Wind-heated molten salt as a thermal buffer for producing oil from unconventional resources

Abstract

Embodiments of the present invention relate to heat transfer fluids (e.g. molten-salt) as a thermal buffer for heating, by thermal energy derived from wind-generated electricity, at least one of (i) a subsurface hydrocarbon-containing formation or (ii) a bed of hydrocarbon-containing rocks. During times when wind is plentiful, wind electricity is used to heat the heat transfer fluid—e.g. by means of an electrically resistive heater immersed in the heat transfer fluid. At any time, thermal energy from the wind electricity may be transferred to the hydrocarbon-containing rocks or subsurface formation by the heat transfer fluid. In some embodiments, the fluid is heated both by wind-generated electricity and by solar radiation. Some embodiments relate to a subsurface molten salt heater (e.g. powered by wind-generated electricity) having a non-thermally insulation portion through which molten salt flows. The heater is configured to maintain a temperature of the circulating molten salt, throughout the substantially non-thermally-insulated portion, at a temperature significantly above a melt temperature of the molten salt.

Description

FIELD OF THE INVENTION[0001]The inventions relates to methods and apparatus for heating a subsurface formation and / or a bed of rocks using electricity generated by wind.BACKGROUND AND RELATED ART[0002]The world's supply of conventional crude oil is declining, and discoveries and access to new resources for are becoming more challenging. To supplement this decline and to meet the rising global demand, unconventional oils are being produced and brought to market. Sources of unconventional oils include tar sands, oil shale formations, heavy oil formations and coal formations.[0003]Despite the need for oil derived from unconventional sources, many policy-makers are concerned about the collateral CO2 footprint associated with both the production of hydrocarbon fluids from unconventional sources and the exploitation of such hydrocarbon fluids.[0004]In order to reduce the output of greenhouse gases associated with production of oil from unconventional sources, U.S. Pat. No. 7,104,319 discl...

AI Technical Summary

Benefits of technology

[0015]One advantage of using wind-generated electricity to indirectly heat the subsurface formation via a heat transfer fluid (i.e. as opposed to only powering subsurface electric heaters by wind electricity) is that it is relatively easy to couple wind and solar as multiple sources of intermittent power to heat the unconventional resources (i.e. a hydrocarbon subsurface formation or a bed of hydrocarbon-containing rocks) so as to produce oil therefrom. If the availability of energy from wind and solar sources peaks at different times, it may be possible to exploit

Problems solved by technology

The world's supply of conventional crude oil is declining, and discoveries and access to new resources for are becoming more challenging.

One of the key issues associated with wind and solar power sources are their inherent intermittent nature.

This may, for example, increase the amount of time required to produce hydrocarbon fluids from the unconventional resource, reducing

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