1887
Volume 25, Issue 3
  • ISSN: 1354-0793
  • E-ISSN:

Abstract

Salt structures present numerous challenges for targeting reservoirs. Salt movement within the subsurface can follow complex pathways, producing deformation patterns in surrounding strata which are often difficult to decipher. Consequently, the relative role of key salt-flow drivers and geological sensitivities on salt-structure evolution are often poorly understood. To address this, we have developed 2D geomechanical models using the finite-element method to simulate salt diapir and pillow development in two extensional tectonic settings. We conducted model sensitivity analyses to examine the influence of geological parameters on field-scale salt structures and their corresponding deformation pattern. Modelled diapirs developing in thin-skinned extensional settings closely resemble published analogue experiments; however, active and passive stages of diapir growth are seldom or never reached, respectively, thus challenging existing ideas that diapir evolution is dominated by passive growth. In all modelled cases, highly strained domains bound the diapir flanks where extensive small-scale faulting and fracturing can be expected. Asymmetrical diapirs are prone to flank collapse and are observed in models with fast extension or sedimentation rates, thin roof sections or salt layers, or initially short or triangular-shaped diapirs. In modelled thick-skinned extensional settings, salt pillows and suprasalt overburden faults can be laterally offset (decoupled) from a reactivating basement fault. This decoupling increases with increased salt-layer thickness, overburden thickness, sedimentation rate and fault angle, and decreased fault slip rates. Contrary to existing consensus, overburden grounding onto the basement fault scarp does not appear to halt development of salt structures above the footwall basement block.

Animations for all model runs are available at https://doi.org/10.6084/m9.figshare.c.4446272

Companion

This article is accompanied by the following content:
Simulation of salt-cavity healing based on a micro–macro model of pressure solution

Companion

This article is accompanied by the following content:
Mechanics of salt systems: state of the field in numerical methods

Companion

This article is accompanied by the following content:
Mechanics of salt systems: state of the field in numerical methods

Companion

This article is accompanied by the following content:
Simulation of salt-cavity healing based on a micro–macro model of pressure solution
Loading

Article metrics loading...

/content/journals/10.1144/petgeo2018-119
2019-04-24
2024-04-19
Loading full text...

Full text loading...

References

  1. Al-Barwani, B. & McClay, K.
    2008. Salt tectonics in the Thumrait area, in the southern part of the South Oman Salt Basin: Implications for mini-basin evolution. GeoArabia, 13, 77–108.
    [Google Scholar]
  2. Albertz, M., Beaumont, C., Shimeld, J.W., Ings, S.J. & Gradmann, S.
    2010. An investigation of salt tectonic structural styles in the Scotian Basin, offshore Atlantic Canada: 1. Comparison of observations with geometrically simple numerical models. Tectonics, 29, TC4017, https://doi.org/10.1029/2009TC002539
    [Google Scholar]
  3. Allen, P.A. & Allen, J.R.
    2013. Basin Analysis: Principles and Application to Petroleum Play Assessment. Wiley–Blackwell, Oxford.
    [Google Scholar]
  4. Allen, J. & Beaumont, C.
    2012. Impact of inconsistent density scaling on physical analogue models of continental margin scale salt tectonics. Journal of Geophysical Research: Solid Earth, 117, B08103, https://doi.org/10.1029/2012JB009227
    [Google Scholar]
  5. Archer, S.G., Alsop, G.I., Hartley, A.J., Grant, N.T. & Hodgkinson, R.
    2012. Salt tectonics, sediments and prospectivity: an introduction. In: Alsop, G.I., Archer, S.G., Hartley, A.J., Grant, N.T. & Hodgkinson, R. (eds) Salt Tectonics, Sediments and Prospectivity. Geological Society, London, Special Publications, 363, 1–6, https://doi.org/10.1144/SP363.1
    [Google Scholar]
  6. Crook, A.J.L., Owen, D.R.J., Willson, S.M. & Yu, J.G.
    2006. Benchmarks for the evolution of shear localisation with large relative sliding in frictional materials. Computer Methods in Applied Mechanics and Engineering, 195, 4991–5010, https://doi.org/10.1016/j.cma.2005.11.016
    [Google Scholar]
  7. Dooley, T., McClay, K.R. & Pascoe, R.
    2003. 3D analogue models of variable displacement extensional faults: applications to the Revfallet Fault system, offshore mid-Norway. In: Nieuwland, D.A. (ed.) New Insights into Structural Interpretation and Modelling. Geological Society, London, Special Publications, 212, 151–167, https://doi.org/10.1144/GSL.SP.2003.212.01.10
    [Google Scholar]
  8. Dooley, T., McClay, K.R., Hempton, M. & Smit, D.
    2005. Salt tectonics above complex basement extensional fault systems: results from analogue modelling. In: Doré, A.G. & Vining, B.A. (eds) Petroleum Geology: North-West Europe and Global Perspectives – Proceedings of the 6th Petroleum Geology Conference. Geological Society, London, 1631–1648, https://doi.org/10.1144/0061631
    [Google Scholar]
  9. Dooley, T.P., Hudec, M.R., Carruthers, D., Jackson, M.P.A. & Luo, G.
    2017. The effects of base-scale relief on salt flow and suprasalt deformation patterns – Part 1: Flow across simple steps in the base of salt. Interpretation, 5, 1–23, https://doi.org/10.1190/INT-2016-0087.1
    [Google Scholar]
  10. Fossen, H.
    (ed.). 2010. Structural Geology. Cambridge University, Cambridge.
    [Google Scholar]
  11. Gaullier, V., Brun, J.P., Gue, G. & Lecanu, H.
    1993. Raft tectonics: the effects of residual topopgraphy below a salt décollement. Tectonophysics, 228, 363–381, https://doi.org/10.1016/0040-1951(93)90349-O
    [Google Scholar]
  12. Ge, H. & Vendeville, B.C.
    1997. Influence of active subsalt normal faults on the growth and location of suprasalt structures. Gulf Coast Association of Geological Societies Transactions, 47, 169–176.
    [Google Scholar]
  13. Ge, H., Jackson, M.P.A. & Vendeville, B.C.
    1997. Kinematics and dynamics of salt tectonics driven by progradation. AAPG Bulletin, 81, 398–423, https://doi.org/10.1306/522B4361-1727-11D7-8645000102C1865D
    [Google Scholar]
  14. Gemmer, L., Ings, S.J., Medvedev, S. & Beaumont, C.
    2004. Salt tectonics driven by differential sediment loading: Stability analysis and finite element experiments. Basin Research, 16, 199–218, https://doi.org/10.1111/j.1365-2117.2004.00229.x
    [Google Scholar]
  15. Gemmer, L., Beaumont, C. & Ings, S.J.
    2005. Dynamic modelling of passive margin salt tectonics: effects of water loading, sediment properties and sedimentation patterns. Basin Research, 17, 383–402, https://doi.org/10.1111/j.1365-2117.2005.00274.x
    [Google Scholar]
  16. Gradmann, S., Beaumont, C. & Albertz, M.
    2009. Factors controlling the evolution of the Perdido Fold Belt, northwestern Gulf of Mexico, determined from numerical models. Tectonics, 28, TC2002, https://doi.org/10.1029/2008TC002326
    [Google Scholar]
  17. Hodgson, N.A., Farnsworth, J. & Fraser, A.J.
    1992. Salt-related tectonics, sedimentation and hydrocarbon plays in the Central Graben, North Sea, UKCS. In: Hardman, R.F.P. (ed.) Exploration Britain: Geological Insights for the Next Decade. Geological Society, London, Special Publications, 67, 31–63, https://doi.org/10.1144/GSL.SP.1992.067.01.03
    [Google Scholar]
  18. Hudec, M.R. & Jackson, M.P.A.
    2007. Terra infirma: Understanding salt tectonics. Earth-Science Reviews, 82, 1–28, https://doi.org/10.1016/j.earscirev.2007.01.001
    [Google Scholar]
  19. Ings, S., Beaumont, C. & Gemmer, K.
    2004. Numerical modeling of salt tectonics on passive continental margins: Preliminary assessment of the effects of sediment loading, buoyancy, margin tilt, and isostasy. Presented at the 24th Annual GCSSEPM Foundation, Bob F. Perkins Research Conference Proceedings, 36–69
    [Google Scholar]
  20. Krantz, R.W.
    1989. Fault inversion in scaled experimental models. Bulletin of Geological Society of America, 21, 176.
    [Google Scholar]
  21. Kukal, Z.
    1990. The Rate of Geological Processes. Earth-Science Reviews, 28, 1–284, https://doi.org/10.1016/0012-8252(90)90017-P
    [Google Scholar]
  22. Luo, G., Nikolinakou, M., Flemings, P.B. & Hudec, M.R.
    2012. Geomechanical modelling of stresses adjacent to salt bodies: Part 1 – Uncoupled models. AAPG Bulletin, 96, 43–64, https://doi.org/10.1306/04111110144
    [Google Scholar]
  23. Nelson, R.A.
    2001. Geologic Analysis of Naturally Fractured Reservoirs. Gulf Professional Publishing, Boston, MA.
    [Google Scholar]
  24. Pizarro, J.O.D.S. & Branco, C.C.M.
    2012. Challenges in implementing an EOR project in the pre-salt province in Deep Offshore Brasil. Paper SPE-155665 presented at theSPE EOR Conference at Oil and Gas West Asia, 16–18 April 2012, Muscat, Oman.
    [Google Scholar]
  25. Reddy, J.N.
    1993. An Introduction to the Finite Element Method. McGraw-Hill, New York.
    [Google Scholar]
  26. Rockfield Global
    . 2015. ELFEN Explicit Manual. Rockfield Software Limited, Swansea, UK.
    [Google Scholar]
  27. Rowan, M.G., Peel, F.J. & Vendeville, B.C.
    2004. Gravity-driven fold belts on passive margins. In: McClay, K.R. (ed.) Thrust Tectonics and Hydrocarbon Systems. AAPG Memoirs, 82, 157–182.
    [Google Scholar]
  28. Rowan, M.G., Munoz, J.A., Roca, E., Fischer, M. & Giles, K.A.
    2017. Rock deformation adjacent to salt diapirs. Presented at theAAPG/SEG International Conference and Exhibition, 15–18 October 2017, London, UK, http://www.searchanddiscovery.com/abstracts/pdf/2017/90310aapg/abstracts/ndx_rowan.pdf
    [Google Scholar]
  29. Schultz-Ela, D.D. & Jackson, M.P.A.
    1996. Relation of subsalt structures to suprasalt structures during extension. AAPG Bulletin, 80, 1896–1924, https://doi.org/10.1306/64EDA230-1724-11D7-8645000102C1865D
    [Google Scholar]
  30. Seni, S.J. & Jackson, M.P.A.
    1983. Evolution of salt structures, east Texas diapir province, part 1: Sedimentary record of halokinesis. AAPG Bulletin, 67, 1219–1244.
    [Google Scholar]
  31. Stewart, S.A. & Clark, J.A.
    1999. Impact of salt on the structure of the Central North Sea hydrocarbon fairways. In: Fleet, A.J. & Boldy, S.A.R. (eds) Petroleum Geology of Northwest Europe: Proceedings of the 5th Conference. Geological Society, London, 179–200, https://doi.org/10.1144/0050179
    [Google Scholar]
  32. Stewart, S.A. & Coward, M.P.
    1995. Synthesis of salt tectonics in the southern North Sea, UK. Marine and Petroleum Geology, 12, 457–475, https://doi.org/10.1016/0264-8172(95)91502-G
    [Google Scholar]
  33. Stewart, S.A., Harvey, M.J., Otto, S.C. & Weston, P.J.
    1996. Influence of salt on fault geometry: examples from the UK salt basins. In: Alsop, G.I., Blundell, D.J. & Davison, I. (eds) Salt Tectonics. Geological Society, London, Special Publications, 100, 175–202, https://doi.org/10.1144/GSL.SP.1996.100.01.12
    [Google Scholar]
  34. Talbot, C.J., Megvedev, S., Alavi, M., Shahrivar, H. & Heidari, E.
    2000. Salt extrusion at Kuh-e-Jahani, Iran, from June 1994 to November 1997. In: Vendeville, B., Mart, Y. & Vigneresse, J.-L. (eds) Salt, Shale and Igneous Diapirs in and around Europe. Geological Society, London, Special Publications, 174, 93–110, https://doi.org/10.1144/GSL.SP.1999.174.01.06
    [Google Scholar]
  35. Thigpen, J.R., Roberts, D., Snow, J.K., Walker, C.D. & Bere, A.
    2019. Integrating kinematic restoration and forward finite element simulations to constrain the evolution of salt diapirism and overburden deformation in evaporite basins. Journal of Structural Geology, 118, 68–86, https://doi.org/10.1016/j.jsg.2018.10.003
    [Google Scholar]
  36. Thornton, D.A. & Crook, A.J.L.
    2014. Predictive modeling of the evolution of fault structure: 3-D modeling and coupled geomechanical/flow simulation. Rock Mechanics and Rock Engineering, 47, 1533–1549, https://doi.org/10.1007/s00603-014-0589-6
    [Google Scholar]
  37. Trusheim, F.
    1960. Mechanism of salt migration in northern Germany. AAPG Bulletin, 44, 1519–1540, https://doi.org/10.1306/0BDA61CA-16BD-11D7-8645000102C1865D
    [Google Scholar]
  38. Vendeville, B.C. & Jackson, M.P.A.
    1991. Deposition, extension, and the shape of downbuilding salt diapirs. AAPG Bulletin, 75, 687–688.
    [Google Scholar]
  39. 1992a. The rise of diapirs during thin-skinned extension. Marine and Petroleum Geology, 9, 331–354, https://doi.org/10.1016/0264-8172(92)90047-I
    [Google Scholar]
  40. 1992b. The fall of diapirs during thin-skinned extension. Marine and Petroleum Geology, 9, 354–371, https://doi.org/10.1016/0264-8172(92)90048-J
    [Google Scholar]
  41. Vendeville, B.C., Ge, H. & Jackson, M.P.A.
    1995. Scale models of salt tectonics during basement-involved extension. Petroleum Geoscience, 1, 179–183, https://doi.org/10.1144/petgeo.1.2.179
    [Google Scholar]
  42. von Nicolai, C.
    2011. The interplay of salt movements and regional tectonics at the passive continental margin of the South Atlantic, Kwanza Basin. PhD thesis, Universität Potsdam, Pottsdam, Germany.
    [Google Scholar]
  43. Warsitzka, M., Kley, J. & Kukowski, N.
    2013. Salt diapirism driven by differential loading–Some insights from analogue modelling. Tectonophysics, 591, 83–97, https://doi.org/10.1016/j.tecto.2011.11.018
    [Google Scholar]
  44. 2015. Analogue experiments of salt flow and pillow growth due basement faulting and differential loading. Solid Earth Discussion, 6, 9–31, https://doi.org/10.5194/se-6-9-2015
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1144/petgeo2018-119
Loading
/content/journals/10.1144/petgeo2018-119
Loading

Data & Media loading...

  • Article Type: Research Article

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error