Downhole fluid separation for drilling a well in a hot subterranean zone

Abstract

A wellbore is drilled in a subterranean zone with a drill bit of a drilling string. The drilling string includes tubing and a fluid separator uphole of the drill bit. While drilling, a drilling fluid is flowed through an interior of the drilling string and through the fluid separator. The fluid separator separates, from the drilling fluid, a fluid stream having a higher water-to-oil ratio than a remainder of the drilling fluid Uphole of the drill bit, the fluid stream is diverted from the fluid separator to an annulus around the exterior of the drilling string based on a specified temperature of a drilling string component while the remainder of the drilling fluid flows from the fluid separator to the drill bit.

Dependencies are inferred from the claim text.