In August 2014, Nautec conducted a pre-job visual inspection of 24 wells for Occidental Oil and Gas, Doha, Qatar. Phase I, the Inspection Phase, was the first stage of a Well Integrity Campaign for strengthening and corrosion protection of structural casing of wells for Dolphin Energy Ltd.
- The General Visual Inspection (GVI) identified a selection of conductors to be serviced in order to secure a safe and smooth operation for the remainder of their design life and beyond.
- Following the initial visual inspection of the conductors, an inspection of the annulus between the conductor and surface casing was carried out by using a down-hole camera. Observations were made to ascertain the following:
- Condition of the conductor and surface casing – to visually check the integrity of the steel surfaces.
- Existence and evaluation of the size of any holes in the surface casing – assessing whether NaX™ grout will be able to plug any leaks or if alternative action needs to be taken on holes in the surface casing – to avoid disappearance and non-return to surface of grout mix.
- Condition, size and depth of the annulus between the conductor and surface casing to establish the size of grout hose to be used during the grouting operation as well as estimate the amount of grout material to be used and prepared for each site.
- The Inspection Phase led to phase II of this campaign i.e. Strengthening and Corrosion Protection of Structural Casing of Wells.
- Further services carried out by Nautec included the cleaning of annulus using an ultra high pressure water jet; final inspection of the annulus using downhole camera after cleaning and the provision of grouting and filling of annulus between structural casing and conductor casing with NaX™ Q110 Ultra High Performance grout.