MULTIBRANCH WELL DRILLING METHOD Russian patent published in 2007 - IPC E21B7/06 

FIELD: oil well drilling technique, particularly directional drilling.

SUBSTANCE: method involves drilling main bore having greater diameter and drilling additional bores having lesser diameters. Main bore is inclined and/or horizontal in producing bore and is inclined towards producing formation bottom. Additional bores having decreasing diameters are serially drilled from inclined and/or horizontal main bore section in downward direction.

EFFECT: possibility of downhole instrument penetration in any additional well branch and selective watered well branch isolation for following well operation.

2 cl, 4 dwg