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OIL AND GAS DEVELOPMENTS IN ARCTIC NORTH AMERICA Abstract Extensive exploration in Arctic North America since 1965 has indicated the presence of at least three sedimentary basins that contain major reserves. These are: the "North Slope" Basin in Alaska; the Beaufort Basin surrounding the delta of the McKenzie River in Canada and the Sverdrup Basin of the Canadian Arctic Islands. The giant Prudhoe Bay field, containing both oil and gas, dominates the Alaskan scene. The Canadian basins, on the other hand, have numerous but smaller discoveries and to date are predominantly gas. The geological factors which determine these distributions are becoming better understood and indicate a large remaining potential. Résumé Les recherches poussées effectuées dans les régions polaires de l'Amérique du Nord depuis 1965 ont indiqué la présence d'au moins trois bassins sédi- mentaires qui contiennent des réserves importantes, à savoir le bassin du "North Slope" en Alaska, le bassin de Beaufort qui entoure le delta du McKenzie au Canada et le bassin de Sverdrup dans les îles Canadiennes de l'Arctique. Le gisements gigantesque de la baie de Prudhoe, qui contient du pétrole et du gaz, est de loin le plus impor- tant de l'Alaska. Dans les bassins canadiens, par contre, on a découvert jusqu'ici de nombreux gisements plus petits, qui contiennent surtout du gaz naturel. On commence à mieux comprendre les facteurs qui influent sur la répartition de ces gisements et qui indiquent l'existence de réserves importantes encore inexplorées. 1.
For the purpose of this paper, Arctic North America is that area north of the Arctic circle, extending from Alaska in the west to Greenland in the east (Fig. 1). The Arctic is truly one of the world's frontier areas. The geography and climate will require great techno- logical advances to allow successful development of oil and gas reserves. It is probably the most difficult and costly environment yet explored for oil and gas anywhere in the world. Despite these constraints, exploration in the form of geological investigations and drilling has identified three major hydrocarbon-bearing areas-the North Slope area of Alaska, the Beaufort Basin at the mouth of the Mackenzie River, and the Sverdrup Basin in the Canadian Arctic Islands. We will concern ourselves mainly with the geology, exploration history, logistics, by DONALD K. McIVOR Imperial Oil Ltd., Toronto, Ontario, Canada, and GEORGE GRYC U.S. Geol. Survey, Menlo Park, California, U.S.A. oil occurrence factors and future potential of these three areas. Geography and climate place severe limitations on Arctic exploration and development. Onshore opera- tions take place mostly during the long winter, with little or no daylight in the coldest mid-winter period. Summer operations are severely restricted, particularly in the North Slope and Beaufort areas, because of the ecologically sensitive nature of the surface layer
Lofting, J. W. (Burmah Oil Company of Australia Ltd, Nedlands, Australia) | Crostella, A. (Burmah Oil Company of Australia Ltd, Nedlands, Australia) | Halse, J. W. (Burmah Oil Company of Australia Ltd, Nedlands, Australia)
EXPLORATION RESULTS AND FUTURE PROSPECTS IN THE NORTHERN AUSTRALASIAN REGION Abstract The geology is summarised for an area encompassed by the Outer Banda Arc and the Papua Fold Belt to the north, and by the Australian Shield to the south. The relationships between the stable Australian con- tinent, the Southeast Asia overthrust zone and the intervening sedimentary basins are discussed. A variety of basin types are present. Exploration to date has been most rewarding in the Mesozoic coastal pull-apart basins of the Australian Northwest Shelf. Further hydrocarbon-producing provinces should be defined with continuing exploration. Upper Tertiary to Pleistocene peri-orogenic basins are considered particularly attractive. The allochthonous regions also have potential. Résumé On donne un aperçu géologique de la zone s'étendant depuis l'Arc Externe de Banda et la ceinture plissée de Papua au Nord jusqu'au bouclier Australien au Sud. On discute les relations entre le continent Australien stable, la zone de chevauchement du Sud-Est Asiatique et les bassins sédimentaires intermédiaires. Différents types de bassins sont représentés. Jusqu'à maintenant les bassins côtiers Mesozoïques de rupture de la plateforme Nord-Ouest Australienne ont été les plus rémunérateurs pour la recherche pétrolière. Cependant la poursuite de l'exploration devrait mettre en évidence d'autres provinces pétrolières. Dans cette optique les bassins périorogéniques, Tertiaire supérieur à Pleistocène, semblent particulièrement interessants. Les régions allochtones présentent aussi des possibilités. 1.
The area covered broadly comprises the region lying between the stable Australian craton and the highly tectonised southeastern part of the Indonesian island arc regime, and is bounded to the south by the present continental coastline of Australia. The northwestern limit is ill-defined in the region south of latitude 123, as deep water has so far discouraged exploration in this direction. Northwards, to approximately latitude 4"S, it is bounded by the front of the Outer Banda Arc. The Irian Jaya/Papua New Guinea foothills belt and the positive Cape York-Oriomo Ridge feature of the Carpentaria Basin are taken as the northern and eastern limits, respectively. The basic geologic frame- work is shown in Fig. i(a), and Fig. l(b) is a location map. The sinuous nature of the region is primarily due to the trends of major subduction zones which have by M. J. W. LOFTING, A. CROSTELLA and J. W. HALSE, Burmah Oil Company of Australia Ltd, 10 Stirling Highway, Nedlands, Western Australia 6009, Australia accommodated relative movement of the Australian plate both westwards and northwards. A variety of sedimentary basin types is present. These range from intra-cratonic Palaeozoic basins to Mesozoic coastal basins developed along a cratonic margin, stable Tertiary shallow-water carbonate basins, and Upper Tertiary peri-orogenic clastic ba
The Cordilleran region extends from the east front of the Rocky Mountains to the Pacific Ocean. The present aspect of this province of great mountain ranges, intermontane valleys and plateaus reflects many spasms of crustal deformation, some of which affected areas of earlier deformation. No attempt is made in the present paper to untangle the complex tectonic history of the Cordillera and to pin down the various structures to any particular epoch of deformation. In the Rocky Mountain region, most of the structural units described probably reached essentially their present forms during what is commonly called the Laramide revolution, active from Late Cretaceous into Early Tertiary time. The Laramide revolution was, however, only a major episode in a long continued history of deformation which started in the far west at least as early as the Triassic reached a culmination there in the Nevadan revolution near the end of the Jurassic, and was active in one place or another throughout the Cretaceous. In a general way, belts of intense orogeny travelled eastward with the passage of time, so that effects of the Laramide revolution were far more violent in the Rocky Mountain region than farther west. Although changing in form from time to time and from place to place, this mighty revolution persisted through the Tertiary and maybe still going on.
PHYSIOGRAPHY OF THE CORDILLERAN REGION
The Cordilleran region, largely mountainous, contrasts strikingly with the monotonous Great Plains to the east, but the western Great Plains were affected by deformation as well as the Cordillera because they rises steadily westward to the east front of the Rockies. Starting with elevations above sea level of a few hundred feet in the Mississippi and Missouri Valleys, the surface rises to 2000 feet in South Dakota, Nebraska, Kansas and Oklahoma, and to 4000 feet in places along the western borders of these states. At the foot of the Front Range elevations reach5 000 feet.
This vast region o f the western Great Plains and Rocky Mountains lay beneath the sea during Upper Cretaceous times, about 6 0,000,000 years ago. Since the Rockies attain elevations exceeding 14,000 feet, and formerly were higher, it is evident hat a sizable segment of the earth's crust has been mightily uplifted.
Within the Cordilleran region relief is strong. Great ranges such as the Front Range, Sangre de Cristo, Sawatch, Uinta, Wasatch and Sierra Nevada contrast with Death Valley, partly below sea level, and the Great Valley of California, close to sea level. Much of the Cordilleran region lies at lower elevations than that of the western Great Plains, but one quarter of it lies above 7000 feet. These high areas are distributed from the Front Range on the east to the Sierra Nevada, California Coast Ranges, Klamath Mountains and north-south Cascades on the west; and from the mountains of western Montana, northern Idaho, and northern Washington on the north, to those of central Arizona and southern California on the south.