Hydrostatically actuated packer

Abstract

A packer is disclosed which uses applied pressure to set the slips and initiate a compressive force on the sealing elements. The compressive force applied to the sealing elements moves components above the sealing elements and allows the available hydrostatic pressure in the wellbore to create an opposing force on the sealing elements to ensure that they properly set. The sealing elements are mounted directly to the packer body, thus eliminating a leakpath from the fluid pressure application port which is located below the sealing elements on the packer body. Various lock rings hold the set of the packer to avoid the creation of boost forces on the sealing elements from applied or induced pressures from above or below the sealing elements. Movement of the body is not required to accomplish setting of this packer. In applications with low hydrostatic pressure, the annulus can be pressurized to assist in obtaining the necessary pack-off pressure. The hydrostatic pressure continues to be available as a pack-off force even when the pressure below the packing element depletes as the reservoir depletes. The packing element, which is mounted directly to the packer body, eliminates leakpaths behind it, while, at the same time, the packing element is set by opposed forces; i.e., hydraulic from below and hydrostatic from above.