Method of identifying gas, oil and water zones in a subsurface formation

摘要

A method of logging a wellbore to identify oil, gas and water zones in a hydrocarbon-bearing formation that is characterized by acoustic velocities which are maximum when saturated with oil, minimum when saturated with water and intermediate when saturated with gas. The formation is logged with a sonic logging system utilizing a frequency within the range of 0.1 to 10 KHz and logged with a lithologic logging system to account for variations in lithology on the sonic log. Thereafter the sonic log is compared with the known acoustic velocity characteristic of the hydrocarbon-bearing formation to identify the oil, gas and water zones therein.