Estimation of gas hydrate saturation using isotropic and anisotropic modelling in the Mahanadi basin

  • Uma ShankarEmail author
  • Ashok Kumar Pandey


A base of gas hydrate stability zone was established after coring and drilling under the National Gas Hydrate Program (NGHP) Expedition-01 in the Mahanadi basin. At two sites, logging-while-drilling log data, and, at one site, wireline log data, were acquired during the NGHP Expedition-01. Gas hydrate reservoirs modelling can be performed in two different ways. One way is isotropic (load bearing) and, on the other hand, anisotropic media (fracture filling with gas hydrate). Here, we have performed anisotropic modelling and estimated gas hydrate saturation using P-wave velocity, assuming an incidence angle of 75\(^{\circ }\) represents the vertical fracture. The estimated gas hydrate saturation at sites NGHP-01-08 and NGHP-01-09, assuming anisotropic media, reduces the estimate by half compared to the saturation estimation by assuming isotropic media. The saturation at site NGHP-01-19 estimated from the isotropic and anisotropic P-wave velocity models are more or less similar except in the zone (175–210 m) just above the bottom simulating reflector depth, and this zone shows similar reduction in saturation as estimated at sites NGHP-01-08 and NGHP-01-09. Observations show that average gas hydrate saturations are relatively low (up to 5% of the pore space). The saturation of a gas hydrate estimated from an isotropic P-wave model varies from 5% to 20%. However, the saturation estimated from the anisotropic P-wave model shows a variation up to 10% of the pore spaces at three sites.


Gas hydrate Mahanadi basin well logs rock physics modelling saturation anisotropy 



We would like to thank DGH and ONGC for their fruitful collaboration, especially by making the seismic and log data sets available for extended studies on the gas hydrate in the Mahanadi basin. We would like to thank the anonymous reviewer for the constructive review.


  1. Bastia R, Radhakrishna M, Srinivas T, Nayak S, Nathaniel D M and Biswal T K 2010a Structural and tectonic interpretation of geophysical data along the Eastern Continental Margin of India with special reference to the deep water petroliferous basins; J. Asian Earth Sci. 39 608–619.CrossRefGoogle Scholar
  2. Bastia R, Radhakrishna M, Das S, Kale A S and Catuneanu O 2010b Delineation of the 85\(^\circ \) E ridge and its structure in the Mahanadi Offshore Basin, Eastern Continental Margin of India (ECMI), from seismic reflection imaging; Mar. Petrol. Geol. 27 1841–1848.CrossRefGoogle Scholar
  3. Berryman J G and Milton G W 1991 Exact results for generalised Gassmann’s equations in composite porous media with two constituents; Geophysics 56 1950–1960.CrossRefGoogle Scholar
  4. Bharali B, Rath S and Sarma R 1991 A brief review of Mahanadi delta and the deltaic sediments in Mahanadi basin; In: Quaternary deltas of India, Memoir, Vol. 22, GSI Publication, Bangalore, pp. 31–49Google Scholar
  5. Carcione J M and Tinivella U 2000 Bottom-simulating reflectors: Seismic velocities and AVO effects; Geophysics 65 54–67.CrossRefGoogle Scholar
  6. Collett T S 2002 Energy resource potential of natural gas hydrates; Am. Assoc. Petrol. Geol. Bull. 86(11) 1971–1992.Google Scholar
  7. Collett T S and Ladd J 2000 Detection of gas hydrate with downhole logs and assessment of gas hydrate concentrations (saturations) and gas volumes on the Blake ridge with electrical resistivity data; In: Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 164, pp. 179–191.Google Scholar
  8. Collett T S, Riedel M, Cochran J R, Boswell R, Presley J, Kumar P, Sathe A V, Sethi A, Lall M and Sibal V, NGHP Expedition 01 Scientists 2008 National gas hydrate program expedition 01; Initial Reports, Directorate General of Hydrocarbons, New Delhi.Google Scholar
  9. Cook A E, Goldberg D and Kleinberg R L 2008 Fractured-controlled gas hydrate systems in the northern Gulf of Mexico; Mar. Petrol. Geol.
  10. Dai J, Xu H B, Snyder F and Dutta N 2004 Detection and estimation of gas hydrates using rock physics and seismic inversion: Examples from the northern deep water Gulf of Mexico; Lead. Edge 23(1) 60–66.CrossRefGoogle Scholar
  11. Dai J, Snyder F, Gillespie D, Koesoemadinata A and Dutta N 2008 Exploration for gas hydrates in the deep water, northern Gulf of Mexico: Part I, a seismic approach based on geologic model, inversion, and rock physics principles; Mar. Petrol. Geol. 25 830–844.CrossRefGoogle Scholar
  12. Dangwal V, Sengupta S and Desai A G 2008 Speculated petroleum systems in deep offshore Mahanadi basin in Bay of Bengal, India; In: Proceeding of 7th international conference and exposition on petroleum geophysics, Hyderabad, India.Google Scholar
  13. Dvorkin J and Nur A 1993 Rock physics for characterization of gas hydrates; In: The future of energy gases (ed) Howell D G, U.S. Geological Survey Professional Paper, Vol. 1570, pp. 293–311.Google Scholar
  14. Dvorkin J and Nur A 1996 Elasticity of high-porosity sandstones: Theory for two North Sea data sets; Geophysics 61 1363–1370.CrossRefGoogle Scholar
  15. Dvorkin J and Nur A 1998 Acoustic signatures of patchy saturation; Int. J. Solids Struct. 35 4803–4810.CrossRefGoogle Scholar
  16. Dvorkin J, Prasad M, Sakai A and Lavoie D 1999 Elasticity of marine sediments: Rock physics modeling; Geophys. Res. Lett. 26(12). Scholar
  17. Dvorkin J, Nur A, Uden R and Taner T 2003 Rock physics of a gas hydrate reservoirs; Lead. Edge 22 842–846.CrossRefGoogle Scholar
  18. Ecker C, Dvorkin J and Nur A 1998 Sediments with gas hydrate: Internal structure from seismic AVO; Geophysics 63 1659–1669.CrossRefGoogle Scholar
  19. Ecker C, Dvorkin J and Nur A 2000 Estimating the amount of gas hydrate and free gas from marine seismic data; Geophysics 65 565–573.CrossRefGoogle Scholar
  20. Fuloria R C, Pandey R N, Bharali B R and Mishra J K 1992 Stratigraphy, structure and tectonics of Mahanadi offshore basin; In: Recent Geoscientific Studies in the Bay of Bengal and the Andaman Sea; J. Geol. Soci. India Spec. Publ. 29 255–265.Google Scholar
  21. Gassmann F 1951 On the elasticity of porous media; Vierteljahr. Naturforsch. Ges. Zurich 96 1–23.Google Scholar
  22. Ghosh R, Sain K and Ojha M 2010 Effective medium modeling of gas hydrate-filled fractures using sonic log in the Krishna–Godavari basin, eastern Indian offshore; J. Geophys. Res. 115 B06101.
  23. Gibson R L Jr and Toksoz M N 1990 Permeability estimation from velocity anisotropy in fractured rocks; J. Geophys. Res. 95 15643–15656.CrossRefGoogle Scholar
  24. Guerin G, Goldberg D and Melsterl A 1999 Characterization of in situ elastic properties of gas hydrate-bearing sediments on the Blake Ridge; J. Geophys. Res. 104 17781–17796.CrossRefGoogle Scholar
  25. Helgerud M B 2001 Waves speeds in gas hydrate and sediments containing gas hydrate: A laboratory and modeling study; PhD Dissertation, Stanford University, 249.Google Scholar
  26. Helgerud M B, Dvorkin J and Nur A 1999 Elastic-wave velocity in marine sediments with gas hydrates: Effective medium modeling; Geophys. Res. Lett. 26 2021–2024.CrossRefGoogle Scholar
  27. Holland M, Schultheiss P, Roberts J and Druce M 2008 Observed gas hydrate morphologies marine sediments; In: Proceedings of the 6th International Conference on Gas Hydrates, Vancouver, BC, Canada, pp. 6–10.Google Scholar
  28. Hyndman R D, Yuan T and Moran K 1999 The concentration of deep sea gas hydrates from downhole electrical resistivity logs and laboratory data; Earth Planet. Sci. Lett. 172 167–177.CrossRefGoogle Scholar
  29. Hyndman R D, Spence G D, Chapman N R, Riedel M and Edwards R N 2001 Geophysical studies of marine gas hydrate in northern Cascadia; In: Natural Gas Hydrates: Occurrence, Distribution, Detection (eds) Paull C K and Dillon W P, Am. Geophys. Union Monogr. 124 273–295.Google Scholar
  30. Jakobsen M, Hudson J A, Minshull T A and Singh S C 2000 Elastic properties of hydrate-bearing sediments using effective medium theory; J. Geophys. Res. 105(B1) 561–577.CrossRefGoogle Scholar
  31. Kastner M, Claypool G and Robertson G 2008 Geochemical constraints on the origin of the pore fluids and gas hydrate distribution at Atwater Valley and Keathley Canyon, northern Gulf of Mexico; Mar. Petrol. Geol. 25 860–872.CrossRefGoogle Scholar
  32. Kuster G T and Toksöz M N 1974 Velocity and attenuation of seismic waves in two phase media: Part I. Theoretical formulations; Geophysics 39 587–606.CrossRefGoogle Scholar
  33. Lee M W and Collett T S 2005 Assessments of gas hydrate concentrations estimated from sonic logs in the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate research production well; In: Scientific results from the Mallik 2002 Gas Hydrate Production Research Well Program, Makenzie delta, Northwest Territories, Canada (eds) Dallimore S R and Collett T S, Bull. Geol. Surv. Can. 585 10.Google Scholar
  34. Lee M W and Waite W F 2008 Estimating pore-space gas hydrate saturations from well log acoustic data; Geochem. Geophys. Geosyst. 9 Q07008. Scholar
  35. Lee M W and Collett T S 2009 Gas hydrate saturations estimated from fractured reservoir at site NGHP-01-10, Krishna–Godavari basin, India; J. Geophys. Res. 114 B07102. Scholar
  36. Lee M W, Hutchinson D R, Dillon W P, Miller J J, Agena W F and Swift B A 1993 Method of estimating the amount of in situ gas hydrates in deep marine sediments; J. Mar. Petrol. Geol. 10 496–506.CrossRefGoogle Scholar
  37. Mathur M C, Sinharay S, Ravindranath R and Sharma M 2008 Identification of sandy marine gas hydrates and deep water depositional elements in gas hydrate stability zones; In: Extended Abstract Presented in 7th Biennial International Conference and Exposition on Petroleum Geophysics, Hyderabad, India, 408p.Google Scholar
  38. Mavko G and Jizba D 1991 Estimating grain-scale fluid effects on velocity dispersion in rocks; Geophysics 56 1940–1949.CrossRefGoogle Scholar
  39. Mavko G, Chan C and Mukerji T 1995 Fluid substitution: Estimating changes in \(V_{{\rm p}}\) without knowing \(V_{{\rm s}}\); Geophysics 60 1750–1755.CrossRefGoogle Scholar
  40. Mohapatra P 2006 Sequence stratigraphic approach for identification of hydrocarbon plays in Mahanadi offshore basin; In: Proceeding of 6th International Conference and Exposition on Petroleum Geophysics, Kolkata, India.Google Scholar
  41. Nur A 1971 Effect of stress on velocity anisotropy in rocks with cracks; J. Geophys. Res. 76 2022–2034.CrossRefGoogle Scholar
  42. Ojha M and Sain K 2013 Quantification of gas hydrates and free gas in the Andaman offshore from downhole data; Curr. Sci. 105 512–516.Google Scholar
  43. Prakash A, Samanta B G and Singh N P 2010 A seismic study to investigate the prospect of gas hydrate in Mahanadi deep water basin, northeastern continental margin of India; Mar. Geophys. Res. 31 253–262.CrossRefGoogle Scholar
  44. Ramana M V, Ramprasad T, Paropkari A L, Borole D V, Ramalingeswara B R, Karisiddaiah S M, Desa M, Kocherla M, Joao H M, Loka-bharathi P, Gonsalves M-J, Pattan J N, Khadge N H, PrakashBabu C, Sathe A V, Kumar P and Sethi A K 2009 Multidisciplinary investigations exploring indicators of gas hydrates occurrence in the Krishna–Godavari basin offshore, east coast of India; Geo-Mar. Lett. 29 25–38.CrossRefGoogle Scholar
  45. Sain K, Ojha M, Satyavani N, Ramadass G A, Ramprasad T, Das S K and Gupta H K 2012 Gas hydrates in Krishna–Godavari and Mahanadi basins: New data; J. Geol. Soc. India 79 553–556.CrossRefGoogle Scholar
  46. Satyavani N, Alekhya G and Sain K 2015 Free gas/gas hydrate inference in Krishna–Godavari basin using seismic and well log data; J. Nat. Gas Sci. Eng. 25 317–324.CrossRefGoogle Scholar
  47. Shankar U and Riedel M 2011 Gas hydrate saturation in the Krishna-Godavari basin from P-wave velocity and electrical resistivity logs; Mar. Petrol. Geol. 28 1768–1778.CrossRefGoogle Scholar
  48. Shankar U and Riedel M 2014 Assessment of gas hydrate saturation in marine sediments from resistivity and compressional-wave velocity log measurements in the Mahanadi basin, India; Mar. Petrol. Geol. 58 265–277.CrossRefGoogle Scholar
  49. Shankar U, Gupta D K, Bhowmick D and Sain K 2013 Gas hydrate and free-gas saturations using rock physics modelling at site NGHP-01-05 in the Krishna-Godavari basin, eastern Indian margin; J. Petrol. Sci. Eng. 106 62–70.CrossRefGoogle Scholar
  50. Subrahmanyam V, Subrahmanyam A S, Murty G P S and Murthy K S R 2008 Morphology and tectonics of Mahanadi basin, northeastern continental margin of India from geophysical studies; Mar. Geol. 253 63–72.CrossRefGoogle Scholar
  51. Subramanian V 1978 Input by Indian rivers into the world oceans; Proc. Indian Acad. Sci. A: Earth Planet. Sci. 87 77–88.Google Scholar
  52. Wang X, Sain K, Satyavani N, Wang J, Ojha M and Wu S 2013 Gas hydrate saturation using geostatistical inversion in a fracture reservoir in the Krishna Godavari basin, offshore eastern India; Mar. Petrol. Geol. 45 224–235.CrossRefGoogle Scholar
  53. White J E 1965 Seismic waves-radiation, transmission, and attenuation; McGraw-Hill, New York, 302p.Google Scholar
  54. Xu H, Dai J, Snyder F and Dutta N 2004 Seismic detection and quantification of gas hydrates using rock physics and inversion; In: Advances in Gas Hydrates Research (eds) Taylor C E and Kwan J T, Kluwer, New York, pp. 117–139.Google Scholar
  55. Yuan T, Hyndman R D, Spence G D and Desmons B 1996 Seismic velocity increase and deep-sea gas hydrate above a bottom-simulating reflector on the northern Cascadia continental slope; J. Geophys. Res. 101 13655–13671.CrossRefGoogle Scholar

Copyright information

© Indian Academy of Sciences 2019

Authors and Affiliations

  1. 1.Department of Geophysics, Institute of ScienceBanaras Hindu UniversityVaranasiIndia

Personalised recommendations