The ADR is recommended whenever there is a risk that wireline tools or guns may become stuck downhole. Typical applications include wireline interventions in deviated wells, ballistic operations, and operations in gas wells (where the coefficient of friction is typically high).
The Addressable Downhole Release separates into two pieces on the command of the surface panel. To initiate a release, a strict protocol must be followed within a limited time period in order to prevent accidental use. Once unlatched, the upper section (including the main tool body and electronics) is pulled out of hole with the wireline.
The lower section remains downhole with a standard 1⅜” fishing neck for subsequent easy retrieval. Both components of the separated tool are fully sealed in order to protect the tools above and below from being flooded with well fluid. The robust surface panel (the ADRP) controls and monitors the position of the ADR in real-time, so the tool status is always known rather than assumed.
A maximum of four individually addressed ADR tools can be run per tool string and operated from a single dedicated control panel. For example, one ADR could be run above a tractor while a second ADR could be run between the tractor and the passenger equipment below.
A full wellsite function check includes unlatching the tool before the job. In order to reset the tool, the two sections are simply pushed together and re-latched.
The mechanical release mechanism has three distinct stages:
- Electrical feed-through isolation
- Mechanical unlatch
- Hydrostatic pressure equalisation and tool separation
Since the electrical feed-through is isolated, any tools above the ADR will continue to operate as normal after unlatching. For example, a CCL can be logged while pulling out of hole.