Specific Procedure for an Offshore Chemical EOR One Spot Pilot in a High Salinity High Temperature Environment

Morel, Danielle (Total SA) | Al-Amrie, Omar (Total ABK) | Delattre, Eric (Total ABK) | Cordelier, Philippe (Total SA) | Greder, Hugues (Total SA) | Rivero, Mayela (Total US) | Romero, Carolina (Total SA) | Bursaux, Romain (Total SA) | Peltier, Sophie (Total SA) | Levitt, David (TOTAL SA, ADMA)



In 2014, Total performed a surfactant-polymer one spot pilot offshore to test the effectiveness of inhouse developed surfactant molecules to mobilize trapped oil. This paper describes the deployment of this pilot, as a key step of the derisking roadmap of chemical EOR under the harsh salinity and temperature conditions of Middle East carbonates. During several years of R&D and focused studies on this field of the Emirates, a surfactant polymer formulation has been developed able to achieve very low residual oil saturation at core level. The question of testing the formulation in the field has been addressed in parallel to the laboratory work, through extensive surface and subsurface integrated studies, in order to define which type of pilot would be the more suitable.

The paper addresses several aspects:

Pilot type selection from a geosciences point of view and versus objectives and information provided: where, how many wells, time response, cost

Monitoring needs: base line establishment, injection and production follow up,

Surface issues related to the pilot in this offshore context: injection and production top side facilities

Chemical logistics when part of the formulation is a R&D chemical, to be manufactured on purpose, and imported in due time, including the choice of premix versus on line mixing products

Management of a pilot as a project but still with the specificities of derisking and qualifying a technology on a mature field (from preliminary study to project execution)

Offshore concerns, with the added difficulty of a H2S environment

After a cautious analysis of the pros and cons, a one spot pilot has been sanctioned. The design of the pilot versus effective realization is provided, together with the decision tree that was constructed in order to face any operational issue. The paper emphasizes how a strong project management, and headquarters/operational team collaboration allowed completing a safe and successful pilot, ultimately achieving ultra low residual oil at the one spot scale.

The success of a pilot project is conditioned to the strict application of a rigorous methodology of study, validation, and execution, like any development project