| abstract |
A method is proposed for inter-well measurement of pH in petroleum reservoirs, as is the use of certain pH-dependent partitioning tracers in such methods. The tracers consist of a substituted phenol of formula (i), wherein each of R 1 to R 5 is independently selected from H, F, CI, Br, I, CF 3 CF 2 CI, CFCI 2 , CCI 3 , OCH 3 , OC 2 H 5 , CHO, CN and NO 2 and wherein at least one of R 1 to R 5 is not H |