METHOD OF EARTH DRILLING USING A SEALED DOWNHOLE BEARING ASSEMBLY, METHOD OF SEALING A DOWNHOLE BEARING ASSEMBLY AND A DOWNHOLE BEARING ASSEMBLY

摘要

A method of earth drilling with a sealed bearing assembly and a sealed bearing assembly. A first step involves providing a bearing assembly that has a bearing chamber sealed with fixed sealing assemblies having a sequential array of axially aligned seals. The sealing assemblies are capable of withstanding an intended pressure differential. A second step involves drilling with the earth drilling assembly in a downhole environment in which pressure within the bearing chamber is less than hydrostatic pressure with the relative pressure differential being borne by the fixed sealing assemblies. The bearings and seals positioned within the sealed bearing chamber operate under relatively low pressure thereby prolonging bearing and seal life.