Distribution and origin of natural gas leakage in the Colorado Basin, offshore Argentina 2 Margin, South America: seismic interpretation and 3D basin modelling


  • Z. ANKA GFZ German Research Centre for Geosciences. Potsdam, Germany.
  • M.J. LOEGERING GFZ German Research Centre for Geosciences. Potsdam, Germany. Sasol101 Wigmore St. London W1U. UK.
  • R. DI PRIMIO GFZ German Research Centre for Geosciences. Potsdam, Germany. Lundin Norway SAStrandveien 50B, P.O. Box 247, N-1326 Lysaker, Norway.
  • D. MARCHAL Petrobras Argentina S.A. Maipú 1 1084 Ciudad de Buenos Aires, Argentina.
  • J.F. RODRIGUEZ Petrobras Argentina S.A. Maipú 1 1084 Ciudad de Buenos Aires, Argentina.
  • E. VALLEJO Petrobras Argentina S.A. Maipú 1 1084 Ciudad de Buenos Aires, Argentina. YPF Tecnología S.A.Torre YPF Macacha Guemes 515, Ciudad de Buenos Aires, Argentina.




Passive continental margin, Gas leakage, South Atlantic, Pockmarks, Seismic chimneys


The detailed analysis of a dense 2D seismic reflection dataset and data from 8 exploration wells, allowed us to identify, map out and characterize possible indications of past and present-day hydrocarbon leakage (i.e. gas chimneys, gas pockets, and seafloor mounds and pockmarks) on the continental shelf and slope of the Colorado Basin, offshore Argentina, where Permian, Jurassic and Early Cretaceous source rocks are potentially present and may be currently mature. Identified gas leakage features, developed both in the syn-rift and post-rift successions, were also analysed in relation to the structural the stratigraphic elements of the basin. A family of seabed pockmarks, located close to an array of submarine channels, was identified on the distal slope of the basin. These pockmarks are overlying a series of sub-vertical to vertical seismic chimneys in the subsurface. A calibrated basin-wide 3D petroleum system model comprising generation and migration of hydrocarbons was carried out and compared with the observations from the seismic analysis. Preliminary results from this model indicate that although synrift and early Cretaceous source rock (SR) intervals may be depleted in the central areas of the basin, an active kitchen from the Aptian SR may be present below the slope areas. Hydrocarbon migration pathways predicted by the 3D model (Hybrid method) coincide with the interpreted seismic chimneys underlying the observed seabed slope pockmarks. Hence, our results indicate that thermogenic gas may be currently generated in the distal slope of the basin from mature early post-rift source rocks within the Early Cretaceous (Aptian) sequences and migrates vertically, due to seal failure, through the stratigraphic column. This migrating thermogenic gas is feeding the seafloor pockmarks identified in the distal slope of the basin, although up-dip lateral migration along stratigraphic layers to the more proximal slope areas cannot be ruled out. The present work represents the first published study integrating detailed seismic analysis and 3D basin modelling linking observed gas-leakage indicators and associated seepage pathways, to their relative abundance, distribution and feeding systems offshore Argentina’s continental margin.


Anka, Z., Berndt, C., Gay, A. (eds.), 2012. Hydrocarbon leakage though focused fluid flow systems in continental margins. Special Volume of Marine Geology, 332–334, 234pp.

Aplin, A.C. and Larter, S.R. 2005. Fluid Flow, Pore Pressure, Wettability and Leakage in Mudstone Cap Rocks, in P. Boult and J. Kaldi (eds.), Evaluating Fault and Cap Rock Seals, American Association of Petroleum Geologists Hedberg Series, 2, 1-12.

Baristeas, N., Anka, Z., di Primio, R., Rodriguez, J. F., Marchal, D., Dominguez, F., Vallejo, E., 2012. Distribution of hydrocarbon leakage indicators in the Malvinas Basin, Offshore Argentine Continental Margin. Marine Geology, 332–334, 56-74.

Ben Avraham, Z., Smith, G., Reshef, M. and Jungslager, E., 2002. Gas hydrate and mud volcanoes on the SW Afrian continental margin. Geology, 30, 927-930.

Berndt, C., 2005. Focused fluid flow in passive continental margins, Astronomy and earth science. Royal Society of London, London, United Kingdom, 2855-2871.

Berndt, C., Bünz, S., Mienert, J., 2003. Polygonal fault systems on the mid-Norwegian margin: A long term source for fluid flow, in P. Van Rensbergen, R. Hillis, A. Maltman, and C. Morley, eds., Subsurface Sediment Mobilization: Geological Society Special Publication, 216, London, UK, Geological Society of London, 283-290.

Boyd, D.L., Anka, Z., di Primio, R., de Wit, M., Aldrich, J., 2009. Distribution and origin of natural gas leakage features on Block 2 of the Orange Basin as interpreted from 2D seismic reflection data off-shore the South African Margin. SAGA Bulletin 2009, 576-581.

Bushnell, D.C., Baldi, J.E., Bettini, F.H., Franzin, H., Kovas, E., Marinelli, R., Wartenburg, G.J., 2000. Petroleum system analysis of the eastern Colorado Basin, offshore northern Argentina, in Mello, M.R., and Katz, B.J., eds., Petroleum systems of the South Atlantic margins:A.A.P.G. Memoir, 73, 403-415.

Charlou, J.L., Donval, J.P., Fouquet, Y., Ondreas, H., Cochonat, P., Levache, D., Poirier, Y.,Jean-Baptiste, P., Fourre, E., and Chazallon, B., 2004. Physical and chemical characterization of gas hydrates and associated methane plumes on the CongoAngola Basin. Chemical Geology, 205, 405-425.

Clayton, C.J., Hay, S.J., 1994. Gas migration mechanisms from accumulation to surface. Bulletin of the Geological Society of Denmark, 41, 12-23.

Cole, D., Stewart, S.A., Cartwright, J.A., 2000. Giant irregular pockmark craters in the Palaeogene of the Outer Moray Firth Basin, UK North Sea. Marine and Petroleum Geology, 17,


Collett, T.S., 2002. Energy resource potential of natural gas hydrates. American Association of Petroleum Geologists Bulletin, 86, 1971-1992.

Fader, G.B.J., 1991. Gas-related sedimentary features from the eastern Canadian continental shelf. Continental Shelf Research, 11 (8-10), 1123-1153.

Gay, A., Lopez, M., Berndt, C., Séranne, M., 2007. Geological controls on focused fluid flow associated with seafloor seeps in the Lower Congo Basin. Marine Geology, 244, 68-92.

Gay, A., Lopez, M., Cochonat, P., Levaché, D., Sermondadaz, G., Séranne, M., 2006. Evidences of early to late fluid migration from an upper Miocene turbiditic channel revealed by 3D seismic

coupled to geochemical sampling within seafloor pockmarks, Lower Congo Basin. Marine Geology, 23(3), 387-399.

Graue, K., 2000. Mudvolcanoes in deepwater Nigeria. Marine Geology, 17, 959-974.

Hartwig, A., Anka, Z., di Primio, R., 2012. Evidence of a widespread paleo-pockmarked field in the Orange Basin: An indication of an early Eocene massive fluid escape event off-shore South Africa. Marine Geology, 332-334, 222-234.

Haskell, N., Grindhaug, J., Dhanani, S., Heath, R., Kantorowicz, J., Antrim, L., Cubanski,M., Nataraj, R., Schilly,M.,Wigger, S., 1999. Delineation of geological drilling hazards using 3-D seismic attributes. Leading Edge 373-382.

Heggland, R., 1997. Detection of gas migration from a deep source by the use of exploration 3D seismic data. Gas in marine sediments, geology/geochemistry/microbiology. Marine Geology, 137 (1-2), 41-47. Elsevier, Amsterdam, Netherlands.

Hempel, P., Spiess, V., Schreiber, R., 1994. Expulsion of shallow gas in the Skagerrak-Evidence from subbottom profiling, seismic, hydroacoustical and geochemical data. Estuarine, Coastal and Shelf Science, 38, 583-601.

Hornbach, M.J., Ruppel, C., Van Dover, C.L., 2007. Threedimensional structure of fluid conduits sustaining an active deep marine cold seep. Geophysical Research Letters, 34 (L5601).

Horsfield, B., 1989. Practical criteria for classifying kerogens: Some observations from pyrolysis–gas chromatography. Geochimica et Cosmochimica Acta. 53, 891–901.

Hovland, M., 2000. Are there commercial deposits of methane hydrates in ocean sediments?. Energy Exploration & Exploitation, 18(4), 339-347.

Hovland, M., 2005. Petroleum geology; gas hydrates, Encyclopedia of geology; Volume 4. Elsevier Academic Press, Oxford, United Kingdom.

Hovland, M. and Judd, J., 1988. Seabed pockmarks and seepages. Impact on Geology, Biology and Marine Environment. Graham and Trorman, London, 293pp.

Hovland, M. and Svensen, H., 2006. Submarine pingoes; indicators of shallow gas hydrates in a pockmark at Nyegga, Norwegian Sea. Marine Geology, 228(1-4), 15-23.

Hustoft, S., Mienert, J., Bünz, S., Nouzé, H., 2007. Highresolution 3D-seismic data indicate focussed fluid migration pathways above polygonal fault systems of the midNorwegian margin. Marine Geology, 245, 89-106.

Judd, A., Davies, G., Wilson, J., Holmes, R., Baron, G., Bryden, I., 1997. Contributions to atmospheric methane by natural seepages on the UK continental shelf. Marine Geology, 137,


Judd, A., Hovland, M., 2007. Seabed Fluid Flow. The Impact on Geology, Biology and Marine Environment. Cambridge University Press, 475pp.

Kuhlmann, G., Adams, S., Campher, C., van der Spuy, D., di Primio, R., Horsfield, B., 2010. Passive margin evolution and its controls on natural gas leakage in the southern Orange Basin, blocks 3/4, offshore South Africa. Marine and Petroleum Geology, 27, 973–992.

Kvenvolden, K.A., Rogers, B.W., 2005. Gaia’s breath – global methane exhalations. Marine and Petroleum Geology, 22, 579–590.

Lawver, L.A., Gahagan, L.M., Dalziel, I.W.D., 1998. A tight fit – Early Mesozoic Gondwana, a plate reconstruction perspective. Polar Research, 53, 214-229.

León, R., Somoza, L., Medialdea, T., Maestro, A., Díaz-del-Río, V., Fernández-Puga, M.C., 2006. Classification of sea-floor features associated with methane seeps along the Gulf of Cadiz continental margin. Deep-Sea Research II, 53, 1464–1481.

Lesta, P.J., Turic, M.A., Mainardi, E., 1978. Actualización de la información estratigráfica en la Cuenca del Colorado, VII° Congreso Geológico Argentino (Neuquén, 1978), Buenos Aires. Actas I, 701-713.

Loegering, M.J., Anka, Z., Autin,J., di Primio, R., Marchal, D., Rodriguez, J.F., Franke, D., Vallejo, E. Tectonic and depositional evolution inferred from seismo-stratigraphy in the Colorado Basin, offshore Argentina, South America (2013). Tectonophysics, 604, 245-263.

Loncke, L., Mascle, J. and Parties, F.S., 2004. Mud volcanoes, gas chimneys, pockmarks and mounds in the Nile deepsea fan (Eastern Mediterranean): geophysical evidences. Marine and Petroleum Geology, 21(6), 669-689.

Løseth, H., Gading, M., Wensaas, L., 2009. Hydrocarbon leakage interpreted on seismic data. Marine and Petroleum Geology, 26, 1304-1319.

MacDonald, I.R., Buthman, D.B., Sager, W.W., Peccini, M.B., Guinasso Jr., N.L., 2000. Pulsed oil discharge from a mud volcano. Geology, 28(10), 907–910.

Mancilla, O., Salinas, A., Soubies, D., Debarre, R. and Granjeon, D., 2001. Numerical stratigraphic modeling of the offshore Colorado Basin of Argentina: Methology and results, AAPG Hedberg Conference.

Marcano Romero, G., Anka, Z., Di Primio, R., 2013. Comparison of Major Controlling Factors on Hydrocarbon Generation and Leakage in South Atlantic Conjugate Margins. Tectonophysics special issue on South Atlantic Margins, 604. 264-279 p. DOI: http://dx.doi.org/10.1016/j.


Mazurenko, L.L., Soloviev, V.A., Belenkaya, I., Ivanov, M.K., Pinheiro, L.M., 2002. Mud volcano gas hydrates in the Gulf of Cadiz. Terra Nova, 14 (5), 321–329.

Mienert, J., Vanneste, M., Bu¨nz, S., Andreassen, K., Haflidason, H., Sejrup, H.P., 2005. Ocean warming and gas hydrate stability on the mid-Norwegian margin at the Storegga Slide. Marine and Petroleum Geology, 22, 233–244.

Naeth, J., Di Primio, R., Horsfield, B., Schaefer, R. G., Shannon, P. M., Bailey, W. R., 2005. Hydrocarbon seepage and carbonate mound formation: A basin modeling study from the Porcupine basin (offshore Ireland). Journal of Petroleum Geology, 28(2), 147-166.

O’Brien, G.W., Lawrence, G.M., Williams, A.K., Glenn, K., Barrett, A.G., Lech, M., Edwards, D.S., Cowley, R., Boreham, C.J., Summons, R.E., 2005. Yampi Shelf, Browse Basin, North-West Shelf, Australia: a test-bed for constraining hydrocarbon migration and seepage rates using combinations of 2D and 3D seismic data and multiple, independent remote sensing technologies. Marine and Petroleum Geology, 22, 517–549.

Orange, D.L., Greene, H.G., Reed, D., Martin, J.B., Mchugh, C.M., Ryan, W.B.F., Maher, N., Stakes, D., and Barry, J., 1999. Widespread fluid explusion on a translational continental margin: Mud volcanoes, fault zones, headless canyons, and organic-rich substrate in Monterrey Bay, California. GSA Bulletin, 111, 992-1009.

Orange, D.L., Yun, J., Maher, N., Barry, J. and Greene, G., 2002. Tracking California seafloor seeps with bathymetry, backscatter and ROVs. Continental Shelf Research, 22, 2273-2290.

Ostanin I., Anka Z., Di Primio R., Bernal A., 2012a. Hydrocarbon leakage above the Snøhvit Gas Field, Hammerfest Basin SW Barents Sea. First Break, 30(11), 55-60. DOI: 10.3997/1365-


Ostanin, I., Anka, Z., di Primio, R., and Bernal, A. (2012b) Identification of a large Upper Cretaceous Polygonal Fault network in the Hammerfest Basin: Implications on the reactivation of regional faults and gas leakage dynamics, SW Barents Sea. Marine Geology, 332–334, 109-125. DOI: http://dx.doi.org/10.1016/j.margeo.2012.03.005.

Ostanin, I. , Anka, Z., di Primio, R., Bernal, A., 2013. Hydrocarbon plumbing systems above the Snøhvit gas field: structural control and implications for thermogenic methane leakage in the Hammerfest Basin, SW Barents Sea. Marine and Petroleum Geology, 43, 127-146.

Pilcher, R. and Argent, J., 2007. Mega-pockmarks and linear pockmark trains on the West African continental margin. Marine Geology, 244, 15-32.

Richards, P., Duncan, I., Phipps, C., Pickering, G., Grzywacs, J., Hoult, R., Merritt, J., 2006. Exploring for fan delta sandstones in the offshore Falklands basins. Journal of Petroleum Geology, 29(3), 199-214.

Rodriguez, J.F., Miller, M., Cagnolatti, M.J., 2008. Sistemas Petroleros de Cuenca Austral, Argentina, Chile, in Simposio de Sistemas Petroleros de las Cuencas Andinas. VII Congreso de Exploración y Desarrollo de Hidrocarburos. Eds. C.E. Cruz, J.F. Rodríguez, J.J. Hechem, H.J. Villar.

Buenos Aires.

Sager, W.W., Macdonald, I.R., Hou, R.S., 2003. Geophysical signatures of mud mounds at hydrocarbon seeps on the Louisiana continental slope, northern Gulf of Mexico. Marine Geology, 198, 97-132.

Schroot, B.M., Klaver, G.T., Schüttenhelm, R.T.E., 2005. Surface and subsurface expressions of gas seepage to the seabed – examples from the Southern North Sea. Marine and Petroleum

Geology, 22, 499-515.

Sibuet M, Juniper S.K., Pautot, G., 1988. Cold-seep benthic communities in the Japan subduction zones: geological control of community development. Journal Marine Research, 46, 333-348.

Unternehr, P., Curie, D., Olivet, J.L., Goslin, J., Beuzart, P., 1988. South Atlantic fits and intraplate boundaries in Africa ans South America. Tectonophysics, 155, 169-179.

Vayssaire, A., Prayitno, W., Figueroa, D., Quesada, S., 2007. Petroleum systems of Colorado and Malvinas basins, deep water Argentina, South Atlantic petroleum systems. Geological Society of London, 10pp.

Van Rensbergen, P., de Batist, M., Klerkx, J., Hus, R., Poort, J., Vanneste, M., Granin, N., Khlystov, O., Krinitsky, P., 2002. Sublacustrine mud volcanoes and methane seeps caused by dissociation of gas hydrates in Lake Baikal. Geology, 30(7), 631-634.

Wood, W.T., Gettrust, J.F., Chapman, N.R., Spence, G.D., Hyndman, R.D., 2002. Decreased stability of methane hydrates in marine sediments owing to phase boundary roughness. Nature, 420(6916), 656-660.