North Slope oil and gas: the Barrow Arch Paradox

Conference · Mon Apr 01 04:00:00 UTC 1985 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6461416

Bird, K J

In the 40-year history of hydrocarbon exploration on the Alaskan North Slope, about 21 accumulations with a total in-place volume of more than 60 billion bbl of oil and 35 trillion ft/sup 3/ of gas have been discovered. Although the density of exploratory drilling this region is not uniform, enough drilling has been done to show a distinct concentration of oil and gas in the Prudhoe Bay area between the Colville and Canning Rivers. Most oil and gas in the Prudhoe area accumulated near the present coastline in reservoirs that overlie a southeasterly plunging basement ridge, the Barrow arch. The location of these accumulations, in low-relief structural-stratigraphic traps midway along the arch and downdip from its apex at Point Barrow, is the paradox. An answer to this paradox is provided by analysis of two cross sections, one along the Barrow arch and one perpendicular, showing their original structural positions for the beginning, middle, and end of Cretaceous time. In the Early Cretaceous (mid-Neocomian), the crest of the barrow arch was near sea level along its entire length. Because of northeasterly sediment progradation during later Cretaceous time, the Barrow area became more deeply buried than the Prudhoe area, thus making the Prudhoe area the focal point for migrating oil and gas. Beginning in the early (.) Tertiary, the Barrow area was slowly uplifted while the Prudhoe area subsided, thus beginning the process that resulted in the reversal of their relative elevations and the focus for migrating oil and gas. Studies show that the Prudhoe Bay field was tilted during the Tertiary, and some oil and gas escaped, migrated toward Barrow, and was trapped in the Kuparuk, West Sak, and Ugnu fields. This analysis suggests that most North Slope oil and gas were generated during the Cretaceous.

• Research Organization: Geological Survey, Menlo Park, CA
• OSTI ID: 6461416
• Report Number(s): CONF-8505215-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 69:4
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
ALASKA
ALASKAN NORTH SLOPE
CENOZOIC ERA
CRETACEOUS PERIOD
DRILLING
EXPLORATION
EXPLORATORY WELLS
FEDERAL REGION X
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGIC TRAPS
GEOLOGY
MESOZOIC ERA
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NORTH AMERICA
PETROLEUM DEPOSITS
RESERVOIR ROCK
RESOURCES
STRATIGRAPHY
TERTIARY PERIOD
USA
WELL DRILLING
WELLS