| Title | Using Electromagnetic Telemetry for Abandonment Cement Slurry Design on Coiled Tubing |
|---|---|
| Authors | J. Anderson, T. Ryan, D. Belle |
| Year | 2021 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Electromagnetic, Measure While Drilling (MWD), Geothermal Cementing, Geothermal Coiled Tubing |
| Abstract | For many years the Coiled Tubing (CT) industry has been developing Electronic Bottom Hole Assembly Technology (E-Coil) where fibre-optic or wireline cable convey operating parameters and sensor readouts from the tools downhole through the CT and back to the surface unit where they can be interpreted. This technology requires a high setup cost to install the telemetry cable, purchase the electronic tools and costly reel management programs to prevent failures of the cable inside the string. Using Electromagnetic (EM) technology from the drilling world, signals containing packets of information can be sent directly from the downhole tools to the surface through the formation rock and existing well casings. This technology requires limited setup cost, and tool purchase is much lower than the e-coil equivalents. The use of new EM technology in conjecture with the right operational planning provided a cost-effective solution to reducing the risk of the flash setting of cement during geothermal plug and abandonment operations with CT. There are limitations of the system due to signal delay, but in the instance of determining the downhole temperature of a static fluid column prior to cementing or to prevent damage to BHA components due to exposure to a temperature above the rated limits, the technology is more than capable of providing this data in nearly real-time. This available signal technology displaces the alternative practice of running memory gauges that could not be cemented through and required an additional CT cycle out of the hole to interpret the data and run back in to perform the cementing operation. In our experience, the tools are designed to be run on large diameter equipment that is standard in geothermal environments. Building custom made components to adapt the tools to be run on the coiled tubing was a challenge but accomplished using proven industry components as well as new innovations. Limitation on the tool is defined by the battery limitations with the electronic components capable of being flasked to prevent damage in extreme environments. |