Environmental Engineering Reference
In-Depth Information
The addition of the fl exural wave information allows for better cement evaluation
when lightweight cements are used which have an acoustic impedance close to that
of mud and in some cases can leave a conventional bond evaluation somewhat
uncertain.
Log Quality Control
The two most important quality control aspects of CBL logging are:
1. Good centralization. Insist on at least three fi n centralizers near the transmitter/
receiver array and spring centralizers, top and bottom of the entire tool string.
2. Calibration tails should conform to the published service company specifi cations.
Appendix: Frequently Used Casing Dimensions
Weight
a
(per foot)
Nominal (ID)
OD (inches)
Drift diameter
b
4
11.60
3.428
3.303
4½
9.50
4.090
3.965
11.60
4.000
3.875
13.50
3.920
3.795
4¾
16.00
4.082
3.957
5
11.50
4.560
4.435
13.00
4.494
4.369
15.00
4.408
4.283
17.70
4.300
4.175
18.00
4.276
4.151
21.00
4.154
4.029
5½
13.00
5.044
4.919
14.00
5.012
4.887
15.00
4.974
4.849
15.50
4.950
4.825
17.00
4.892
4.767
20.00
4.778
4.653
23.00
4.670
4.545
5¾
14.00
5.290
5.165
17.00
5.190
5.065
19.50
5.090
4.965
22.50
4.990
4.865
(continued)
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