Temperature data recorded from the digital array while it was spooled on a reel at the operating base. (Image courtesy of Schlumberger)

A newly introduced digital sensor array system enables communication and data transmission from the upper to lower completions. The WellWatcher Flux system is designed to serve as a permanent installation that has the ability to provide dynamic, distributed flow monitoring over the entire completion.

The system, which can be used in all environments worldwide, is particularly suited for multistage subsea completions where high costs and risks are associated with well intervention. The digital sensor array system can mitigate costly and risky interventions because it can provide the ability to determine the most prolific producing zones, monitor changes, predict flow profile across the sand face, and monitor the efficacy of clean-up phases.

The Schlumberger system uses a unique, field-proven inductive coupler to provide wireless power and real-time data transmission between the upper and lower completions.
This innovation eliminates the need for wet-mate connections between the upper completion and lower completion measurement array. It also removes any requirement for azimuthal orientation of the upper completion.

The WellWatcher Flux system provides dynamic flow of information over the life of the reservoir through the use of miniaturized, digital temperature sensors that are distributed at intervals along a single-spooled bridle, which is quickly and easily deployed. The sensors can be clamped to the exterior of the sand screens and do not cause any restriction in the wellbore.

The system is compatible with existing subsea hardware, such as commercially available connectors, and requires no additional subsea penetrations.

Once the upper completion and tree are landed, the digital sensor array system automatically energizes and begins to transmit data that is readily available to an operator’s location anywhere in the world using secure, industry-standard Internet connections.

Seeking a robust system that could operate efficiently and reliably in a two-stage completion in the Bay of Bengal, one operator chose the WellWatcher Flux system to monitor six high-rate deepwater gas wells, estimate reservoir connectivity, and optimize drainage and flow assurance.

In 2008, sensor arrays were deployed on the exterior of the sand screens as they were deployed into the well. Once the upper completion was landed, flow profile information was transmitted in real-time from the sandface up to the subsea wellhead and from there to the operator’s onshore facilities. Data was transmitted during both clean-up and production phases. Real-time communication and reservoir interpretation data combined to provide essential data from the lower completion.

Based partly upon the information provided by the system, the operator is now planning subsequent in-fill well drilling to optimize reservoir drainage across the field.