SEALED AND HYDROSTATICALLY LOCKABLE RETRIEVABLE MWD LANDING SYSTEM

摘要

A sealed mule shoe assembly for use in directional drilling, comprising an outer mule shoe and an inner housing for containing a directional measurement tool which is slidably insertable in the outer mule shoe. The mule shoe assembly advantageously has half-moon mating surfaces which advantageously allow use circumferential seals to thereby prevent ingress of abrasive materials into the landing area between the outer mule shoe and the inner housing, thereby greatly prolonging the life of the mule shoe assembly. Such seals further make use of hydrostatic forces downhole which cause locking landed engagement of the inner tool within the outer mule shoe. Cup seals or a check valve are used to allow escape of fluid when the inner tool is inserted within the outer mule shoe, and similarly prevent ingress of abrasive fluids and drill cuttings into the area of landed engagement.