Pumping barite plug through coiled tubing

Hello there,

In an upcoming abandonment campaign, we are considering an option to set a barite suspension plug. This will allow for the removal of a subsea vertical tree in order to remove the tubing and set an abandonment cement plug.

However, we have identified a few technical challenges in deploying the barite plug though our fluid handling set up.

Equipment set up:

The Light Well Intervention Subsea Intervention Device (dual riser equivalent but without riser to surface) is installed on top of the subsea vertical tree, which allows for pumping through the tubing (via a crossover from the tree to the Subsea Intervention Device) and annulus (via the annulus access line) with hoses connected from the rig to the tree (see drawing attached). No fluid is actually pumped through the Subsea Intervention Device’s BOP or lubricator system.

The production access hose is a 400m long 2” (ID) BlackEagle hose on a reeler deployed to ~150m water depth from a rig.

The flow path is from the cement unit -> through the hose on the reeler -> through two 2” isolation valves subsea -> through the VXT/Subsea Intervention Device x-over outlet -> through the vertical x-tree and into the tubing.

Return fluid from the well is taken through a similar hose connected to the annulus access port on the subsea tree to the rig.

Following challenges envisaged for barite plug deployment:

• barite may plug the hose on the reeler
• 2” valves could become inoperable after pumping the barite plug through them

While our set-up may be unusual, I can draw the analogy to a coiled tubing operation, where fluid is pumped through the hose (coiled-tubing) stored on a reeler. Pumping cement or frac-fluid (high solid content fluid) is a common operation.

We would like to ask the forum about experience of deploying barite plugs through similar set ups or through coiled tubing.

Has it been done? If yes, what are the lessons learned? Are there any points we need to consider to make the operation successful?

Documents uploaded by user:

Fluid handling set up.pdf

3 Answer(s)

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