CLUSTER WELL CONSTRUCTION METHOD Russian patent published in 2005 - IPC

FIELD: well construction, particularly to built cluster wells.

SUBSTANCE: method involves lowering pipe string provided with deflector on end thereof in casing pipe; perforating the casing pipe within previously selected interval; performing the following alternating operations including lowering flexible pipe with nozzle in casing string into above perforation area under the action of the deflector, supplying pressurized liquid through flexible pipe with nozzle, translating thereof to form additional well bores having predetermined depths and lifting the flexible pipe after the predetermined number of well bores forming, finally removing the flexible pipe from the casing pipe. Before casing pipe lowering casing pipe is provided with retained guide. The guide includes process case with through orifices and bush. Formed on inner surface of process case are guiding slots and cylindrical recess located in through orifice area. The bush is inserted in the recess to seal through orifices. The bush is restricted from axial downward displacement by rest. During the lowering operation performing through orifices are arranged within above perforation interval and casing pipe is secured, deflector provided with a number of guiding channels and spring-loaded inserts displaces the bush up to the rest and the spring-loaded inserts cooperate with guiding slots to bring outlet orifices of guiding channels in register with through orifices. To obtain demanded number of well bores flexible pipe with nozzle is removed only from pipe string and deflector after each additional well bore creation.

EFFECT: reduced number of trip operations during well construction.

4 dwg, 1 ex