hundred nineteen wells drilled in the Mesozoic structural play of western Sverdrup Basin resulted in one of the technically most successful Canadian petroleum exploration efforts discovering 19 major petroleum fields, including 8 crude oil and 25 natural gas pools. The total original in-place reserve of 294 x 10 6 m 3 crude oil and 500 x 10 9 m 3 natural gas at standard conditions is about equivalent to 10% and 23%, respectively, of the remaining national reserves of conventional crude oil and natural gas. Using and comparing both discovery process and volumetric petroleum assessment methods the petroleum resource can be confidently estimated to be between 540 x 10 6 m 3 and 882 x 10 6 m 3 original in-place crude oil, and 1242 x 10 9 m 3 to 1423 x 10 9 m 3 original in-place natural gas at standard conditions. The total resource is expected to occur in approximately 93 fields, containing about 25 crude oil pools and 117 natural gas pools larger than or equal to the smallest oil and gas pools discovered. Both exploration data and resource assessment results suggest that the largest natural gas pools were found efficiently, and that 9 of the 17 largest gas pools are now discovered. The two largest natural gas pools are believed to have been discovered in the Drake and Hecla fields. There remain undiscovered 17 or 18 natural gas pools larger than or equal to 10 x 10 9 m 3. In contrast, oil pools, of which no significant discoveries were made during the first nine years of exploration, appear to have been found inefficiently, if not randomly. Although five of the ten largest crude oil pools have been discovered, there remain undiscovered between 7 and 9 crude oil pools expected to have individual resources greater than or equal to 10 x 10 6 m 3. Among these is an undiscovered oil pool predicted to be greater than or equal to 100 x 10 6 m 3, similar in size to the largest discovered crude oil pool at Cisco in the Awingak Formation. The ability to compare discovery process and volumetric methods of assessment increases confidence in these results, while illustrating the relative merits of each technique. The Geo-anchored discovery process model analyzes oil and gas pools simultaneous while it independently and objectively estimates numbers of accumulations, without reference to subjective exploratory risk evaluations or efficiencies of geophysical prospecting. This suggests that similar assessments could be improved by: a) the use of the Multivariate Discovery Process Model to obtain unbiased distributions of reservoir volumetric parameters, b) the simultaneous estimation of oil and gas pools numbers using the Geo-anchored method, and c) the validation of assessments by comparing the predictions of different methods.
In the last 20 years, over a hundred HC fields were discovered which reserves exceed 500 million barrels of oil equivalent. Almost half of the gas reserves were discovered at shallow sea depths. Large gas reserves were found on the shelf of Iran and Indo-nesia. Oil giants were mainly discovered in the basins on the passive margins of West Africa, the Gulf of Mexico, Brazil, and the Caspian Sea. It is assumed that about 100 billion tons of hydrocarbons in oil equivalent are concentrated on the continental shelf of the Russian Federation (Kaminsky et al., 2006). However, the share of oil accounts for about 13%; the rest are gas resources. The main oil-and-gas resources are recorded on the largest Arctic shelf with major sedimentary basins containing oil and gas; this is about 80% of the total resources of the shelf. Generally , the geological and geophysical exploration maturity of the Russian shelf is low compared to the developed oil-and gas-producing areas of the world and is highly irregular. Seismic and drilling exploration maturity of the Russian shelf is tens and hundreds of times lower than the exploration maturity of the foreign water areas in the USA, Norway, and the United Kingdom. On the entire vast shelf of Russia with an area of about 6.5 million km 2 , by 2010, there were only 1,345,000 line km of seismic surveying , that is, the density is 0.2 km/km 2. For comparison, in the North Sea, the density of seismic surveying exceeds 4 km/km 2. Overall, on the Russian shelf, 252 wells were drilled including the parametric and wildcat wells. The best studied shelf areas are the southern seas, the shelf of Sakhalin, and the southern Barents and Kara Seas. The northern Barents and Kara Seas and the entire East Arctic shelf were not covered by the orientation-parametric drilling (Laptev, East Siberian, and Chukchi Seas). There the network of the seismic lines is rare or almost absent, and the general level of the geological and geophysical exploration maturity is rather low. The East Siberian Sea is the least-studied sea in the Russian Arctic. The specific feature of this area with a shallow depth and a thick ice cover is the necessity of using special under-ice equipment for its development. The geological structure of a number of shelf basins in the Arctic seas of Russia is in many respects similar to that of the passive margins of the Atlantic Ocean or the