U.S. patent application number 12/365750 was filed with the patent office on 2009-11-19 for radio and microwave treatment of oil wells.
This patent application is currently assigned to BJ Services Company. Invention is credited to Harold L. Becker.
Application Number | 20090283257 12/365750 |
Document ID | / |
Family ID | 41315034 |
Filed Date | 2009-11-19 |
United States Patent
Application |
20090283257 |
Kind Code |
A1 |
Becker; Harold L. |
November 19, 2009 |
RADIO AND MICROWAVE TREATMENT OF OIL WELLS
Abstract
A method including exposing a substance to a first type of
electromagnetic waves generated by a first device. The frequency of
the first type of electromagnetic waves is in the radio frequency
range and the device consumes no more than about 1,000 Watts of
power. The exposure takes place for a period of time and at a
frequency sufficient to detectably alter at least one physical
property of the substance as it existed prior to the exposure.
Inventors: |
Becker; Harold L.; (Tomball,
TX) |
Correspondence
Address: |
McGLINCHEY STAFFORD, PLLC;Attn: IP Group
301 Main Street, 14th Floor
Baton Rouge
LA
70802
US
|
Assignee: |
BJ Services Company
Houston
TX
|
Family ID: |
41315034 |
Appl. No.: |
12/365750 |
Filed: |
February 4, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61054157 |
May 18, 2008 |
|
|
|
Current U.S.
Class: |
166/248 |
Current CPC
Class: |
E21B 43/2401
20130101 |
Class at
Publication: |
166/248 |
International
Class: |
E21B 43/00 20060101
E21B043/00 |
Claims
1. A method comprising exposing a substance to a first type of
electromagnetic waves generated by a first device, the frequency of
the first type of electromagnetic waves being in the radio
frequency range and the device consuming no more than about 1,000
Watts of power, the exposure taking place for a period of time and
at a frequency sufficient to detectably alter at least one physical
property of the substance as it existed prior to the exposure.
2. The method according to claim 1, wherein the frequency of the
first type of electromagnetic waves is in the range of about 1 to
about 900 MHz.
3. The method according to claim 2, wherein the frequency of the
first type of electromagnetic waves is in the range of about 1 to
about 100 MHz.
4. The method according to claim 3, wherein the frequency of the
first type of electromagnetic waves is in the range of about 30 to
about 50 MHz.
5. The method according to claim 1 further comprising transmitting
the first type of electromagnetic waves to the substance from a
first antenna.
6. The method according to claim 5 wherein the first antenna is a
well head assembly, casing, and tubing.
7. The method according to claim 5 wherein the first antenna is a
dipole antenna or a monopole antenna, the first antenna being
disposed within (i) an annulus of a well bore comprising casing and
tubing; (ii) a pipeline comprising hydrocarbonaceous material; or
(iii) a tank comprising hydrocarbonaceous material.
8. The method according to 6 or 7 further comprising adjusting a
load impedance of the first antenna to match an output impedance of
the first device.
9. The method according to claim 4 or 5, wherein the frequency of
the first type of electromagnetic waves is in the range of about 40
to about 50 MHz.
10. A method according to claim 1, wherein the step of exposing the
substance to the first type of electromagnetic waves is carried out
at least while concurrently exposing the substance to a second type
of electromagnetic waves generated by a second device which
together with the first device, consumes no more than about 1,000
Watts of power, wherein the frequency of the second type of
electromagnetic waves is in the microwave frequency range.
11. The method according to claim 10, wherein the frequency of the
second type of electromagnetic waves is in the range of about 20 to
about 40 GHz.
12. The method according to claim 11, wherein the frequency of the
second type of electromagnetic waves is in the range of about 20 to
about 30 GHz.
13. The method according to claim 12, wherein the frequency of the
first type of electromagnetic waves is in the range of about 40 to
about 50 MHz.
14. The method according to claim 10 or 13, further comprising
transmitting the first type of electromagnetic waves to the
substance from a first antenna.
15. The method according to claim 10 or 13, further comprising
transmitting the second type of electromagnetic waves to the
substance from a second antenna.
16. The method according to claim 15 wherein the second antenna is
a well head assembly, casing, and tubing.
17. The method according to claim 15 wherein the second antenna is
a dipole antenna or monopole antenna, the second antenna being
disposed within (i) an annulus of a well bore comprising casing and
tubing; (ii) a pipeline comprising hydrocarbonaceous material; or
(iii) a tank comprising hydrocarbonaceous material.
18. The method according to claim 14 further comprising adjusting a
load impedance of the first antenna to match an output impedance of
the first device.
19. The method according to claim 10 or 13, further comprising
transmitting the first type of electromagnetic waves to the
substance and the second type of electromagnetic waves to the
substance from a single antenna.
20. A method comprising transmitting electromagnetic waves at one
or more radio frequencies through at least one first antenna (i)
connected to, or disposed within, a wellhead assembly, well casing
or well tubing of a hydrocarbon well; (ii) disposed within a
pipeline comprising hydrocarbonaceous material; or (iii) disposed
within a tank comprising hydrocarbonaceous material, the radio
frequencies each being in the range of about 1 to about 900 MHz and
amplified to no more than about 1000 Watts of total power, wherein
the process is conducted for a time sufficient to modify at least
one physical property of a substance within the well, pipeline, or
tank while consuming no more than about 1000 Watts of power.
21. The method according to claim 20, wherein the radio frequency
is in the range of about 40 to about 50 MHz.
22. The method according to claim 21 further comprising generating
the electromagnetic waves from a signal generating unit.
23. The method according to claim 22 further comprising adjusting a
load impedance of the first antenna to match an output impedance of
the signal generating unit.
24. The method according to claim 20 further comprising
transmitting electromagnetic waves at a microwave frequency of at
least about 24 GHz through at least one second antenna (i)
connected to, or disposed within, the wellhead assembly, well
casing or well tubing of the well (ii) disposed within a pipeline
comprising hydrocarbonaceous material; or (iii) disposed within a
tank comprising hydrocarbonaceous material, the microwave frequency
being amplified to consume energy at a rate of no more than about 8
Watts, wherein the first antenna and the second antenna may be
separate antennae or may be combined into the form of a single
antenna, wherein the process is conducted for a time sufficient to
modify at least one physical property of a substance within the
well, pipeline, or tank while consuming no more than about 1000
Watts of power.
25. The method according to claim 23 further comprising
transmitting electromagnetic waves at a microwave frequency of at
least about 24 GHz through at least one second antenna (i)
connected to, or disposed within, the wellhead assembly, well
casing or well tubing of the well (ii) disposed within a pipeline
comprising hydrocarbonaceous material; or (iii) disposed within a
tank comprising hydrocarbonaceous material, the microwave frequency
being amplified to consume energy at a rate of no more than about 8
Watts, wherein the first antenna and the second antenna are
separate antennae, wherein the process is conducted for a time
sufficient to modify at least one physical property of a substance
within the well, pipeline, or tank while consuming no more than
about 1000 Watts of power.
26. The method according to claim 1, wherein the at least one
physical property comprises the effective permeability ratio of
hydrocarbon to water for at least a portion of a well
formation.
27. The method according to claim 26, wherein the ratio of
hydrocarbon permeability to water permeability for at least a
portion of the well formation is increased.
28. The method according to claim 27, wherein the ratio of
hydrocarbon permeability to water permeability for at least a
portion of the well formation is increased by a factor of 2 or
more.
29. The method according to claim 27, wherein the ratio of
hydrocarbon permeability to water permeability for at least a
portion of the well formation is increased by a factor of 4 or
more.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/054,157, filed May 18, 2008, the disclosure of
which is incorporated herein by reference.
TECHNICAL FIELD
[0002] This invention relates to a method for altering physical
properties of hydrocarbonaceous material through the application of
electromagnetic waves, specifically radio waves or a combination of
radio waves and microwaves.
THE INVENTION
[0003] The present invention provides, amongst other things, a
system for, and a method of, altering the composition of a
hydrocarbonaceous material by exposing the hydrocarbonaceous
material to combination of electromagnetic waves for a time and
under conditions sufficient to alter the molecular structure or a
physical property of at least one component of the
hydrocarbonaceous material. As used herein, the term physical
property may include London-Van DerWal forces of induction,
hydrogen bonding, waxy paraffin solubility in crude oils, decreased
viscosity of complex fluids, and oil to water ratios in produced
crude oil etc. The exposure may be accomplished conveniently
through the use of a radio frequency (RF) generator and a RF power
amplifier, or through the use of such a RF generator and RF power
amplifier in combination with a microwave generator and microwave
amplifier combination. The invention enables rapid and economical
improvement in the production of hydrocarbon (e.g., gas and/or oil)
wells while consuming a relatively lower level of power.
[0004] In an embodiment of the present invention, provided is a
method comprising exposing a substance to a first type of
electromagnetic waves generated by a first device. The frequency of
the first type of electromagnetic waves is in the radio frequency
range and the device consumes no more than about 1,000 Watts of
power. The exposure takes place for a period of time and at a
frequency sufficient to detectably alter at least one physical
property of the substance as it existed prior to the exposure.
[0005] In another embodiment of the present invention, provided is
a process comprising transmitting electromagnetic waves at one or
more radio frequencies through at least one first antenna (i)
connected to, or disposed within, a wellhead assembly, well casing
or well tubing of a hydrocarbon well; (ii) disposed within a
pipeline comprising hydrocarbonaceous material; or (iii) disposed
within a tank comprising hydrocarbonaceous material. Each of the
radio frequencies is in the range of about 1 to about 900 MHz and
amplified to no more than about 1000 Watts of total power, wherein
the process is conducted for a time sufficient to modify at least
one physical property of a substance within the well, pipeline, or
tank while consuming no more than about 1000 Watts of power.
[0006] One system of the invention comprises a frequency generator
capable of producing frequency radio waves having a frequency of
about 1 to about 900 MHz, a RF power amplifier electrically coupled
to the radio frequency generator, a microwave frequency generator
and microwave amplifier producing microwaves, and a crude stream
conduit, wherein each of the frequency generators are disposed
proximate to at least a portion of the crude stream conduit, for
example, the wellhead of an oil or gas well. In at least one
embodiment of the present invention, the system further comprises a
low pass filter assembly coupled to the at least one of the
amplifiers wherein the low pass filter assembly filters out
frequencies produced by the radio and/or microwave frequency
generator that may interfere with commercial transmissions. It has
been found that this invention has a variety of applications,
including, but not limited to, breaking down paraffin buildup
within a well bore of an oil or gas well. This and other
applications of the invention may be carried out at relatively low
power output conditions, as noted above and as will be further
described below.
[0007] In one particular implementation of the invention, the radio
frequency generator comprises four voltage-controlled oscillators
(VCO) that are capable of producing a broad range of
electromagnetic waves. The spectrum of radio waves produced by this
particular frequency generator may include, e.g., ranges of 45-70
MHz, 60-110 MHz, 110-140 MHz, and 140-200 MHz. It should be
appreciated, however, that any commercial frequency generator may
be used that is capable of producing frequencies within a range of
about 1 MHz to about 900 MHz and capable of producing the power
output as disclosed below when used in conjunction with the RF
power amplifier. In one implementation, the microwave frequencies
are generated by a separate microwave generator and amplifier
combination powered by a fly-back & Kuk voltage control,
wherein a -8V, 3.5V, 5V, and 12V variable source may be used to
control the microwave signal. However, it should be appreciated
that any commercial microwave generator may be used that is capable
of producing frequencies in the range of about 20 GHz to about 40
GHz and capable of producing the power output as disclosed below
when used in conjunction with the microwave amplifier. For example,
the microwave frequency generator is a conventional type, such as
that which is commercially available from Phase Matrix, Inc. of San
Jose, Calif. The microwave frequencies generated by the frequency
generator in one implementation include ranges of about 19 to about
24 GHz and about 24 to about 30 GHz, wherein these frequencies are
generated and amplified with a power output of up to about 1 W. In
another implementation, the power output of the microwave amplifier
may be up to about 8 W. The output of the very high frequency
generator is fed to a RF power amplifier. The RF power amplifier
may be any commercially available amplifier capable of producing a
power output with a range of about 30 to about 1000 Watts. For
example, the RF amplifier may be one commercially available from AR
Modular RF of Bothell, Wash. The AR Modular RF unit requires only
110 V.sub.AC and produces a maximum of about 40 watts of power for
the very high RF frequencies, whereas the microwave amplifier
produces about 1 Watt for the microwave frequencies. An example of
a radio frequency generator is shown in the attached schematic
diagram (consisting of FIGS. 2A, 2B, 2C and 2D).
[0008] In another aspect of the invention, a method of altering the
composition of hydrocarbons down hole in a well is provided. This
method comprises placing the frequency generators electrically
coupled to their respective amplifiers as disclosed above proximate
to a wellhead in such a manner that the electromagnetic waves
produced by the frequency generators may be transmitted into the
well; generating a first signal from the radio frequency generator
and RF amplifier, the first signal comprising a radio frequency
electromagnetic wave; generating a second signal from the microwave
frequency generator and amplifier, the second signal comprising a
microwave frequency electromagnetic wave; and transmitting the
first signal and the second signal into the well, wherein the first
signal and the second signal alter the composition of at least one
hydrocarbon in the well.
[0009] In certain aspects of the invention, the first signal and
the second signal may be combined and transmitted into the well
simultaneously. The first signal may be a carrier wave for the
second signal, which may be the program signal. The signals may be
mixed or in certain implementations, the first signal may be
transmitted separately from the second signal.
[0010] The methods of this invention include generating a radio
frequency electromagnetic wave. A radio frequency generator may be
used to produce frequencies in the range of about 1 to about 900
MHz, and preferably, the radio frequency electromagnetic wave may
be in the frequency ranges of 45-70 MHz, 60-110 MHz, 110-140 MHz,
and 140-200 MHz, while most preferably, the radio frequencies may
be in the range of about 40 to about 50 MHz. The microwave
frequency electromagnetic wave may be in the ranges of about 19 to
about 24 GHz and about 24 to about 30 GHz. Without being bound to
theory, it is believed that the radio frequency ranges and the
microwave frequency ranges may correspond to the quantum spin level
of the nucleus and the electron, respectively. It is desirable for
each of the spin states energy levels of the nuclear protons and
electrons of hydrocarbons found in the well to be found within the
ranges of the electromagnetic radiation transmitted.
[0011] In another aspect of the present invention, a system for
altering the composition of hydrocarbons down hole in a well
comprises at least one frequency generator capable of generating
radio and microwave frequencies, a crude stream conduit, wherein at
least one of the frequency generators is disposed proximate to the
crude stream conduit. By proximate it is meant that the generator
is sufficiently close to the conduit that the output has the
desired effective on at least one hydrocarbon within the well bore.
In most cases, the distance of the generator from the conduit will
be something less than 2 meters. The crude stream conduit in this
embodiment is a well comprising a wellhead assembly, tubing, and
casing. The system further comprises an electrical conduit
connecting the frequency generator to the tubing located in the
well and a wave-guide proximate to the tubing and casing, wherein
the waveguide is inserted into an annular space therebetween. The
electrical conduit must be a coaxial cable, for example. The well
head assembly, tubing, and casing will serve as the transmitting
antenna for the 40 to 100 MHz RF signal, while the wave-guide will
be the transmitter for the microwave 24-30 GHz signal. In an
alternate embodiment, the well head assembly, tubing, and casing
will also serve as the transmitting antenna for the microwave
signal.
[0012] In yet another aspect of the present invention, a method of
altering the composition of hydrocarbons down hole in a well
comprises placing a transmitting unit (electronic component case)
comprising a RF frequency generator and a microwave frequency
generator and respective power amplifiers proximate to a crude
stream conduit. In this embodiment, the crude stream conduit is a
well comprising a wellhead assembly, tubing, and casing. The
transmitting unit may include a housing for the frequency
generators and respective amplifiers. The method further comprises
attaching an electronic conduit to the well head assembly or tubing
of the well and placing a wave-guide for the microwave frequency
generated electromagnetic waves in the annular space (between the
tubing and the casing). The electrical conduit may be a coaxial
cable, for example. The tubing and casing will be the transmitting
antenna for the 40 to 100 MHz RF, while the wave-guide will be the
transmitter for the microwave 24-30 GHz signal. A signal analyzer
or oscilloscope may be used to adjust the radio and/or microwave
signals to achieve optimal signals. The method further comprises
transmitting the radio signal and the microwave signal into the
well, wherein the radio signal and the microwave signal alter the
composition of at least one hydrocarbon in the well. The
transmitting unit may operate continuously or intermittently. In
certain embodiments of the invention, it will operate continuously
at first for a period of time (e.g., in the range of 100 to 1000
hours), but later be set to an intermittent mode (e.g., pulsing
every 1800 to 3600 seconds). The duration of operation may be more
or less than these durations, and will vary depending production
volumes upon the desired effect and the magnitude of the problem
confronted (blockage down hole, for example).
[0013] These and other embodiments, features and advantages of the
present invention will be further evident from the ensuing detailed
description, including the appended figures and claims.
SUMMARY OF THE FIGURES
[0014] FIG. 1 is a graphical representation of data obtained from
the GC and MS analysis of Gulf wax diluted in diesel samples before
and after treatment in accordance with the present invention, with
an overlay graph showing the difference, in area percent, for each
carbon chain length present in the sample after treatment in
accordance with the invention.
[0015] FIGS. 2A, 2B, 2C and 2D, together, are a schematic diagram
of the circuitry of a frequency generator of one embodiment of the
present invention.
[0016] FIGS. 3A and 3B are a graphical representation of data
obtained from the GC and MS analysis of docosane diluted in diesel
samples before and after treatment in accordance with the present
invention, showing the difference, in area percent, for each carbon
chain length present in the sample before and after treatment in
accordance with the invention.
[0017] FIG. 4 is a graphical representation of data obtained from
the gas chromatography analysis of a Well #174 before and after
treatment in accordance with the present invention, showing the
difference, in area percent by gas chromatography, for the
percentage of higher carbon fractions produced.
[0018] FIG. 5 is a block diagram of one embodiment of the present
invention of the system used to transmit radio and/or microwave
transmissions to hydrocarbonaceous material. The block diagram
includes the signal generating unit, the amplifier, the SWR meter,
the impedance matching network, and the dipole antenna or well head
assembly.
[0019] FIG. 6 is a Summary of Effective Permeability Results as
disclosed in Example 8.
[0020] Like reference indicators are used to refer to like parts or
steps described amongst the several figures.
FURTHER DETAILED DESCRIPTION OF THE INVENTION
[0021] Without being bound by theory, it is believed that this
invention takes advantage of the spin properties of atoms and
molecules. Proton or hydrogen spin state (1=1/2) is perturbed by
electromagnetic radiation in the 3 to 100 MHz range (NMR or Nuclear
Magnetic Resonance), and electron spin is perturbed by
electromagnetic waves in the 24 to 30 GHz range (ESR or Electron
Spin Resonance). If the energy supplied by the radiation is
sufficient to alter the spin states of one or both the proton and
the electron then the promoted spin states of each will act to
accommodate or discourage hydrogen bonding or cleavage. In addition
to bonding, radicals formed in the process of going from the ground
state to an elevated energy state are capable of abstracting
hydrogen from carbon chains and leaving a point of attack in the
molecule. If the attack takes place on adjacent carbons double
bonds can result, but the attacks do not stop at this stage; they
go on and carbon-carbon bond cleavage can result. This can take
place even if the radiation is of very low energy (e.g., 31 total
Watts) with the process of cleaving and isomerization occurring
because of quantum tunneling. This then means that although
carbon-carbon bond cleavage is energetically unfavorable under the
conditions of low power irradiation (from 30 to 300 Watts), it can
still take place because of the enormous incidence of wave particle
interaction under the conditions of this invention.
[0022] In one embodiment of the present invention, a process is
provided to expose a substance to electromagnetic waves and to
detectably alter at least one physical property of the substance as
it existed prior to the exposure. Substances to be altered will
include hydrocarbonaceous material and will generally include
hydrocarbons associated with oil and gas production and their
location within well bores, formations, pipelines, storage tanks,
and the like. The process includes providing a radio frequency
generator capable of producing radio frequencies in the range of
about 1 MHz to about 900 MHz. It should be appreciated that the
radio frequency generator may be any commercially available
frequency generator capable of producing the frequencies in the
above mentioned range. Preferably, the radio frequency generator
may generate electromagnetic waves having a frequency of about 1
MHz to about 100 MHz, Still more preferable, the radio frequency
generator may generate electromagnetic waves having a frequency of
about 30 MHz to about 50 MHz. Still yet more preferable, the radio
frequency generator may generate electromagnetic waves having a
frequency of about 40 MHz to about 50 MHz. Most preferably, the
radio frequency generator may generate electromagnetic waves having
a frequency of at least about 46.2 MHz.
[0023] In one embodiment, a radio frequency power amplifier is
electrically coupled to the radio frequency generator. The radio
frequency power amplifier may be any RF power amplifier capable of
receiving the signal from the frequency generator, wherein the
signal has a frequency in the range of about 1 MHz to about 900
MHz, and further capable of producing a power output of about 30 W
to about 1000 W. It should be appreciated that the frequency
generator and amplifier may be separate components or may be
constructed so as to form an integral unit. The radio frequency
generator and RF power amplifier in combination generate and
amplify electromagnetic waves at a selected frequency in the range
of the frequencies mentioned above. It should be appreciated that
the frequency generator and amplifier may be powered by a generator
or other means depending on the environment in which the
hydrocarbonaceous material is found, e.g., a well site, pipeline
facility, refinery, etc. Other electrical components such as, for
example, a AC/DC converter or duty cycle timer may be used. The
radio frequency generator and RF amplifier and other electrical
components, including a microwave generator and amplifier discussed
below, may be contained in a housing or transmittal unit.
[0024] The RF amplifier may be electrically coupled to a standing
wave ratio (SWR) meter, wherein the SWR meter is electrically
coupled to an impedance matching network in at least one embodiment
of the present invention. The SWR meter may be used to measure the
forward power versus the reflected power. The SWR meter is
indicative of the impedance match between the radio frequency
generator and amplifier, i.e., signal generating unit, and the load
impedance, which will be discussed further below. The impedance
matching network will be electrically coupled to a transmitting
device or antenna. It should be appreciated that in certain
embodiments, the SWR meter and the impedance matching network may
be an integral unit. For example, the integral unit may be a
MAC-200, manufactured by SGC of Bellevue, Wash. FIG. 5 illustrates
a block diagram of the configuration in one embodiment of the
present invention.
[0025] The antenna used in one embodiment may be the well head
assembly, tubing, and casing of an oil or gas well. In such an
embodiment, the impedance matching network is electrically coupled
to the well head assembly, casing, and tubing. One end of a coaxial
cable is coupled to the impedance matching network and the other
end of the coaxial cable will be electrically coupled to the well
head assembly, casing, and tubing. Specifically, the braided outer
conductor of the coaxial cable will be attached to a metal stake
placed in the surface of the earth proximate to the well to serve
as the ground. The center wire of the coaxial cable will be coupled
to the well head assembly, typically the flow line of the well. As
such, the entire well head assembly, casing, and tubing is
conductive and serves as the antenna.
[0026] In another embodiment, the antenna may be at least one
dipole antenna. In another embodiment, the antenna may be at least
one monopole antenna. In certain embodiments, the dipole antenna
may be a quarter wave or half wave dipole antenna. The dipole
antenna may be coupled to the impedance matching network by coaxial
cable and run into the well head assembly through the gate valve in
the well head assembly. In such an embodiment, the dipole antenna
will be disposed within the annulus of a well bore comprising
casing and tubing. The length of the dipole antenna will vary based
on its characteristics, e.g., half wave, full wave, etc. In one
embodiment, the dipole antenna is disposed at a depth of about
twelve feet from the well head assembly in the annulus. It should
be appreciated that the antenna may also be run through the tubing
in certain embodiments.
[0027] Additionally, the monopole or dipole antenna may be disposed
within a pipeline or tank comprising hydrocarbonaceous material. In
one embodiment, a dipole antenna is inserted into one end of the
pipeline, approximately eight to twelve feet into an inner central
portion of the end portion of the pipeline. In another embodiment,
a dipole or monopole antenna is inserted into each end portion of
the pipeline. In still yet another embodiment, a monopole or dipole
antenna may be inserted into a tank comprising hydrocarbonaceous
material. In the embodiments disclosed above, the dipole or
monopole antennas may transmit radio waves and/or microwaves. In
certain embodiments, radio and microwaves may be transmitted on a
single antenna. In at least one embodiment, radio waves will be
transmitted on a separate antenna from the antenna transmitting
microwaves.
[0028] Optionally, a microwave frequency generator may be provided,
the microwave generator being any commercially available microwave
generator capable of producing electromagnetic waves having a
frequency range of about 20 to about 40 GHz. Preferably, the
microwave frequency generator produces electromagnetic waves having
a frequency range of about 20 GHz to about 30 GHz. Most preferably,
the microwave frequency generator produces electromagnetic waves
having a frequency range of at least about 24 GHz. In one
embodiment, the microwave generator is electrically coupled to a
microwave amplifier, the amplifier being any commercially available
amplifier capable of receiving the signal from the microwave
frequency generator, wherein the signal has a frequency in the
range of about 20 GHz to about 40 GHz, and further capable of
producing a power output of up to about 8 W. It should be
appreciated that the frequency generator and amplifier may be
separate components or may be constructed so as to form an integral
unit. In at least one embodiment, the radio frequency generator and
RF amplifier and the microwave frequency generator and amplifier
are all housed in a single transmittal unit. Microwaves may be
transmitted in conjunction with the radio waves, and may be
transmitted concurrently or before or after the radio waves are
transmitted.
[0029] In one embodiment, the microwave amplifier is electrically
coupled to the antenna. The antenna may be a dipole antenna, a
monopole antenna, or the well head assembly, tubing, and casing
disclosed above. The microwaves and radio waves may be transmitted
from a single antenna or each amplifier may be electrically coupled
to a separate antenna. In coupling the microwave amplifier to the
antenna, a coaxial cable is used. One end of the coaxial cable is
coupled to the microwave amplifier whereas the other end of the
coaxial cable is coupled to the dipole antenna. In another
embodiment, the antenna is the well head assembly, tubing, and
casing. In such an embodiment, the end of the coaxial cable not
coupled to the microwave amplifier is coupled to the well head
assembly, wherein the center wire of the coaxial cable is attached
to the polished rod of the well head assembly and the outer sheath
of the coaxial cable is attached to a metal stake urged into the
surface of the earth, thus functioning as a ground wire.
[0030] The impedance matching network will function to match the
output impedance of the signal generating unit, wherein the signal
generating unit comprises the radio frequency generator and RF
amplifier, with the load impedance, wherein the load impedance may
be defined as the impedance of the antenna and the coaxial cable
coupling the antenna to the impedance matching network. The
impedance matching network may be adjusted manually or
automatically. In adjusting the impedance matching network, the
impedance matching network comprises variable inductors and
variable capacitors capable of varying the impedance in order to
match the output impedance of the signal generating unit with the
load impedance. The impedance may be matched automatically by the
use of such devices as the MAC-200 disclosed above. It should be
appreciated that the foregoing system to transmit the
electromagnetic waves generated by a radio frequency generator and
the microwave frequency generator consumes no more than about 1,000
Watts of power
EXAMPLE 1
[0031] The foregoing has been confirmed by Gas Chromatography
combined with Mass Spectroscopy used to examine a sample of Gulf
wax (food grade) diluted with xylene (27% by weight) before and
after irradiation. Treatment was made by exposing samples to be
treated to radio frequency (76 MHz) electromagnetic waves and
microwaves (29 GHz) for a period of 2.5 hours. Aliquots of 25 ml
were taken from the very bottom of the graduated cylinders treated
and untreated samples and placed in two weigh dishes. The samples
were then placed in a room temperature (25.degree. C.) vacuum oven
and a 22 inch vacuum was pulled on the samples until they contained
no more solvent. After the samples had lost all their solvent the
weigh dishes were weighed to compare the amount of material in
each. The treated sample was found to contain 20% less by weight
than the untreated sample, verifying that the RF/Microwave
treatment kept more of the wax in solution than the untreated
sample.
EXAMPLE 2
[0032] Gulf wax (food grade) similarly diluted in diesel was
further analyzed before and after RF/Microwave treatment. Results
are summarized in Table 1 below.
TABLE-US-00001 TABLE 1 Total Gulf Wax Charged grams Total Diesel
grams 235.00 870.00 Wt % Wax Wt % Diesel 21.27 78.73 Percent Wax
recovered Percent Wax recovered by filtration by filtration (after
RF treatment) (no treatment) 40.63 93.54 Percent Wax left in Diesel
Percent Wax left in Diesel (treated) (no treatment) 59.37 6.46
[0033] Gas Chromatography and Mass Spectrometry analysis revealed
that the RF/Microwave treated sample gave a larger percentage of
lower carbon number species, a clear decrease in the waxy carbon 18
to 30 chain lengths, and an increase in some 30+ carbon chains, all
of which is quite consistent with carbon-carbon bond breakdown seen
in other methods of hydrocarbon cracking. FIG. 1 graphically
illustrates the data obtained.
EXAMPLE 3
[0034] The procedure of Example 2 was repeated, except that Aldrich
reagent grade, 99 percent pure docosane was substituted for the
Gulf wax of Example 2. The resulting Gas Chromatography/Mass
Spectrometry analysis is plotted on FIGS. 3A and 3B. It is apparent
that the results do not show clear cut indications of carbon-carbon
cleavage. It appears likely that the two electromagnetic wave
frequencies interact with forming hydrogen bonds to prevent
aggregation of the wax crystals to form wax deposits.
EXAMPLE 4
[0035] At least one method as disclosed above was applied to
seventeen oil wells located in West Texas, wherein radio (40.68
MHz) at 40 Watts and microwave (24.4 GHz) at 1 Watt signals were
transmitted into the well bore by a transmitting unit. All
seventeen wells were observed to have positive effects (e.g.,
increased oil production, increased total fluid, solid paraffin
removal, flow line pressure drops, and added gas production) upon
exposure to the radio and microwave signals. The combination
frequency effects have proven to affect intermolecular aggregation,
and anecdotal evidence has confirmed these frequencies are
effective in removing near well bore damage. Results of this
experiment are summarized in Table 2.
TABLE-US-00002 TABLE 2 Bbls Bbls Oil Water Bbls Oil Bbls Water Well
No. before RF before RF after RF after RF Comments 348 2 15 16 107
Lots of gas 336 8 80 10 56 Lots of gas 527 8 112 9 112 Lots of gas
and water 394 3 10 8 9 Lots of gas 493 12 34 15 29 Lots of gas 550
9 20 11 13 Big wads wax released 498 15 20 17 20 Lots of gas 365 9
22 12 20 Lots of gas 91 10 30 13 40 Lots of gas 538 9 50 11 65 Lots
of gas 31 7 8 11 8 Lots of gas 27 6 11 9 12 Lots of gas 375 8 21 11
14 Lots of gas 438 8 44 12 53 398 4 18 7 19 Lots of gas 174 3 22 25
12 Lots of gas Quantum 2 29 12 35 Lots of gas Total 123 210
Increase 87 Bbl. Oil
EXAMPLE 5
[0036] Well testing by oil company personnel was performed after
the treatments as disclosed above on these five oil wells located
in West Texas for an extended period of time, the period of time
lasting for at least two weeks and summarized in Table 3 below.
Radio waves (40.68 MHz) at 40 Watts and microwave waves (24.4 GHz)
at 1 Watt signals were transmitted into the well bore by a
transmitting unit at time intervals of no more than two hours. All
five wells were observed to have positive effects (e.g., increased
oil production, increased total fluid, solid paraffin removal, flow
line pressure drops, and added gas production) upon exposure to the
radio and microwave signals. The combination frequency effects have
proven to affect intermolecular aggregation, and anecdotal evidence
has confirmed these frequencies are effective in removing near well
bore damage. Results of this experiment are summarized in Table
3.
TABLE-US-00003 TABLE 3 Well Bbls Oil Bbls Water Bbls Oil Bbls Water
No. before RF before RF after RF after RF Comments 348 12 22 17 56
Lots of gas Test lasted 2 weeks 336 6 77 11 53 Lots of gas Test
lasted 2 weeks 498 17 22 23 27 Lots of gas Test lasted 3 weeks 438
12 48 16 56 Lots of gas Test lasted 2 weeks 174 9 5 14 9 Lots of
gas Test lasted 2 weeks Total 56 81 Increase 25 Bbls.Oil
EXAMPLE 6
[0037] Initially, a well was plugged off with paraffin wax and the
operating company could not pump any solvent into the well. The
well was treated with radio signals and microwave signals of 40 MHz
and 24 GHz, respectively. After an hour, the tubing pressure rose
to 1,000 psi. An attempt to flow the well was made, but the
differential pressure was too great. After opening the flow line,
the pressure dropped back to 0 psi and it took another 20 minutes
to gain 1,000 psi. The flow line was opened again and the pressure
dropped to 0 psi again. The tubing pressure was increased to 1,500
psi. A subsequent operator observed that the wax obstruction was
removed down to 750 feet. It appears the exposure of the paraffin
wax to the radio waves and microwaves resulted in a decrease in the
obstruction of the paraffin wax in the well.
EXAMPLE 7
[0038] Three wells were treated with the same RF and microwave
frequency set up, except that power for the VHF RF transmitter was
50 Watts and the transmitters were connected to two antennae, and
those were inserted twelve (12) feet into the back side annular
space of a low-pressure well that had its pressure bled off prior
to antennae placement. The unit was powered up and remained on for
two (2) hours. Two days later, well test was run on each well, and
production increase was 5 bbls. oil increase per day on two of the
wells, and 3 bbls. oil increase in production on the third.
EXAMPLE 8
[0039] Formation material from natively oil-wet sandstone was used
in this study. Cylindrical test samples were drilled using Isopar-L
as the bit coolant and lubricant. The samples were trimmed to right
cylinders prior to use. Mineralogical information had previously
been determined and is listed below
TABLE-US-00004 Summary of X-Ray Diffraction (wt. %) Mineral Phases
(wt. %) Quartz 62 Plagioclase Feldspar 8 Potassium Feldspar 10
Dolomite 1 Kaolinite 4 Mica and/or Illite 2 Mixed-Layer
Illite.sub.90/Smectite.sub.10 12
[0040] Flow Test Conditions:
[0041] Temperature: 150.degree. F.
[0042] Net Confining Stress: 1500 psi
[0043] Backpressure=200 psi
[0044] Fluids:
[0045] Brine: Two percent by weight potassium chloride (2% KCl)
solution, prepared with deionized water and reagent grade salts.
Filtered and evacuated prior to use.
[0046] Crude Oil: Heavy crude oil known to contain asphaltenes.
Viscosity at test temperature=16.2 centipoise (cp).
[0047] Mineral Oil: Isopar-L, a laboratory grade mineral oil.
Filtered and evacuated prior to use. Viscosity at test
temperature=0.96 cp.
[0048] Flow Test Procedures:
[0049] Effective Permeability to Water at Residual Oil Saturation,
KwSor (Native-State Condition)
[0050] The sample was loaded under confining stress in a HASSLER
load coreholder. The 2% KCl brine was injected against 200 psi
backpressure at a constant flow rate. Differential pressure was
monitored and an effective permeability to water at residual oil
(KwSor) is calculated. KwSor=3.04 mD (millidarcies)
[0051] Effective Permeability to Oil at Irreducible Water
Saturation, KoSwi
[0052] Heavy crude oil injection against 200 psi backpressure
followed brine injection to establish irreducible water saturation
and to potentially place asphaltenes on the grain surfaces.
Differential pressure and flow rate were monitored and an effective
permeability to oil at irreducible water saturation (KoSwi) was
calculated. Crude Oil KoSwi=0.890 mD.
[0053] Isopar-L was injected against 200 psi backpressure to remove
the crude oil from the pore space. Differential pressure and flow
rate were monitored to allow calculation of KoSwi prior to RF
treatment. KoSwi=0.937 mD.
[0054] RF Treatment
[0055] The coreholder assembly with the test sample still loaded,
was transported for RF treatment and returned. The RF treatment was
carried out as follows: Core sample was placed inside the rubber
bladder of a Hassler-type core holder between the two feed lines of
the end plates. The RF transmission line ground (outer shield of
the coaxial cable) was place on one end feed line and the center of
the coaxial cable was attached to the other feed line. The
microwave transmission line was wrapped around the rubber bladder
(which is permeable to both RF and microwave). 50 watts of RF at 40
MHz and 1 watt of microwave at 24 GHz was applied for approximately
7.5 minutes. Power was then turned off and the sample was ready for
analysis.
[0056] Effective Permeability to Oil at Irreducible Water
Saturation, KoSwi Post Treatment
[0057] Following RF treatment, Isopar-L was injected against 200
psi backpressure. Differential pressure and flow rate were
monitored to allow calculation of KoSwi after RF treatment. KoSwi
after treatment=1.80 mD, indicating a significant improvement in
oil productivity.
[0058] Effective Permeability to Water at Residual Oil Saturation,
KwSor Post Treatment
[0059] The 2% KCl brine was injected against 200 psi backpressure
at a constant flow rate to establish residual oil saturation.
Differential pressure was monitored and KwSor after treatment was
calculated as 1.25 mD, a decline in water productivity exceeding
50%. A summary of effective permeability results is illustrated in
the graph found in FIG. 6. From the numbers presented in FIG. 6, it
can be seen that the ratio of hydrocarbon effective permeability
(e.g., crude oil) to water effective permeability (the oil to water
mobility ratio) increased from 0.3 prior to treatment to 1.44 after
treatment. This represents a substantial increase in the
permeability of hydrocarbon and concurrent substantial decrease in
the permeability of water in the formation sample which underwent
treatment.
[0060] While the invention has been described here in the context
of down hole applications in oil & gas well treatment, it will
be appreciated by those of at least ordinary skill in the art,
having the benefit of the present disclosure, that the invention
has applications in many other areas in which the alteration of a
one or more physical properties of a substance, under low power
consumption conditions, could be desirable. Accordingly, the
invention should not be construed as limited to the particular
applications described in detail herein.
* * * * *