International oilfield services company Expro, has accomplished the first proven wireless transmission of reservoir pressure data to surface, from a recently abandoned subsea appraisal well which incorporated a rock-to-rock cement plug.
The system was installed in the North Sea and will be used to improve understanding of the reservoir and to optimize future development planning of the field, while ensuring full compliance with local well abandonment regulations, the company announced in a press release.
“This latest achievement demonstrates our leading position in understanding the physics behind downhole EM telemetry,” said Alistair Geddes, the company’s executive VP. “It allows us to instrument more wells with casing breaks or longer open-hole sections, partnering with customers to develop the most effective plug and abandonment strategies.”
This achievement aims to provide operators with a more cost-effective option for well abandonment design and consideration of wider well barrier techniques, while maintaining the ability to monitor the reservoir or plug integrity.
Expro’s cableless telemetry system (CaTSTM) wireless gauges, using electromagnetic (EM) technology, were installed in the reservoir of the main bore and casings were cut below the side-track kickoff point to install the cap rock cement plug.
CaTS repeaters placed in the side-track enabled data transmission across the open-hole section and to the seabed transceiver for storage and transmission to an overhead vessel.
The system provided continuous reservoir data, which began immediately after the drill stem test (DST), allowing extended pressure build-up analysis without rig support.
“We recognize the value that technology brings to our industry, which is why we continue to expand our capability and deliver maximum value through innovative new applications,” Geddes said.