A method for sealing and controlling fluid pressure in an annular fluid passageway in a wellbore related process, wherein a wellbore related fluid passes through the annular fluid passageway around a drilling tubulars string, e.g. in a closed fluid circulation wellbore related process, e.g. in a managed pressure drilling process, wherein use is made of an annular fluid passageway sealing device, which sealing device comprises: - a housing, - a chamber within said housing, - a lower chamber end member delimiting said chamber at a lower end thereof, - an upper chamber end member delimiting said chamber at an upper end thereof, wherein the lower and upper chamber end members (23,24) are each provided with an opening therein, which openings are aligned on an axis of the sealing device and are dimensioned so that the drilling tubulars string passes along said axis through said chamber and said chamber end members (23,24), wherein the lower chamber end member is exposed, at least partially, to wellbore related fluid pressure in said annular fluid passageway, wherein the housing is provided with: - an inlet in communication with said chamber to introduce a liquid into said chamber, - an outlet in communication with said chamber to discharge said liquid from said chamber, wherein further use is made of a pump that feeds said liquid into said chamber via said inlet, said liquid being discharged via said outlet and returned to the pump so that said liquid is circulated through said chamber via said inlet and outlet, wherein the liquid circulated through the chamber is in direct contact with the drilling tubulars string passing through the chamber, characterized in that the inlet and the outlet are vertically offset from each other, wherein the inlet feeds into a feed zone of the chamber adjacent the lower chamber end member and wherein the outlet discharges from a discharge zone of the chamber adjacent the upper chamber end member, and in that the chamber is provided with one or more narrow annular gap defining members (35; 82-85) that are arranged between said vertically spaced apart feed zone and discharge zone and that envelope the drilling tubular string, and in that the one or more narrow annular gap defining members (35; 82-85) define in combination with the drilling tubulars string an elongated and radially narrow annular gap through which said circulating liquid passes from the feed zone to the discharge zone, and in that the circulated liquid is a high viscosity liquid, and in that the circulation of said high viscosity liquid and the elongated and radially narrow annular gap are such that shear of the high viscosity liquid is induced in said elongated and radially narrow annular gap, resulting in a pressure drop between said feed zone and said discharge zone such that high viscosity liquid pressure in said feed zone assists the lower chamber end member in absorbing the wellbore related fluid pressure in said annular fluid passageway, preferably entirely balances said wellbore related fluid pressure. - a housing, - a chamber within said housing, - a lower chamber end member delimiting said chamber at a lower end thereof, - an upper chamber end member delimiting said chamber at an upper end thereof, - an inlet in communication with said chamber to introduce a liquid into said chamber, - an outlet in communication with said chamber to discharge said liquid from said chamber,