RADIO AND MICROWAVE TREATMENT OF OIL WELLS

- BJ Services Company

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.

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Description
REFERENCE TO RELATED APPLICATIONS

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

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

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.

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.

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.

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.

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 VAC 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).

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.

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.

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.

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.

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).

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

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.

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.

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.

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.

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.

FIG. 6 is a Summary of Effective Permeability Results as disclosed in Example 8.

Like reference indicators are used to refer to like parts or steps described amongst the several figures.

FURTHER DETAILED DESCRIPTION OF THE INVENTION

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=½) 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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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° 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

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 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

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

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

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 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

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 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

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

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

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

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 Illite90/Smectite10 12

Flow Test Conditions:

Temperature: 150° F.

Net Confining Stress: 1500 psi

Backpressure=200 psi

Fluids:

Brine: Two percent by weight potassium chloride (2% KCl) solution, prepared with deionized water and reagent grade salts. Filtered and evacuated prior to use.

Crude Oil: Heavy crude oil known to contain asphaltenes. Viscosity at test temperature=16.2 centipoise (cp).

Mineral Oil: Isopar-L, a laboratory grade mineral oil. Filtered and evacuated prior to use. Viscosity at test temperature=0.96 cp.

Flow Test Procedures:

Effective Permeability to Water at Residual Oil Saturation, KwSor (Native-State Condition)

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)

Effective Permeability to Oil at Irreducible Water Saturation, KoSwi

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.

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.

RF Treatment

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.

Effective Permeability to Oil at Irreducible Water Saturation, KoSwi Post Treatment

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.

Effective Permeability to Water at Residual Oil Saturation, KwSor Post Treatment

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.

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.

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 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.

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,

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 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.

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,

25. The method according to claim 23 further comprising 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.

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,

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.

Patent History
Publication number: 20090283257
Type: Application
Filed: Feb 4, 2009
Publication Date: Nov 19, 2009
Applicant: BJ Services Company (Houston, TX)
Inventor: Harold L. Becker (Tomball, TX)
Application Number: 12/365,750
Classifications
Current U.S. Class: Electric Current Or Electrical Wave Energy Through Earth For Treating (166/248)
International Classification: E21B 43/00 (20060101);