A REVIEW OF NOTABLE INTELLECTUAL PROPERTY FOR IN SITU ELECTROMAGNETIC HEATING OF OIL SHALE
Dwight E. Kinzer
Quasar Energy LLC
Introduction
Electromagnetic in situ heating may be the most effective, reliable, efficient, and
environmentally friendly means for heating and pyrolyzing kerogen within a
formation compared to slow thermal (convection) heat transfer or chemical
conversion processes that must infiltrate low-permeability rock. This promising
technology has been researched, patented, and field-tested over the last fifty
years by major oil companies, research institutions, large corporations, small
companies, and private individuals.
Resistive (Ohmic or Joule), radio frequency, and microwaves have been utilized in
various apparatuses and methods of in situ electromagnetic heating of oil shale
for pyrolyzing kerogen to capture shale oil. These methods have included
volumetric, selective, rapid, and controlled heating that are sometimes combined
with critical fluids or carbon sequestration. This poster summarizes the notable
intellectual property of in situ electromagnetic heating of oil shale. Categories
presented include radio frequency heating, resistive heating, microwave heating,
and downhole tool.
Radio Frequency Heating
At least thirty-seven patents have been granted for in situ radio frequency heating
of oil shale, more than any other category of electromagnetic heating. Radio
frequency can instantly radiate molecule excitement from tens to hundreds of
meters within an oil shale formation. RF is best suited on formations that have
minimal amounts of connate water because water has high dielectric properties
that absorb the signal.
Laboratory tests have shown a skin depth of 12 meters for an 8 MHZ radio
frequency signal in oil shale with 84% moisture; this distance increases to 150500 meters at 0% moisture (Sweeney et al.).
RF frequency ranges from 3 KHz to 300 MHz. Two methods are available to apply
radio frequency dielectric heating to a formation: 1) two or more emitters that are
out of phase with each other (typically two or three emitters that are 180° out of
phase), or 2) a single emitter in which the signal is grounded to the formation.
…Capture And Sequester Of CO2… Extraction Of Hydrocarbon Fuels… and Critical
Fluids
Raytheon Company
Claim Summary: Injecting CO2 as a critical fluid and a catalyst into a well, applying in situ
heat (RF), obtaining, converting, and processing CO2, CH4, oil, steam/water, and vapors
from well.
7,461,693
…Using Electrical Energy And Critical Fluids
Brian C. Considine et al.
4,438,816 (expired)
Processing Of Hydrocarbons…
… Recovery Of Hydrocarbons From Oil Shale
Dwight E. Kinzer
Quasar Energy LLC
Claim Summary: Adjust the RF frequency to match the resonance frequency for most
recently sensed temperature.
7,115,847
Raytheon Company
Claim Summary: 1) In situ transmit electrical energy (RF) to fossil fuels to a predetermined
temperature, 2) inject critical fluids (CO2 with N2O or O2) with reactants or catalysts, 3)
RF-heat fossil fuels and critical fluids to a predetermined temperature.
Reference
Sweeney, Jerry J., Roberts, Jeffery J., and Harben, Philip E. 2007. Study of
Dielectric Properties of Dry and Saturated Green River Oil Shale. Energy
& Fuels, 21(5):2769-2777.
Peter Urban et al.
UOP Inc.
Claim Summary: Heating oil shale in the presence of a gas selected from the group
consisting of nitrogen, hydrogen sulfide, ammonia, mercaptan, hydrocarbon, sulfur dioxide,
carbon monoxide, carbon dioxide, water and mixtures thereof at subcritical conditions of
selected gas and at a temperature of from about 650 F. to about 825 F. to produce a
solvent extractable material and to liberate a first portion of the hydrocarbon.
Resistive Heating
Microwave Heating
Resistive heating, also known as Ohmic heating and Joule heating, is the process
by which the passage of an electric current through a conductor releases heat.
Microwave heating is similar to radio frequency heating in that they both subject
the oil shale to an electromagnetic wave that causes the molecules to oscillate,
thereby generating heat. However, the microwave frequency range is 300 MHz to
300 GHz, which produces a significantly shorter wavelength that provides an
attenuation distance that is typically between a few inches to several feet.
At least fourteen patents have been granted for in situ resistive heating of oil
shale. Most of the resistive heating patents include injecting an electrolyte or
conductive fluid into the formation.
At least eleven patents have been granted for in situ microwave heating of oil
shale.
Variable Frequency Dielectric Heating
Dwight E. Kinzer
Quasar Energy LLC
Claim Summary: Determine, by operation of computer, a relationship between the most
recently sensed impedance of hydrocarbonaceous material and the heating rate of the
targeted chemical compositions; and adjust the heating rate of the targeted chemical
composition based on the temperature and impedance relationship.
7,109,457
… Automatic Impedance Matching Radio Frequency Dielectric Heating
Dwight E. Kinzer
Quasar Energy LLC
Claim Summary: Automatically matching the effective load impedance to the output
impedance of a signal generating unit by a.) adjusting the frequency at which the radio
frequency waveform is applied , or b.) tuning a tunable impedance matching network such
that the effective adjusted load impedance is approximately equal to the output impedance
of the signal generating unit, or both a.) and b.) above.
7,091,460
… Variable Frequency Automated Capacitive Radio Frequency Dielectric Heating
Dwight E. Kinzer
5,236,039 (expired)
Balanced-Line RF Electrode System For Use In RF Ground Heating To Recover Oil
From Oil Shale
General Electric Co.
Shell Oil Co.
Claim Summary: A conductive electrode located in the hydrocarbon bearing layer having a
length related to the radio frequency signal and adapted for radiating energy into said
hydrocarbon bearing layer for causing shade oil to be extracted; a plurality of matching
elements, each matching element coupled, respectively, between each respective
electrode and a respective coaxial line for maximizing radiation emitted by the electrodes
when they receive the radio frequency signal; and a plurality of producer wells adapted for
collecting the extracted shale oil.
“The advantages of the present invention are:
1. The voltage relative to ground for the balanced-line is half that of the triplate device [for
triplate device, see Bridges RE 30,738], leading to a safer installation;
2. The required power per well for the triplate device is twice that of the balanced-line RF
array;
3. The maximum temperature at the production wells is significantly hotter for the triplate
device (460 C. vs. 350 C.), leading to thermal cracking of liquid hydrocarbons;
4. There can be RF leakage outside the triplate device to distant grounds, as well as
significant current return to the grounded outer conductor of the coaxial line. This
leakage will not occur with the balanced-line RF array; and
5. There are 8.83 holes to be drilled per acre in the RF pattern compared with 16.62 in
the thermal conduction pattern.”
Poster Author Comments: Automatic impedance matching, automatic impedance matching
with automatic tuning, variable frequency, and automatic impedance matching with
variable frequency will further increase the efficiency of a Balanced-Line RF system and
maybe more importantly provide robust controls that prevent arcing and over-heating
during pyrolysis.
7,331,385
4,396,062 (expired)
...Time-Domain Tracking Of High-Speed Chemical Reactions
Magdy F. Iskander
Claim Summary: An apparatus for time-domain tracking high-speed chemical reactions
comprising: radiating RF energy into a volume wherein chemical reaction is to occur; probe
means in the volume to measure complex permittivity in the volume; and feedback means
driven by the probe means to control the RF means by adjusting the frequency of the RF
means as a function of relaxation frequency as determined by permittivity measured by the
probe means.
4,373,581 (expired)
…RF Heating Of Hydrocarbonaceous Formations Including An Impedance Matching
Technique
Robert L. Toellner
Methods of treating a subterranean formation to convert organic matter into
producible hydrocarbons
University of Utah
Halliburton Company
William A. Symington et al.
ExxonMobil Upstream Research Co.
Claim 1: A method of treating a subterranean formation that contains solid organic matter, said
method comprising:
a) providing one or more wells that penetrate a treatment interval within the
subterranean formation;
b) establishing at least one fracture from at least one of the wells, whereby the fracture
intersects at least one of the wells;
c) placing electrically conductive material in the fracture; and
d) passing electric current through the fracture such that the current passes through at
least a portion of the electrically conductive material and sufficient heat is generated
by electrical resistivity within the portion of the electrically conductive material to
pyrolyze at least a portion of the solid organic matter into producible hydrocarbons.
4,495,990 (expired)
Apparatus for passing electrical current through an underground formation
4,301,865 (expired)
In Situ RF Selective Heating Process…
Raymond S. Kasevich et al.
Raytheon Company
Claim Summary: Applying directional radiation patterns at a frequency between 100 KHZ to
1000 MHZ to a formation from a radiation system comprising a plurality of radiators spaced
apart in body by a distance greater than a tenth of a wavelength in body at frequency at an
intensity which heats organic compounds in a region to a temperature in the range
between 200 C and 500 C.
RE 30,738 (expired)
...In Situ Heat Processing Of Hydrocarbonaceous Formations
Jack Bridges et al.
IIT Research Institute
Claim Summary: A plurality of conductive means inserted in formations and bounding a
particular volume of formations; electrical excitation means for establishing alternating
electric fields in volume; the frequency of excitation means being selected as a function of
the volume dimensions so as to establish substantially non-radiating electric fields which
are substantially confined in volume; whereby volumetric dielectric heating of the
formations will occur to effect approximately uniform heating of volume.
3,522,842 (expired)
…Spontaneous Emission Of Radiation
Robert V. New
Summary: Introducing into an oil bearing reservoir a heated gas (i.e., helium, neon, argon,
krypton, xenon, radon) and in addition nitrogen and carbon dioxide, and/or mixtures of two
or more thereof, and causing such gases to be excited by electromagnetic waves, in a
manner to emit infra-red radiation. Poster Author Comments: Borrowing from ruby laser
technology of its time, this patent combines CO2 with gases and RF heating to radiate
infra-red waves as the gases pass through the formation.
5,082,054 (expired)
In-situ tuned microwave oil extraction process
Abstract: Continuous variations of impedance, of the type encountered during the heating of
the formation, may be matched in unambiguously defined Smith chart regions by varying
two of the three reactances to minimize reflected power from the transmission line.
Quasar Energy LLC
Claim Summary: Automatically adjusting the effective load impedance to match the output
impedance of a signal generating unit.
William A. Edelstein
Harold J. Vinegar et al.
7,562,708
Brian C. Considine et al.
7,312,428
Dwight Kinzer
E-mail: [email protected]
Cell: 701.388.3645
Charles H. Titus et al.
Electro-Petroleum, Inc.
Claim Summary: Electrical current from a first terminal of a D.C. power source is passed
through an underground formation to a cathode remote from the anode which is
connected to the second terminal of the power source, the anode comprising: a
containment positioned proximate to the underground formation; a first layer of generally
wet conduction material suitable for ion conduction positioned in the containment to
enhance conduction between the anode and the underground formation, the containment
permitting conduction between the first layer of conduction material and the underground
formation; conductor means connected with the first terminal of the power source for
providing a flow of electrical current for the anode; and a second layer of generally dry
conduction material positioned in the containment in contact with the first layer of
conduction material and generally surrounding the conductor means to isolate the
conductor means from the first layer of material and the underground formation to prevent
deterioration of the conductor means by electrolysis; whereby electrical current from the
power supply is passed through the conductor means, the second layer and the first layer
and into the underground formation.
3,428,125 (expired)
Hydro-Electropyrolysis of Oil Shale In Situ
Anoosh I. Kiamanesh
Summary of Invention: The invention is a process of devising and applying an
electromagnetic irradiation protocol customized to each reservoir. This protocol controls
frequency, intensity, wave form, duration and direction of irradiation of electromagnetic
energy in such a way that it generates and utilizes the desired combination of effects
defined as microwave flooding, selective heating, molecular cracking and plasma torch
activation, under controlled conditions in time and space within the reservoir.,
comprising:
a) taking at least one core sample of the reservoir;
b) testing the core sample to determine the respective amounts of constituent
hydrocarbons in the petroleum, the molecular resonance frequencies of the
hydrocarbons, the change in properties and responses to various frequencies,
intensities, durations, and wave forms of electromagnetic field energy applied to the
hydrocarbons;
c) developing a strategy for the application of electromagnetic energy to the reservoir
based on the results of core sample tests and geophysical data and water content of
the reservoir;
d) excavating at least one canal or well in the reservoir for draining water from the
reservoir and collecting hydrocarbons from the reservoir;
e) generating electromagnetic waves of mainly microwave frequency range and
deploying the electromagnetic waves to the reservoir to irradiate the hydrocarbons
within the reservoir and thereby produce one or more of microwave flooding, plasma
torch, molecular cracking and selective heating of pre-determined hydrocarbons in
the reservoir, to increase temperature and reduce viscosity of the hydrocarbons in the
reservoir; and
f) removing the treated hydrocarbons from the underground canal or well.
Downhole Tool
At least four patents have been granted for an electromagnetic heating applicator
downhole tool, of which three are by Texaco specifically for oil shale.
4,553,592 (expired)
Method of protecting an RF applicator
Mark D. Looney et al.
H. W. Parker
Phillips Petroleum Company
Claim 1: A method for producing hydrocarbons from oil shale formations in situ penetrated by
at least two wells which comprises fracturing said formation to increase the overall flow
permeability between the wells through the formation, introducing an aqueous electrolyte
into the formation, imposing a potential drop across the formation to promote current
flow there through and consequent heating thereof and maintaining sufficient pressure
on the formation to retain an aqueous electrolyte conductive phase within the formation.
Texaco Inc.
Abstract: A method which protects an RF applicator during the in situ RF retorting of a
hydrocarbon stratum from a borehole which traverses the hydrocarbon stratum including
lining that portion of the borehole traversing the hydrocarbon stratum with a nonconductive high temperature material.
4,660,636 (expired)
Protective device for RF applicator in in-situ oil shale retorting
Herbert A. Rundell et al.
Texaco Inc.
Abstract: In the in situ retorting of oil shale using radio frequency electrical energy, an
applicator is inserted into a borehole and energized at a radio frequency. A protective
device protects the applicator from expansion of the oil shale formation.