Hydraulic Retrievable Hanger
Oil & Gas wells often have several casing stings installed in the well bore. Some casing strings extend from the bottom depth of the well to surface, while other casing strings may not extend to surface. A typical example of this situation in a well bore would be an Intermediate Casing string cemented in place to surface. The Production Casing would then extend from the bottom of the cemented Intermediate Casing to the bottom depth of the drilled well bore. This Production Casing would be set or hung near the bottom of the Intermediate casing using a Casing Hanger. This eliminates the need to run Production Casing to surface through an area of the well that is already cased. This can reduce the cost of completing a well.
Depending on the well type, Casing Hangers can vary in design. On Vertical wells, where the Production Casing is hung off bottom, from the bottom portion of the Intermediate Casing, Directional Slips are provided with the Hanger to hold the Production Casing from moving down the well bore. Depending on the well bore pressures, these Directional Slips may be required to prevent upward movement of the Production Casing in the well bore. In some Thermal Wells, the Production Casing may be required to have no movements in both directions, while other Thermal applications require freedom of movement, using no Slip Assemblies at all.
These Casing Hangers are also equipped with an Element or Seal, which are activated and set during the process of setting the Bi-Directional Slips. The setting movements of the components within the Casing Hangers are either mechanically or hydraulically controlled. The Elements or Seals of the Hangers are made of an Elastomer material, and can be designed for either Cold or Thermal environments. Custom designed features of the Elements allow for higher pressure sealing, than conventional elements.
The Hydraulic Retrievable Hanger (HRH) is set, hung, and released hydraulically, and is mechanically retrieved/obtained from the well bore. The design of the Slips on the HRH, will not allow them to fall off the tool or drag, when retrieving/obtaining the tool to surface.