Bond Log Theory and Interpretation. April 16th, Variable Density Log ( VDL). • Examples of good . Single CBL 3′ amplitude can not identify channeling. 23 May A standard CBL (Cement Bond Logging) tool uses sound energy to determine how well bonded the Below is the explanation of bonded pipe. Cement Bond Log Interpretation – Free download as PDF File .pdf), Text File .txt ) or SBT is a combination of CBL/VDL and pad sonic devices that provides a.
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Track 4 provides the average, minimum, and maximum values of the pipe radius that is shown in Track 5. If the gate opening is too large, there may be interference between early and late-arriving signals. Depending on the size of it, a dry gap could have a lesser inter;retation on CBL Cbl vdl interpretation would show formation arrivals in either case than a wet gap CBL can appear almost as free pipe.
cbl vdl interpretation I guess what I have to say is that all your points are obviusly interpretatlon and all where already addressed vigorously during the investigation.
The cbl vdl interpretation waveforms are presented together with the travel time and a casing-amplitude curve, which displays the amplitude of the acoustic signal that has traveled through the casing but not through the cement and formation.
Cement bond logs –
And for practical purposes I would agree, however certain situations can blur that assumption: Maybe I can add some help in cbl vdl interpretation subject. Track 1 contains the gamma ray for correlation and acoustic travel time for quality control.
Just as filtrate invasion and formation alteration may produce changes in formation acoustic properties, and thus variation in acoustic logs over time,    so too, cement-bond interpretatiln may vary over time inteepretation the cement cures and its properties change.
Track 5 is a CBL-type display.
Now you can understand why cement in cbl vdl interpretation of permeable formations was needed in these projects. Plus the exchange of fluids with the formation, and the effect on hydration and setting, is not simple.
These are the bond between casing and cement and, to a lesser extent, that between cement and formation.
Cement bond logs
Centering in the cased hole is more critical because the higher-operating frequencies i. Track 3 shows a cross section of the pipe wall. The data relate to an interval that overlaps with the conventional CBL in Fig.
Tool eccentering reduces signal amplitude and travel time Fig. The data for circumferential inspection of the casing, as described above, and for the evaluation of cement bonding are cbl vdl interpretation on the same logging pass. Channeling is significant because it prevents a hydraulic seal. Two important things here: A cement log days after can be totally different Cement will always set.
Track 3 cbl vdl interpretation the average and minimum attenuation at each sampling level. Interpretatin condition is indicated by the lack of later-arriving cbl vdl interpretation energy. This is similar to 5.
Quick Cement Log Interpretation Guide
As a cementer, I rely on pumping ijterpretation That is the only direct measurement we have that proves we put cement in the annulus. Regarding the logs even additional processing of the raw data and playback creating scenarios indicated conclusively presence of any of both slurries, lead and tail, there were no losses and plenty of returns were seen, cap cement was pumped with no cbl vdl interpretation of falling back.
The tool has to be centered. Measurements from these devices are influenced cbl vdl interpretation the same factors as openhole televiewer devices. Lenin Diaz is ingerpretation oil industry specialist with 19 years of technical cbl vdl interpretation ingerpretation expertise in fluids, cementing, water control and shut-off. Track 2 contains the acoustic attenuation logs for the six pads. Now, what about what we see in the log: However, in foamed cements or when exotic additives are used, these calibrations can be inaccurate.
The third scenario, bond to casing only, is a common condition in which cement is bonded to the casing but not to the cbll. Impressive post Cbl vdl interpretation Omar Diaz Torres!
The USI cannot distinguish between gas-filled cement and fluids, but it can quantify the acoustic impedance of the cement. The zigzag, wavy, or chevron pattern between these two arrivals is the formation signal indicating varying acoustic transit time.
However, two things I believe that must be taking into consideration perhaps 3 of you want to consider eccentering of ultrasonic tools but one that is always in play is that any interprrtation cbl vdl interpretation any log will cbl vdl interpretation reacting to where its seeing very near the casing. Here is the first reason why Light Weight Cement looks like in the logs as mud or Foam cement like free pipe.
The acoustic signal travels through borehole fluid, cbl vdl interpretation, cement, and the formation itself. In addition, each tool design also provides a conventional 5-ft VDL waveform measurement to provide information about the cement-to-formation bond.
Days, weeks and as Gary and Matteo said even a month. Lenin lives in Tenerife, Spain and is the creator of this website. Properly run and interpreted, cement-bond logs CBL provide highly reliable estimates of well integrity and zone isolation. Matteo has some very valid points and from what I am hearing about the operation I am rather suspicious of a micro annulus that you created and did NOT fully remove before logging. For all the cbl vdl interpretation with doubt or when complex cement is used, I suggest the consideration of SPE and its application.
These tools cbl vdl interpretation operate at higher frequencies than conventional openhole tools—between 20 and 30 kHz. Cbl vdl interpretation would the one string be well centralized inside the second string.
You should be able to see contamination on the job data. When channeling occurs, it is generally localized and nonuniform; that is, it occurs over relatively short intervals and can frequently be identified by variations in the amplitude response. Matteo Loizzo it is excellen to have you cbl vdl interpretation and ready to further discussions on these matters; this group in particular is always ready for great discussion and cbl vdl interpretation.
In this case, the eccentricity cbo both tool and casing eccentricity resulting from formation movement salt flow. I have seen it take several months and the two logs looked like the difference between daylight and dark!