The most prolific production trend (Figure 1) is found along the Barrow Arch, a regional structural high that forms the catchment for hydrocarbons generated both south and north of the Arch (Figure 2). Most production is concentrated, fortuitously for the State of Alaska, on State lands in the eastern end of the Arch. Producing fields include the two largest reservoirs in North America, Prudhoe Bay Field (~30 BBO in place) and Kuparuk River Field (~6 BBO in place).
The Lithostratigraphic Column (Figure 3) shows that productive horizons are found throughout the sedimentary rock column. Oil gravities vary depending on the geography of both the reservoirs and the source rocks/migration pathways (Figure 2). The North Slope play was opened by the 1968 discovery of Prudhoe Bay Field; Kuparuk River Field was discovered in 1970. Completion of the TransAlaska Pipeline System (TAPS) began in 1978. These 'traditional objectives' are characterized by good reservoir quality but heavier oils. The 'new play fairways', mainly west of Kuparuk River Field have higher gravity, more mobile oil, and include the Alpine and Tarn fields with a combined EUR of ~2 BBO.