Scientific Results of the Hydrate-01 Stratigraphic Test Well Program, Western Prudhoe Bay Unit, Alaska North Slope

• Published in: Energy & Fuels
• Main Authors: Boswell, Ray, Collett, Timothy S., Yamamoto, Koji, Okinaka, Norihiro, Hunter, Robert, Suzuki, Kiyofumi, Tamaki, Machiko, Yoneda, Jun, Itter, David, Haines, Seth S., Myshakin, Evgeniy, Moridis, George
• Language: unknown
• Published: 2023
• Subjects: 58 GEOSCIENCES; Alaska North Slope; north slope; Prudhoe Bay; Alaska
• Online Access: http://www.osti.gov/servlets/purl/1925179; https://www.osti.gov/biblio/1925179; https://doi.org/10.1021/acs.energyfuels.2c00327

The United States Department of Energy, the MH21-S Research Consortium of Japan, and the United States Geological Survey are collaborating to enable gas hydrate scientific drilling and extended-duration reservoir response testing on the Alaska North Slope. To feasibly execute such a test, a location is required that is accessible from existing roads and gravel pads and that can be occupied without disrupting ongoing industry operations. A review of potential locations meeting these criteria determined the likely occurrence of gas hydrate in two fine-grained marginal-marine sands of Tertiary age in the vicinity of the inactive “Kuparuk State 7-11-12” exploration pad in the western Prudhoe Bay Unit (PBU). Existing well and seismic data for that site were insufficient to preclude the potential for free gas occurrence within the deeper (and most prospective) target sand. Therefore, with support from the PBU Working Interest Owners, Alaska Department of Natural Resources, and Petrotechnical Resources Alaska, the Hydrate-01 Stratigraphic Test Well (STW) was drilled in December 2018 to confirm the suitability of the site for future gas hydrate scientific testing. The Hydrate-01 well was successfully drilled to -3290 ft (1003 m) subsea vertical depth at a bottom hole location of approximately 900 ft (~275 m) east of the surface location. The drilling program featured acquisition of a full suite of logging while drilling data, the collection of side-wall pressure cores, and the installation of distributed temperature and distributed acoustic sensor fiber-optic cables. The log data acquired confirmed the occurrence of gas hydrate at high saturation in two target sands. Integrated evaluation of log and sidewall core data provide petrophysical and geomechanical property information that allow for potential reservoir response to depressurization to be simulated. The deeper “B1 sand” is deemed to be most favorable for reservoir response testing as a result of confirmed gas hydrate occurrence in sediments of high intrinsic ...