Table 3. Collection of Oil-Wetting Results from Experiments under Varying Conditions.

Sr. no.	Rock	Organic materials	Water saturation	Salinity	pH	Temperature (°C)	Pressure	Aging time	Testing method	Aging results	Ref
1	Berea sandstone	Crude oil	0.15–0.261 (Swi)	22.2 g/L	NA	88	Ambient	10 days	Amott test	Oil-wetness increased with time gradually	(187)
2	Berea sandstone	Asphaltenes	∼0.25 (Swi)	0.09–0.51 M	3.3–11.2	Ambient	Ambient	10 days	Amott test	Oil-wetness increased rapidly in the first 12 h	(6)
3	Silica and calcite crystals	Crude oil	0.155–0.408 (connate water)	Synthetic formation brine	NA	100	NA	2255 h	Contact angle and relative permeability	Some reservoir rock became oil-wet after 300 h; some reservoir rock remained water-wet after 2255 h	(185)
4	Berea sandstone	Moutray crude oil	0–0.5	2.5–3.0%	6.80, 6.85	Ambient	Ambient	20 days	Amott test	Initially, strongly water-wet rock became weakly water-wet	(188)
5	Berea sandstone	Crude oil	0.192–0.393	22.2–38.6 g/L	NA	Ambient ∼75	NA	75 days	USBM test	Water-wet changed to mixed-wet conditions; aging time beyond 10 days does not have a significant impact	(46)
6	Berea sandstone	Loudon crude oil	0.2–0.3 (Swi) and ∼0.75	21507 g/cm3	6.6–6.89	24.5	NA	54 days	USBM test	Strongly water-wet to mixed-wet	(59)
7	Berea sandstone (treated to a reduced state)	Loudon crude oil	0.2–0.3 (Swi) and ∼0.75	21507 g/cm3	6.6–6.89	24.5	NA	54 days, 196 days	USBM test	Remained water-wet after 54 days, but changed to mixed-wet after 196 days	(59)
8	Iceland-spar calcite	n-decane + organic acids	0 (mineral plate)	NA	NA	25–130	NA	1 day	Contact angle	When the temperature was higher, calcite was more water-wet	(176)
9	Calcite	Crude oil	0.295–0.348 (connate)	NA	NA	65	NA	3 days	Relative permeability and contact angle	Intermediate-wet sample became weakly oil-wet	(52)
10	Calcite	1 wt % stearic acid + toluene	0	206911	NA	90	NA	5 days	Contact angle	Intermediate-wet	(112)
11	Dolomite	Crude oil	0 (dry)	100072.5 ppm	NA	75	NA	40 days	Contact angle	Rock became strongly oil-wet	(147)
12	Shale	Crude oils	0	1676–307213 ppm	NA	76.7	NA	49 days	Contact angle	A minimum of 35 days is required to reach a stable wettability condition	(81)
13	Pure chalk, sandstone, and silica-containing chalk	Crude oil with <1% of asphaltenes	0.1	62830, 50000	6.7, 5.8	50	20 bar, 10 bar	3 days	Spontaneous imbibition	Water-wetness for all cases was significantly reduced	(109)
14	Chalk	Crude oil	0	44.94 g/L	8.0	50	Ambient	4 days	Spontaneous imbibition	Chalk plugs were unevenly aged, with the outer layer oil-wet and the center water-wet	(99)