US 11,719,090 B2
Enhanced cement bond and micro-annulus detection and analysis
Pawel J. Matuszyk, Spring, TX (US); and Douglas J. Patterson, Magnolia, TX (US)
Assigned to Baker Hughes Oilfield Operations LLC, Houston, TX (US)
Filed by Baker Hughes Oilfield Operations LLC, Houston, TX (US)
Filed on Mar. 18, 2020, as Appl. No. 16/822,797.
Claims priority of provisional application 62/822,382, filed on Mar. 22, 2019.
Prior Publication US 2020/0300077 A1, Sep. 24, 2020
Int. Cl. E21B 47/005 (2012.01); G01N 29/09 (2006.01); G01N 29/04 (2006.01); E21B 33/14 (2006.01)
CPC E21B 47/005 (2020.05) [G01N 29/041 (2013.01); G01N 29/09 (2013.01); E21B 33/14 (2013.01); G01N 2291/2636 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method of identifying a micro-annulus outside a casing in a cemented wellbore, the method comprising:
transmitting an acoustic pulse incident on the casing;
making a measurement of a first acoustic impedance value from pulse-echo information generated responsive to an echo of the acoustic pulse reflected from the casing;
propagating a circumferential acoustic wave in the casing;
making a measurement of a second acoustic impedance value from propagating wave information generated responsive to the propagating acoustic wave; and
determining from the first acoustic impedance value and the second acoustic impedance value a presence of a micro-annulus between the casing and the cement.