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Illitization and silicification in Greater Alwyn: I. Assessing and synthesizing experimental data

Published online by Cambridge University Press:  09 July 2018

C. Durand*
Affiliation:
Institut Français du Pétrole, Rueil-Malmaison, France
J. C. Matthews
Affiliation:
Total Oil Marine, Aberdeen, UK
Y. Le Gallo
Affiliation:
Institut Français du Pétrole, Rueil-Malmaison, France
E. Brosse
Affiliation:
Institut Français du Pétrole, Rueil-Malmaison, France
F. Sommer
Affiliation:
CST-Total, St Rémy les Chevreuse, France
*

Abstract

Silicification and illitization due to diagenesis result in the modification of porosity and permeability in many North Sea reservoirs, including Greater Alwyn. A good estimation of the mineral composition is required as input/output data for geochemical modelling modes intended to reproduce these effects. Using sedimentological studies to determine laterally equivalent facies, three facies were chosen. ‘Initial states’ for modelling were thus defined as the present-day composition of less-evolved laterally-equivalent facies, ‘final states’ as the present-day composition in the most evolved part of the basin. Precise actual mineral compositions were calculated using a reconciliation program, DATREC. Average compositions calculated for each facies in each field provided data useful in constraining input/output values used in modelling, and gave insights into depositional variation. Arithmetic tests assuming isochemical transformations, constraining the chemical compositions of ‘initial states’ to fit actual mineralogical compositions of ‘final states’, were run using this software. They show that, from an arithmetical point of view, if the assumption of equivalent facies holds, isochemical reactions can occur in some, but not in all facies, thereby demonstrating the importance of checking equivalence of facies and diagenesis hypotheses by quantitative calculations.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

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Footnotes

Present address: Geologica, Stavanger, Norway.

References

Bazin, B., Brosse, E. & Sommer, F. (1997) Chemistry of oil-field brines in relation to diagenesis of reservoirs. 2. Reconstruction of palaeo-water composition for modelling illite diagenesis in the Greater Alwyn area (North Sea). Marine Petrol. Geol. 14, 14497.Google Scholar
Bjørkum, P.A. (1996) How important is pressure in causing dissolution of quartz in sandstones. J. Sed. Res. 66, 66147.Google Scholar
Bjørkum, P.A. & Gjelsvik, N. (1988) An isochemical model for formation of authigenic kaolinite, K-feldspar and illite in sediments. J. Sed. Pet. 58, 58506.Google Scholar
Bjørlykke, K., Nedkvitne, T., Ramm, M. & Saigal, G.C. (1992) Diagenetic processes in the Brent group. Pp. 263–288 in: Geology of the Brent Group (Morton, A.C., Haszeldine, R.S., Giles, M.R. & Brown, S., editors). Geological Society, London, Spec. Publ. 61.Google Scholar
Brosse, E., Le Gallo, Y. & Matthews, J. (2000) Related quartz and illite cementation in the Brent sandstones: a modelling approach. In: Quartz Cement in Oil Field Sandstones (Worden, R. & Morad, S., editors). Int. Assoc. Sedim. Spec. Publ. Blackwells, Oxford (in press).Google Scholar
Caujolle, J.P. & Renaud, J.L., (1989) Application des traitements de coherence aux installations de raffinage ELF France. IFAC Int. Symp. Nancy, France. Google Scholar
Didier, B., Eschard, R. & Feroul, J.M. (1995) Mode of transgression of a wave- and tide-dominated deltaic system in a tectonically active setting: The Brent Group on Alwyn South Fields, North Sea, UK. Int. Assoc. Sedimentologists 16th Regional Meeting of Sedimentology. Abstracts, p 57.Google Scholar
Durand, C., Szymanski, R. & Renaud, J.L. (1991) Reconciliation of bulk and local analyses to assess the clay content of a sandstone. Rev. IFP, 46, 46295.Google Scholar
Giles, M.R., Stevenson, S., Martin, S.V., Cannon, S.J.C., Hamilton, P.I, Marshall, J.D. & Samways, G.M. (1992) The reservoir properties and diagenesis of the Brent group: a regional perspective. Pp. 289–328 in: Geology of the Brent Group (Morton, A.C., Haszeldine, R.S., Giles, M.R. & Brown, S., editors). Geological Society, London, Spec. Publ. 61.Google Scholar
Glasmarm, J.R. (1992) The fate of feldspars in Brent group reservoirs, North Sea: a regional synthesis of diagenesis in shallow, intermediate and deep burial environments. Pp. 329–350 in: Geology of the Brent Group (Morton, A.C., Haszeldine, R.S., Giles, M.R. & Brown, S.). Geological Society, London, Spec. Publ. 61.Google Scholar
Guilhaumou, N., Cordon, S., Durand, C. & Sommer, F. (1998) P-T conditions of silicification in diagenetic sandstones from the Brent formation of Dunbar (North Sea). Eur. J. Miner. 10, 10355.CrossRefGoogle Scholar
Hogg, A.J.C. (1989) Petrographic and isotopic constraints on the diagenesis and reservoir properties of the Brent Group sandstones, Alwyn South, Northern UK, North Sea. PhD Thesis, Univ. Aberdeen, UK.Google Scholar
Hogg, A.J.C., Sellier, E. & Jourdan AJ. (1992) Cathodoluminescence of quartz cements in Brent group sandstones, Alwyn South, UK North Sea. Pp. 421–440 in: Geology of the Brent Group (Morton, A.C., Haszeldine, R.S., Giles, M.R. & Brown, S.). Geological Society, London, Spec. Publ. 61.Google Scholar
Inglis, I. & Gerard, J. (1991) The Alwyn North Field, Block 3/9a, 3/4a, UK North Sea. Pp. 21-32 in: United Kingdom Oil and Gas Fields, 25 Years Commemorative Volume (Abbotts, I.L., editor). Geological Society Memoir, 14.Google Scholar
Johnson, A. & Eyssautier, M. (1987) Alwyn North Field and its regional context. Pp. 963–977 In: Petroleum Geology of North West Europe (Brooks, J. & Glennie, K.W., editors). Graham & Trotman, London.Google Scholar
Jourdan, A., Thomas, M., Brevart, O., Robson, P., Sommer, F. & Sullivan, M. (1987) Diagenesis as the control of the Brent sandstone reservoir properties in the Greater Alwyn Area (East Shetland Basin). Pp. 951–961 in: Petroleum Geology of North West Europe (Brooks, J. & Glennie, K.W., editors). Graham & Trotman, London.Google Scholar
Le Gallo, Y., Bildstein, O. & Brosse, E. (1998) Coupled reaction-flow modelling of diagenetic changes in reservoir permeability, porosity and mineral compositions. J. Hydrol. 209, 209366.Google Scholar
Liewig, N., Clauer, N. & Sommer, F. (1987) Rb-Sr and K-Ar dating of clay diagenesis in Jurassic sandstone reservoirs, North Sea. Am. Assoc. Petrol. Geol. Bull. 71, 711467.Google Scholar
Pelletier, I. (1997) Traitement de donnees de reservoir en vue d'une simulation de la diagenese. Application a l'illitisation du Brent dans un champ de la Mer du Nord. PhD thesis, IPG, Paris, France.Google Scholar
Potdevin, J.-L. & Hassouta, L. (1997) Bilan de matiere des processus d'illitisation et de surcroissance de quartz dans un reservoir petrolier du champ d'Ellon (zone Alwyn, mer du Nord). Bull. Soc. Geol. Fr. 219-229.Google Scholar
Ragot, J., Darouach, M. & Maquin, D. (1990) Validation de Donnees et Diagnostic. Hermes Science Publications.Google Scholar
Sommer, F. (1978) Diagenesis of Jurassic sandstones in the Viking Graben. J. Geol. Soc. 135, 13563.Google Scholar
Tamhane, A.C. & Mah, R.S.H. (1985) Data reconciliation and gross error detection in chemical process networks. Technometrics, 27, 409.Google Scholar
Van der Plas, L. & Tobi, A.C. (1965) A chart for judging the reliability of point-counting results. Am. J. Sci. 263, 26387.Google Scholar
Walderhaug, O. (1994) Precipitation rates of quartz Cement in sandstones from the Norwegian continental shelf: evidence from fluid inclusions. J. Sed. Res. 64, 64311.Google Scholar
Yvon, J., Baudracco, J., Cases, J.M. & Weiss, I. (1990) Elements de mineralogie quantitative en micro-analyse des argiles. Pp. 475-489 in: Materiaux Argileux: Structure, Properietes et Applicants (Decarreau, A., editor). SFMC, Paris, France.Google Scholar