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Confirmation of Hydrocarbon Shows in the Mobil #3 Offshore Hyde County Well, North Carolina

Coleman, James L.; Reid, Jeffrey C.; Hall, Don L.

In 1965, Socony Mobil Oil Company drilled the #3 State of North Carolina well (NCGS #HY-OT-01-65; API 32-095-00009; Hyde County, North Carolina) to a total depth of 7309 ft in Pamlico Sound. The well penetrated 7222 ft of Cenozoic and Mesozoic strata before ending in Paleozoic(?) leucogranodiorite. Well data and thermal modeling examined prior to this study indicated that the entire section penetrated in the well bore was thermally immature for the local generation of thermogenic petroleum. However, mud log reports while drilling indicated that insoluble asphaltenes were encountered within the Lower Albian - Berriasian interval at 6710 ft, 6750 ft, and 7160 ft. Drill cuttings between 1007 ft and 7336 ft were collected from this well archived at the North Carolina Geological Survey repository, prepared, and examined using fluid inclusion stratigraphic analysis technology and fluid inclusion petrography. The results of this initial examination indicate both liquid and gaseous petroleum throughout much of the well bore.

Mixed biogenic and thermogenic gas indications as well as thermogenic oil responses were observed in the Tertiary and Cretaceous shallow and intermediate intervals. Responses within the deeper Lower Cretaceous intervals show thermogenic gas and liquid indicators. Occurrences of gas- and oil-prone kerogen were also observed. Rare occurrences of mature oil-prone kerogen were observed, as well as rare instances of low gravity (possibly immature) oil inclusions. Specific responses which might have confirmed the recorded observation of asphaltenes were not observed; however, a rare, dead hydrocarbon stain was observed in thin section from samples near total depth.

Finally, organic acid anomalies are indicated, which, among other possibilities, can reflect reservoired charge within a several kilometer radius. The indications of petroleum within this analysis do not necessarily imply the presence of a missed or bypassed hydrocarbon discovery at the borehole location, but they do suggest that a petroleum system may be present within the Atlantic Coastal Plain and continental rise area of eastern North Carolina.

 

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013