Dynamic reservoir data are a key driver for offshore operators to meet or exceed the forecasted production plateaus of their fields. However, many challenges during the well testing phase can prevent them from gathering the mission-critical reservoir characterization data that they need to make more informed field development planning decisions that result in optimal production. Some of these challenges include reduced exploration and capex budgets; complex geologic structures; and inclement weather conditions that reduce the well testing time window.

After discovering Neptun and Triton fields in the Sea of Okhotsk, Russia, Gazprom Neft commissioned two appraisal wells in 2018 and 2019 to characterize the reservoir. However, icy conditions and large storms restricted the drilling window, limiting the number of drillstem tests (DSTs) to only four zones, using a traditional downhole testing toolstring. Due to the anticipated, high bubble point pressure and heterogeneous geologic structures comprising the reservoir, Gazprom Neft required as much subsurface information as possible to reduce uncertainty for making key field appraisal and development planning decisions. This meant that more zones needed to be tested for each of the appraisal wells to get the desired evaluation results, but the tests had to be done more efficiently to satisfy the tight turnaround time.

Schlumberger provided a solution using the Symphony live downhole reservoir testing platform united by Muzic wireless telemetry to achieve the required tests in one run—without the need for wireline intervention. The result was a safer and significantly more efficient well testing operation that yielded the dynamic reservoir data that Gazprom Neft needed to de-risk their reserves and optimize the field appraisal program.

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