METHOD AND DEVICE FOR MEASUREMENT OF PERFORATION SIZES Russian patent published in 2015 - IPC E21B47/85 

FIELD: measurement equipment.

SUBSTANCE: invention relates to measurement of perforations in oil wells. The method comprises a. placement of the logging device comprising an ultrasonic receiver-radiator in a well with a casing pipe, and the ultrasonic receiver-radiator has a focal point located at a distance from the ultrasonic receiver-radiator so that it is located behind the internal surface of the casing pipe. b. radiation of ultrasonic signal from the ultrasonic receiver-radiator, c. detection of reflection of ultrasonic signal from internal part of the perforation passing through the casing pipe into formation, d. measurement of time passed between the transmission and reception of ultrasonic signal, e. determination of position of the ultrasonic receiver-radiator, corresponding to ultrasonic transmission and reception of the reflected signal, f. iteration of the step b) - e) several times and record of the obtained data. g. computer processing of the obtained data and determination of sizes of the perforation, h. meanwhile the ultrasonic receiver-radiator is located at a distance from the casing pipe of a borehole, at least, one third of the minimum length of the open channel to be measured, i. meanwhile the distance is such that reflections from the casing pipe reverberate and significantly dissipate before the reflection from inside the perforation is received by the ultrasonic receiver-radiator.

EFFECT: reduction of reverberation noise.

12 cl, 12 dwg