The primary reason for placing a casing in a well or take a well, is to provide protection to the hole in a safe, reliable and economical.
Among the most important functions of the casing are:
- Preventing landslides in the well during drilling.
- Avoid contamination of surface water.
- Provide control formation pressures.
- Prevent contamination of growing areas with strange fluids.
- At the cement, communication can isolate the formations of interest.
- Confine well production at intervals.
- To facilitate surface equipment installation and production.
The number of casing string is placed in a well depends on the nature of the formations to cross and the final depth of hole. Different strings of casing that can be placed in a well are:
- Driver ocean / pipe pile foundation or kneeling.
- Conductor casing.
- Surface casing.
- Intermediate casing.
- Production casing.
- Shirt or «Liner»: Intermedia or goggles. Production.
- Removable liner or «Tie-back
- Pipe Production: Conductor casing. Surface casing. Intermediate casing. Production casing. Shirt or «Liner»
- Intermediate or Protective: Shirt or «Liner» production. Production tubing. Driver. Tie back.