As packers are probably one of the most important items of downhole equipment in well completions, great care must be taken with their preparation and installation where they are used. All packers should have been functionally checked and pressure tested in Base workshops before dispatch to the well site but should still be inspected before use.
The different makes/types of packer have different featured which must be inspected with reference to the vendor literature, however the following should not be overlooked:
- ·correct size and type;
- ·cutting edges of teeth on internal/external slips;
- ·location and integrity of springs;
- ·positioning of sleeves;
- ·number and correct material of shear pins/screws and release value;
- ·insertion/removal of set screws as required;
- ·positioning of locking devices (snap rings, etc.);
- ·expanding elements, comet hardnesss and condition;
- ·clearances between components;
- ·location and integrity of 'O'-rings, chevron and other seals;
- ·condition of screw threads;
- ·condition of polished/honed surfaces;
- ·freedom of movement of flappers;
- ·packers operating envelope.
Instances have been known where the incorrect size has been stamped on the packer body. It is therefore recommended to physically measure the OD of the packer to ensure that the correct size is being used.