Gas Hydrate Energy Research – 2024 Update
Review of International Gas Hydrate Research and Development Activities
Gas hydrates may represent an important future source of energy; however, much remains to be learned about their characteristics and occurrence in nature. Gas hydrates have been encountered, recovered, or inferred to exist in numerous sedimentary basins in Arctic permafrost settings, regions of alpine permafrost, marine sediments of outer continental margins and in deep lakes. Despite the great abundance of potential gas hydrate resources in the world, a large portion of these resources reside in clay-rich sediments and fracture dominated reservoir systems, and are not generally considered producible with existing technology, but may have future potential with the emergence of new technologies. For a large portion of the world, gas hydrate in sand reservoirs has become a viable production target and the focus of the first production testing efforts. Short term production tests in northern Canada and Alaska have demonstrated that natural gas can be produced from hydrates hosted in sand-dominated sediments with existing conventional production technologies. Production can be achieved through the depressurization method and possibly by more complex methods such as molecular substitution (e.g., CO2-CH4 exchange). In 2013, a gas hydrate production test was conducted in a marine setting in the offshore of Japan. An additional test was conducted in Japan in 2017 to further evaluate alternative well completion technologies. Also in 2017, China initiated a 60-day gas hydrate production test in the Shenhu region of the South China Sea. From October 2019 to April 2020 the China Geological Survey conducted a second gas hydrate production test in the Shenhu region. Most recently, in October of 2023, an US and Japanese partnership launched an extended gas hydrate depressurization production test in the Alaska North Slope. This report reviews the results of recent geologic and production testing studies associated with gas hydrate accumulations on the Alaska North Slope, in the Gulf of Mexico, the Nankai Trough in the offshore of Japan, the South China Sea, and the Bay of Bengal in the offshore of India.
Recent Gas Hydrate R&D Activities
Alaska North Slope Activities
The U.S. Department of Energy (DOE) National Energy Technology Laboratory, the Japan Oil, Gas and Metals National Corporation (JOGMEC), and the U.S. Geological Survey (USGS) are leading an effort to conduct an extended gas hydrate production test in the Alaska North Slope (ANS). The ongoing production test in Alaska required the drilling of an initial stratigraphic test well (STW) to confirm the geologic conditions of the proposed test site. The Hydrate-01 STW was completed in December 2018 in cooperation with the Alaska Prudhoe Bay Unit Interest Owners. With the successful confirmation of the presence of hydrate-bearing reservoirs suitable for production testing at the site of the Hydrate-01 STW, the next goal of the ANS gas hydrate production testing effort was to establish the operational plan for the planned extended depressurization test and the construction of the test site in the Prudhoe Bay Unit. The reported plan for the “Alaska Gas Hydrate Production Field Experiment” is to conduct a long-term (as along as 9-12 months) scientific reservoir response test utilizing depressurization production technology, which was reported to have started in October of 2024.
References
https://pubs.acs.org/doi/10.1021/acs.energyfuels.2c00327
https://pubs.acs.org/doi/full/10.1021/acs.energyfuels.1c04087
https://www.netl.doe.gov/node/8020
https://www.energy.gov/fecm/articles/alaska-north-slope-gas-hydrates-site-visit
https://www.energy.gov/fecm/articles/project-update-doe-and-international-partners-start-conduct-gas-hydrates-production#:~:text=The%20installation%20of%20wells%2C%20which,in%202018%20and%202022%20respectively
Gulf of Mexico Activities
One of the more significant gas hydrate research projects in the US has been the Gulf of Mexico (GOM) gas hydrate scientific drilling program being led by the University of Texas (UT) Austin and funded by the U.S. Department of Energy (DOE). As part of this effort, UT and their project research partners have published two special issues of the Bulletin of the American Association of Petroleum Geologists that summarize the operational and scientific results of the 2017 UT-GOM2-1 pressure coring expedition in the Gulf of Mexico, which were published in September 2020 and May 2022. The 2017 UT-GOM2-1 pressure coring expedition, as executed in the Green Canyon Block 955 (GC955), was initially described in an industry hazard site review study as a confluence of sand-prone gas hydrate-bearing facies that are closely associated with abundant gas migration pathways. The JIP Leg II logging while drilling expedition conducted in 2009 confirmed the occurrence of gas hydrate associated with the previous seismic inferred sand-prone facies in GC955. In 2014, the DOE partnered with UT to further develop state-of-the-art pressure coring and pressure core evaluation equipment to gather, disseminate, and analyze gas hydrate samples. In May 2017, UT conducted the UT-GOM2-1 gas hydrate pressure coring expedition in Block GC955. UT also established plans for a second conventional and pressure coring expedition to be conducted in the Walker Ridge Block 313 area of the Terrebonne Basin in the Gulf of Mexico. UT has reported that shipboard science operations associated with UT-GOM2-2 Expedition were conducted in August of 2023.
References
https://pubs.geoscienceworld.org/aapgbull/issue/104/9
https://pubs.geoscienceworld.org/aapgbull/issue/106/5
https://ig.utexas.edu/energy/gom2-methane-hydrates-at-the-university-of-texas/
https://ig.utexas.edu/energy/gom2-methane-hydrates-at-the-university-of-texas/gom2-2-expedition/
https://ig.utexas.edu/energy/gom2-methane-hydrates-at-the-university-of-texas/gom2-news-media/
Nankai Trough Japan Activities
In 2001, the Japan Ministry of Economy, Trade, and Industry (METI) launched a new project entitled “Japan’s Methane Hydrate Exploitation Program,” operated by the Methane Hydrate 2001 Consortium (also known as MH21), to evaluate the resource potential of deepwater gas hydrates in the Nankai Trough. The MH21 program culminated in 2013 with the completion of the first-ever test of gas production from marine gas hydrates. The deepwater drilling vessel D/V Chikyu was used for drilling and coring operations to establish the MH21 Nankai Trough 2012-2013 test site, named the AT1 site. At the AT1 site, one production well (AT1-P), two monitoring wells (AT1-MC and MT1), and one core well (AT1-C) were established in 2012. The cumulative gas and water produced during the 6 day 2013 test were approximately 119,500 m3 and 1,250 m3, respectively. Based on the results of this first test, a second test was designed and executed in 2016 to acquire more quantitative data for the assessment of various offshore gas hydrate production completion technologies. In June of 2017, METI announced the completion of the second gas hydrate production test in the Nankai Trough. The amount of gas produced from the first of two wells established during the 2017 Nankai Trough gas hydrate production test was approximately 35,000 m3 in a total of 12 days; a second well produced approximately 200,000 m3 of gas in a total in 24 days.
References
https://pubs.acs.org/doi/10.1021/acs.energyfuels.6b03143
https://pubs.rsc.org/en/content/articlelanding/2019/ra/c9ra00755e#!divAbstract
https://www.mh21japan.gr.jp/english/news_264.html
South China Sea Activities
Since 2003, the China Geological Survey (CGS) has been assessing natural gas hydrate resources in the Shenhu area in the South China Sea (SCS). In 2015 and 2016, the CGS carried out two gas hydrate scientific drilling expeditions and discovered several significant gas hydrate occurrences. In 2017, the CGS conducted their first gas hydrate production test in the Shenhu area of the SCS. The test lasted for 60 days with a total volume of produced gas exceeding 309,000 m3. The China Ministry of Natural Resources reported on 27-March-2020 that several breakthroughs were made during a second gas hydrate production test in the SCS. The March 2020 test was also conducted in the Shenhu area at a water depth of 1,225 m; the test produced 861,400 m3 of gas, with an average daily gas production rate of 28,700 m3. The second gas hydrate depressurization test in the Shenhu area featured directional drilling and a horizontal completion, reservoir stimulation, and the deployment of advanced sand control systems. In comparison to the first test, both the cumulative gas production volumes and the daily gas production rates were much greater during the second test in 2020.
References
https://www.sciencedirect.com/science/article/pii/S209651921930014X
https://www.sciencedirect.com/science/article/pii/S2096519220300719
Bay of Bengal India Activities
The India National Gas Hydrate Program (NGHP) was initiated by the Ministry of Petroleum and Natural Gas (MoP&NG) in 1997 and is coordinated by the Directorate General of Hydrocarbons. The NGHP has supported numerous laboratory, modeling, and field studies, including the NGHP-01 Expedition in 2006 and NGHP-02 Expedition in 2015. During the NGHP-01 Expedition, a total of 21 drill sites were established in the Kerala-Konkan (1 site), Krishna-Godavari (15 sites), Mahanadi (4 sites), and Andaman (1 site) deep offshore areas. NGHP-01 drilling results yielded evidence of gas hydrate at most of the sites established during the expedition. Gas hydrates discovered during NGHP-01 were found to be mostly filling fractures in fine-grained sediments, a morphology that is generally not considered conducive to exploitation by conventional production methods. In response to the results of the NGHP-01 Expedition, NGHP-02 was designed with the primary goal of discovering and characterizing the geologic controls on highly saturated gas hydrate occurrences in sand reservoirs that are believed to be more suitable for production. The NGHP-02 Expedition was led by the Oil and Natural Gas Corporation Limited of India on the behalf of the MoP&NG. The analysis of the data and core samples collected during the NGHP-02 Expedition confirmed the presence of extensive sand-rich depositional systems throughout the deepwater portions of the Krishna-Godavari and Mahanadi Basins in the Bay of Bengal. Two areas of the Krishna-Godavari Basin, referred to as Areas B and C under the NGHP-02 effort, was shown to contain substantial gas hydrate accumulations in sand-rich systems and therefore represent candidate sites for future potential energy exploitation.
References
https://www.sciencedirect.com/journal/marine-and-petroleum-geology/vol/108/suppl/C
https://www.sciencedirect.com/science/article/pii/S0264817219302284
