First we had drilled to rock-bed at 170’,& inserted casing pipe.
Continued drilling & got water at 275’ but a low flow.
At 400’ met a good water strata.
Drilled to 600’ as insurance against water table level drop in poor rainfall years.
Withdrew drill. Inserted submersible pump. Found a
blockage at 275’, aborted the pump installation.
Referred matter to geologist. His opinion is that water strata at 275’ may be having loose boulders that move into bore and block it. Advised us flush the bore & insert MS casing to 300’ depth to :-
-prevent rocks from blocking the bore / falling into the bore
-protect the subm pump
-facilitate pump removal for maintenance.
Q: For flushing bore,removing drill & insert casing to 275’ time needed 8 hours. If within this time rocks move again into bore WILL PRESSURE OF MS CASING INSERTION BE SUFFICIENT TO DISLODGE ROCK BLOCK TO COMPLETE CASING INSERTION? OR CAN BLOCK PREVENT CASING INSERTION? IF THIS HAPPENS WHAT DO WE DO?
2006-08-16
19:43:13
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2 answers
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asked by
santha r
1