What is Heatflow?

The term ‘geothermal heatflow’ refers to the thermal energy that dissipates constantly from its sources within the earth to the surface, either by convection or conduction. Geothermal heat is the driving force for a variety of multi-scale geologic processes taking place in the earth’s crust e.g. plate tectonics. It is also driving chemical reactions like the thermal degradation of organic matter, which leads to hydrocarbon (oil and gas) formation. The internal temperature of the earth increases with depth. Near the surface, the average geothermal gradient is relatively constant with on average 30 K for every kilometer of depth. However, there are also places where it can be higher e.g. along mid-ocean ridges or mantle plumes.

How is heatflow determined?

Even though called heatflow measurements, heatflow itself is not measured directly. But based on the assumption, that heat conduction is the dominant transport process through the earth´s crust, and conductive heatflow occurs in the direction of decreasing temperature, heatflow can be calculated as the product of the vertical thermal gradient and thermal conductivity (Fouriers law). If however other mechanisms like heat advection are involved (for example fluid flow processes), heat transport may be characterized by non-linear thermal gradients and also occur horizontally.

What is the use of heatflow measurements?

In the field of petroleum geology heatflow measurements are essential in the exploration of new oil and gas reservoirs, as they provide critical constraints for sedimentary basin modeling and aid in thermal maturity calculations. Heatflow measurements also enable stability analysis of gas hydrate deposits.

The booming offshore wind energy market has opened a new field of activity for heatflow measurements, as in particular thermal conductivity values provide useful information for estimating the dissipation mechanisms of thermal energy and also the environmental impact of power cables.

Read our brochures for detailed information:

“Heatflow” brochure “Prediction of Sediment Temperatures” brochure

TRT measurements Off-/Near-/Inshore Holland – cooperation with MSH

This autumn, FIELAX has gathered data for two cable route projects with Marine Sampling Holland (www.marinesamplingholland.nl). We have measured a total of more than 100 profiles of temperature and TRT (thermal resistivity) data offshore Holland as well as in the Ijsselmeer. As the requirement was high resulotion profiling to a sub-bottom-depth of >6m, special coiled sensor tubes with a total length of 8m were manufactured. Read more

TRT measurements in tidal seas

Since spring this year, FIELAX performs TRT measurements in tidal seas down to 6m below sea floor. The picture shows the installation of a 3,5m sensor string. The whole equipment can be transported 'per pedes' through the Wadden Sea.

World Premiere: HeatFlow measurements at great depths (10.000m)

10.000m equates to 1000bar - that's quite a lot.

The mean depth of the world ocean is 'only' about 3.700m but the great deep sea plains are below that and the tectonic trenches often reach water depths well in the 7-8-thousand meter range. However, so far only 12 locations are known where the ocean depth exceeds 10.000m from which the deepest is the so-called Vityaz Deep (a part of the Challenger Deep, cf. https://en.wikipedia.org/wiki/Challenger_Deep).

We proudly announce that we have managed to modify our well-established measuring system to resist 1000bar of outer pressure and herewith present the new model HeatFlowProbe UD (UD for Ultra Deep).You are invited to find out about heat flow in the greatest depths ofthe ocean (as long as your wire is long enough...).