ARRANGEMENT FOR SEALING IN-TUBE SPACE OF PUMP-COMPRESSOR PIPE STRING WHEN BEING LIFTED FROM WELL UNDER PRESSURE Russian patent published in 1997 - IPC

FIELD: oil and gas production. SUBSTANCE: invention relates to pipe string with variable diameter. Improved structure of arrangement housing and structure of drive of fixation facilities' housing provide more reliable sealing of variable-diameter pump-compressor pipe string and enable lifting the string from well under pressure. Arrangement is fit to be set in larger-diameter pipes, to be introduced and led in in-tube space of lesser-diameter pipes, to transfer sealing member inside wear- protection housing, to stop arrangement near string bottom, to fix it in in-tube space by two fixation systems, and to separate in-tube space from downhole pressure near string bottom. To this end, additional housing is telescopic-wise disposed in relation to main housing and is joined with the latter by means of shear pins. Upper part of additional housing accommodates (i) sleeve gaskets to seal relative to pump-compressor pipe string and (ii) centering members. Main string has primary and secondary fixation facilities relative to pump-compressor pipe string and their drives. Drive of the former is made in the form of spring-loaded rod with cam on which pusher of fixation facilities is located. Its control mechanism contains ear hinged at rod - in its opening, fixed are two splints with rollers installed in main housing on shafts. Drive of secondary fixation facilities contains rod with in-tube space sealing members. Additional sealing member is protected by housing. EFFECT: improved reliability of sealing. 8 dwg