Improvements in or relating to means for removing debris from bore holes or wells

摘要

570,842. Well &c. tools. CUTHILL. J., and OIL WELL ENGINEERING CO., Ltd. Feb. 18, 1943, No. 2725. [Class 85] Means for removing front boreholes and wells material such as pieces of broken tools comprises a cylindrical body 8 with a threaded member 9 for connection to suspension tubing, and with an internal open-ended cylinder 11 containing a piston 13 normally held in raised position by spring-pressed balls 15 engaging a groove 16 ; the piston is connected at its lower end to a, bell 19 guided by an annular rib 20 and provided with lugs 21 to which claws 22 are pivoted, the lower ends of the claws engaging guide apertures 24 in a shoe 25 secured to the body 8 and provided with cutting edges 26. Passages 28, Fig. 7, are provided inside the body 8 for passage of fluid downwardly to passages 29 in the shoe 25, the fluid passing upwardly through the bell 19 and out through ports 31, 32. In use, the tool is lowered into the borehole &c., and liquid is pumped down the suspension tubing to depress the piston 13 and thereby cause the claws 22 to move inwardly below broken tools or other debris, which is then raised to the surface. In another form, the piston is connected by spaced bars to a ring to which the claws are pivoted, the ring having such a depth that when in its lowest position it closes apertures 23 in the body to prevent escape of liquid therethrough.