Patent ID: 8424619
Filing Date: 2013-04-23
Classification: C09K

Abstract:
1. A process for drilling a well into a subterranean formation which comprises boring a hole into the earth by rotary drilling, wherein a drilling fluid is circulated down a drilling pipe and returned to the surface of the earth through a pipe hole annulus, wherein the drilling fluid is comprised of (a) an organic liquid; (b) water; (c) an emulsifier; (d) a weighting material; (e) a fluid loss reducing agent; and (f) a chlorosulfonated α-olefin copolymer which is comprised of repeat units that are derived from ethylene and an α-olefin that contains from 4 to about 20 carbon atoms, wherein the chlorosulfonated α-olefin copolymer contains from 0.5 to 10 weight percent chlorine.