The Rebco JO Unlatching Tool with J Head is the instrument deployment system used to lower a recording instrument or Bomb Well assembly to depth and leave it on top of a pre-set depth stop, such as a Collar Stop, Slip Stop, or DO Collar Lock, without the need for any separate latching, setting, or jarring action at the instrument itself. The J Head is attached directly to the bottom of the instrument or Bomb Well. The JO Running Tool engages the J Head through a J-slot mechanism. As the assembly lands on the pre-set stop and the weight of the tool string acts downward, the J-slot geometry automatically unlatches the J Head, releasing the JO Running Tool and leaving the instrument assembly at depth while the wireline tool string is retrieved to the surface.

When the survey is complete, and the instrument must be retrieved, the J Head's external fishing neck is engaged with the appropriate Pulling Tool (Section IV, Product Code 40), and the full instrument assembly is pulled back to the surface. The J Head is available with either a ¾"–16 Box Thread (Amerada) or 15/16"–10 Box Thread (Sucker Rod) lower connection to match the instrument thread, and J Heads with 15/16"–10 connections are available on request.

The JO Running Tool is selected by nominal size (2" covers 2⅜" through 3½" tubing). See Section III, Page III-25 for running tool sizing.

How to Order: Assembly number 4107202000 (¾"-16 Box Thread) or 4107202001 for 2⅜"-3½" tubing size. Specify box thread connection type. For J Heads ordered as part of the assembly, specify fishing neck size (1.187" or 1.375") and box thread required.