The semi-submersible drilling
research vessel Helix Q4000.
Gulf of Mexico Gas Hydrate Joint Industry Project Leg II
Press Release: Significant Gas Resource Discovered in U.S. Gulf of Mexico
USGS Press Release (5/29/09)
The National Methane Hydrates R&D Program
NETL News Release (3/30/2010)
Initial Scientific Results Available from DOE-Sponsored Gas Hydrate Expedition
Reports Detail Findings from 2009 Expedition in the Gulf of Mexico
NEW Scientific Results of the Gulf of Mexico Gas Hydrate Joint Industry Project Leg II
Journal of Marine and Petroleum Geology: Volume 34, Issue 1, Pages 1-224 (June 2012)
Resource and hazard implications of gas hydrates in the Northern Gulf of Mexico: Results of the 2009 Joint Industry Project Leg II Drilling Expedition [READ MORE ...]
The National Methane Hydrates R&D Program
2009 Gulf of Mexico JIP - Leg II
On May 6, 2009 a government and industry consortium, lead by the U.S. Department of Energy (DOE), the U.S. Geological Survey (USGS), U.S. Minerals Management Service (MMS) and a group of U.S. and international energy industry companies under the management of Chevron completed the first ever drilling project with the expressed goal to collect geologic data on gas-hydrate-bearing sand reservoirs in the Gulf of Mexico. Other resource assessment studies in northern Alaska by the USGS and offshore Japan, have shown that gas hydrates in conventional sand reservoirs are likely the closest to potential commercialization.
The goals of the Gulf of Mexico Gas Hydrates Joint Industry Project (JIP) include (1) to develop and implement a research and technology plan to assist in the characterization of sediments containing naturally occurring hydrates in deepwater in the GOM; (2) assess and understand the potential safety hazards associated with drilling wells through sediments containing gas hydrates; (3) develop a database of seismic, core, log, thermophysical, and biogeochemical data to identify current hydrate containing sites in deepwater GOM; (4) plan and execute drilling and coring expeditions to collect data needed to characterize the hydrate containing sediments in the GOM; (5) develop wellbore and seafloor stability models pertinent to hydrate containing sediments in the GOM.
Gas hydrates are a solid form of concentrated methane that occurs under certain temperature-pressure conditions with an adequate supply of gas, mostly methane. Gas hydrates are a global phenomenon, occurring in permafrost regions of the arctic and in deep water portions of most continental margins worldwide. The amount of natural gas contained in the world's gas hydrate accumulations is enormous, but these estimates remain highly speculative. Researchers have long speculated that gas hydrates could eventually become a producible energy resource yet technical and economic hurdles have historically made gas hydrate development a distant goal rather than a near-term possibility. This view has begun to change with the results of several key field projects, including those of the recently completed gas hydrate drilling project in the Gulf of Mexico.
In 2005, the Gulf of Mexico Gas Hydrate Joint Industry Project Leg I (GOM JIP Leg I) conducted drilling, coring, and downhole logging operations designed primarily to assess gas hydrate-related hazards associated with drilling through the clay-dominated sediments that typify the shallow sub-seafloor in the deepwater Gulf of Mexico. Upon analysis of Leg I results, the JIP membership decided to expand its effort to assess issues related to the occurrence of gas hydrate within coarser-grained sediments. The 2009 drilling project, named the Gulf of Mexico Gas Hydrate Joint Industry Project Leg II (GOM JIP Leg II), featured the collection of a comprehensive set of logging-while-drilling (LWD) data through expected gas-hydrate-bearing sand reservoirs in seven wells at three locations in the Gulf of Mexico. The semi-submersible drilling vessel Helix Q4000 was mobilized at sea in the Gulf Mexico and drilling was conducted in the Walker Ridge, Green Canyon and the Alaminos Canyon protraction blocks. The LWD sensors just above the drill bit provided unprecedented information on the nature of the sediments and the occurrence of gas hydrate. The full research-level LWD data set on formation lithology, electrical resistivity, acoustic velocity, and sediment porosity enabled the greatly improved evaluation of gas hydrate in both sand and fracture dominated reservoirs.
The two holes drilled at Walker Ridge yielded evidence of a laterally continuous thick fracture-filling gas hydrate section, but more importantly both wells also encountered sand reservoirs, between 40- to 50-ft-thick, nearly saturated with gas hydrate. Gas-hydrate-bearing sands were also drilled in two of the Green Canyon wells, with one occurrence slight more than 100-ft-thick. Initial interpretation of the Alaminos Canyon drilling results is that the sands appear to exhibit uniformly low gas hydrate saturation over a large area. Never the less, the discovery of thick hydrate-bearing sands at Walker Ridge and Green Canyon validates the integrated geological and geophysical approach used in the pre-drill site selection process, and provides increased confidence in assessment of gas hydrate volumes in the Gulf of Mexico and other marine sedimentary basins.
The most important operational and technical accomplishments of this drilling expedition included:
- GOM JIP Leg II was completed on time and under budget, with zero safety incidents.
- The collection of a comprehensive set of logging-while-drilling (LWD) data through expected hydrate-bearing sand reservoirs in seven wells at three locations in the Gulf of Mexico.
- LWD acquired data provided unprecedented information on the on the nature of the sediments and the occurrence of gas hydrate in the Gulf of Mexico.
- The expedition discovered gas hydrate in both sand and fracture dominated reservoirs.
- The discovery of thick gas-hydrate-bearing sands validates the pre-drilling integrated geological and geophysical approach used to identify the targets and provides increased confidence in assessing the energy resource potential of marine gas hydrates. The USGS also coordinated and lead the pre-drilling site selection review process.
- In the case of the Walker Ridge and Green Canyon drill sites gas-hydrate-bearing sand reservoirs between 50 and 100 ft thick were discovered.
- This drilling expedition has documented that highly saturated gas-hydrate deposits do not need to be linked to seismic identified bottom simulating reflectors (BSRs). Rather, the gas hydrate petroleum systems approach is a better strategy for finding highly-saturated gas hydrate accumulations.
- The discovery concentrated gas hydrates in sand reservoirs have made Walker Ridge and Green Canyon prime locations for future research drilling, coring, and production testing; making the Gulf of Mexico the first place that we can consider gas hydrate as a potential marine energy resource with attractive research and development targets.
An objective of the 21-day expedition was to confirm the hypothesis that gas hydrates can and does occur at high saturations within reservoir quality sands in the Gulf of Mexico. This objective was fully met, with highly-saturated gas hydrate-bearing sands discovered at least in two of three sites drilled. The presence of significant gas hydrate accumulations in both pore-filling mode in sands and as fracture-filling material in shallow muds, should make both Walker Ridge and Green Canyon prime locations for future research into energy research potential of gas hydrates in marine environments.
GOM JIP Leg II operations were also supported by AOA Geophysics, the Borehole Research Group at Lamont-Doherty Earth Observatory of Columbia University, Schlumberger, and the crew of the Helix Q4000.
SCIENTIFIC RESULTS REPORT
The scientific results of the 2009 Gulf of Mexico Joint Industry Program Leg II Logging-While-Drilling (LWD) expedition have been published as a special issue of the Journal of Marine and Petroleum Geology (Volume 34, Issue 1). This special issue, co-edited by Timothy S. Collett (USGS) and Ray Boswell (DOE-NETL), contains 14 papers that detail the geophysical/geological program that guided the selection of the drill sites, describe the field operations, and report on the scientific interpretations derived from the acquired LWD data. Contributors to the papers include scientists from the National Energy Technology Laboratory, the U.S. Geological Survey, the Bureau of Ocean Energy Management, Columbia University, Schlumberger, and AOA Geophysics.
Journal of Marine and Petroleum Geology: Resource and hazard implications of gas hydrates in the Northern Gulf of Mexico: Results of the 2009 Joint Industry Project Leg II Drilling Expedition (Volume 34, Issue 1, June 2012)
Collett, T.S. and Boswell, R., eds., 2012. Resource and hazard implications of gas hydrates in the Northern Gulf of Mexico: Results of the 2009 Joint Industry Project Leg II Drilling Expedition: Journal of Marine and Petroleum Geology, Volume 34, Issue 1.
Birchwood, R., Noeth, S., Horizontal stress contrast in the shallow marine sediments of Walker Ridge 313 and Atwater Valley 13 and 14-geological observations, effects on wellbore stability, and implications for drilling
Boswell, R., Collett, T., Frye, M., Shedd, W., McConnell, D., Shelander, D., Subsurface gas hydrates in the northern Gulf of Mexico
Boswell, R., Frye, M., Shelander, D., Shedd,W., McConnell, D., Cook, A., Architecture of gas-hydrate-bearing sands from Walker Ridge 313, Green Canyon 955, and Alaminos Canyon 21: Northern deepwater Gulf of Mexico
Collett, T., Lee, M., Zyrianova, M., Mrozewski, S., Guerin, G., Cook, A., Goldberg, D., Gulf of Mexico Gas Hydrate Joint Industry Project Leg II logging-while-drilling data acquisition and analysis
Cook, A., Anderson, B., Rasmus, J., Sun, K., Li, Q., Collett, T., Goldberg, D., Electrical anisotropy of gas hydrate-bearing sand reservoirs in the Gulf of Mexico
Frye, M., Shedd, W., Boswell, R., Gas hydrate resource potential in the Terrebonne Basin, Northern Gulf of Mexico
Lee, M., Collett, T., Pore- and fracture-filling gas hydrate reservoirs in the Gulf of Mexico Gas Hydrate Joint Industry Project Leg II Green Canyon 955 H well
Lee, M., Collett, T., Lewis, K., Anisotropic models to account for large borehole washouts to estimate gas hydrate saturations in the Gulf of Mexico Gas Hydrate Joint Industry Project Leg II Alaminos Canyon 21 B well
McConnell, D., Zhang, Z., Boswell, R., Review of progress in evaluating gas hydrate drilling hazards
Miller, P., Dasgupta, S., Shelander, D., Seismic imaging of migration pathways by advance attribute analysis, Alaminos Canyon 21, Gulf of Mexico
Myshakin, E., Gaddipati, M., Rose, K., Anderson, B., Numerical simulation of depressurization-induced gas production from gas hydrate reservoirs at the Walker Ridge 313 site, Northern Gulf of Mexico
Shedd, W., Boswell, R., Frye, M., Godfriaux, P., Kramer, K., Occurrence and nature of “bottom simulating reflectors” in the northern Gulf of Mexico
Shelander, D., Dai, J., Bunge, G., Singh, S., Eissa, M., Fisher, K., Estimating saturation of gas hydrates using conventional 3D seismic data, Gulf of Mexico Joint Industry Project Leg II
Zhang, Z., McConnell, D., Han, D., Rock physics based seismic trace analysis of unconsolidated sediments containing gas hydrate and free gas in Green Canyon 955, Northern Gulf of Mexico