Method and apparatus for well tubular flotation
A wellbore tubular flotation device comprises a housing having a locking element disposed thereon. The housing is shaped to move through an interior of a wellbore tubular segment. The locking element is shaped to engage the interior of the wellbore tubular segment. The locking element comprises a locking mechanism configured to urge the locking element into contact with the interior of the wellbore tubular. A burst disk is engaged with the housing and is shaped to close the tubular segment to fluid flow. A release mechanism is configured to reverse the urging of the locking mechanism when a release tool is moved through the housing.
1. A method for moving a tubular string into a wellbore comprising:
locking a flotation device comprising a housing and a burst disk in a tubular segment of the tubular string, wherein the tubular segment has a smooth internal bore absent of features over its entirety;
moving the tubular string to a selected depth in the wellbore;
pumping on the tubular string to rupture the burst disk; and
releasing the entire flotation device from the tubular string by pumping a release tool into the flotation device, wherein the release tool causes locking elements to disengage from contact with an interior wall of the tubular string.
2. The method of claim 1 wherein the locking the flotation device comprises applying hydraulic pressure to a piston engaged with each of the locking elements.
3. The method of claim 2 wherein the releasing comprises moving a release sleeve in the flotation device to expose the hydraulic pressure to a volume to relieve the hydraulic pressure.
4. The method of claim 1 wherein the pumping the release tool comprises pumping a plug into a ring in the flotation device, the ring having a diameter larger than a nose of the plug and smaller than a body of the plug, whereby pumping the plug moves the ring and consequently the release sleeve.
5. The method of claim 4 wherein the locking comprises moving at least one cam in a first direction to urge the locking elements into contact with the tubular segment.
6. The method of claim 5 wherein the releasing comprises the release tool moving the at least one cam in a direction opposed to the first direction.
7. The method of claim 6 wherein the moving the at least one cam in the opposed direction comprises pumping a plug into a ring in the flotation device, the ring having a diameter larger than a nose of the plug and smaller than a body of the plug, whereby pumping the plug moves the ring and consequently the at least one cam.
8. A method for moving a tubular string into a wellbore comprising:
locking a flotation device comprising a housing and a burst disk in the tubular string, wherein the locking comprises moving at least one cam in a first direction to urge a locking element into contact with the tubular string;
moving the tubular string to a selected depth in the wellbore;
pumping on the tubular string to rupture the burst disk; and
releasing the flotation device from the tubular string by pumping a release tool into the flotation device, wherein the pumping the release tool comprises pumping a plug into a ring in the flotation device, the ring having a diameter larger than a nose of the plug and smaller than a body of the plug, whereby pumping the plug moves the ring and consequently a release sleeve.
9. The method of claim 8 wherein the releasing comprises moving the release sleeve in the flotation device to expose the hydraulic pressure to a volume to relieve the hydraulic pressure.
10. The method of claim 8 wherein the releasing comprises the release tool moving the at least one cam in a direction opposed to the first direction.