Mitigation of Drilling Risk with Near-surface Hydrocarbon Detection, a Case Study: Gulf of Suez, Egypt1
J. L. Gevirtz, J. M. Vargo, 2002. "Mitigation of Drilling Risk with Near-surface Hydrocarbon Detection, a Case Study: Gulf of Suez, Egypt", Surface Exploration Case Histories: Applications of Geoschemistry, Magnetics, and Remote Sensing, Dietmar Schumacher, Leonard A. LeSchack
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In the last 50 years, surface geochemical detection of microseeps has gained credibility as a viable petroleum exploration tool. Traces of organic compounds measured in the near-surface sediments provide a rapid and inexpensive method for diagnosing the probable hydrocarbon content of potential trapping features that have been delineated in the subsurface by seismic methods.
Light-hydrocarbon yield, composition, fluorometric-intensity, and magnetic-susceptibility data obtained from analysis of seafloor samples were used to estimate the fluid contents of potential reservoirs defined by more conventional exploration methods in the Zaafarana and North Zaafarana concessions in the Gulf of Suez. Acid-released gas yields, compositions, and relative fluorometric intensities indicate that the area is one in which active petroleum generation is occurring. Mapped acid-released-gas, fluorometric-intensity, and magnetic-susceptibility patterns are concordant and coincide with major structural features and generating basins. Local geochemical disturbances near the surface coincide with structural targets that have been defined in the subsurface by seismic methods. Detailed analysis of these disturbed areas demonstrates that subtle differences can be observed. Drilling results from wells drilled in several of these areas after completion of this study demonstrate that these differences represent the surface expression of reservoired hydrocarbons and the leakage of hydrocarbons from the hydrodynamic system, as seen at the surface. This study demonstrates the necessity of carefully integrating data from several surface geochemical methods with data obtained by more conventional exploration methods. We believe that surface hydrocarbon-exploration techniques, when prudently integrated with conventional subsurface tools such as seismic and geologic analysis, can be used to high-grade drilling targets and ultimately to reduce exploration risk.
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Surface Exploration Case Histories: Applications of Geochemistry, Magnetics, and Remote Sensing provides an overview of successful applications of surface exploration methods. Through a series of independent case histories, this volume presents clearly documented evidence that demonstrates how surface exploration methods can significantly reduce exploration risk and finding costs: geochemical, magnetic, and remote sensing. The 19 chapters in this volume reflect the broad scope of applications for these methods: frontier basin reconnaissance, prospect development, prospect evaluation, and field development and production. The case histories span the globe: 1. North America 2. Africa 3. South America 4. Europe 5. Middle East 6. Australia. This book will interest explorationists and managers who seek to get the most out of each exploration dollar.