DEVICE FOR OPERATION OF MULTIPLE WELLS Russian patent published in 2003 - IPC

FIELD: drilling equipment; applicable in selective entry of pipe string, instruments into required branch of multiple well in its completion and operation. SUBSTANCE: device has pipe string with curved lower part installed for its possible withdrawal from well. In this case, installed in upper part of branches, in internal cavity of casing string is bushing with upper and lower chamfered at acute angle ends. Bushing generating lines, maximum and minimum in length, are located in same plane. Bushing inside minimum-length generating line has recess whose width increases with counting branches from top downward. Curved lower part of pipe string has key whose width for entering each underlying branch exceeds width of recess of preceding branch but is less than width of recess of next branch. EFFECT: higher efficiency of multiple well construction. 1 dwg