000			01845nab a2200205 4500
005			20260520004419.0
008			260224s2013 xxu ing
041			_aInglés
245	0	0	_aSurface Complexation Modeling for Waterflooding of Sandstones
260			_a _b _cabr. 2013
270			_a28/05/2013 ; 28/05/2013
300			_a4 p. ; 214-218
520			_aTranscripción del resumen del autor: A theoretical surface coordination model of oil attraction to sandstone-reservoir surfaces confirms the two primary oil/mineral coordination reactions to be electrostatic linking of anionic kaolinite-edge sites to protonated nitrogen bases at pH < 6 and calcium carboxylate groups at pH > 6. Kaolinite basal planes are calculated to link to oil through oil -NH+ groups at pH < 6-7 and through oil -COOCa+ groups at pH > 6-7, and may be important to oil attraction where basal planes are more exposed than edges (the ranges shift, depending on the oil, acid, and base numbers). Model predictions are most sensitive to the dissociation constant of oil surface carboxylate groups but are relatively insensitive to other surface equilibria and temperature. The model shows that, although low-salinity, low-Ca waterfloods can enhance oil recovery by decreasing the number of Ca2+ bridges and anionic kaolinite-edge sites, dissolution of sandstone carbonate minerals dampens the low-salinity effect by buffering decreases in waterflood Ca2+ levels. Better model predictions require more-accurate predictions of Ca2+ levels during waterflooding, high-temperature sulfateadsorption analyses, and more-precise measurements of oil acidity and basicity.
581			_a2
773	0		_tSPE Journal _g18
942			_cARTICULO
100	1		_aSurface, Patrick V. _953246
100	1		_aKrumhansl, James L. _953247
999			_c187718 _d187718