Patent ID: 8496063

Claim:
A device for recovering drilling fluid which is used in connection with the provision of a subsea well ( 10 ), in which the drilling fluid is circulated from a vessel ( 20 ) on a sea surface ( 21 ) via a drill string ( 12 ) and out through a drill bit ( 12 ′) into an annulus ( 13 ) which is defined by a borehole and the drill string ( 12 ), said device comprises: a filtering device ( 1 ) comprising a first chamber ( 3 ′, 52 ) and a second chamber ( 5 ′, 54 ), the first chamber ( 3 ′, 52 ) being separated from the second chamber ( 5 ′, 54 ) at least partly by means of a filter ( 3 ; 31 , 33 , 35 ) arranged to retain and store drill cuttings ( 4 ) exceeding a predetermined size, the first chamber ( 3 ′, 52 ) being connected to said annulus ( 13 ) by means of a fluid supply line ( 16 ); and a fluid line ( 7 ) extending from a portion of the second chamber ( 5 ′, 54 ) to the vessel ( 20 ), the fluid line ( 7 ) being arranged to carry drilling fluid which has been separated from the drill cuttings ( 4 ) back to the vessel ( 20 ); and wherein the filtering device ( 1 ) is further connected, in respect of fluid, to a circulation line arranged to carry at least partially filtered drilling fluid from a circulation line inlet portion to a circulation line outlet portion, the circulation line inlet portion being downstream of the circulation line outlet portion.