XACT service enabled openhole screen running in tight margin wells
Deepwater wells drilled into shallow reservoirs continue to be a particularly challenging pressure environment. By necessity, these wells are high angle to achieve reservoir contact, with high build-up rates due to the shallow depth below the seafloor. In addition, these wells have challenging mud-weight windows, typically less than 1 ppg. Due to these challenges, operators are increasingly using managed pressure drilling (MPD) systems to drill and complete shallow, deepwater reservoirs.
The difference between effectively developing a field and failure comes down to safely and effectively managing these wells in real time. Recent examples demonstrate that the correct use of real-time downhole data can significantly aid the success rate of these wells.
Yet, to acquire and transmit downhole data in these environments requires a system that is full through bore and allows the transmission of data irrespective of fluid levels or flow and can send data even while tripping in and out of the well.
A customer in deepwater Gulf of Mexico needed to effectively manage the downhole conditions by monitoring both pressures and weights downhole and along the string while running the screens and setting the packer. Swab and surge while running the screens and full pressure management during displacement operations were critical due to the narrow mud weight window. Additionally, weights at the packer and back along the string were also important in high-angle and high build-up wells to avoid damaging the screens and to ensure safe and efficient operations.
After setting the screens, the customer needed to monitor displacement and subsequent acid treatment in terms of downhole equivalent circulating densities. Contingencies were also in place to monitor the top of fluid as a safe barrier in case of losses during the operation.
To collect the downhole data, Baker Hughes, a GE company (BHGE), deployed the XACT™ downhole acoustic telemetry service as part of the completion string with tools positioned directly above the setting packer. Two further tools were distributed along the string, both in the build-up section and in the vertical section of the well, above the blowout preventer. Downhole pressures and weights were sent back to the surface in real time and used to aid in the real-time decision-making process.
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