| 摘要 |
Apparatus and method for obtaining from a well drilled into the subsurface of the earth the information necessary to determine the location of the liquid surface in same. A source of pressure pulses is coupled to the well surface casing in order that the pulses are transmitted downhole where they are reflected by all surfaces present therein such as, the liquid surface, tubing collars and tubing anchors. A transient pressure transducer is provided which generates an electrical output in response to all reflections of the transmitted pulse. All of the reflections occurring in the well are recorded for a sufficient amount of time to ensure the recording of the first reflection from the liquid surface present in the well. By processing all of the recorded reflections utilizing known values such as the spacing of the tubing collars in the well, a microprocessor in combination with ROM and RAM discriminates between the liquid surface reflection and other reflections in the well, determines the average pressure pulse velocity in the well and the travel time in the well of the liquid surface reflection. All such information is stored in memory for further processing to accurately provide the location of the liquid surface in the well.
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