Traceable integration of automated in-line rheology measurements with automated drilling control and diagnostic

RheoThix project is a research project from IMS, partnered with NORCE, Sekal and OMV into the time based effect of the Rheological behaviour of Drilling Fluid, more commonly known as Drilling Mud. The Rheological behaviour describes how the mud density, viscosity and ability to carry cuttings is affected over time when flowing. This research will provide a much needed insight into this effect and will lead to a better understanding of how this affects drilling fluid performance. The research will be carried out primarily in the IMS Technology Centre in Stavanger, utilising IMS RheoSense with some necessary verification in the NORCE laboratory. This will lead to an improved understanding of the overall rheological behaviour and to improved mathematical models and traceable and more robust measurement techniques.

Oilfield drilling fluid property measurements ensure that the drilling fluid is maintained according to specification, and as input to mathematical models for estimating behaviour in the well, used for controlling the drilling process. Traditional manual drilling fluid measurements provide poor predictability, due to low rate of measurements. To address this, IMS has developed a continuous measurement, in-flow instrument (RheoSense) to measure density and rheology of the drilling fluid. However, the typical time-dependent non-Newtonian properties of drilling fluids are a challenge for measurement traceability for such pipe-rheometer measurements. There is a lack of understanding of the variability in a fluid’s rheological behaviour as a function of flow history, and of the relation between reference lab rheometer measurements. This lack of understanding poses a challenge in quantifying the measurement uncertainty and achieving traceable calibration of the pipe rheometer and the resulting effect on Automated Drilling Control. Using IMS RheoSense in experimental study with representative drilling fluids, mathematical models for the time-dependent rheological behaviour will be developed and built into the IMS pipe rheometer. Further experimental study with the updated IMS pipe rheometer, will be compared against measurements from a reference lab rheometer, yielding results to allow development of time-dependent models for drilling control automation. This will lead to an understanding of the correlation between lab rheometer measurements and flowline pressure, applicable for calibration of a pipe rheometer, and providing improved accuracy in estimation of wellbore pressures in drilling control systems such as Sekal Drilltronics.