USING FLUIDS AT ELEVATED TEMPERATURES TO INCREASE FRACTURE GRADIENTS

摘要

A method for drilling a wellbore in a formation using a drilling fluid,wherein the drilling fluid has a first temperature, and wherein the wellborehas a first wellbore depth. In one embodiment, the method comprisesdetermining at least one fracture gradient, wherein the fracture gradient isdetermined at about the first wellbore depth; increasing the temperature ofthe drilling fluid from the first temperature to a desired temperature atabout the first wellbore depth; drilling into the formation at increasingwellbore depths below the first wellbore depth, wherein at least oneequivalent circulating density of the drilling fluid is determined at aboutthe first wellbore depth; and setting a casing string at a depth at which theequivalent circulating density is about equal to or within a desired range ofthe fracture gradient. In other embodiments, an automated system is used tomaintain the temperature of the drilling fluid at about first wellbore depth.