Flow properties of water-based drilling fluids

Abstract

The objective of this master thesis was to investigate the flow properties of water based drilling fluids, utilizing measurements in both the micro and macro scale. The research was performed on two realistic drilling fluids by the use of a viscometer, a rheometer and a realistic flow loop, where the latter represents the macro scale. The research outcome could possibly improve the understanding of flow behavior in wellbores, and remove uncertainties associated with annular friction. The two fluids utilized in the research was made up with the goal of having equal rheological qualities, when measured with a Fann 35 viscometer. A more thorough examination of the two fluid's rheology was then executed by using a Anton Paar MCR302 rheometer. The macroscopic properties was researched employing a flow loop, capable of simulating realistic wellbore conditions.The main outcome of this thesis is that even though two fluids appear to have the same rheoligical properties when measured on simple equipment, their fundamental different microscopic structure will exhibit variations when the fluids are utilized in real applications.Due to problems encountered when mixing the fluids, as well as problems with one of the fluids itself, not all intended experiments were conducted. The experiments should be replicated with an emphasis on temperature control, avoiding bubbles and foam, and be conducted within a shorter time period.