000 02257nab a2200205 4500
005 20260520000314.0
008 260224s2011 xxu
245 0 0 _aDiagenetic controls on reservoir quality in Middle to Upper Jurassic sandstones in the South Viking Graben, North Sea
260 _a
_b
_cnov. 2011
270 _a16/04/2012 ; 16/04/2012
300 _a22 p. ; 1937 - 1958
520 _aResumen del autor: The deeply buried synrift play of the South Viking Graben is characterized by highly variable reservoir quality. An integrated approach incorporating petrophysics, petrography, and one-dimensional basin modeling methods was applied to investigate these variations. Analysis shows that average porosities below 4000 m (>13,123 ft) (vertical depth below sea floor) range from approximately 5% to as much as about 25% in comparable quartz arenitic sandstones. From porosity-depth trends, three porosity categories can be recognized (normal-, low-, and high-porosity sandstones). Normal-porosity sandstones fall along the regional average porosity-depth trend. Low-porosity sandstones have been subject to extensive quartz cementation as a consequence of a higher degree of thermal maturity and plot below the regional porosity-depth trend. High-porosity sandstones plot above the regional porosity-depth trend. Here, quartz cementation has been inhibited by grain-coating microquartz, and thus porosity has been preserved. Hydrocarbon emplacement has previously been thought to have inhibited quartz cementation in the study area, but this study concludes that the reservoirs are mainly water-wet, allowing for continued quartz cementation despite the presence of hydrocarbon pore fluids. Predicting the distribution of microquartz-coated sandstones and the degree of thermal maturity is therefore fundamental for successful exploration in the deeply buried parts of the synrift play. This study presents a regional and stratigraphic framework for such predictions that may be incorporated into play models in the area.
581 _a11
773 0 _tAAPG Bulletin
_g95
942 _cARTICULO
100 1 _aMaast, Tom Erik
_952437
100 1 _aJahren, Jens
_952438
100 1 _aBjorlykke, Knut
_935491
999 _c187063
_d187063