In 2008 an international partnership led by the Directorate General of Hydrocarbons (DGH) under the Ministry of Petroleum and Natural Gas (Government of India) and the U.S. Geological Survey (USGS) released the results of the most complex and comprehensive gas hydrate field venture yet conducted. Upon the occasion of the Indian National Gas Hydrate Program Gas Hydrate Conference held February 6-8, 2008 in New Delhi, India, the leadership and participants in the Indian National Gas Hydrate Program (NGHP) Expedition 01 are pleased to release the results of the first modern, fully integrated gas hydrate research and exploration program conducted in the offshore of India.
Press Release: USGS Indian Ocean Hydrate Research Press Release
What Are Gas Hydrates?
Gas hydrates are a naturally occurring “ice-like” combination of natural gas (usually methane) and water that have the potential to provide an immense resource of natural gas from the world’s oceans and polar regions. In 1990’s, the U.S. Geological Survey made the first systematic assessment of the volume of gas stored in natural gas hydrates. That study suggested that the amount of gas in the gas hydrate accumulations of the world greatly exceeds the volume of known conventional gas resources. However, gas hydrates represent both a scientific and technologic challenge and much remains to be learned about the geologic, engineering, and economic factors controlling the ultimate energy resource potential of gas hydrates.
The amount of natural gas contained in the world's gas hydrate accumulations is enormous, but these estimates are speculative and range over three orders of magnitude from about 2,800 to 8,000,000 trillion cubic meters of gas. By comparison, conventional natural gas accumulations (reserves and technically recoverable undiscovered resources) for the world are estimated at approximately 440 trillion cubic meters as reported in the USGS World Petroleum Assessment 2000 (http://pubs.usgs.gov/dds/dds-060/). Gas recovery from hydrates is hindered because the gas is in a solid form and because hydrates commonly occur in remote Arctic and deep marine environments. Proposed methods of gas recovery from hydrates generally deal with dissociating gas hydrates in situ by heating the reservoir beyond the temperature of gas hydrate formation, or decreasing the reservoir pressure below hydrate equilibrium. The pace of gas hydrate energy characterization and assessment projects has accelerated over the past several years. Researchers have long speculated that gas hydrates could eventually be a commercial resource yet technical and economic hurdles have historically made gas hydrate development a distant goal rather than a near-term possibility. This view began to change with the realization that this unconventional resource could be developed in conjunction with conventional gas fields.
NGHP Expedition 01 was designed to study the gas hydrate occurrences both spatially and temporally off the Indian Peninsula and along the Andaman convergent margin with special emphasis on understanding the geologic and geochemical controls on the occurrence of gas hydrate in these two diverse settings. The primary goal of NGHP Expedition 01 was to conduct scientific ocean drilling/coring, logging, and analytical activities to assess the geologic occurrence, regional context, and characteristics of gas hydrate deposits along the continental margins of India in order to meet the long term goal of exploiting gas hydrates as a potential energy resource in a cost-effective and safe manner. During NGHP Expedition 01, dedicated gas hydrate coring, drilling, and downhole logging operations were conducted from 28 April, 2006 to the 19 August, 2006.
Based on analysis of geological and geophysical data, the Expedition was planned to visit ten sites in four areas: the Kerala-Konkan Basin in the Arabian Sea – western continental shelf of India; the petroliferous Krishna-Godawari Basin and Mahanadi Basin in the Bay of Bengal – eastern continental shelf of India; and the previously unexplored Andaman Islands. The goals of the cruise were to conduct scientific drilling, well logging, coring, and shipboard scientific analyses of recovered samples from each site to provide further insight into:
- the distribution and nature of gas hydrate in marine sediments
- the geologic controls on the formation and occurrence of gas hydrate in nature
- the processes that transport gas from source to reservoir
- the effect of gas hydrate on the physical properties of the host sediments
- the microbiology and geochemistry of gas hydrate formation and dissociation
- the calibration of geophysical and other predictive tools to the observed presence and concentration of gas hydrates.
NGHP Expedition 01 was planned and managed through a collaboration between the Directorate General of Hydrocarbons (DGH) under the Ministry of Petroleum and Natural Gas (Government of India), the U.S. Geological Survey (USGS), and the Consortium for Scientific Methane Hydrate Investigations (CSMHI) led by Overseas Drilling Limited (ODL) and FUGRO McClelland Marine Geosciences (FUGRO). The platform for the drilling operation was the research drill ship JOIDES Resolution (JR), operated by ODL. Much of the drilling/coring equipment used was provided by the Integrated Ocean Drilling Program (IODP) through a loan agreement with the US National Science Foundation (NSF). Wireline pressure coring systems and supporting laboratories were provided by IODP/Texas A&M University (TAMU), FUGRO, USGS, U.S. Department of Energy (USDOE) and HYACINTH/GeoTek. Downhole logging operational and technical support was provided by Lamont-Doherty Earth Observatory (LDEO) of Columbia University.
The science team was led by Dr. Timothy Collett of the USGS, and consisted of more than 100 leading scientists and professionals representing the following organizations:
- Binghamton University
- Colorado School of Mines
- Directorate General for Hydrocarbons (India)
- Fugro-McClelland, Inc.
- GAIL (India) Ltd
- Geological Survey of Canada
- Geotek Ltd
- Idaho National Laboratory
- Integrated Ocean Drilling Program
- Joint Oceanographic Institutions, Inc.
- Lamont-Doherty Earth Observatory
- Ministry of Petroleum and Natural Gas (India)
- McGill University
- National Energy Technology Laboratory
- National Institute of Oceanography (India)
- National Institute of Ocean Technology (India)
- Oil and Natural Gas Corporation (India)
- Ocean Drilling Limited
- Oregon State University
- OIL India Ltd
- Pacific Northwest National Laboratory
- Reliance Industries Limited (India)
- Technical University of Berlin
- Texas A&M University
- University of California, San Diego
- University of Cardiff
- University of New Hampshire
- Universität Bremen
- University of Rhode Island
- U.S. Department of Energy
- U.S. Geological Survey
- U.S. National Science Foundation
- Woods Hole Oceanographic Institution
During its 113.5-day voyage, the expedition cored or drilled 39 holes at 21 sites (one site in the Kerala-Konkan Basin, 15 sites in the Krishna-Godavari Basin, four sites in the Mahanadi Basin and one site in the Andaman deep offshore areas), penetrated more than 9,250 meters of sedimentary section, and recovered nearly 2,850 meters of core. Twelve holes were logged with logging-while-drilling (LWD) tools and an additional 13 holes were wireline logged. The operational highlights of NGHP Expedition 01 included the following:
- 113.5 days of operation without any reportable injury or incident.
- Only 1% of total operation time was down time due to equipment malfunction or weather.
- Examination of 9,250 meters of sedimentary section at 39 locations within 21 sites located in four geologically-distinct settings.
- Extensive sample collection to support a wide range of post-cruise analyses, including:
- Collected about 6,800 whole round core samples for examination of interstitial water geochemistry, microbiology, and other information.
Collected more than 12,500 core subsamples for paleomagnetic, mineralogical, paleontological, and other analyses.
- Collected about 140 gas-hydrate-bearing sediment samples for storage in liquid nitrogen.
- Collected five one-meter-long gas-hydrate-bearing pressure cores for analysis of the physical and mechanical properties of gas-hydrate-bearing sediment.
- Collected 21 re-pressurized cores (nine representing sub-samples from gas-hydrate-bearing pressure cores).
- Conducted 97 deployments of advanced pressure coring devices, resulting in the collection of 49 cores that contain virtually undisturbed gas hydrate in host sediments at near in situ pressure conditions.
Scientific Findings and Impact
The NGHP Expedition 01 Initial Reports, released at the conference in New Delhi, includes a series of integrated site chapters (Sites 1-21) describing the operational history and scientific data collected during the expedition. The Initial Reports volume also includes a companion publication that contains all downhole log data collected during the expedition.
The NGHP Expedition 01 science team utilized extensive on-board lab facilities to examine and prepare preliminary reports on the physical properties, geochemistry, and sedimentology of all the data collected prior to the end of the expedition. Although the data will continue to inform gas hydrates science for years to come, the following are some key scientific highlights of the expedition to date:
Conducted comprehensive analyses of gas-hydrate-bearing marine sediments in both passive continental margin and marine accretionary wedge settings.
- The calculated depth to the base of the methane hydrate stability zone, as derived from downhole temperature measurements, closely matches the depth of the seismic identified bottom simulating reflectors (BSRs) at most of the sites established during this expedition.
- Discovered gas hydrate in numerous complex geologic settings and collected an unprecedented number of gas hydrate cores.
- Most of the recovered gas hydrate was characterized as either pore-filling grains or particles disseminated in coarser grain sediments or as a fracture-filling material in clay dominated sediments.
- The occurrence of concentrated gas hydrate is mostly controlled by the presence of fractures and/or coarser grained (mostly sand-rich) sediments.
- Gas hydrate was found occurring in “combination reservoirs” consisting of horizontal or subhorizontal coarse grained permeable sediments (sands for the most part) and apparent vertical to subvertical fractures that provide the conduits for gas migration.
- Delineated and sampled one of the richest marine gas hydrate accumulations ever discovered (Site NGHP-01-10 in the Krishna-Godavari Basin).
- Discovered one of the thickest and deepest gas hydrate occurrences yet known (offshore of the Andaman Islands, Site NGHP-01-17) which revealed gas-hydrate-bearing volcanic ash layers as deep as 600 meters below the seafloor.
Established the existence of a fully developed gas hydrate system in the Mahanadi Basin of the Bay of Bengal.
- Most of the gas hydrate occurrences discovered during this expedition appear to contain mostly methane which was generated by microbial processes. However, there is also evidence of a thermal origin for a portion of the gas within the hydrates of the Mahanadi Basin and the Andaman offshore area.
- Gas hydrate in the Krishna-Godavari Basin appears to be closely associated with large scale structural features, in which the flux of gas through local fracture systems, generated by the regional stress regime, controls the occurrence and distribution of gas hydrate
NGHP Expedition 01 has shown that conventional sand and fractured-clay reservoirs are the primary emerging targets for gas hydrate production in India. Because conventional marine exploration and production technologies favor the sand-dominated gas hydrate reservoirs, investigation of sand reservoirs will likely have a higher near-term priority in the NGHP program. It is perceived that the NGHP effort will likely include future seismic studies, drilling, coring, and field production testing. It has been concluded that Site 10 represents a world class shale dominated fracture gas hydrate reservoir, worthy of further investigation. NGHP Expedition 01 also discovered significant sand and silt dominated gas hydrate reservoirs. It has been proposed that in a 2012-2013 time-frame, NGHP Expedition 02 may be constituted to drill and log several of the most promising gas hydrate sand-dominated prospects.
SCIENTIFIC RESULTS REPORT
The scientific results of the India National Gas Hydrate Program Expedition 01 (NGHP-01) have been published as a special issue of the Journal of Marine and Petroleum Geology (Volume 58, Part B). This special issue, co-edited by Timothy S. Collett (USGS), contains 31 papers that include new insight into the nature, formation, occurrence, and physical properties of gas hydrate-bearing sediments in the offshore of India. The primary objective of the NGHP-01 expedition was to contribute new data on the occurrence of gas hydrate systems to advance the general understanding of the controls on the formation of gas hydrate accumulations in nature. An unprecedented amount of high-quality downhole logging and core data were obtained during this expedition over a significant number of pore-filling, fracture- filling, and sediment-displacement type gas hydrate occurrences. This thematic issue contains an extensive list of important topical reports on the acquisition and analysis of samples and data acquired during NGHP-01. This issue also contains reports detailing the invaluable operational experience obtained during the expedition. This special issue starts with two reports that summarize the results of NGHP-01 and review the geologic controls on the occurrence of gas hydrates in the offshore of India. The remaining 29 submissions have been organized into topical sections that focus on the (1) lithostratigraphic controls on the occurrence of gas hydrate, (2) physical properties of gas hydrate-bearing sediments, (3) interstitial-water and gas geochemistry, (4) microbiologic systems, (5) well log analysis, (6) geophysical analysis, (6) basin and systems analysis, and (7) gas hydrate production and energy assessment.
Journal of Marine and Petroleum Geology: Geologic implications of gas hydrates in the offshore of India: Results of the National Gas Hydrate Program Expedition 01 (Volume 58, Part B, 2014).
T.S. Collett, R. Boswell, J.R. Cochran, P. Kumar, M. Lall, A. Mazumdar, M.V. Ramana, T. Ramprasad, M. Riedel, K. Sain, A.V. Sathe, K. Vishwanath and NGHP Expedition 01 Scientific Party, Geologic implications of gas hydrates in the offshore of India: Results of the National Gas Hydrate Program Expedition 01.
P. Kumar, T.S. Collett, R. Boswell, J.R. Cochran, M. Lall, A. Mazumdar, M.V. Ramana, T. Ramprasad, M. Riedel, K. Sain, A.V. Sathe, K. Vishwanath, U.S. Yadav and NGHP Expedition 01 Scientific Party, Geologic implications of gas hydrates in the offshore of India: Krishna – Godavari Basin, Mahanadi Basin, Andaman Sea, Kerala–Konkan Basin.
K.K. Rose, J.E. Johnson, M.E. Torres, W.-L. Hong, L. Giosan, E.A. Solomon, M. Kastner, T. Cawthern , P.E. Long and H. Todd Schaef, Anomalous porosity preservation and preferential accumulation of gas hydrate in the Andaman accretionary wedge, NGHP-01 site 17A.
S.C. Phillips, J.E. Johnson, M.B. Underwood, J. Gu , L. Giosan and K. Rose, Long-timescale variation in bulk and clay mineral composition of Indian continental margin sediments in the Bay of Bengal, Arabian Sea, and Andaman Sea.
W.J. Winters, R.W. Wilcox-Cline, P. Long, S.K. Dewri, P. Kumar, L. Stern and L. Kerr, Comparison of the physical and geotechnical properties of gas-hydrate-bearing sediments from offshore India and other gas-hydrate-reservoir systems.
M. Holland and P. Schultheiss, Comparison of methane mass balance and X-ray computed tomographic methods for calculation of gas hydrate content of pressure cores.
S. Dai and J.C. Santamarina, Sampling disturbance in hydrate-bearing sediment pressure cores: NGHP-01 expedition, Krishna – Godavari Basin example.
J.A. Priest, C.R.I. Clayton and E.V.L. Rees, Potential impact of gas hydrate and its dissociation on the strength of host sediment in the Krishna – Godavari Basin.
C.V.V. Eswari, B. Raju, V.D. Chari, P.S.R. Prasad and K. Sain, Laboratory study of methane hydrate formation kinetics and structural stability in sediments.
L.A. Stern and T.D. Lorenson, Grain-scale imaging and compositional characterization of cryo-preserved India NGHP 01 gas-hydrate-bearing cores.
W.-L. Hong, E.A. Solomon and M.E. Torres, A kinetic-model approach to quantify the effect of mass transport deposits on pore water profiles in the Krishna – Godavari Basin, Bay of Bengal.
E.A. Solomon, A.J. Spivack, M. Kastner, M.E. Torres and G. Robertson, Gas hydrate distribution and carbon sequestration through coupled microbial methanogenesis and silicate weathering in the Krishna – Godavari Basin, offshore India.
P.P. Sujith, M.J.B.D. Gonsalves, V. Rajkumar and V. Miriam Sheba, Manganese cycling and its implication on methane related processes in the Andaman continental slope sediments.
U. Shankar and M. Riedel, Assessment of gas hydrate saturation in marine sediments from resistivity and compressional-wave velocity log measurements in the Mahanadi Basin, India.
A.E. Cook, D.S. Goldberg and A. Malinverno, Natural gas hydrates occupying fractures: A focus on non-vent sites on the Indian continental margin and the northern Gulf of Mexico.
M. Riedel, D. Goldberg and G. Guerin, Compressional and shear-wave velocities from gas hydrate bearing sediments: Examples from the Indiaand Cascadia margins as well as Arctic permafrost regions.
G. Sriram, P. Dewangan and T. Ramprasad, Modified effective medium model for gas hydrate bearing, clay-dominated sediments in the Krishna – Godavari Basin.
P. Jaiswal, S. Al-Bulushi and P. Dewangan, Logging-while-drilling and wireline velocities: Site NGHP-01-10, Krishna – Godavari Basin, India
V.R. Mangipudi, A. Goli, M. Desa, R. Tammisetti and P. Dewangan, Synthesis of deep multichannel seismic and high resolution sparker data: Implications for the geological environment of the Krishna–Godavari offshore, Eastern Continental Margin of India.
P. Dewangan, R. Mandal, P. Jaiswal, T. Ramprasad and G. Sriram, Estimation of seismic attenuation of gas hydrate bearing sediments from multi-channel seismic data: A case study from Krishna – Godavari offshore basin.
R. Mandal, P. Dewangan, T. Ramprasad, B.J.P. Kumar and K. Vishwanath, Effect of thermal non-equilibrium, seafloor topography and fluid advection on BSR-derived geothermal gradient.
S.A. Wegner and K.J. Campbell, Drilling hazard assessment for hydrate bearing sediments including drilling through the bottom-simulating reflectors.
J.E. Johnson, S.C. Phillips, M.E. Torres, E. Piñero, K.K. Rose and L. Giosan, Influence of total organic carbon deposition on the inventory of gas hydrate in the Indian continental margins.
J.A. Flores, J.E. Johnson, A.E. Mejía-Molina, M.C. Álvarez, F.J. Sierro, S.D. Singh, S. Mahanti and L. Giosan, Sedimentation rates from calcareous nannofossil and planktonic foraminifera biostratigraphy in the Andaman Sea, northern Bay of Bengal, and eastern Arabian Sea.
B.M.A. Teichert, J.E. Johnson, E.A. Solomon, L. Giosan, K. Rose, M. Kocherla, E.C. Connolly and M.E. Torres, Composition and origin of authigenic carbonates in the Krishna – Godavari and Mahanadi Basins, eastern continental margin of India
A. Usapkar, P. Dewangan, M. Kocherla, T. Ramprasad, A. Mazumdar and M.V. Ramana, Enhanced methane flux event and sediment dispersal pattern in the Krishna – Godavari offshore basin:Evidences from rock magnetic techniques.
R.K. Joshi, A. Mazumdar, A. Peketi, P.B. Ramamurty, B.G. Naik, M. Kocherla, M.A. Carvalho, P. Mahalakshmi, P. Dewangan and M.V. Ramana, Gas hydrate destabilization and methane release events in the Krishna – Godavari Basin, Bay of Bengal.
T. Cawthern, J.E. Johnson, L. Giosan, J.A. Flores, K. Rose and E. Solomon, A late Miocene – Early Pliocene biogenic silica crash in the Andaman Sea and Bay of Bengal
S.C. Phillips, J.E. Johnson, L. Giosan and K. Rose, Monsoon-influenced variation in productivity and lithogenic sediment flux since 110 ka in the offshore Mahanadi Basin, northern Bay of Bengal.
T.J. Kneafsey and G.J. Moridis, X-Ray computed tomography examination and comparison of gas hydrate dissociation in NGHP-01 expedition (India) and Mount Elbert (Alaska) sediment cores: Experimental observations and numerical modeling
S. Ramesh, N. Vedachalam, R. Ramesh, N. Thulasi Prasad, G.A. Ramadass and M.A. Atmanand, An approach for methane hydrates reservoir dissociation in a marine setting, Krishna Godhavari Basin, east coast India.
Project Website: Gas Hydrates
Assessment Website: National Oil and Gas Assessment