scholarly journals Influences of temperature-dependent thermal conductivity on surface heat flow near major faults

2013 ◽  
Vol 40 (15) ◽  
pp. 3868-3872 ◽  
Author(s):  
Byung-Dal So ◽  
David A. Yuen
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Surface Heat ◽  
Temperature Dependent ◽  
Surface Heat Flow ◽  
Temperature Dependent Thermal Conductivity

Heat production and thermal conductivity of rocks from the Pikwitonei–Sachigo continental cross section, central Manitoba: implications for the thermal structure of Archean crust

1987 ◽  
Vol 24 (8) ◽  
pp. 1583-1594 ◽  
Author(s):  
David M. Fountain ◽  
Matthew H. Salisbury ◽  
Kevin P. Furlong
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Cross Section ◽  
Heat Production ◽  
Thermal Structure ◽  
Granulite Facies ◽  
Surface Heat ◽  
Gamma Ray Spectrometry ◽  
Surface Heat Flow ◽  
Greenstone Belts

The Pikwitonei and Sachigo subprovinces of central Manitoba provide a cross-sectional view of the Superior Province crust. In cross section, the upper to mid-level crust is composed of synformal greenstone belts surrounded by tonalitic gneisses, both of which are intruded by granitoid plutons. This crustal structure persists downward into the granulite facies, where keels of the greenstone belts can be found. To constrain thermal models of the crust, we measured heat production and thermal conductivity in 60 rocks from this terrain using standard gamma-ray spectrometry and divided bar techniques. Large vertical and lateral heterogeneities in heat production in the upper crust are evident; heat production is high in granites and metasedimentary rocks, intermediate in tonalite gneisses, and low in the portions of greenstone belts dominated by mafic meta-igneous rocks. In the deeper granulite facies rocks, heat production decreases by a factor of two in the tonalitic gneisses and remains low in the high-grade mafic rocks. When applied to the Pikwitonei–Sachigo crust cross section, the laboratory data here do not support step function or exponential models of the variation of heat production with depth. However, estimates of surface heat flow and surface heat production for various sites in the crustal model yield the well-known linear relationship between surface heat production and surface heat flow observed for heat-flow provinces for both one- and two-dimensional models. This demonstrates that determinations of heat production with depth based on inversion of the linear heat-production–heat-flow relationship are nonunique.

scholarly journals Subsurface temperature from seismic reflection data: application to the post break up sequence offshore Namibia

2021 ◽  
Author(s):  
Arka Dyuti Sarkar ◽  
Mads Huuse
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Seismic Reflection ◽  
Surface Heat ◽  
Passive Margin ◽  
Petroleum Exploration ◽  
Subsurface Temperature ◽  
Seismic Reflection Data ◽  
Surface Heat Flow ◽  
Subsurface Temperatures

Accurate estimations of present-day subsurface temperatures are of critical importance to the energy industry, in particular with regards to geothermal energy and petroleum exploration. This paper uses seismic reflection observations of bottom-simulating reflections and subsurface velocities coupled with an empirical velocity to thermal conductivity transform to estimate subsurface temperature in a process dubbed reflection seismic thermometry. The case study is a frontier passive margin extending from the shelf edge to deep water in the central Lüderitz Basin, offshore Namibia. The bottom simulating reflector is used to derive surface heat flow. The thermal conductivity model was applied to seismic processing velocities to determine the subsurface thermal conductivity. Knowledge of surface heat flow and thermal conductivity structure allowed us to estimate subsurface temperatures across the study area. The results suggest the Lüderitz Basin has a working hydrocarbon system with the inferred Aptian Kudu source interval within the gas generation window.

Heat flow in the Uinta Basin determined from bottom hole temperature (BHT) data

Geophysics ◽  
1984 ◽  
Vol 49 (4) ◽  
pp. 453-466 ◽  
Author(s):  
David S. Chapman ◽  
T. H. Keho ◽  
Michael S. Bauer ◽  
M. Dane Picard
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Thermal Resistance ◽  
Geothermal Gradient ◽  
Surface Heat ◽  
Subsurface Temperature ◽  
The South ◽  
Uinta Basin ◽  
Surface Heat Flow ◽  
Bottom Hole

The thermal resistance (or Bullard) method is used to judge the utility of petroleum well bottom‐hole temperature data in determining surface heat flow and subsurface temperature patterns in a sedimentary basin. Thermal resistance, defined as the quotient of a depth parameter Δz and thermal conductivity k, governs subsurface temperatures as follows: [Formula: see text] where [Formula: see text] is the temperature at depth z=B, [Formula: see text] is the surface temperature, [Formula: see text] is surface heat flow, and the thermal resistance (Δz/k) is summed for all rock units between the surface and depth B. In practice, bottom‐hole and surface temperatures are combined with a measured or estimated thermal conductivity profile to determine the surface heat flow [Formula: see text] which, in turn, is used for all consequent subsurface temperature computations. The method has been applied to the Tertiary Uinta Basin, northeastern Utah, a basin of intermediate geologic complexity—simple structure but complex facies relationships—where considerable well data are available. Bottom‐hole temperatures were obtained for 97 selected wells where multiple well logs permitted correction of temperatures for drilling effects. Thermal conductivity values, determined for 852 samples from 5 representative wells varying in depth from 670 to 5180 m, together with available geologic data were used to produce conductivity maps for each formation. These maps show intraformational variations across the basin that are associated with lateral facies changes. Formation thicknesses needed for the thermal resistance summation were obtained by utilizing approximately 2000 wells in the WEXPRO Petroleum Information file. Computations were facilitated by describing all formation contacts as fourth‐order polynomial surfaces. Average geothermal gradient and heat flow for the Uinta Basin are [Formula: see text] and [Formula: see text], respectively. Heat flow appears to decrease systematically from 65 to [Formula: see text] from the Duchesne River northward toward the south flank of the Uinta Mountains. This decrease may be the result of refraction of heat into the highly conductive quartzose Precambrian Uinta Mountain Group. More likely, however, it is related to groundwater recharge in late Paleozoic and Mesozoic sandstone and limestone beds that flank the south side of the Uintas. Heat flow values determined for the southeast portion of the basin show some scatter about a mean value of [Formula: see text] but no systematic variation.

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