METHOD FOR DRILLING OIL AND GAS WELLS

摘要

When drilling or completing an oil or gas well, it is often desirable to drill a borehole at an angle to the initial borehole. A process for deflecting a well tool towards the wall of a well bore comprises positioning within the well bore a radially expandable pipe designed to curve longitudinally when its diameter is expanded, expanding the diameter of the radially expandable pipe thereby causing the pipe to curve and passing the well tool through the curved pipe: The process is particularly suitable for through-tubing operations in which a lateral bore is initiated from a production well having within the well a smaller diameter production tubing (14) comprising (i) passing through the production tube (14) a radially expandable pipe (1) designed to curve longitudinally as its diameter is expanded, into a section of well bore (12) having a diameter greater than the diameter of the production tubing (14) (ii) expanding the diameter of the radially expandable pipe (1) thereby causing the pipe to curve, (iii) passing through the curved pipe a milling device or drill bit and (iv) milling the casing or drilling into the well bore wall.