| US 7,487,835 B2 | ||
| Method of developing a re-entry into a parent wellbore from a lateral wellbore, and bottom hole assembly for milling | ||
| Thurman B. Carter, Jr., Houston, Tex. (US); Robert E. Robertson, Bakersfield, Calif. (US); Hubert E. Halford, Rosharon, Tex. (US); and Thomas M. Redlinger, Houston, Tex. (US) | ||
| Assigned to Weatherford/Lamb, Inc., Houston, Tex. (US) | ||
| Filed on May 20, 2004, as Appl. No. 10/850,046. | ||
| Prior Publication US 2005/0257930 A1, Nov. 24, 2005 | ||
| Int. Cl. E21B 29/06 (2006.01) | ||
| U.S. Cl. 166—298 [166/313; 166/50; 166/55.7] | 42 Claims |
| 39. A bottom hole assembly for laterally milling a lip in a tubular body, the bottom hole assembly comprising:
a drill collar;
a sub connected to the drill collar; and
a lead mill, the lead mill comprising:
a body connected to the sub, and having an inner bore and a first outer diameter “d1”;
one or more cutting surfaces at a point along the outer diameter of the body, the cutting surfaces forming a second outer
diameter “d2” and having a length “h”,
wherein:
the sub has an outer diameter that is smaller than the outer diameter of the cutting surfaces along the lead mill; and
the outer diameter of the sub is generally tapered to become smaller from the drill collar to the lead mill.
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