WELL CASING STRADDLE ASSEMBLY

摘要

A well casing assembly 1 comprises a length of line at 2 having two packer/seal assemblies 3, 4 at the upper end thereof and two packer/seal assemblies 5, 6 at the lower end thereof. The packer/seal assemblies 5, 6 are inverted relative to the packer/seal assemblies 3, 4. By appropriate design of the setting elements o f the packer/seal assemblies each is selected to have a different setting force. Accordingly, when the tool is set by longitudinal compression thereof t he packer/seal assemblies set in a pre-determined sequence. The packer/seal assemblies are preferably of the type in which an annular slip is expanded b y means of a swage. Variations in the setting force may be obtained by variations in material characteristics and/or thickness or by variations in the swage ramp angle, or by any other suitable means.