1887

Abstract

Summary

The presence of continuous chlorite coats on detrital grains can preserve anomalously good reservoir quality in deeply buried sandstones by inhibiting quartz cementation. Two sandstones in the Gulf of Mexico basin—Upper Cretaceous Tuscaloosa sandstone in central and eastern Louisiana and Eocene Upper Wilcox sandstone in south Texas—have intervals that retain high porosity and permeability at temperatures >175°C because of extensive chlorite coats. However, significant variation exists in the morphology and orientation of the chlorite cement on detrital grains in these sandstones. Scanning electron microscope (SEM) observation of chlorite-cemented sandstone samples prepared by argon-ion-beam milling provides excellent views of grain/chlorite boundaries. This technique gives insight into the formation of the chlorite and development of quartz overgrowths within chlorite coats. Quartz overgrowths formed in gaps between chlorite crystals oriented perpendicular to detrital grains in Tuscaloosa sandstones of central Louisiana. In contrast, densely packed chlorite crystals oriented parallel to the detrital grains, such as those observed in Wilcox sandstones in south Texas, prevented precipitation of quartz overgrowths within the chlorite coats. Viewing ion-milled sandstone samples in SEM is a useful technique that can provide new insights into formation of diagenetic cements and preservation of reservoir quality in deeply buried sandstones.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201600701
2016-05-30
2024-04-19
Loading full text...

Full text loading...

References

  1. Ajdukiewicz, J.M. and Larese, R.E.
    [2012] How clay grain coats inhibit quartz cement and preserve porosity in deeply buried sandstones: observations and experiments. American Association of Petroleum Geologists Bulletin, 96, 2091–2119.
    [Google Scholar]
  2. Ambrose, W.A., Loucks, R.G. and Dutton, S.P.
    [2015] Sequence-stratigraphic and depositional controls on reservoir quality in lowstand incised-valley-fill and highstand shallow-marine systems in the Upper Cretaceous (Cenomanian) Tuscaloosa Formation, Louisiana, U.S.A. GCAGS Journal, 4, 43–66.
    [Google Scholar]
  3. Bloch, S., Lander, R.H. and Bonnell, L.
    [2002] Anomalously high porosity and permeability in deeply buried sandstone reservoirs: origin and predictability. American Association of Petroleum Geologists Bulletin, 86, 301–328.
    [Google Scholar]
  4. Dutton, S.P., Ambrose, W.A. and Loucks, R.G.
    [2013] Controls on distribution of chlorite coats and reservoir quality in Cretaceous Tuscaloosa sandstones, Gulf of Mexico (ext. abs.). London '13, 75th EAGE Conference & Exhibition incorporating SPE EUROPEC 2013, London, United Kingdom, June10–13, 2013, 5 p.
    [Google Scholar]
  5. Dutton, S.P., Kohut, M.E., Ambrose, W. and Loucks, R.G.
    [2015] Comparing chlorite-coat coverage and reservoir quality in deep Tuscaloosa sandstones, Louisiana Gulf Coast, USA (abs.). American Association of Petroleum Geologists Annual Convention and Exhibition, Denver, Colorado, May31-June3, abstract no. 2089357, CD-ROM.
    [Google Scholar]
  6. Ehrenberg, S.N.
    [1993] Preservation of anomalously high porosity in deeply buried sandstones by grain-coating chlorite: examples from the Norwegian continental shelf. American Association of Petroleum Geologists Bulletin, 77, 1260–1286.
    [Google Scholar]
  7. Galloway, W.E., Whiteaker, T.L. and Ganey-Curry, P.
    [2011] History of Cenozoic North American drainage basin evolution, sediment yield, and accumulation in the Gulf of Mexico Basin. Geosphere, 7, 938–973.
    [Google Scholar]
  8. Loucks, R.G., Reed, R.M., Ruppel, S.C. and Jarvie, D.M.
    [2009] Morphology, genesis, and distribution of nanometer-scale pores in siliceous mudstones of the Mississippi Barnett Shale. Journal of Sedimentary Research, 79, 848–861.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201600701
Loading
/content/papers/10.3997/2214-4609.201600701
Loading

Data & Media loading...

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