Cbl-vdl Log Interpretation Pdf

This is vdp a great discussion and I like to thank you all here and those who cantacted me privately. This map can indicate the presence of channels and their orientations. This tool can also operate in open hole as a formation imager see Borehole Imaging.

CBL VDL INTERPRETATION EPUB

The third scenario, bond to casing only, is a common condition in which cement is bonded to the casing but not to the formation. On the basis of empirical data, the log can be calibrated directly in terms cbl-vel cement compressive strength. Impressive post Lenin Omar Diaz Torres! Your email address vcl not be published. As with openhole tools, cement-bond tools require centralization to ensure accurate measurements.

By analyzing the entire waveform, an acoustic-impedance map of the cement can be constructed. Interpretation techniques combining these different measurements provide improved evaluation in lightweight cements, especially in the annulus, beyond the casing-cement bond. On the basis of interpretagion data, interprtation log can be calibrated interprwtation in terms of cement compressive strength. Bond Log Theory and Interpretation. Energy is transmitted at one pad and is received at an adjacent pad.

If cement is bonded to the casing, there will be a strong reflection. Big pressure differential between two adjacent formations, with a natural barrier in between. Grow and Glow in Life you wanna grow? Basically, a cement liquid phase filtrates into the permeable formation or b formation fluids invade the cement during the transition liquid to solid stage. These are the bond between casing and cement and, to a lesser extent, that between cement and formation.

An interesting example of the complementary nature of these data has been presented by De Souza Padilha and Da Silva Araujo. They operate on the principle that acoustic amplitude is rapidly attenuated in good cement bond but not in partial bond or free pipe. Acoustic energy is reflected at interfaces that correspond to changes in acoustic impedance the product of acoustic velocity and density. In the last scenario, partial bond, a space exists within an otherwise well-bonded casing.

The pad spacing is such that the first arrival is the wave that has passed through the casing. The method allows localized zones of good hydraulic seal to be identified in a way that is independent of borehole-fluid type. Tool response depends on the acoustic impedance of the cement, which, in turn is function of density and velocity.

CBL VDL INTERPRETATION PDF

CEMENT BOND LOG INTERPRETATION

At the same time, the annulus outside the cement sheath provides poor acoustic coupling. For example, the presence of shear-wave amplitudes on the full-waveform display cbl vdl interpretation an indication of good acoustic coupling to the formation. If there is unset cement or water behind the casing, there will be a weak reflection. At greater depths, the pipe is well bonded. There is poor cement cbp between X and X depth units.

This map can indicate the presence of interpretatlon and their orientations. It deals with the problem of gas-contaminated cement, which has been a longstanding interpretation problem in the industry. When conducting a cement evaluation, information on the type of cement used interpretatjon essential. On a variable-density log, free pipe and fluid arrivals if present are easily identified as straight dark and light lines interprehation homogenous acoustic properties at either side of the vdp Fig. The use of new high-performance low-density, foam, and complex cements is increasing.

Like an upper lost zone and lower high-pressure zone. Variable density is a continuous-depth time display of full-waveform amplitude presented as shades of black and white. In the first scenario, free pipe, there is no cbl vdl interpretation bond between the casing and cement. In this example, the partial bonding is sufficient to provide hydraulic isolation.

CBL-VDL LOG INTERPRETATION PDF

CBL VDL INTERPRETATION PDF

CEMENT BOND LOG INTERPRETATION

Centering in the cased hole is more critical because the higher-operating frequencies i. Here is the first reason why Light Weight Cement looks like in the logs as mud or Foam cement like free pipe. In contrast, a microannulus a small gap between the casing and cement sheath may extend over cbl vdl interpretation sections of casing but may not prevent a hydraulic seal. In the second scenario, good bond, cement is properly bonded to casing and to the formation. In this case, the eccentricity comprises both tool and casing eccentricity resulting from formation movement salt flow.

CBL VDL INTERPRETATION EPUB DOWNLOAD

Otherwise, the analysis cbl vdl interpretation become more of an educated guess than vbl objective fact-based report. The method allows localized zones of good hydraulic seal to be identified cbl vdl interpretation a way that cbl vdl interpretation independent of borehole-fluid type.

CBL-VDL LOG INTERPRETATION PDF

The most recent tools have a gdl rotating transducer that incorporates both the source and receiver of ultrasonic energy. An interesting example of the complementary nature of these data has been interpetation by De Souza Padilha and Da Silva Araujo. However, the presence of gas in cement slurries, as an inert component or as contamination, may seriously affect ultrasonic-tool interpretation. For example, the presence of interpreetation amplitudes on the full-waveform display is an indication of good acoustic coupling to the formation.

CBL-VDL LOG INTERPRETATION PDF

The data for circumferential inspection of the casing, as described above, and for the evaluation of cement bonding are obtained on the same logging pass. Interpretaiton the same time, the annulus outside the cement sheath provides poor acoustic coupling. However, in foamed cements or when exotic additives are used, these calibrations can be inaccurate.

How did you take a thickness reading? Fixed-gate systems are commonly used for amplitude measurements and floating gates for travel-time measurements. This Schlumberger tool comprised an array of eight ultrasonic transducers that allowed a limited radial inspection of intepretation casing and its annulus. In the first scenario, free pipe, there is no cement bond between the casing and cement.

It deals with the problem of gas-contaminated cement, which has been a longstanding interpretation problem vel the industry. New interpretation methods integrate ultrasonic and attenuation measurements from conventional tools to provide improved cement evaluation in these conditions. In the second scenario, good bond, pivot table tutorial excel 2007 pdf cement is properly bonded to casing cbl vdl interpretation to the formation. Dark zones are the most strongly bonded.

The first reflection is at the casing itself. This may occur with the presence of a microannulus or channels within the cement.