Institutional Repository
Technical University of Crete
Technical University of Crete
EN
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EL
| URI: | http://purl.tuc.gr/dl/dias/E6ECD3D7-A868-48FF-9F85-5CCA77AD856A | ||
| Year | 2010 | ||
| Type of Item | Peer-Reviewed Journal Publication | ||
| License |
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| Bibliographic Citation | V.C. Kelessidis, R. Maglione, G. Bandelis," On the end-effect correction for Couette type oil-field direct-indicating viscometers for Newtonian and non-Newtonian fluids," Journal of Petroleum Science and Engineering, vol. 71, no. 1-2, pp. 37–46, Mar. 2010. doi: 10.1016/j.petrol.2010.01.001 https://doi.org/10.1016/j.petrol.2010.01.001 | ||
| Appears in Collections |
Analysis and experimental results are presented which quantify the magnitude of end-effects for direct-indicating, narrow gap, rotating cylinder viscometers used extensively in oil-field, for Newtonian and non-Newtonian fluids. Such viscometers have already embedded at manufacturing stage an end-effect correction and give directly the shear stress which does not allow end-effect quantification in a straight forward manner. The presented analysis resolves this problem by estimating the embedded correction, which has been determined as 6.69% of the torque developed along the cylindrical part of the stationary bob of this viscometer.Experimental results with Newtonian and non-Newtonian fluids show that there is no additional end-effect from the bottom of the stationary bob. However, there is additional end-effect contribution from the top section of the bob, which has not been taken into account in the design and manufacturing of the instrument. Its magnitude ranges from 5 to 6% for the Newtonian fluid and the high shear rate range for the non-Newtonian fluid, to 12% for the low shear rate range for the non-Newtonian fluid tested, while the impact on drilling situations is also discussed.
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