| 摘要 |
<p>An expansion tool for use in a wellbore includes an expansion surface made up of a concave portion, a convex portion and a straight section therebetween. In one aspect, the center section is formed according to a formula Y= (1.26)(X)-0.13, where X is the wall thickness of a tubular and Y is the length of the center section. In another aspect, the expansion surface includes a first concave portion and a convex portion having an arc length extending the concave portion to a trailing edge of the tool. In another embodiment, the concave and convex portions are radius-shaped. The arrangement of the shapes and their relation to each other reduces relatively high and low contact pressures and lessens the effects of axial bending in a tubular or a connection.</p> |
