Hydraulic Non-Retrievable Hanger
Oil and gas wells often have several casing stings installed in the wellbore. Some casing strings extend from the bottom depth to the surface, while other casing strings may only line the lower portion of the wellbore. A typical example of this situation 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 wellbore. 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. In vertical wells where the production casing is hung off the bottom portion of the intermediate casing, the hanger will incorporate directional slips. These slips will hold the production casing from slipping and moving down the wellbore. The location of wellbore pressures pertaining to the hanger will determine the type of slips required. Directional slips may be required to prevent upward or downward movements of the production casing in the wellbore. 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.
These casing hangers are equipped with an element or seal, which is activated when setting the hanger. If the hanger is equipped with slips, both the seal elements and the slips are set simultaneously. The setting movements of the components within the casing hangers are either mechanically or hydraulically controlled. Depending on the style of the hanger used, a 1 ball drop, or 2 ball drop system can be used to function the hanger. A 1 ball system sets the elements and releases the hanger using the same hydraulic movement. A 2-ball system sets the elements and releases the hanger in 2 independent hydraulic movements. The seal elements of the hangers are made of an elastomer material and are designed for either cold or thermal environments. Custom designed features of the elements allow for higher pressure sealing than conventional elements.
The Hydraulic Non-Retrievable Hanger (HNH) is set, hung, and released hydraulically. Typically, a 2-ball drop system is used to eliminate the chance of setting the element improperly. The HNH is designed to operate using rig pumps. The HNH (depending on the application) may contain slips, but the design will not allow the release of the slips and the retrieval of the hanger. When retrieval is not required, the HNH is a more economical hanger to be used compared to the Hydraulic Retrievable Hanger (HRH).
- Vertical and horizontal wells.
- Cold or hot temperature wells.
- Low to high pressure wells.
- Multi directional anchor requirements.
- Hardened and non-corrosive finish to the slip & ratchet components, and mandrel.
- Ratchet ring assembly provides a positive memory to the slips and seals.
- Tie Back capabilities.
- Can be set using rig pumps. No high-pressure pumps are required to function the HNH.
- Easy to hydraulically set and deploy.
- Highest temperature and pressure ratings on thermal seal elements.
- Economical hanger.