IMPROVED WEAR BUSHING INSTALL AND RETRIEVE SYSTEM

The invention is a petroleum well wear bushing install and retrieve system comprising - a wear bushing (1), - for being arranged in a wellhead (4), and - being of large bore for a drill pipe string (O, OL, OU) carrying a drill bit or other well tool below to pass through it, and - said wear bushing (1) provided with two or more internal, upward-closingJ-slots (10) with upward bottoms (11), - a running tool (2), - said running tool arranged for being run as part of said drill pipe string (0, 0U, 0L) at least extending above said running tool (2) and having a through-bore tool mandrel (20), - said running tool having radially extending ribs (22) with an outer diameter allowing to pass said J-slots, characterized in that said ribs (22) having radially extending spring-loaded dogs (21) arranged for controlled engagement with said internal J-slots (10), - each said radial dogs (21) having an upward directed key profile (210) for engaging with a corresponding lock profile (110) in said upward bottom (11), - shear pins (3) arranged for initially, for running in said wear bushing (1) to said wellhead (4), said shear pins (3) connecting said radial ribs (21) to said wear bushing (1); so as for allowing running in said wear bushing (1) on said running tool (2) and inserting it in said wellhead (4), and for then putting weight on said drill pipe string (0U) to shear out said shear pins (3) and pass said running tool (2) further downwardly for further operations below said wear bushing (1) or retrieving said running tool (2) upwardly. L'invention concerne un système d'installation et de récupération de douille d'usure de puits de pétrole, comprenant - une douille d'usure (1), - destinée à être disposée dans une tête de puits (4), et - présentant un grand alésage pour une colonne de tiges de forage (O, OL, OU) portant un trépan ou un autre outil de puits en dessous pour passer à travers, et - ladite douille d'usure (1) comportant au moins deux fentes en J internes, fermant vers le haut (10) avec des fonds vers le haut (11), - un outil de fonctionnement (2), - ledit outil de fonctionnement étant agencé pour être amené à fonctionner en tant que partie dudit train de tiges de forage (0, 0U, 0L) s'étendant au moins au-dessus dudit outil de fonctionnement (2) et ayant un mandrin d'outil de trou traversant (20), - ledit outil de fonctionnement ayant des nervures s'étendant radialement (22) avec un diamètre externe permettant le passage desdites fentes en J, caractérisé en ce