{HEAD ~ Substantial savings} in drilling time and cost may be realized according to {TAIL ~ the present invention}, along with benefits of reduced environmental contamination and enhanced well safety 
realized according to
{ HEAD ~ Substantial savings } in drilling time and cost may be realized according to { TAIL ~ the present invention } , along with benefits of reduced environmental contamination and enhanced well safety
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH