Patent attributes
Re-treatment of a formation having a wellbore, which can be an open hole or a cased hole lined with casing, involves deploying a tubing string in the casing having tools disposed at intervals thereon. The tools position on the tubing string, and the tubing string with the tools thereon is inserted into the casing. Biasing rings of the tools passively engage with the casing. The annulus is accessed between the tubing string and the casing at the intervals between the tools. For example, sliding sleeves on the tubing string can be opened (selectively), or new plug and perforation operations can be used to create perforations in the tubing string at desired intervals between the tools. With access achieved, retreatment is pumped down the tubing string, out the access to the annulus, and at least partially sealed by the engaged rings in the intervals between the tools.