Compressibility, permeability and index property data for sediment from the seal interval overlying the B1 sand reservoir in the HYDRATE 02 Geo Data Well (GDW), collected for the extended-duration gas hydrate reservoir response test project on the Alaskan North Slope

A gas hydrate reservoir depressurization production project was recently undertaken in the Alaska North Slope (ANS) by a consortium led by the Japan Organization for Metals and Energy Security (JOGMEC), U.S. Department of Energy (US-DOE), and U.S. Geological Survey (USGS) [Nakatsuka et al., 2025b; Okinaka et al., 2025]. During the “Collaborative Gas Hydrate Research and Development Project in Alaska,” core specimens were collected via pressure coring from the HYDRATE 02 Geologic Data Well (HY02, GDW) in late 2022 [Collett et al., 2025]. This dataset focuses on fine-grained sediment from above the gas hydrate-bearing interval known as the “B1 sand” [Collett et al., 2025; Okinaka et al., 2025; Phillips et al., 2025]. Gas hydrate is a naturally-occurring crystalline solid formed from water and (generally) methane, and is stable at the elevated pressures and reduced temperatures in the permafrost-associated sediments of the ANS. For the 2023-2024 field-scale reservoir response test [Nakatsuka et al., 2025a], the B1 sand was depressurized to investigate the in situ gas hydrate breakdown process while measuring the overall system behavior. Production efficiency from gas hydrate-bearing reservoirs is partly controlled by properties of the bounding layer sediments, particularly their permeability and compressibility [Boswell et al., 2020; Jang et al., 2020; Yamamoto et al., 2022]. Specifically, 1) do the bounding layers act as effective seals, with low sediment permeability that prevents fluid from entering the reservoir during production; 2) as the bounding layers compact or expand during production, does the sediment compressibility lead to large or small changes in the permeability? To help evaluate these questions, this dataset quantifies compressibility, permeability and index properties (grain size, grain density, liquid limit) for sediment in cores HY02-13P-1 and HY02-14P, both collected from the bounding interval overlying the B1 sand. Results are based on laboratory measurements and theoretical correlations described in Garcia et al. [2025], which is included in the Project’s 2025 scientific results volume published in Energy and Fuels. This data set is presented as one spreadsheet, with six tabs: AlaskaGasHydrateProductionTest_B1SealSedimentProperties_Data.xlsx 1. Overview: Summarizes and provides links to each tab, provides references for citations within the data release. 2. Specimen Characterization: Downhole locations and specimen index properties for the Core 14P specimens tested for compressibility and permeability in this study. 3. Consolidation: Tabulated and plotted consolidation data from all Core 14P tests, including compression and swelling indices. 4. Permeability: Tabulated and plotted permeability data for Core 14P, including data from direct-flow tests in the High-Stress Permeameter, and from log-time calculations based on 1-dimensional consolidation tests in oedometers. 5. Grain Size and Density: Tabulated and plotted data from laser diffraction (grain size) and gas pycnometer (grain density) measurements for Core section 13P-1 and Core 14P. Includes grain-size-dependent estimate of permeability. 6. Composition: Tabulated data and calculations for estimating Core 14P sediment compressibility from minerology data. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. References Boswell, R., S. Hancock, K. Yamamoto, T. Collett, M. Pratap, and S.-R. Lee (2020), 6 - Natural Gas Hydrates: Status of Potential as an Energy Resource, in Future Energy (Third Edition), edited by T. M. Letcher, pp. 111-131, Elsevier, doi:https://doi.org/10.1016/B978-0-08-102886-5.00006-2 Collett, T. S., S. Marsteller, R. Boswell, W. F. Waite, S. C. Phillips, J. Pohlman, M. V. Zyrianova, S. S. Haines, J. Yoneda, T. T. Aung, N. Okinaka, Y. Nakatsuka, W. Isaacson, A. Dial, D. Cismoski, P. Schultheiss, M. Mimitz, M. Holland and S. Merey (2026), Alaska North Slope HYDRATE 02 Geo Data Well (GDW) Downhole Logging, Pressure Coring, and Completion Operations and Data, Energy and Fuels, doi: https://doi.org/10.1021/acs.energyfuels.6c00867. Garcia, A. V., W. F. Waite, S. C. Phillips, J. Yoneda, A. Hiruta, and T. S. Collett (2026), Permeability and Compressibility of Unit B Seal Sediment from the Hydrate-02 Geologic Data Well, Prudhoe Bay Unit, Alaska North Slope, Energy and Fuels, doi: https://doi.org/10.1021/acs.energyfuels.5c04831. Jang, J., W. F. Waite, and L. A. Stern (2020), Gas hydrate petroleum systems: What constitutes the “seal”?, Interpretation, 8(2), T231-T248, doi:https://www.doi.org/10.1190/int-2019-0026.1. Nakatsuka, Y., N. Okinaka, S. Otsuki, Y. Arima, Y. Takai, D. Cismoski, P. Curley, S. Shirzadi, R. Boswell, and T. S. Collett (2026a), Operational overview of the JOGMEC-DOE-USGS Gas Production Test from gas hydrate on the Alaska North Slope, Energy and Fuels, doi: https://doi.org/10.1021/acs.energyfuels.6c01130. Nakatsuka, Y., N. Okinaka, S. Otsuki, Y. Arima, Y. Takai, K. Kawaguchi, H. Sugiyama, D. Cismoski, P. Curley, S. Shirzadi, K. Kawaguchi, H. Sugiyama, R. Boswell, and T. S. Collett (2026b), Overview of the monitoring program in the Alaska North Slope extended-duration gas production test from gas hydrate, Energy and Fuels, doi: https://doi.org/10.1021/acs.energyfuels.6c01126. Okinaka, N., Y. Nakatsuka, S. Ohtsuki, T. S. Collett, D. Cismoski, K. Kawaguchi (2026), Project overview of the production test on the Alaska North Slope, Energy and Fuels, doi: https://doi.org/10.1021/acs.energyfuels.6c01134. Phillips, S. C., S. J. Widlansky, J. Yoneda, A. Hiruta, B. A. L. Grimm, J. E. Johnson, A. Geist, M. E. Holland, P. J. Schultheiss, and T. S. Collett (2026), Depositional environment and diagenetic history of gas hydrate-bearing sediments from the Alaska North Slope (Hydrate-02 Geo Data Well), Energy and Fuels, doi: https://doi.org/10.1021/acs.energyfuels.5c05174 Yamamoto, K., R. Boswell, T. S. Collett, S. R. Dallimore, and H. L. Lu (2022), Review of Past Gas Production Attempts from Subsurface Gas Hydrate Deposits and Necessity of Long-Term Production Testing, Energy & Fuels, 36(10), 5047-5062, doi: https://www.doi.org/10.1021/acs.energyfuels.1c04119