US 2022/0010671 A1 · DETERMINING THE LEVEL OF A LIQUID IN A BOREHOLE FOR CONTROLLING OPERATION OF A SUBMERGED PUMP

Abstract

A stand-alone apparatus for determining the level (X) of liquid (F) in oil boreholes (P) overcomes the need of a pressurized gas source. A loudspeaker-type electroacoustical transducer (11) both emits characteristic acoustical signals through the mouth of the borehole and detects the return of an echo from the surface of the liquid downhole for clocking the time-interval between emission and return to determine the level of the liquid. To overcome the limited power inherent in a loudspeaker-type transducer relative to masking borehole acoustic noise, a method of operation correlates the intensity amplitude of the detected echo with the emitted signal. Another solution comprises repeating emission and detection cycles a number of n times and then adding or integrating the n curves into a resulting curve which is filtered. The detected liquid level may be used for determining the submergence and regulating the speed of a pump in the borehole.

Claims20

Dependent claims

A level detector for determining the level of a liquid in a borehole and which includes:

a signal generator for generating a first signal including a recognisable, characteristic,
an acoustical emitter for emitting said signal as an acoustical wave towards the liquid in the borehole,
an acoustical wave detector for receiving a return acoustic wave containing a reflection from the liquid of the emitted acoustic signal and
a detected wave processor for receiving said first signal generated by the signal generator and a second signal from said detector representative of said return acoustic wave and adapted for measuring intervals of time lapsed between emitted waves and detected waves and determining said level based on the measured time-interval;
wherein the acoustical wave emitter and the acoustical wave detector are integrated in a same electroacoustical transducer.

2 more elements

A method for determining the level of a liquid in a borehole and which includes the steps of:

(a) emitting an acoustic signal towards the liquid in the borehole,
(b) detecting an acoustic wave containing a reflection from the liquid of the acoustic signal emitted in step (a),
(c) logging the curve of variation of the amplitude of the detected acoustic wave as a function of time,
(d) locating in said curve an amplitude maximum of the acoustic wave relevada corresponding to the reflection in the liquid of the emitted acoustic signal,
(e) measuring the time-interval between the emission of the acoustic signal and the amplitude maximum of the logged acoustic wave, and
(f) determining the distance travelled by the acoustic wave reflected from the borehole based on the measured time-interval and the acoustic propagation velocity inside the borehole;
wherein step (d) includes filtering the amplitude maximum by cross-correlating the curve logged in step (c) with a signal generating the acoustic signal emitted in step (a).

4 more elements

Dependencies are inferred from the claim text.

Determining the level of a liquid in a borehole for controlling operation of a submerged pump

Life of this patent

Determining the level of a liquid in a borehole for controlling operation of a submerged pump

Life of this patent

Abstract

Claims20