Regional Fluid Flow of the North Slope Foreland Basin, Alaska

Belanger, Anna M.¹, Dr. Jeffrey S. Hanor², Dr. Jeffrey A. Nunn² (1) Louisiana State University, Baton Rouge, LA (2) Louisiana State University,

Previous work at LSU in mapping spatial variations in formation water salinity, temperature, and hydraulic head in the National Petroleum Reserve Alaska (NPRA) has established evidence for the presence of a regional, topographically-driven flow regime. Groundwaters are recharged in the Brooks Range, flow northward, and discharge near the coast. The waters may descend several km into the subsurface, and as they ascend, heat is transported upward. The results of numerical modeling of fluid flow and heat transport in the NPRA support this hypothesis. The purpose of this study is to determine how this regional meteoric flow system may be contributing to the known biodegradation of crude oil in the area and to the thermal stability of methane hydrates in shallow onshore and offshore sediments. Two west-east transects have been constructed, which extend the previous work in the NPRA eastward into the prolific hydrocarbon province of the Prudhoe Bay - Coville Delta area. Preferential pathways for meteoric fluid flow are being identified from log-derived fluid and sediment properties, including salinity, porosity, and lithofacies. Initial results suggest there are spatial correlations between low API gravity oils, which have been biodegraded, and less saline waters that have a strong meteoric component.