Field comparison of conventional and new technology temperature logging systems

Wisian, Ken W.; Blackwell, David; Bellani, S.; Henfling, Joseph A; Normann, R.A.; Lysne, P. C.; Förster, Andrea; Schrötter, Jörg

doi:10.1016/s0375-6505(97)10013-x

Cited by 41 publications

(19 citation statements)

References 9 publications

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“…Through the deployment of fibre-optic distributed temperature sensing (DTS) technology, quasi-continuous temperature profiles can be measured with high temporal resolution (Wisian et al, 1998).…”

Section: Fibre-optic Distributed Temperature Measurementsmentioning

confidence: 99%

Temperature field of the Mallik gas hydrate occurrence - implications on phase changes and thermal properties

Henninges¹,

Schrötter²,

Erbaş³

et al. 2005

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Three 1200 m deep wells, spaced at 40 m, were equipped with permanent fibre-optic sensor cables. The variation of temperature within a continental, permafrost-associated gas hydrate occurrence was measured deploying the distributed temperature-sensing technology. Analysis of the transient temperature changes induced by the drilling and completion of the wells indicates that the base of the ice-bearing permafrost and the base of the gas hydrate occurrences is 604-609 ± 3.5 m, and 1108-1109 ± 3.5 m, respectively. Twenty-one months after the completion of the boreholes, the well temperatures are within ± 0.1°C of equilibrium with the formation temperature. The analysis of the geothermal gradient shows that high gas hydrate saturations within the pore space have only a minor effect on the bulk-rock thermal conductivity compared to changes in lithology. câbles-sondes permanents à fibres optiques permettant par détection thermique simultanée (distributed temperature sensing) de mesurer les variations de température dans une accumulation continentale d'hydrates de gaz associée à du pergélisol. L'analyse des changements transitoires de température occasionnés par le forage et l'achèvement des puits indique que la base du pergélisol contenant de la glace se situe entre 604 et 609 ± 3,5 m, alors que la base de la zone d'hydrates de gaz se trouve entre 1 108 et 1 109 ± 3,5 m. Vingt et un mois après l'achèvement des forages, les températures mesurées dans les puits s'écartaient d'un maximum de ± 0,1°C de l'équilibre avec la température des sédiments. L'analyse du gradient géothermique montre que, comparativement aux changements lithologiques, la forte saturation en hydrates de gaz de l'espace interstitiel a un effet mineur sur la conductivité thermique globale des formations.

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Section: Fibre-optic Distributed Temperature Measurementsmentioning

confidence: 99%

Temperature field of the Mallik gas hydrate occurrence - implications on phase changes and thermal properties

Henninges¹,

Schrötter²,

Erbaş³

et al. 2005

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“…Using this equation, it can be shown that for normal geothermal gradients (approximately 25 °C/km), convection can be expected in boreholes with diameters greater than about 5 cm. However, several field investigations by Urban et al (1978), Diment (1967), Gretener (1967), and Wisian et al (1998), as well as the observations by this author, have shown that although convection cells do form, they rarely extend vertically more than a few borehole diameters before dying out. Thus, the general effect of convection within boreholes is to decrease the signal-to-noise ratio of a temperature log without interfering with broader temperature trends.…”

Section: Thermal Gradientmentioning

confidence: 62%

Temperature Profiles and Hydrologic Implications from the Nevada Test Site

Gillespie¹

2005

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Groundwater temperature is sensitive to the competing processes of heat flow from below and the advective transport of heat by groundwater flow. Because groundwater temperature is sensitive to conductive and advective processes, groundwater temperature may be utilized as a tracer to further constrain the uncertainty of predictions of advective radionuclide transport models constructed for the Nevada Test Site (NTS). Since heat transport, geochemical, and hydrologic models for a given area must all be consistent, uncertainty can be reduced by excluding those models that do not match estimated heat flow.The initial objective of this study was to identify the quantity and quality of available heat flow data at the NTS. Although thousands of temperature logs have been conducted at the NTS, most are recorded on paper and not easily examined. Therefore, only those temperature logs in digital format were considered. During the course of an earlier investigation, 145 temperature logs from 63 boreholes on the NTS were examined. Of these, 13 boreholes were found to have temperature profiles suitable for the determination of heat flow values from one or more intervals within the boreholes. The successful analysis of the initial 13 temperature profiles led to the acquisition of an additional 21 temperature profiles from boreholes at the NTS, during fiscal year (FY) 2003. Five of these 21 temperature profiles were obtained in boreholes that had been previously profiled and were collected to ensure the previously collected profiles were representative of ambient conditions. The other 16 profiles were obtained in boreholes that had not been previously profiled. Additionally, a previously measured temperature profile (borehole UE-18t) that was overlooked in the initial investigation of existing temperature profiles from the NTS was discovered, and borehole PM-1 was relogged during an operational check of a new wireline for DRI's geophysical logging unit. During FY04, an additional 15 temperature profiles were obtained. Five of the temperature profiles were obtained in boreholes that had been previously profiled. The other 10 profiles were measured in boreholes from which previous stabilized temperature profiles had not been obtained. Interpretation of a temperature profile in a lithology without major variations in thermal conductivity may be fairly straightforward; interpretation of a temperature profile crossing several hydrostratigraphic units requires accurate knowledge of the thermal properties of the corresponding hydrostratigraphic units, and is complicated if advective heat transport is occurring.Heat flow values for intervals contained within the boreholes ranged from a low of 5.0 mW m -2 to a high of 181.6 mW m -2 . Vertical variations in heat flow values, within individual boreholes, were readily explained by the advection of heat by groundwater flow. Horizontal consistencies and variations in heat flow values between various boreholes were dependent upon the geologic setting of the borehole, and the effect o...

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“…4 measurements obtained during 20 h in LUHE; 6 measurements during 36 h in LH31; Table 1) and in the light of modern advances in logging technology (e.g. Wisian et al, 1998), it will be economically feasible to obtain considerably more data (≥ 30) in field applications. Longer time period for measuring BHT should also be considered.…”

Section: Resultsmentioning

confidence: 99%