Cement Bond Logs
A cement bond log documents the evaluation of the integrity of cement work performed on an oil well. In the process of drilling and completing a well, cement is injected through the wellbore and rises up the annulus between the steel casing and the formation.
How does cement bond log work?
Conventional cement-bond logs (CBLs) comprise a pulsed transmitter and several receivers of acoustic energy positioned as a vertical array of transducers. The acoustic signal travels through borehole fluid, casing, cement, and the formation itself. The signal is received, processed, and displayed as a microseismogram.
Oil-well cementing is the process of pumping cement slurry down the annulus between the casing and wellbore. This is known as the primary cementing. The objective is to form a cement sheath that will ensure zonal isolation, support, and protect the casing