Conference: Publication Date: 18 March 2013

The advent of computerized tomography (CT) has revolutionized the way engineers approach nondestructive testing and evaluation exercises these days. There has been a recent laboratory study (at Leibniz University Hannover) that uses a similar X-ray CT scanner for a three-phase flow system having industrial equivalent in the oil exploration industry. This study has applied “KT-1 signature” approach for such applications. It is based on Sobolev space analysis and utilizes different Hamming filters (for a given Fourier cut-off frequency) for tomographic reconstructions from Fourier transform based techniques. This work relates the point wise theoretical error in reconstruction of objects that belong to certain Sobolev space. The present work extends this concept to characterize types of flow pattern that may be encountered in oil industry applications and “KT-2 signature” approach is adopted. This analysis is also based on Sobolev spaces and it utilizes different Fourier cut-off frequencies for a fixed Hamming filter. This approach is global in nature and it guarantees the order of error in tomographic reconstructions. These signatures give a linear relationship between inherent error and Fourier cut-off frequency. The slope of this linear behaviour is used to characterize the flow images. Such a technique provides very useful input for three-phase flow pumping phenomenon that is relevant to oil exploration industry. A three-phase bubble column reactor is investigated in this study. Three phases in this bubble column were: air, water and polyvinyl chloride (PVC). The composition of PVC was made 5% of the total volume of bubble column. Water was injected with velocity of 0.07 m/s and four different air velocities used were 0.06 m/s, 0.08 m/s, 0.12 m/s and 0.14 m/s. This bubble column was scanned at two different heights of 1.7 m and 3.2 m from the inlet.

References

1. Bruvik, E.M., B.T. Hjertaker and A. Hallanger, “Gamma-ray tomography applied to hydro-carbon multi-phase sampling
and slip measurements,” Flow Measurement and Instrumentation, 2010; 21:240-248.
2. Dyakowski, T., “Process tomography applied to multi-phase flow measurement,” Meas. Sci. Techno., 1996; 7:343-353.
3. Munshi, P., P. Jayakumar, P. Satyamurthy, T.K. Thiyagarajan, N.S. Dixit and N. Venkatramani, “Void-fraction
Measurements in a Steady-state Mercury-Nitrogen Flow Loop,” Experiments in Fluids, 1998; 24:424-430.
4. Herman, G.T., Image Reconstruction from Projections: The fundamentals of computerized tomography, Academic Press,
New York, 1980.
5. Munshi, P., R.K.S. Rathore, K.S. Ram and M.S. Kalra, “Error Estimates for Tomographic Inversion,” Inverse Problems,
1991; 3: 399-408.
6. Munshi, P., “Error Analysis of Tomographic Filters I: Theory,” NDT & E International, 1992; 25:191-194.
7. Gulati, S., M. Behling, P. Munshi, A. Luke and D. Mewes, “Tomographic KT-1 signature of phase-fraction distributions
in multiphase bubble columns,” Flow Measurement and Instrumentation, 2010; 21: 249-254.
8. Athe, P., S. Shakya, P. Munshi, A. Luke and D. Mewes, “Analysis of phase fraction distribution in multi-phase bubble
columns using KT-1 signature and Fractal dimension,” Proceedings of ISPT6 - ISBN 978-0-620-53039-2, 2012,
Cape Town.
9. Munshi, P., R.K.S. Rathore and S. Vijay, “A Numerical Study of an Inverse Theorem for Computerized Tomography,”
European Journal of NDT, 1994; 3:104-107.
10. Munshi, P., M. Maisl and H. Reiter, “Experimental Aspects of the Approximate Error Formula for Tomographic
Reconstruction,” Material Evaluation, 1997; 55:188-191.
11. Frøstein, T., H. Kyandal and H. Aakre, “Dual energy gamma tomography system for high pressure multiphase flow,”
Flow Measurement and Instrumentation, 2005; 16:99-112.
12. Hubbell, J.H., “Photon mass attenuation and energy-absorption coefficient from 1 keV to 20 MeV,” Int J Appl Radiat Isot
1982; 33:1269-1290.
13. Thorat, B.N., A.V. Shevade, K.N. Bhilegaonkar, R.H. Aglawe, U.P. Veera, S.S. Thakre, A.B. Pandit, S.B. Sawant and
J.B. Joshi, “Effect of sparger design and height to diameter ratio on fractional gas hold up in bubble column,” Chemical
Engineering Research and Design, 1998; 76: 823-834.
14. Groth, T., M. Reichwage, D. Mewes and A. Luke, “Effects of dissolving and degassing phenomena on multiphase oil and
gas boosting,” 14th International Conference Multiphase Production technology, 2009; Cannes, France.
15. Averbuch, D., “Recent developments in the risk management of offshore production systems,” 16th European
Symposium on Computer Aided Process Engineering and 9th International Symposium on Process Systems Engineering,
2006; 21: 39-44.

Metrics

Usage | Shares |
---|---|

Total Views 48 Page Views |
Total Shares 0 Tweets |

48 0 PDF Downloads |
0 0 Facebook Shares |

Total Usage | |

48 |