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