ACT Locator Tubing Seal Assembly is the most basic packer sealing system for packers incorporating a sealing bore. It is run in the well on the production tubing string until its No-Go shoulder locates on the to of the packer. This positions one or more seal stacks in the packer’s seal bore and establishes a seal between the packer and tubing. When a locator tubing-seal assembly is landed in a packer, the tubing is normally set in compression to compensate for any contraction of the tubing during treating operations. However, it is not always possible or desirable to slack off sufficient weight, particularly in deep deviated wells. In such cases, additional length must be added to the packer’s seal bore using seal bore extensions and to the locator tubing-seal assembly using a combination of spacer tubes and additional seal units.