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Cow Camp CCU -023 OB Completion Notes <br />October 10 <br />• Drill 6-1/4" pilot hole to 60'. <br />• Ream 0' -40' to 11 ". <br />• Set 40' of 8 -5/8" OD, .188 wall, steel casing. <br />• Cement down annulus with tremie pipe and 125 gallons (10 sx) of <br />grout. <br />October 11 -20 <br />• Drill ahead from surface casing with 6-1/4" bit to core point. <br />• Core Wadge overburden - coal - underburden zone. <br />October 21 <br />• Drill ahead for rathole for screen section (for underburden well). <br />• Encounter broken zone at 1220' that locked up the bit and drill <br />string. Zone was caving and driller could not work his way through <br />the zone. <br />• Decision made to cement back through the top of the coal and turn <br />this into the overburden well. <br />• Run logs to 1218'- safely above the broken zone. <br />NOTE: Artesian water flow encountered above the Twentymile SS. <br />Flow volume about 1 gpm. Flow volume did not increase until drilling <br />through the Wadge overburden sandstones. Flow increased again at the <br />base of the Wadge, and in a broken zone at 1220'. The total flow was <br />estimated at -10 gpm; the water was warm to the touch. <br />The broken zone below the Wadge stopped the bit rotation, causing the <br />rotary table to torque up the drill string. The driller reported that he <br />needed to work the string to free it. <br />October 22 <br />• Trip in hole with tremie to 1220'. <br />• Start grout pour. Cement from TD with 1 stage of 15 pound per <br />gallon neat cement. Mix and pump -240 gallons of slurry (25 sacks <br />cement). Trip out of hole with tremie and stand in derrick. <br />• Flow reduced to -I gpm. Cap well to maintain pressure. <br />October 23 <br />• Trip in hole with tremie and tag cement at 1145'. Trip out tremie and <br />lay down. <br />• Pick up a new 6-1/4" bit and trip in hole. Tag cement and drill out to <br />1195'. TD hole, circulate to clean up, and trip out. <br />