HYDROMAGNETIC MILL-CATCHER Russian patent published in 2002 - IPC

FIELD: oil and gas producing industry, withdrawal from wells of items possessing ferromagnetic properties, particularly, magnetic catchers with pumping of washing fluid through them. SUBSTANCE: hydromagnetic mill-catcher has body connected with stab sub and milling funnel. Body accommodates magnetic system with washing channel. It has filter plate installed in sub lower part having symmetrically arranged holes whose axes are parallel to body axis, forming washing channel of catcher. Magnetic system has sleeve whose internal walls form washing channel of system which is connected with catcher washing channel. Sleeve bottom has inclined holes diverging toward bottom hole. Diameter of catcher washing channel is larger than that of system washing channel. Diameter of holes in filter plate is smaller than that in hole of sleeve bottom. Total passage area of holes in plate exceeds that in sleeve bottom. EFFECT: higher efficiency of bottom-hole cleaning and operating reliability of catcher. 1 dwg