Cement evaluation during new well construction or PnA – Do we trust? (Amit Govil, Schlumberger)

Cement evaluation during new well construction or PnA – Do we trust?

by Amit Govil, Schlumberger

will be presented at 11:00 on Wednesday the 2 nfd of September, 2020, at the Solastranden Gård .


Well Integrity is a very critical concern throughout the lifecycle of a well. One part of ensuring well integrity is by evaluating the barrier in the casing annulus. Sonic/Ultrasonic tools are the most common and effective technology for annulus evaluation. For annulus evaluation with ultrasonic measurements, the acoustic impedance of borehole fluid is a critical input for the accurate determination of the acoustic impedance of annulus material and its subsequent bond quality. In Norway, where most of the wells are highly deviated or horizontal, overtime while waiting for any intervention, static mud settles and segregates on the low side of the wellbore. This becomes a challenge when interpreting cement evaluation data, in such environment.
Keeping above challenges in mind developed a novel pulse-echo inversion scheme called R+, that accurately determine azimuthal as well as depth wise variations in the acoustic impedance of borehole mud, for all casing and cement types, based on the inversion using validated 3D models without prior knowledge of mud properties. With the help of the new R+ inversion, the operators managed to take informed intervention decisions much clearer and quicker saving rig time and cost.
Cemented casing sections were recovered from the upper part of a North Sea production well during a permanent abandonment operation. The barrier quality of the cement sheath, which has been sandwiched between two casing strings for more than thirty years since the well was constructed, has been evaluated utilizing acoustic logging, fluid leakage testing and core plug analysis.
The presentation will describe the full-scale test performed at the research institute, including the lab experiments and data acquisition covering SPE #197338 (ADIPEC-2019) and SPE#199609, 199575 (IADC-20)


Amit Govil joined Schlumberger in 1993 as a Wireline Field Engineer. During his initial 9 years in the field, he worked with many clients and cased hole Wireline technologies both in India and Qatar. In 2003, he began supporting operations and interpretation as a Cased Hole Domain Champion. Since 2007, Amit has been working as Principal Production Services (Cased hole operations, intervention and interpretation) Domain Champion for Scandinavia, based first in Bergen and later in Stavanger. He has authored multiple technical papers, presented at ICoTA, SPE, PACE, DrillWell, ADIPEC, IADC conferences. Since 2017, he is involved with SPE Stavanger Section, as a Treasurer.