Table 6

Comparison of the residual oil saturation computed from the ester and alcohol arrival times, according to equation (33), when using first- and second-order schemes and performing a grid refinement (see also Fig. 12). Expected residual oil saturation is . Arrival times , and are computed from the tracer, ester and alcohol outlet concentration profiles maximum peak amplitudes.

Scheme	n	S orw (−)	t t  − t 0 (days)	t e  − t 0 (days)	t a  − t 0 (days)	t e  − t a (days)
(1)	1	0.138	1.64	1.51	0.84	0.67
	2	0.160	1.69	1.62	0.83	0.79
	4	0.177	1.72	1.68	0.81	0.87
	8	0.172	1.73	1.71	0.84	0.87
	16	0.165	1.74	1.73	0.87	0.86
	1	0.136	1.69	1.57	0.88	0.69
	2	0.177	1.73	1.66	0.80	0.86
	4	0.189	1.75	1.71	0.79	0.92
	8	0.175	1.75	1.73	0.84	0.89
	16	0.159	1.76	1.73	0.89	0.84
	1	0.132	1.86	1.64	0.93	0.71
	2	0.172	1.83	1.69	0.83	0.86
	4	0.172	1.81	1.69	0.83	0.86
	8	0.140	1.72	1.65	0.91	0.74
	16	0.112	1.59	1.60	0.96	0.64