Patent ID: 7784331

Claim:
A method for acoustically determining a temperature-dependent property of a reservoir material, the method comprising: (a) acoustically coupling an acoustic radiation generator and a reservoir, with the acoustic radiation generator located external to the reservoir; (b) activating the acoustic radiation generator to generate acoustic radiation and direct the acoustic radiation generated through an exterior surface of the reservoir toward an interior surface of the reservoir such that acoustic radiation is thereafter reflected from the interior surface of the reservoir; (c) measuring a temperature-dependent characteristic of the reflected acoustic radiation, said characteristic selected so as to correlate with a temperature-dependent property of a reservoir material; and (d) analyzing the characteristic to determine the temperature-dependent property of the reservoir material, wherein a temperature T R1 of the reservoir is lower than 20° C. or greater than 25° C. and wherein the temperature-dependent characteristic of the reflected acoustic radiation is an acoustic velocity V R1 in the reservoir material at the temperature T R1 , and wherein (d) comprises comparing the acoustic velocity V R1 with an acoustic velocity V R-RT in the reservoir material at a temperature T RT in the range of 20° C. to 25° C.