Field Applications of Fiber-Optic Sensors. Part I: Temperature Measurements in a Geothermal Well

Angel, S. M.; Garvis, D.; Sharma, Shiv K.; Seki, Arthur S.

doi:10.1366/0003702894202922

Cited by 4 publications

(1 citation statement)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…DTS temperature measurements in oil and groundwater wells, production pipelines, and mining areas are well documented in previous studies (Majorowicz and Smith 1999;Kersey 2000;Johnson et al 2006;Nath et al 2006;Brown 2009;Inaudi and Glisic 2010;Frings and Walk 2011;Sanders 2011;Ukil et al 2012;Banks et al 2014;Lumens 2014;Hartog 2017) as well as the use within the scope of borehole heat exchanger installations for distributed thermal response tests (Fujii et al 2006(Fujii et al , 2009Acuña et al 2009;Latal et al 2011;Hartog 2017;Franco and Conti 2020). Regarding the use of DTS in geothermal wells, laboratory and field tests were carried out in the late 1980s to prove the ability of FO-techniques for temperature and pressure measurements (Angel et al 1986). After that, DTS has been installed in geothermal wells for various applications, such as for testing DTS systems or assessing lithology in boreholes (Hurtig et al 1994(Hurtig et al , 1996Reinsch and Henninges 2012;Reinsch et al 2013;Förster et al 1997;Wisian et al 1998;Henninges et al 2005;Freifeld 2008;Siska et al 2016).…”

Section: Dtsmentioning

confidence: 88%

Monitoring cold water injections for reservoir characterization using a permanent fiber optic installation in a geothermal production well in the Southern German Molasse Basin

et al. 2021

View full text Add to dashboard Cite

Fiber optic sensing has gained importance for wellbore monitoring and reservoir characterization in geothermal fields as it allows continuous, spatially highly resolved measurements. Distributed acoustic sensing (DAS) and distributed temperature sensing (DTS) technologies, among others, enable monitoring of flow regimes and heat transport inside the wellbore to describe the dynamical behavior of the reservoir. The technically challenging installation of a permanent fiber optic monitoring system in a geothermal production well over the entire wellbore length was conducted for the first time at the geothermal site Schäftlarnstraße in Munich, Germany. One cable with two DAS fibers, two DTS fibers, and one fiber for a downhole fiber optic pressure/temperature gauge were clamped to ¾-in. sucker rods and installed to 3.7 km measured depth to collect data from the wellbore after drilling, during testing, and during operations. We present DTS profiles during 3 months of well shut-in and show the results of two cold water injection tests conducted to localize inflow zones in the reservoir and to test the performance of the fiber optic setup. A vertical displacement in temperature peaks of approximately 1.5 m was observed during the injection tests, presumably resulting from thermal contraction of the sucker rod–cable setup. This was verified by analyzing the strain information from the DAS records over 1 h of warm-back after cold water injection with the calculated theoretical thermal contraction of DTS of the same period. We further verified the flowmeter measurements with a gradient velocity analysis of DTS profiles during injection. Intake to the major inflow zone was estimated to 93.5% for the first injection test, respective 94.0% for the second, intake of flowmeter was calculated to 92.0% for the same zone. Those values are confirmed by analyzing DTS profiles during the warm-back period after the well was shut.

show abstract

Section: Dtsmentioning

confidence: 88%

Monitoring cold water injections for reservoir characterization using a permanent fiber optic installation in a geothermal production well in the Southern German Molasse Basin

et al. 2021

View full text Add to dashboard Cite

show abstract

Waveguides as Chemical Sensors

Dessy¹

1989

Anal. Chem.

View full text Add to dashboard Cite

Waveguides are thin cylinders or films made of glass or plastic that efficiently conduct light (1). Developed originally for telecommunications and optical computing applications, they have found another home in analytical chemistry as chemical and physical sensors. Their small size, flexible geometry, ability to channel light over long distances, and noise immunity make these sensors ideal for remote sensing,

show abstract

Near-IR Fiber-Optic Temperature Sensor

Lin

Brown

1993

Appl Spectrosc

View full text Add to dashboard Cite

A fiber-optic temperature sensor based on the perturbations of near-IR water bands has been developed. These fiber-optic sensors are very simple and readily fabricated. Models for expressing temperature can be developed by linear regression (LR) of the absorbance at one selected wavenumber, by multilinear regression (MLR) of the absorbances at several selected wavenumbers, or by principal component regression (PCR) using entire spectra. The standard errors of prediction for temperature are 0.53 to 1.64°C for the LR model, 0.22 to 0.85°C for the MLR model, and 0.16 to 0.32°C for the PCR model over a temperature range of 5 to 85°C. Potentially, these fiber-optic sensors can be used in the remote sensing of temperature and in hostile electrical environments.

show abstract

Field Applications of Fiber-Optic Sensors. Part I: Temperature Measurements in a Geothermal Well

Cited by 4 publications

References 2 publications

Monitoring cold water injections for reservoir characterization using a permanent fiber optic installation in a geothermal production well in the Southern German Molasse Basin

Monitoring cold water injections for reservoir characterization using a permanent fiber optic installation in a geothermal production well in the Southern German Molasse Basin

Waveguides as Chemical Sensors

Near-IR Fiber-Optic Temperature Sensor

Contact Info

Product

Resources

About