000			02685nab a2200217 4500
005			20260520002038.0
008			260224s2013 xxu ing
041			_aInglés
245	0	0	_aInvestigation of Wettability Alteration and Oil-Recovery Improvement by Low-Salinity Water in Sandstone Rock
260			_a _b _cmar. 2013
270			_a03/06/2013 ; 03/06/2013
300			_a10 p. ; 144-154
520			_aTranscripción del resumen del autor: Optimization of any oil-recovery process is based on understanding of the recovery mechanisms, whereas the underlying mechanisms of improving oil recovery by low-salinity-water injection are still debated. Wettability alteration is one of the mechanisms suggested to be the primary mechanism of low-salinity water. Therefore, wettability alteration by low-salinity water in sandstone reservoirs is examined by using the contact-angle technique. The effect of changing ionic strength on the electrokinetic charges is investigated by use of the zeta-potential technique to explain the causes of wettability alteration by low-salinity water. Moreover, coreflood experiments were performed in order to correlate between the wettability alteration and oil-recovery improvement caused by low-salinity water. Mica sheets were used for the contact-angle measurements to represent sandstone rock. The effect of water salinity on wettability was studied by using synthetic water over a wide range of salinities (from 0 to 174 000 mg/L), with two different crude oils at different conditions of pressure and temperature. Zeta-potential tests were conducted to measure the electrokinetic charges for combinations of each of the two crude oils or Berea sandstone and different brines. Berea sandstone cores were used for waterflooding experiments by injecting the same brines tested in the wettability measurements. Low-salinity water showed lower contact angles compared with high-salinity water for the two types of crude oil, which demonstrates the ability of low-salinity water to alter the rock wettability to more water-wet. In addition, low-salinity water made the surface charges at rock/brine and oil/brine interfaces strongly negative. As a result, the repulsive forces between rock and oil surfaces increase, which leads to expansion of the double-layer and, consequently, wettability alteration and oil-recovery improvement as confirmed by coreflood experiments.
581			_a2
773	0		_tJournal of Canadian Petroleum Technology _g52
942			_cARTICULO
100	1		_aNasralla, Ramez A. _951767
100	1		_aBataweel, Mohammed A. _953308
100	1		_aNasr-El-Din, Hisham _938694
999			_c187751 _d187751