Tubular strings now experience rotational movement of a through tubing drill string. Other completion operations could also involve rotation. Many types of devices that are part of the tubular string have internal seal bores or other sensitive areas that can be damaged by the whip action of the through tubing rotating string. In the past, various solutions have been attempted. In one design, the seal bores are recessed so that the whip motion of the string or the running in and out of the hole on a wireline does not damage the recessed seal bore. An example of such a design is U.S. Pat. No. 5,865,255. Recessing the seal bore then requires equipment able to spread the seals of subsequent equipment introduced into the tubing and designed to seal against the seal bore.
Protective sleeves have been tried to overlay the seal bore but the problem with them was that they were not rotationally locked and the whip action of the through tubing drill string making contact with such a protective sleeve, either eroded it away by spinning it or got the protective sleeve so hot from rotation that it fused itself to the seal bore. This effect ruined the seal bore and made the protective sleeve effectively non-removable.
The problem that has not been addressed by the prior designs has been how to make a removable protective sleeve that is rotationally locked, simple to install before the through tubing operation and just as simple to remove after the through tubing operation when access to the seal bore was needed. The preferred embodiment described below provides the solution for a sleeve that goes in or out simply and is locked rotationally when in place.
The following U.S. patents are generally related to the use of internal seal bores and the sealing assemblies that can engage them: U.S. Pat. Nos. 1,762,211; 2,751,235; 2,754,136; 3,244,424; 4,899,816; 5,180,008 and 6,024,172.
Those skilled in the art will better understand the various embodiments from a description of the preferred embodiment and the drawings that appear below, with the claims defining the full scope of the invention.
USPTO Backgrounds
USPTO Backgrounds