Field testing of an optical fiber temperature sensor in a geothermal

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

doi:10.1016/0375-6505(90)90048-g

Cited by 10 publications

(7 citation statements)

References 2 publications

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“…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). Further, a few studies have shown that DTS-measurements in geothermal wells can identify hydraulically active zones and fracture characteristics and measure pressure profiles (Sharma et al 1990;Sakaguchi and Matsushima 2000;Smithpeter et al 1999). With the same aims, DTSmeasurements were conducted in combination with cold water injections (Henninges et al 2005;Patterson et al 2017).…”

Section: Dtsmentioning

confidence: 99%

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

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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.

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Section: Dtsmentioning

confidence: 99%

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

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“…For example, in the last 5 years, technological advances in laser optics have led to an increase of almost 10 6 times in the amount of light that can be practically recovered from weak emitters. These new developments have led to increased use of remote in situ sensing of oceanic and geothermal parameters by laser-induced Raman scattering (e.g., Sharma et al 1990;Schoen et al 1992).…”

Section: Raman Scatteringmentioning

confidence: 99%

LIDAR applications to fisheries monitoring problems

Gauldie¹,

Sharma²,

Helsley³

1996

Can. J. Fish. Aquat. Sci.

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Recent advances in lasers, spectrometers, and multichannel detectors have significantly improved the capabilities of LIDAR (LIght Detection And Ranging) systems in the blue-green region of the electromagnetic spectrum. Because ocean water has minimum absorbance in the blue-green region of the spectrum, the LIDAR has great potential to become a versatile tool capable of providing the kind and the quantity of biomass and water quality (including temperature) data that have been thus far inaccessible to fisheries scientists. The basic physics of the LIDAR is described including the physics relevant to the problems of light scattering, reflection, and penetration of water. Two extremes of potential LIDAR application (broad, shallow light path and narrow, deep light path) are discussed in terms of estimation of floating egg abundance and fish aggregation at thermal fronts, respectively. It is anticipated that the application of LIDAR will allow better estimates of instantaneous rates of change in fish stock parameters, as well as increasing the amount of data collected to assess heterogeneity of stock abundance in both space and time.Résumé : Les récents progrès dans les domaines du laser, des spectromètres et des détecteurs multicanal ont conduit à une amélioration marquée de la capacité de résolution des LIDAR (détection et télémétrie par la lumière) dans la région du spectre électromagnétique correspondant au bleu-vert. Puisque l'absorbance de l'eau de mer passe par un minimum à ces longueurs d'onde, le LIDAR pourrait se révéler être un instrument polyvalent et très utile pour recueillir les données, du type et de la quantité requis, sur la biomasse et la qualité de l'eau (notamment la température) que les spécialistes des pêches ne pouvaient se procurer jusqu'alors. Les principes physiques du LIDAR sont esquissés, notamment la physique des problèmes avec la diffusion, la réflection et la pénétration dans l'eau. Les auteurs envisagent deux formes extrêmes d'application du LIDAR (un éclairage large et peu profond et un éclairage étroit et profond) dont les applications sont examinées en termes d'estimation de l'abondance des oeufs flottants et de l'agrégation du poisson sur les fronts thermiques, respectivement. On pense que les applications du LIDAR envisagées dans cet article donneront de meilleures évaluations des taux instantanés de variation des paramètres décrivant les stocks de poisson et qu'elles permettront de recueillir plus de données servant à estimer l'hétérogénéité en termes d'abondance des stocks dans le temps et dans l'espace. [Traduit par la Rédaction]

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“…In shallow boreholes the Raman DTS technique -simply referred to as DTS belowhas been used for about three decades with first applications in hydrogeology [2,16,17]. In the reviewed literature, application of the DTS technique to GSHP research first appears in the context of Distributed Thermal Response Testing (DTRT) [18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Calibration and Uncertainty Quantification for Single-Ended Raman-Based Distributed Temperature Sensing: Case Study in a 800 m Deep Coaxial Borehole Heat Exchanger

Pallard¹,

Lazzarotto²,

Acuña³

et al. 2023

Preprint

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Raman-based Distributed Temperature Sensing (DTS) is a valuable tool for field testing and validating heat transfer models in Borehole Heat Exchanger (BHE) and Ground Source Heat Pump (GSHP) applications. However, temperature uncertainty is rarely reported in the literature. In this paper, a new calibration method is proposed for single-ended DTS configurations, along with a method to remove fictitious temperature drifts due to ambient air variations. The methods are implemented for a Distributed Thermal Response Test case study in an 800 m deep coaxial BHE. The results show that the calibration method and temperature drift correction are robust and give adequate results, with a temperature uncertainty of ± 0.58, 0.74, 1.1 and 1.7 K found at depths of 200, 300, 500 and 800 m, respectively. The temperature uncertainty increases non-linearly with depth and is dominated by the uncertainty in the calibrated parameters for depths larger than 200 m. The paper also offers insights into thermal features observed during the DTRT, including a heat flux inversion along the borehole depth and the slow temperature homogenization under circulation. Distributed temperature measurements and their uncertainties are useful tools in determining the strengths and drawbacks of ground heat transfer models.

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Field testing of an optical fiber temperature sensor in a geothermal

Cited by 10 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

LIDAR applications to fisheries monitoring problems

Calibration and Uncertainty Quantification for Single-Ended Raman-Based Distributed Temperature Sensing: Case Study in a 800 m Deep Coaxial Borehole Heat Exchanger

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