Diagenetic Relationships and Reservoir Quality Implications in Brookian Clastic Sequences, National Petroleum Reserve-Alaska

Petrologic and petrophysical investigations of Brookian sandstones and siltstones from wells in the National Petroleum Reserve in Alaska revealed new information about the diagenetic development of these rocks. Several kinds of labile materials are present, and secondary dissolution porosity has been developed to various degrees. Mineralogic, geochemical, and textural characteristics indicate the potential for development of appreciable porosity of this type in equivalent horizons and/ or similar materials within northern Alaska.

Known regional geological, geochemical, and geophysical relationships are consistent with this view. Considerations of hydrocarbon resource potential should include concern for these relationships as integral to appreciation of the overall diagenetic evolution of the region.

Heretofore, the potential for the occurrence of significant reservoir rocks in these horizons has been considered to be rather low, based on primary petrologic characteristics. However, this should be reappraised.