DECENTRALIZING, CENTRALIZING, LOCATING AND ORIENTING SUBSYSTEMS AND METHODS FOR SUBTERRANEAN MULTILATERAL WELL DRILLING AND COMPLETION

摘要

A decentralizer for a diverter, a centralizing guide bushing and a downhole- deployable locating and orienting subsystem. The subsystem is capable of thr ee modes of operation: (a) a running mode in which an actuating mandrel is in a first axial limit position with respect to a common mandrel, the actuating mandrel placing fir st and second double-acting springs in a stowed position wherein locating and orien ting keys are retracted radially inwardly with respect to the common mandrel to shield the locating and orienting keys from substantial contact with a surrounding well flow conduct or as the common mandrel traverses therethrough, (b) a locating mode in which the actu ating mandrel is in an intermediate axial position with respect to the common mand rel, the actuating mandrel placing the first and second double-acting springs in a de ployed position resiliently to bias the locating and orienting keys radially outwardly with respect to the common mandrel to seek a locating and orienting profile on an inner surface of a surrounding honed bore within the surrounding well flow conductor, and (c) a set mode in which the actuating mandrel is in a second axial limit position with resp ect to the common mandrel, the actuating mandrel directly engaging and stiffly retainin g the locating and orienting keys in engagement with the locating and orienting profile the reby to fix the common mandrel in a desired location and orientation with respect to the hon ed bore.