LONG-TERM MONITORING OF A GEOTHERMAL EXCHANGE BOREFIELD WITH FIBER OPTIC DISTRIBUTED TEMPERATURE SENSING

2017 ◽  
Author(s):  
Lauren K. Thomas ◽  
◽  
James Tinjum ◽  
David J. Hart ◽  
Dante Fratta
2013 ◽  
Vol 53 (6) ◽  
pp. 872-877
Author(s):  
Dita Jiroutová ◽  
Miroslav Vokáč

In recent years, the field of structure monitoring has been making increasing use of systems based on fiber-optic technologies. Fiber-optic technology offers many advantages, including higher quality measurements, greater reliability, easier installation and maintenance, insensitivity to the environment (mainly to the electromagnetic field), corrosion resistance, safety in explosive and flammable environments, the possibility of long-term monitoring and lower cost per lifetime. We have used SOFO fibre-optic strain gauges to perform measurements to check the overall relative deformation of a real reinforced concrete structure. Long-term monitoring of the structure revealed that the measurement readings obtained from these fibre-optic strain gauges differed from each other. Greater attention was therefore paid to the calibration of the fibre-optic strain gauges, and to determining their measurement accuracy. The experimental results show that it is necessary to calibrate SOFO strain gauges before they are used, and to determine their calibration constant.


2021 ◽  
Vol 6 (4) ◽  
pp. 81-91
Author(s):  
Andrey I. Ipatov ◽  
Mikhail I. Kremenetsky ◽  
Ilja S. Kaeshkov ◽  
Mikhail V. Kolesnikov ◽  
Alexander  A. Rydel ◽  
...  

The main goal of the paper is demonstration of permanent downhole long-term monitoring capabilities for oil and gas production profile along horizontal wellbore in case of natural flow. The informational basis of the results obtained is the data of long-term temperature and acoustic monitoring in the borehole using a distributed fiber-optic sensor (DTS + DAS). Materials and methods. At the same time, flowing bottom-hole pressure and surface rates were monitored at the well for rate transient analysis, as well as acoustic cross-well interference testing [1], based on the results of which “well-reservoir” system properties were evaluated, the cross-well reservoir properties of the were estimated, and the possibility of cross-well testing using downhole DTS-DAS equipment was justified. The research results made it possible to assess reliability of DTS-DAS long-term monitoring analysis results in case of multiphase inflow and multiphase wellbore content. In particular, DTS-DAS results was strongly affected by the phase segregation in the near-wellbore zone of the formation. Conclusions. In the process of study, the tasks of inflow profile for each fluid phase evaluation, as well as its changes during the well production, were solved. The reservoir intervals with dominantly gas production have been reliably revealed, and the distribution of production along the wellbore has been quantified for time periods at the start of production and after production stabilization.


Geothermics ◽  
2018 ◽  
Vol 72 ◽  
pp. 193-204 ◽  
Author(s):  
Adam McDaniel ◽  
Dante Fratta ◽  
James M. Tinjum ◽  
David J. Hart

2016 ◽  
Vol 6 (3) ◽  
pp. 321-327 ◽  
Author(s):  
Florian Moser ◽  
Werner Lienhart ◽  
Helmut Woschitz ◽  
Hartmut Schuller

2020 ◽  
Author(s):  
Bart Schilperoort ◽  
Karl Lapo ◽  
Anita Freundorfer ◽  
Bas des Tombe

<p>Distributed Temperature Sensing (DTS) using fiber optic cables is a promising technique capable of filling in critical gaps between point observations and remote sensing. While DTS only directly measures the fiber temperature, it has been used to make spatially distributed observations of air temperature, wet bulb temperature, wind speed, and more, on the scales of centimeters to kilometers at temporal resolutions as fine as a second. Of particular interest for the flux community, the spatially distributed nature of DTS allows us to place point observations within a spatial context, highlighting missing physics and linking processes across scales.</p><p>However, DTS is not without its drawbacks. It is not a push button operation – each DTS array is unique, requiring an exceptional investment in time for the deployment and for turning DTS observations into physically-meaningful results. Characteristics of DTS observations change with the DTS device used, but also with, e.g., the type of the fiber, the layout of the fiber optic array, and properties of the reference sections used in calibration. These issues create two main challenges in processing DTS data: 1) the need for a robust calibration and 2) management of data that can exceed a terabyte, especially with large or long-term installations. To address these challenges and simplify the use of this powerful technique we present two tools, which can be used both standalone and in conjunction with each other.</p><p>First is ‘python-dts-calibration’, a Python package which is aimed at performing thorough calibration of DTS data, as calibration by DTS devices is often lacking in quality. It is able to perform a more robust calibration than the device default, and provides confidence intervals for the calibrated temperature. The confidence intervals vary along the fiber and over time and are different for every setup. The second tool, ‘pyfocs’, is a Python package meant for managing larger, long term installations. This tool automates the workflow including checking data integrity, calibration, and physically mapping the data. pyfocs incorporates ‘python-dts-calibration’ at its core, allowing the tool to robustly calibrate any DTS configuration. Lastly, the package provides the option for calculating other parameters, such as wind speed.</p><p>Both tools are open-source and hosted on GitHub<sup>[1][2]</sup>, allowing for everyone to check the code and suggest changes. By sharing our tools, we hope to make the use of fiber optic DTS in geosciences easier and open the door of this new technology to non-specialists.</p><p> </p><p>[1] https://github.com/dtscalibration/python-dts-calibration</p><p>[2] https://github.com/klapo/pyfocs</p>


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