Optimum antenna-like exciters for heating earth media to recover thermally responsive constituents
AssigneeIIT Research Institute
InventorJack E. Bridges
Life of this patent
Estimating the term…
Abstract
Optimum antenna-like exciters for heating earth media which may be used to recover hydrocarbons. A high frequency power supply is connected to an exciter emplaced in the subsurface formation which radiates high frequency power. The exciters include one or more conducting cylinders which make up monopole and dipole antenna-like apparatus. Substantially uniform heating of the subsurface formation is provided thus suppressing excessive heating of edge and power input regions. The equal distribution of electric fields eliminates intense electric fields which would normally exist thus mitigating excessively heated regions and providing substantially uniform heating of the subsurface formation.
Claims22
An apparatus for high frequency in situ heating of subsurface formations for recovery of thermally responsive constituents, comprising:
- high frequency power supply means, and
- an exciter emplaced in said subsurface formation disposed to radiate said high frequency power, said exciter comprising:
- a first conducting cylinder having edges,
- a second conducting cylinder having edges and being positioned coaxially to said first conducting cylinder so there remains a gap therebetween, and
- gap insulation means for electrically insulating said gap between said first and second conducting cylinders for suppressing excessively heated regions near the edges and a power input point of said exciter and thereby providing substantially uniform heating of said subsurface formation.
A method of suppressing intense electric fields and excessively heated regions of an exciter having a plurality of poles, the excessively heated regions being between said poles in an apparatus for high frequency in situ heating of subsurface formations for recovery of thermally responsive constituents, comprising the steps of:
- applying a high frequency signal to said exciter,
- equally distributing the electric field across the distance between the poles with elements providing electrical reactance, thereby mitigating intense electric fields and excessively heated regions around the exciter between the poles providing substantially uniform heating of said subsurface formation,
- measuring any of the set of temperature, impedance, of electric field strength in the area between said poles, and
- adjusting any of the set of the frequency applied to said exciter, the power applied to said exciter or the exciter impedance in response to said measurements to limit heating in said area.
Dependencies are inferred from the claim text.