ExxonMobil in Alaska: Miller, Krohn describe geology
The Point McIntyre … hydrocarbon reservoir is the early Cretaceous age Kemik sand. ….
The field was discovered by conscientious re-evaluation of all the available data in the area. Previously drilled wells had been abandoned and interest in the area waned until careful re-mapping identified the hydrocarbon potential.
The field is a low-side fault trap on the north side of a large splay of the Prudhoe Bay Fault. The Kemik sand is present only on the low side of the trapping fault and is not generally preserved on the high side of the fault in the field area. The trap is sealed updip by juxtaposition of the Kemik reservoir sands against Jurassic Kingak shales in the footwall of the fault.
Although the structure is not complex, it was difficult to map correctly in depth because of large long-period static problems in the seismic data. This is due to rapid lateral changes in near-surface velocities caused by changing permafrost thickness near the shoreline. Impedance modeling of the seismic data also helped define the areal extent and quality of the reservoir interval.
The Kemik sand became a new producing reservoir on the North Slope of Alaska. These sands are age equivalent to the Kuparuk “C” sands which produce in the Kuparuk Field to the west. The depositional environment is interpreted to be a near shore marine facies with excellent reservoir characteristics. Point McIntyre field is an excellent example of a major oil field discovered in an overlooked and subtle trap.
—Abbreviated version of “Geology and History of Discovery of the Point McIntyre Field, North Slope, Alaska” by ExxonMobil’s Keith R. Miller & Steve Krohn for AAPG 2009 Arctic Conference and Exhibition in Moscow, Russia.
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