Field development planning in complex geological environments is challenging for operators. During the planning process, the geological and geophysical (G&G) and drilling teams must work together to reach a consensus, in full understanding of the requirements and risks. The more complex the geology, the more complex the planning process is for multidisciplinary teams, making collaborative working increasingly crucial.

GDF Suez was facing a challenging multiwell development project in the North Sea Cygnus field, characterized by complex faults and thin reservoir targets presenting increased drilling risks and hazards.

Collaborative workshop

As communication between the GDF Suez G&G and drilling teams was critical to producing an optimal field development plan (FDP), a tailored collaborative well planning session was organized. This brought all the decision makers together, in one location, to optimize well planning discussions in an immersive environment using the Petrel Well Design module. Subsurface models were brought to life with the latest graphic display methods to deepen insight into the target area.

A Petrel field model was provided by GDF Suez before the meeting, allowing the Schlumberger team time for familiarization. Then, during the session, the model was closely examined by the entire group, allowing all possible trajectories to be assessed, with Schlumbergerexperts providing drilling, engineering, and geomechanical advice.

Clear plans

As a result of the first collaborative session, several well trajectories were redesigned. The relative merits of various drilling tools were discussed, and trajectories refined based upon the most desired tool options. A second session was held, at the request of GDF Suez, to focus on a landing strategy for particularly challenging wells in the vicinity of an unconformity. During the session one of the pilot holes was redesigned, and the heel positions of two wells were amended for optimum placement in relation to the completion design.

GDF Suez concluded the sessions with revised well paths and other information required for submission of the field development plan. As a result GDF Suez finalized plans for drilling up to six wells from each of its two wellhead platforms on the field. The company intends to apply this collaborative process throughout the rest of the project as the efficiencies generated were very beneficial.