Casing transition nipple and method of casing a well to facilitate well completion, re-completion and workover
A casing transition nipple and method of casing a well facilitates well completion, re-completion and workover while increasing safety and reducing expense. The casing transition nipple provides a connection between a large diameter production casing joint suspended by a wellhead and a standard production casing string. The large diameter production casing joint permits long downhole tool strings to be lubricated into the well without leaving a high lubricator profile and reduces the cost of performing many other well completion, re-completion and workover procedures.
1 . A casing transition nipple, comprising:
a tubular body having a top end adapted for fluid tight connection to a well casing of a fist diameter and a bottom end adapted for fluid tight connection to a well casing of a second, smaller diameter; and
a smooth annular tool guide surface between the first and second ends.
2 . The casing transition nipple as claimed in claim 1 wherein the fluid tight connections to the top and bottom ends comprise one or more of: threaded, welded, locking or glued connections.
3 . The casing transition nipple as claimed in claim 2 wherein the wherein the top end is box threaded and the bottom end is box threaded.
4 . The casing transition nipple as claimed in claim 2 wherein where in the top end is box threaded and the bottom end is pin threaded.
5 . The casing transition nipple as claimed in claim 2 wherein the top end is pin threaded and the bottom end is box threaded.
6 . The casing transition nipple as clamed in claim 2 wherein the top end is pin threaded and the bottom end is pin threaded.
7 . The casing transition nipple as claimed in claim 1 wherein the annular tool guide surface slopes downwardly at an angle of a 30°-60° with respect to a plain that is perpendicular to the top and bottom ends.
8 . A method of casing a wellbore, comprising:
running a production casing of a first diameter into the wellbore until a bottom end of the production casing of the first diameter is approximately a predetermined distance from a bottom of the wellbore;
connecting a bottom end of a casing transition nipple to a top end of the casing of the first diameter;
connecting a bottom end of a production casing of a second, larger diameter to a top end of the casing transition nipple, the production casing of the second diameter having a length approximately equal to the predetermined distance; and
suspending the production casing of the second, larger diameter from a wellhead of the well.
9 . The method as claimed in claim 8 wherein suspending the production casing of the second, larger diameter from the wellhead comprises suspending the production casing using a casing mandrel.
10 . The method as claimed in claim 8 wherein suspending the production casing of the second, larger diameter from the wellhead comprises suspending the production casing using casing slips.
11 . The method as claimed in claim 8 wherein the predetermined distance is 6-60 feet.
12 . The method as claimed in claim 8 wherein the diameter of the first casing is one of 4½, 5 and 5½ inches.
13 . The method as claimed in claim 10 wherein a diameter of the second casing is 5½-8 inches.
14 . The method as claimed in claim 8 further comprising using at least one casing collar to connect at least one of the casings of the first and second diameter to the casing transition nipple.
15 . A method of casing a wellbore of a predetermined depth, comprising:
running a production casing of a first diameter into the wellbore until a bottom end of the production casing of the first diameter is at a depth that is less than the predetermined depth of the wellbore;
connecting a bottom end of a casing transition nipple to a top end of the production casing of the first diameter;
connecting a bottom end of a production casing of a second, larger diameter to a top end of the casing transition nipple; and
running the production casing of the second, larger diameter into the wellbore until the wellbore is cased.
16 . The method as claimed in claim 15 further comprising suspending the production casing of the second, larger diameter from a wellhead that suspends a surface casing in the wellbore.
17 . The method as claimed in claim 16 wherein suspending the production casing comprises connecting a top end of the production casing to a casing mandrel and landing the casing mandrel in a casing bowl of the wellhead.
18 . The method as claimed in claim 16 wherein suspending the production casing comprises landing casing slips around the production casing in a casing bowl of the wellhead, and cutting off a top of the production casing above the casing slips.
19 . The method as claimed in claim 15 wherein a difference between the depth of the wellbore and the depth to which the production casing of the first diameter is run into the wellbore is about 6-60 feet.
20 . The method as claimed in claim 15 wherein a difference in a diameter of the production casing of the first diameter and the production casing of the second diameter is about 1½″-3½″.