FIELD: mining.
SUBSTANCE: group of inventions relates to downhole pumpdown tools, downhole systems with said tools and methods for forming cement plug in well. Downhole tool comprises pumpdown module containing the first expanding sleeve, configured to provide the first sealing with said inner wall; the second expanding sleeve configured to provide the second sealing with said inner wall; two said sleeves in the expanded state jointly restrict isolated zone of annular space; at least one tubular element extending in lengthwise direction between two sleeves, the said tubular element provides a passageway for fluid between the inlet hole located in one end of the tubular element, and outlet hole located in tubular element between the sleeves; the second expanding collar is connected to slide with tube element and displacement in longitudinal direction from first expanding collar under action of pumped fluid pumped into the isolated zone, thus increasing the distance between two collars; note here that pumpdown module additionally comprises retaining coupling arranged to slide around the expanding sleeves to prevent undesired opening of expanding sleeves during introduction of the downhole tool, note here that retaining coupling is made to slide in longitudinal direction, and expanding sleeves are released by moving the retaining coupling in longitudinal direction.
EFFECT: technical result consists in filling and complete sealing of the well shaft at fluid pumping down.
15 cl, 8 dwg
