scholarly journals Summary of heat flow studies in Nigeria

2019 ◽  
pp. 121-132
Author(s):  
Vladimir I. Zui ◽  
Lukman Akinyemi
Keyword(s):  
Magnetic Field ◽  
Heat Flow ◽  
Heat Conductivity ◽  
Traditional Approach ◽  
Geothermal Gradient ◽  
Depth Interval ◽  
Flow Density ◽  
Flow Data ◽  
Heat Flow Density ◽  
Two Parameters

A traditional approach for heat flow determination requires two parameters. They are a geothermal gradient and heat conductivity of rocks comprising the considered depth interval. The geothermal gradient is determined from a thermogram recorded in a wellbore and the heat conductivity is obtained from the laboratory measurements of selected rock samp les. There are some variations of this approach to both get the gradient and heat conductivity values. However, there are many areas without boreholes to register their thermograms, or at least to have several temperature readings at intermediate positions of bottom holes and traditional methods of heat flow determinations cannot be used. Recently another method was proposed to estimate heat flow. It was derived from spectral analysis of magnetic field. During last years it was widely used in Nigeria for areas where deep boreholes are absent. It uses estimates of depths to the base and bottom of the causative body derived from analysis of the magnetic field maps. The base of the causative body corres ponds to the depth of the Curie surface at which rocks lose their magnetic properties. It is known that it happens at the temperature around 580 °C that slightly varies depending on the content of magnetite within the causative body. The temperature at the top of this body is estimated. The heat flow density can be calculated knowing the geothermal gradient within this depth interval and heat conductivity of rocks. A preliminary heat flow density map was compiled based on all accessible heat flow data. A comparison of heat flow data from several regions of the country, determined using both methods provides rather good agreement.

On the effects of thermal properties structure and water bottom temperature variation on temperature gradients in lake sediments

1986 ◽  
Vol 23 (9) ◽  
pp. 1257-1264 ◽  
Author(s):  
K. Wang ◽  
P. Y. Shen ◽  
A. E. Beck
Keyword(s):  
Heat Flow ◽  
Temperature Variation ◽  
Stratified Medium ◽  
Depth Interval ◽  
Flow Density ◽  
Detailed Knowledge ◽  
Bottom Temperature ◽  
Temperature Variations ◽  
Density Values ◽  
Finite Sum

In heat flow determinations, it is customary to treat the surface temperature variation as a finite sum of Fourier components. The medium is assumed to be homogeneous or horizontally stratified with each layer having a constant conductivity and diffusivity. This allows the effect of each periodic component to be calculated analytically. We extend this formulation to include cases where thermal conductivities in some layers of a stratified medium may vary linearly with depth as have been found in the sediments of some continental lakes. The application of this formalism to temperature measurements in Lake Greifensee and Lac Leman shows that even with excellent records of bottom temperature variations over several years, failure to take into account the conductivity variation leads to errors as high as 20% in heat flow density values, depending on the depth interval used. The combined effects of lack of detailed knowledge of conductivity structure and the use of too short and (or) inaccurate records of bottom temperature variations, leading to very significant errors, are also discussed, with particular reference to the problems arising from a lack of recognition of the existence of nonannual terms in the bottom temperature variation and the use of probes that do not penetrate the sediments deeply enough.

scholarly journals OIL AND GAS MODELING GENERARION IN THE JURASSIC SEDIMENTS IN THE SOUTH-EASTERN OF THE WEST SIBERIAN PETROLEUM PROVINSE

2021 ◽  
Vol 2 (1) ◽  
pp. 38-43
Author(s):  
Elena A. Glukhova ◽  
Pavel I. Safronov ◽  
Lev M. Burshtein
Keyword(s):  
Heat Flow ◽  
Thermal History ◽  
Oil And Gas ◽  
Flow Density ◽  
Basin Modeling ◽  
Heat Flow Density ◽  
The West ◽  
One Dimensional ◽  
History Of ◽  
The One

The article presents the one-dimensional basin modeling performed in four wells to reconstruct the thermal history of deposits and reconstruct the effective values of the heat flow density.

scholarly journals Heat flow density estimates in the Upper Rhine Graben using laboratory measurements of thermal conductivity on sedimentary rocks

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Pauline Harlé ◽  
Alexandra R. L. Kushnir ◽  
Coralie Aichholzer ◽  
Michael J. Heap ◽  
Régis Hehn ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Ambient Temperature ◽  
Sedimentary Rocks ◽  
Flow Density ◽  
Upper Rhine Graben ◽  
Heat Flow Density ◽  
Density Estimates ◽  
Wet Rocks ◽  
Upper Rhine

AbstractThe Upper Rhine Graben (URG) has been extensively studied for geothermal exploitation over the past decades. Yet, the thermal conductivity of the sedimentary cover is still poorly constrained, limiting our ability to provide robust heat flow density estimates. To improve our understanding of heat flow density in the URG, we present a new large thermal conductivity database for sedimentary rocks collected at outcrops in the area including measurements on (1) dry rocks at ambient temperature (dry); (2) dry rocks at high temperature (hot) and (3) water-saturated rocks at ambient temperature (wet). These measurements, covering the various lithologies composing the sedimentary sequence, are associated with equilibrium-temperature profiles measured in the Soultz-sous-Forêts wells and in the GRT-1 borehole (Rittershoffen) (all in France). Heat flow density values considering the various experimental thermal conductivity conditions were obtained for different depth intervals in the wells along with average values for the whole boreholes. The results agree with the previous heat flow density estimates based on dry rocks but more importantly highlight that accounting for the effect of temperature and water saturation of the formations is crucial to providing accurate heat flow density estimates in a sedimentary basin. For Soultz-sous-Forêts, we calculate average conductive heat flow density to be 127 mW/m2 when considering hot rocks and 184 mW/m2 for wet rocks. Heat flow density in the GRT-1 well is estimated at 109 and 164 mW/m2 for hot and wet rocks, respectively. Results from the Rittershoffen well suggest that heat flow density is nearly constant with depth, contrary to the observations for the Soultz-sous-Forêts site. Our results show a positive heat flow density anomaly in the Jurassic formations, which could be explained by a combined effect of a higher radiogenic heat production in the Jurassic sediments and thermal disturbance caused by the presence of the major faults close to the Soultz-sous-Forêts geothermal site. Although additional data are required to improve these estimates and our understanding of the thermal processes, we consider the heat flow densities estimated herein as the most reliable currently available for the URG.

Continental Heat-Flow Density

1988 ◽  
pp. 167-222 ◽  
Author(s):  
W. G. Powell ◽  
D. S. Chapman ◽  
N. Balling ◽  
A. E. Beck
Keyword(s):  
Heat Flow ◽  
Flow Density ◽  
Heat Flow Density

Surface heat flow density at the phlegrean fields caldera (SOUTHERN ITALY)

Geothermics ◽  
1998 ◽  
Vol 27 (4) ◽  
pp. 469-484 ◽  
Author(s):  
Gennaro Corrado ◽  
Salvatore De Lorenzo ◽  
Francesco Mongelli ◽  
Antonio Tramacere ◽  
Gianmaria Zito
Keyword(s):  
Heat Flow ◽  
Southern Italy ◽  
Surface Heat ◽  
Flow Density ◽  
Heat Flow Density ◽  
Surface Heat Flow ◽  
Phlegrean Fields

First heat flow density assessments in Cuba

1984 ◽  
Vol 103 (1-4) ◽  
pp. 283-296 ◽  
Author(s):  
V. čermák ◽  
M. Krešl ◽  
J. Šafanda ◽  
M. Nápoles-Pruna ◽  
R. Tenreyro-Perez ◽  
...  
Keyword(s):  
Heat Flow ◽  
Flow Density ◽  
Heat Flow Density

scholarly journals Thermal conditions for geothermal energy exploitation in the Transcarpathian depression and surrounding units

2016 ◽  
Vol 46 (1) ◽  
pp. 33-49 ◽  
Author(s):  
Dušan Majcin ◽  
Roman Kutas ◽  
Dušan Bilčík ◽  
Vladimír Bezák ◽  
Ignat Korchagin
Keyword(s):  
Temperature Field ◽  
Heat Flow ◽  
Field Distribution ◽  
Geothermal Energy ◽  
Thermal Conditions ◽  
Flow Density ◽  
Heat Flow Density ◽  
Temperature Field Distribution ◽  
Energy Exploitation

Abstract The contribution presents the results acquired both by direct cognitive geothermic methods and by modelling approaches of the lithosphere thermal state in the region of the Transcarpathian depression and surrounding units. The activities were aimed at the determination of the temperature field distribution and heat flow density distribution in the upper parts of the Earth’s crust within the studied area. Primary new terrestrial heat flow density map was constructed from values determined for boreholes, from their interpretations and from newest outcomes of geothermal modelling methods based on steady-state and transient approaches, and also from other recently gained geophysical and geological knowledge. Thereafter we constructed the maps of temperature field distribution for selected depth levels of up to 5000 m below the surface. For the construction we have used measured borehole temperature data, the interpolation and extrapolation methods, and the modelling results of the refraction effects and of the influences of source type anomalies. New maps and other geothermic data served for the determination of depths with rock temperatures suitable for energy utilization namely production of electric energy minimally by the binary cycles. Consequently the thermal conditions were used to identify the most perspective areas for geothermal energy exploitation in the region under study.

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