METHOD FOR DIRECTED WELL DRILLING ALONG SMOOTH PATH Russian patent published in 2006 - IPC E21B7/04 

FIELD: well drilling, particularly to bore inclined and horizontal wells.

SUBSTANCE: method involves drilling vertical borehole, spudding-in inclined well borehole and serially drilling well profile parts having different radii of curvature, wherein inclined well borehole follows a path with reducing radius of curvature. Well profile parts having different radii of curvature are butted one to another through additional curvilinear borehole intervals having monotonically changing radii of curvature. The additional curvilinear borehole intervals are bored during above well profile parts drilling. Radii of curvature of additional borehole interval and of well profile parts in butt points are equal.

EFFECT: reduced bending stresses in casing pipe and intervals between curvilinear well profile part and vertical and horizontal boreholes, improved casing pipe centering inside well and increased quality of well cementing, as well as improved sucker-rod pump working conditions during well operation.

5 dwg