An Analytical Model To Determine the Rheological Properties of Well Fluids Using a Novel Downhole Sensor Conference Paper uri icon


  • The ability to measure the true viscosity of formation fluids at downhole conditions is highly desirable in reservoir fluid characterization. A novel downhole viscosity sensor that can provide the real-time measurement of the viscosity of a flowing fluid at downhole conditions is discussed in this paper. The measurement can be obtained during open hole sampling of reservoir fluids, or during fluid profiling to characterize the reservoir properties at a vertical resolution much higher than that of traditional sampling methods. This leads to reservoir better understanding of the reservoir, leading to better decision-making with regards to field modeling, facilities planning and production optimization. A prototype of a downhole sensor was previously calibrated and tested with fluids of 1-28 cP viscosity, under a temperature range of 100° to 160°F. The sensor's viscosity readings were validated against independent measurements taken with a Brookfield viscometer. Following on from that work, this paper presents a generalized mathematical model to describe the performance of the sensor with Newtonian and Non-Newtonian fluids. The model characterizes the response of the sensor as a function of the parameters from a power-law model rheological description and the geometry of the device. The previously gathered experimental data suggest the validity of this model for predicting the sensor response under realistic operating conditions. The model can be used to calculate optimum dimensions to fabricate a device for customized applications. Copyright 2010, Society of Petroleum Engineers.

author list (cited authors)

  • Rondon, J., Naughton, M., Barrufet, M. A., & Falcone, G.

citation count

  • 0

publication date

  • September 2010


  • SPE  Publisher