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