Figure F19 (continued). Y. Under gauge and worn Smith tricone bit used for Run 15 (W). Z, AA. 9 inch Smith FH3VPS tricone bit used for Run 16. This more armored bit (compare with the previous one in Y) was more efficient to ream and clean the undergauge bottom of the hole. It returned in gauge to the rig floor, and six large teeth were missing. BB. Heavily worn and undergauge 9 inch flat-bottomed milling tool used for Run 17. This tool worked at the bottom of the hole for 12 h; its final (terminal) state indicates the very abrasive nature of metal debris and/or rocks at the bottom of the hole and an undergauge lowermost portion (tens of centimeters) of the hole. Note for comparison the hard-facing structure of the next milling tool (DD) on the right side of the picture. (Continued on next page.)
Previous | Close | Next | Top of page