The objects and advantages of the invention are achieved by the drilling fluid and {TAIL ~ the processes} of {HEAD ~ the invention} 
The objects and advantages of the invention are achieved by the drilling fluid and { TAIL ~ the processes } of { HEAD ~ the invention }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD