Missing real-time information on drilling mud behavior accounts for a significant part of 30% loss of offshore drilling production time resulting from poor drilling reliability. Drilling efficiency and safety is a priority area in the OG21 strategy for NCS and high North drilling activities. Equinor approached Xsens AS 2018 for testing of clamp-on ultrasonic flow meters installed directly on the mud pipe and test results (SPE-195624-MS) confirms the potential to cover required mud qualities and fluid complexity. The planned innovation project target in- and return-flow of both water- and oil-based mud flow rate measurement. Information on mud density and viscosity will also be addressed, as well as partly filled pipe flow measurement. The project R&D team covers acoustics, mud rheology, machine learning and industry expertise. Research is required to obtain a model for the velocity profile calculation of non-Newtonian drilling fluids, valid for fluid information obtained by multi-path acoustic guided wave sensors, forming chordal paths within the pipe cross-section, at a known distance between pipe center and pipe wall. The model must account for variation in mud rheology of different mud qualities including presence of cuttings and gas. In addition to flow measurement correction, the model will be used for calculation and correction of mud density and viscosity measurement. The most critical research challenge is to obtain the accuracy required for the complex fluid behavior and variation in fluid qualities of mud, hence multi-path and multi-mode measurement enhanced by machine learning will be implemented for continuous measurement improvement. The project includes prototype testing at North Sea offshore drilling facilities towards end of the project. For Xsens the planned clamp-on mud flow meter represents an attractive business case at high ROI for oil companies and drilling operators, for commercialization immediately after project completion.
Project leader: Kjell-Rune Toftevåg
Institution: XSENS AS