CONSTRUCTION METHOD OF ADDITIONAL SHAFT IN WELL Russian patent published in 2014 - IPC E21B7/08 E21B43/10 

FIELD: mining.

SUBSTANCE: at implementation of the method, the main shaft is drilled and fixed till design depth; after that, the shaft is enlarged by cutting-out a casing string interval of the main shaft so that upper and lower parts of the main shaft are obtained. Enlargement interval is cemented; cement is drilled at enlargement interval with creation of interaction of the upper and lower parts of the main shaft with simultaneous enlargement of the diameter exceeding inner diameter of the casing string by wall thickness of long element of the support plate. An additional shaft is drilled and a removable diverting wedge is installed. The diverting wedge is removed prior to lowering of the support plate that is oriented during lowering to the well as per geophysical instruments, installed and rigidly fixed by enlargement so that a side branch of the support plate can be arranged in the additional shaft.

EFFECT: possibility of performing construction of additional shafts out of wells cased with a production string so that flow passage of the main shaft is maintained without considerable reduction of diameter of the additional shaft.

6 dwg