CCS: TAQA (Porthos) – P18, Plug & Abandonment of multilateral well

Plug & Abandonment P18

Start Engineering: May 2021
End Execution: June 2022

Objective: Plug & Abandonment of multilateral well

Depth (MD): 4000m
Depth (TVD): 3500m

Client: TAQA (Porthos)
Location: Dutch sector North Sea
Well: P18
Start Engineering: May 2021
End Execution: June 2022
Objective: Abandonment of multilateral well to make the reservoir suitable for CO2 injection from other wells in the field
Depths (MD): 4000m
Depths (TVD): 3500m
Role of WEP: Supply of senior well engineer to the TAQA project team during preparation and execution of the project. Supply of Sr. DSV during the rig operations.
Challenges: Losses due to the well being connected to two depleted reservoir sections. Retrieval of the whipstock to regain access to the motherbore well section.

Project Description

Involvement of WEP in the project started in May 2021 in preparation phase of the project; consisting of the preparation of the well intervention design, work program and various procurement.

The original offshore well was drilled in 1997 and a sidetrack to convert the well to a multilateral was added in 2003. The well was producing gas co-mingled prior the well operations. Operations were performed with the Valaris 123 jack-up rig.


The lower abandonment plugs were designed to be a CO2 resistant fullbore formation plug. To set this plug in the motherbore, the sidetrack liner and whipstock needed to be recovered. As a contingency, in case of inability to retrieve the whipstock, an intercept well design and program was prepared in cooperation with Wild Well Control.

Jackup Valaris 123 positioned next to P18 platform