Laserfiche WebLink
Evaluation of cement -American Soda #28-17 <br />CBL and CAST tools were run in [he above listed well [o evaluate [he placement and quality of the cement slurry. CBL/CAST logs were run in both casings, from [he base <br />of each string to surface or [o the Fluid level in the casing string. A cement basket is positioned near the bottom of the shorter string and cement is placed in the annulus from <br />the cement basket to near surface. <br />The logs on [his well indicate [he following: <br />Depth Interval Description Isolation <br />Evaluation CAST <br />Impedance Value CAST <br />Impedance Character CBL Pipe Amplitude MSC pipe signal <br />TD to 1,746' Free Pipe (long string) No isolation 2.0 Flat consistent High, Free pipe value strong <br />1,746' Cement Basket N/A N/A N/A N/A N/A <br />1,746' [0 1,734' Bentonite Plug Good >2 Active, > mud value < Gee pipe value faded < Bee <br />1,734' to 1,700' Good conventional cement Good > 4 High activity Low, < 10 None <br />1,700' to 1,6&6' Spherelite cement Good < I Active, < fluid value < free pipe value Faded < free <br />1,686' to 1,472' Conventional and Spherelite cement Good >3 or < ~ Med. To high Acuvity < free pipe value Faded < free <br />1,472' [0 1,445' Partial cement, could communicate Poor 2.0 Flat consistent High, Free pipe value strong <br />1,445' to top of log Conventional and Spherelite cement Good >3 or < 2 Med. To high Activity < free pipe value Faded < free <br /> <br />Circumjerentia! Acoustic Scanning Too[ (CAST) tmpedance values for fluids are very consistent and manifests itself as a favly straight line on the log. Cement slurries, <br />are more variable and show up as curves with much more activity or variability. By analyzing the value and [he character of the impedance curves, it is possible to <br />successfully evaluate the cement quality of conventional and lightweight cements. Typical impedance values for common materials or Fluids are: <br />Gas or au < .5 high activity curve response <br />Water I.5 Flat consistent curve response <br />Drilling Mud 1.5 - 2.5 Fla[ consistent curve response <br />Lightweight Cements <1 - 4 high activity curve response <br />Conventional Cements 2 - 6 medium to high activity curve response depending on consistency of slurry <br />Cement Bond Log (CBL) tools evaluate cement bonding to pipe and formation by measuring the changes in sound waves traveling through casing, cement, <br />and formation. Log presentations include a pipe amplitude curve and aMicro-Seismogram ®display in the form of light to dark shades. The amplitude <br />curve in lightweight cements will not read as low as published values for conventional cements. Comparisons to lowest value and to free pipe value are <br />necessary to fully evaluate. Pipe signal will not completely disappear in lightweight cement as in conventional cements. <br />Respectfidly, <br />Tom Riebel <br />Halliburton Energy Services <br />