Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by BARCLAY, S. A. Articles by WORDEN, R. H. Search for Related Content GeoRef GeoRef Citation

Geochemical modelling of diagenetic reactions in a sub-arkosic sandstone

S. A. BARCLAY and R. H. WORDEN^*,

School of Geosciences, The Queen’s University of Belfast, Belfast BT7 1NN, UK

^* E-mail: r.worden{at}liv.co.uk

(Received 1 May 1998; revised 21 July 1999)

A reaction path model was constructed in a bid to simulate diagenesis in the Magnus Sandstone, an Upper Jurassic turbidite reservoir in the Northern North Sea, UKCS. The model, involving a flux of source rock-derived CO₂ into an arkosic sandstone, successfully reproduced simultaneous dissolution of detrital K-feldspar and growth of authigenic quartz, ankerite and illite. Generation of CO₂ occurred before and during the main phase of oil generation linking source rock maturation with patterns of diagenesis in arkosic sandstones and limiting this type of diagenesis to the earlier stages of oil charging. Independent corroborative evidence for the model is provided by formation water geochemical data, carbon isotope data from ankerite and produced gas phase CO₂ and the presence of petroleum inclusions within the mineral cements. The model involves a closed system with respect to relatively insoluble species such as SiO₂ and Al₂O₃ but is an open system with respect to CO₂. There are up to seven possible rate-controlling steps including: influx of CO₂, dissolution of K-feldspar, precipitation of quartz, ankerite and illite, diffusive transport of SiO₂ and Al₂O₃ from the site of dissolution to the site of precipitation and possibly the rate of influx of Mg²⁺ and Ca²⁺. Given the large number of possible controls, and contrary to modern popular belief, the rate of quartz precipitation is thus not always rate limiting.

KEYWORDS: quartz cementation, diagenesis, geochemical modelling, K-feldspar reaction, carbon dioxide

This article has been cited by other articles:

				M. Wilkinson, R. S. Haszeldine, and A. E. Fallick Hydrocarbon filling and leakage history of a deep geopressured sandstone, Fulmar Formation, United Kingdom North Sea AAPG Bulletin, December 1, 2006; 90(12): 1945 - 1961. [Abstract] [Full Text] [PDF]

				M. WILKINSON, R. S. HASZELDINE, and A. E. FALLICK Jurassic and Cretaceous clays of the northern and central North Sea hydrocarbon reservoirs reviewed Clay Minerals, March 1, 2006; 41(1): 151 - 186. [Abstract] [Full Text] [PDF]

				S. J. Baines and R. H. Worden The long-term fate of CO2 in the subsurface: natural analogues for CO2 storage Geological Society, London, Special Publications, January 1, 2004; 233(1): 59 - 85. [Abstract] [PDF]