Abstract: A method and an arrangement for operating a process for extracting a fluid in a borehole are optimized. In the case of deep wells, the location of an interface depth in the borehole is detected. A pressure measurement of the pressure at the head of the borehole is made. The pressure in the liquid in the borehole below the interface depth is determined from the measured pressure at the head of the borehole and the detected location of the interface depth. The determination of this pressure is used for regulating the performance of an extracting device for the liquid that is to be extracted.

Abstract: In a method for logging the location of a fluid depth in a wellbore, an acoustic event is allowed to take place in a specific manner at the ground surface. This acoustic event generates pressure waves. The pressure waves travel in the wellbore downward. The pressure waves traveling in the wellbore are reflected at least also at the fluid depth. At the ground surface, the pressure waves traveling there out of the wellbore are picked up and the time of travel since the acoustic event is measured. The picked-up and measured pressure waves are analyzed and, together with the associated time of travel, the location of the fluid depth is deduced. The acoustic event generates a signal pattern having a predetermined, time-variable frequency spectrum. The signal pattern is emitted as vibration event into the wellbore, travels downward, and is reflected. At the ground surface, the picked-up signals originating from the wellbore are analyzed.

Abstract: In a method for logging the location of a fluid depth in a wellbore, an acoustic event is allowed to take place in a specific manner at the ground surface. This acoustic event generates pressure waves. The pressure waves travel in the wellbore downward. The pressure waves traveling in the wellbore are reflected at least also at the fluid depth. At the ground surface, the pressure waves traveling there out of the wellbore are picked up and the time of travel since the acoustic event is measured. The picked-up and measured pressure waves are analyzed and, together with the associated time of travel, the location of the fluid depth is deduced. The acoustic event generates a signal pattern having a predetermined, time-variable frequency spectrum. The signal pattern is emitted as vibration event into the wellbore, travels downward, and is reflected. At the ground surface, the picked-up signals originating from the wellbore are analyzed.