MULTILATERAL WELL BUILDING METHOD Russian patent published in 2006 - IPC E21B7/08 

FIELD: well building, particularly to erect well clusters.

SUBSTANCE: method involves lowering pipe string provided with diverter at pipe string end in casing pipe; cutting casing pipe within predetermined interval; lowering flexible pipe with nozzle until flexible pipe enters into opened casing pipe zone under the action of the diverter in alternation with supplying pressurized liquid via flexible pipe provided with nozzle; performing translational flexible pipe movement to create additional well bores having necessary lengths along with removing the flexible pipe to create predetermined number of additional bores; finally removing the flexible pipe from the casing pipe. The diverter has several guiding channels, spring-loaded centralizer and beveled lower end surface. Before casing pipe lowering in the well the casing pipe is provided with rigidly secured hollow insert comprising technological body with through orifices and bush with movable stop. The bush has beveled upper end surface. Inner surface of technological body comprises technological groove. The bush is inserted in the technological body in air-tight manner so that the bush closes through orifices and movable stop is arranged in the technological groove. During casing pipe lowering operation through orifices are located in predetermined opening interval along with following casing pipe securing, diverter displaces bush with movable stop downwards up to reaching technological groove end, beveled upper and lower end surfaces of the bush and the diverter cooperate with each other to register outlet orifices of guiding channels with the through orifices. After each additional well bore forming flexible string with nozzle is removed only from diverter to create predetermined number of additional bores.

EFFECT: reduced number of trips and prevention of pipe string rotation during well building.

2 dwg