METHOD OF DRILLING AND RUNNING CASING IN LARGE DIAMETER WELLBORE

摘要

A well is drilled and casing installed utilizing a casing drilling technique. A bottom hole assembly having a drill bit and a fluid diverter is secured to a string of drill pipe and installed within a casing string. Drilling fluid is pumped down the drill pipe string to cause the drill bit to rotate and drill the well while the fluid diverter is in a drilling mode position. At the total depth for the casing string, the operator moves the fluid diverter to a cementing position and pumps cement down the drill pipe and up the casing string annulus. After cementing, the operator moves the fluid diverter to a packer set position and again pumps drilling fluid down the drill string to set the packer.

主权项

1. A method of drilling a well and installing casing, comprising:
(a) making up a casing string; (b) securing to a drill pipe string a bottom hole assembly (BHA) having an earth boring bit and a fluid diverter, locking the drill pipe string to the casing string for rotation therewith and placing the fluid diverter between a passage of the drill pipe string and the interior of the casing string; (c) rotating the bit to drill the well and pumping drilling fluid down the passage of the drill pipe string while the fluid diverter is in a drilling mode position, which causes the drilling fluid to flow out the drill bit; (d) at a total depth for the casing string, moving the fluid diverter to a cementing position and pumping cement down the drill pipe, which flows out the chill pipe string above the drill bit and up a easing string annulus surrounding the casing string; and (e) retrieving the BHA from the casing string after the cement has been dispensed.