Team 1 Hydrocarbon Potential Evaluation Team Summary of Knowledge With respect to ANWR the Definition of an A Summary of Knowledge wrtANWR defA Team 1 November 12 2003 Introduction This document serves as a summarization of the research that Team 1 has done regarding its task of determining the potential of ANWR with respect to hydrocarbons Team 1 took it upon itself to determine both the estimated volume of hydrocarbons in ANWR and the value of these hydrocarbons in the global market The results you will see here include the following Formation of Hydrocarbons Geologic History Hydrocarbon Reservoirs Value of Hydrocarbons Sources used Enjoy Team 1 2 Summary of Knowledge wrtANWR defA Team 1 November 12 2003 Formation of Hydrocarbons Formation of Hydrocarbons Information from Petroleum Geology for Geophysicists and Engineers by Richard Selley Five Major Types of Hydrocarbons Kerogen Kerogen is a fine grained amorphous organic matter It is not soluble to normal petroleum solvents like carbon disulfide Its chemical compositioin is 75 C 10 H 15 other sulfur oxygen nitrogen etc It is very important in the formation of hydrocarbons because it is what generates oil and gas Source rocks must contain significant amounts of kerogen Asphalt Asphalt is a solid at surface temperatures It is soluble to petroleum solvents It is produced by the partial maturation of kerogen or the degradation of crude oil Crude Oil Crude oil is a liquid at surface temperatures It is soluble to normal petroleum solvents It has four main groups of organic compounds paraffin naphthalene aromatics and resins Natural Gas Is a hydrocarbon gas The major natural gases are methane ethane propane and butane Condensates These are hydrocarbons transitional between gas and crude oil Five Parameters for Hydrocarbon Accumulation 1 Source rocks are required to generate hydrocarbons Generally has greater than 5 organic matter kerogen by weight 2 Reservoir rocks are required to store hydrocarbons 3 Seal or cap rocks are present to prevent the upward escape of hydrocarbons from reservoir 4 Traps occur where the source reservoir and seal are arranged in a way that the hydrocarbons can move from the source to the reservoir 5 Source rock must have been heated sufficiently for oil greater than 60 C and gas greater than 150 C Three Phases of Alteration of Organic Matter Diagenesis Diagenesis occurs at the surface at normal temperatures The organic matter goes under bacterial decay oxidation dehydration and decarboxylation The resultant is kerogen The porosity decreases 60 to 40 3 Summary of Knowledge wrtANWR defA Team 1 November 12 2003 Catagenesis Temperatures increase to 250 C and kerogen generates oil or gas The porosity decreases to 10 Metagenesis Occurs at 250 C right when the kerogen is going to change into oil or gas Catagenesis is the most important stage and is different for the three different types of kerogen Three Types of Kerogen Type I Algal It is very rich in hydrogen low in oxygen and contains lipids It generates oil and is present in oil shales Type II Liptinic It is made from algal detritus phytoplankton and zooplankton It has aliphatic compounds and more hydrogen than carbon It can generate oil or gas Type III Humic It has more carbon than hydrogen and is rich in aromatic compounds It is produced form lignin in higher woody plants It generates gas Type I and Type II are usually found in marine environment and Type III is found in continental environments That is why there is the generalization that marine produces oil and continental produces gas Migration of Hydrocarbons Primary migration of hydrocarbons is the movement of oil and gas from source rock to permeable carrier beds Secondary migration is the movement from permeable carrier beds to the reservoir beds Secondary migration occurs through porous rocks due to buoyancy and capillary and regional pressure gradients 4 Summary of Knowledge wrtANWR defA Team 1 November 12 2003 The Geologic History of ANWR The purpose of this section is to provide everyone with a basic understanding of how ANWR came about geologically speaking This information is important in understanding why hydrocarbons are where they are and is also important in understanding its current geological condition such as seismic activity how that impacts exploitation and so forth The information is very brief and the sources used are at the conclusion Geographic Placement The 1002 area of the Arctic National Wildlife Refuge is a 1 5 million acre area in northeastern Alaska It is bounded on the east by the Canning and Staines Rivers on the north by the Beaufort Sea on the east by the Aichilik River and the Canadian border and to the south by Brooks Range and is roughly 105 miles east west and 16 40 miles northsouth Most of the 1002 area lies within the Arctic Coastal Plain physiographic province a marshy area that slopes gradually towards the Arctic Ocean on the north A small part along the southern margin that constitutes less than 5 of the total area lies within the Arctic Foothills physiographic province a series of hills and ridges that descend from more than 500 m in the Brooks Range to 300 m in elevation to the northern foreland The area is treeless tundra covered and 99 wetland Topographically speaking it is comprised of foothills 95 of area river flooded plains 25 hilly coastal plains 22 lagoons and oceans 5 thaw lake plains 5 and mountains less than 1 It also has beaches low steep cliffs barrier islands shallow lagoons and river deltas form the coast of the 1002 area with hills rising to more than 300 m in the south Many rivers and stream flow between these hills towards the Arctic Ocean History The geologic history of ANWR is briefly as follows Development of Devonian to Triassic south facing in present day coordinates passive continental margin Northern Part margin rifted in Jurassic to early cretaceous time for an unknown parent continent Coeval with the North and arc continent collision occurred in the south producing and organic land mass and adjacent foreland basin As the foreland basin filled continuing deformation resulted in a foreland fold and thrust belt 5 Summary of Knowledge wrtANWR defA Team 1 November 12 2003 Youngest foreland basin sediments where fold and thrust belt intersects and overrides the earlier formed rift margin and when the deformation and related sedimentation continues to present More geologically complex that anywhere in Northern Alaska Part of the North Slope
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