US4084638A
Expired / Lapsed
US
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Method of production stimulation and enhanced recovery of oil
Assignee: Probe Inc
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Filing: 1975-10-16
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Granted: 1978-04-18
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Expires: 1995-10-16
Abstract
Abstract The present invention relates to an improved method of recovery of petroleum from presently existing wells which are either non-producing or low production types. The method utilizes surges and oscillations of electrical energy in excess of 150 kilovolts involving the use of heavy current flow over a carbonaceous path in order to establish heat, electrical and physical shock, and steam fracturing (or shattering) within certain sedimentary rock formations, thereby giving rise to an increase in the effective well and reservoir radius both within an existing well and between wells. The method involves the use of a minimum of two existing wells, one being an injection well and the other being a production or recovery well. In each well, insulated high voltage cable is secured within the well casing in order to feed required electrical energy into a probe rod which, at the bottom of each well is driven into the oil stratum in a configuration in which each probe is directed toward the other. The distance of the respective probes from each other will, depending upon factors of voltage, current flow and geological conditions, be disposed as close as 25 feet apart or, in any given instance, as far as 3,000 feet apart.
Inventors
- 👤 Cuthbert R. Whiting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:58
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/17; E21B43/003; E21B43/24; E21B43/2401
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
171 words
A method of production stimulation and enhanced oil recovery from existing oil wells, comprising the steps of: (a) disposing an insulated high voltage cable within an injection well and embedding a conductive probe at the end of said cable within an oil-bearing stratum; (b) disposing an insulating high voltage cable within a recovery well and embedding a probe at the end of said cable within an oil-bearing stratum, said recovery well being between 25 feet and 3,000 feet distance from said injection well; (c) connecting a high energy charging and discharge circuit, at the surface level, between each of said cables associated with said injection and recovery wells; (d) applying a voltage, current, frequency and pulse width control circuit to said charging and discharge circuit; and (e) selectively actuating the above circuitry in order to produce sequential high energy electrical impulses originating at the electrode embedded within the injection well, thereby producing electrical, thermal, physical and sonic shock effects sufficient to produce geological fracturing and, thereby, oil flow between said electrodes.
Claim 2
Independent Claim
171 words
A method of production stimulation and enhanced oil recovery from existing oil wells, comprising the steps of: (a) disposing an insulated high voltage cable within an injection well and embedding a conductive probe at the end of said cable within an oil-bearing stratum; (b) disposing an insulating high voltage cable within a recovery well and embedding a probe at the end of said cable within an oil-bearing stratum, said recovery well being between 25 feet and 3,000 feet distance from said injection well; (c) connecting a high energy charging and discharge circuit, at the surface level, between each of said cables associated with said injection and recovery wells; (d) applying a voltage, current, frequency and pulse width control circuit to said charging and discharge circuit; and (e) selectively actuating the above circuitry in order to produce sequential high energy electrical impulses originating at the electrode embedded within the injection well, thereby producing electrical, thermal, physical and sonic shock effects sufficient to produce geological fracturing and, thereby, oil flow between said electrodes.
Claim 3
Dependent Claim
46 words
The method as recited in claim 1 in which said method further comprises reversing the direction of current flow in order to secure advantageous results in those situations where the physical and chemical parameters of the oil-bearing stratum are more receptive to such a reverse current.
Claim 4
Dependent Claim
51 words
The method as recited in claim 1 in which said method further comprises the step of actuating the discharge of electrical energy in such a manner as to maximize the transfer of thermal energy to the sedimentary stratum thereby enhancing the possibility of a coking or charring effect within said stratum.
Claim 5
Dependent Claim
45 words
The method as recited in claim 1 in which said method further comprises the step of repetitiously discharging a maximum amount of electrical energy during the smallest possible time frame, thereby maximizing the shock wave effect and, thus, the fracturing experienced by the sedimentary stratum.
Claim 6
Dependent Claim
46 words
The method as recited in claim 1 in which said method further comprises the step of placing either or both of said probes near a subterranean deposit of water so as to maximize the possibility of water expansion and thereby of attaining so-called rock burst phenomenon.
Claim 7
Dependent Claim
37 words
The method as recited in claim 1 in which the present method further comprises the step of placing said electrode probes within the strata of crystalline rock, thereby maximizing the potential for physical fracture of said strata.
Claim 8
Dependent Claim
50 words
The method as recited in claim 1 in which said method further comprises the step of applying said electrodes in a stratum which is rich in metallic and mineral deposits so as to give rise to inductive effects which may act to enhance the possibility of fracturing through transductive phenomena.
Claim 9
Dependent Claim
54 words
The method as recited in claim 1 in which said method further comprises the steps of directing said probes in a co-linear disposition with respect to each other in order to maximize the uni-directionality of current flow between the electrodes, said step being particularly applicable in geological environments of high metallic and mineral content.
Claim 10
Dependent Claim
66 words
The method as recited in claim 1 in which said method further comprises the step of frequency-modulating the DC current flow in order to thereby optimize the ionization of mineral molecules within the oil stratum, thusly causing an electrolysis to occur and thereby creating an electrolytic condition exhibiting an enhanced current flow, especially within regions of salt water and liquid minerals which occur within oil-bearing strata.
Claim 11
Dependent Claim
67 words
The method as recited in claim 1 in which said method further comprises the step of applying said electrodes within a sedimentary stratum, thereby, by virtue of the nature of said stratum, giving rise to an electro-osmotic effect in which oil is advanced within said stratum to the cathode electrode or recovery well, while salt water is advanced in the direction of the anode or injection well.
Claim 12
Dependent Claim
60 words
The method as recited in claim 1 in which said method further comprises the step of maximizing the discharge time of each pulse in order to convey a maximum of thermal energy to water and oil deposits, thereby creating a steam or gas expansion which will provide necessary pressure in order to enhance the ease and efficiency of oil recovery.
Claim 13
Dependent Claim
58 words
The method as recited in claim 1 in which said method further comprises the step of maximizing the discharge time within each pulse in order to convey a maximum of thermal energy to deposits of oil, asphalt, and paraffine, thereby reducing the viscosity of said materials, thus enhancing their flow rates and ultimately increasing their ease of recoverability.
Claim 14
Dependent Claim
60 words
The method as recited in claim 1 in which said method further comprises the step of maximizing the discharge time in order to convey a maximum of thermal energy to the oil stratum in order to decrease the electrical resistance thereof, thus increasing the conductivity with a concomitant enhancement of total energy flow, and thus recovery efficiency, within said stratum.
Claim 15
Dependent Claim
55 words
The method as recited in claim 1 in which said method further comprises the step of applying spike pulses of the highest attainable amplitude in order to create shock waves within strata of cap rock, thereby enhancing the efficiency of the fracture within said strata in order to therein open paths to new oil reserves.
Claim 16
Dependent Claim
53 words
The method as recited in claim 1 in which said method further comprises the step of continually applying electrical energy at a fixed frequency, established amplitude, and sufficient power in order to give rise to a condition, with the stratum of interest, of a physical resonance, with a concomittant enhancement of sedimentary fracturing.
Claim 17
Dependent Claim
39 words
The method as recited in claim 15 in which said method further comprises the step of selectively adjusting the input parameters of frequency, amplitude and power in order to attain a condition of physical resonance within the sedimentary stratum.
Claim 18
Dependent Claim
48 words
The method as recited in claim 1 in which said method further comprises steps of: (i) applying an AC current between said electrodes; and (ii) selectively adjusting the input parameters of frequency, amplitude and power in order to attain a condition of physical resonance within the sedimentary stratum.
Claim 19
Dependent Claim
65 words
The method as recited in claim 1 in which said method further comprises the step of forming an annular cylindrical cavity about the surface region of both said injection well and said recovery well in order to remove the conductive surface layer from the vicinity of the casing and to thereby reduce the liklihood of high voltage flashover to ground potential from the current conductors.
Claim 20
Dependent Claim
30 words
The method as recited in claim 18 in which said method further comprises the step of filling each of said annular cavities with an epoxy or similar such insulating medium.
Claim 21
Dependent Claim
28 words
The method as recited in claim 18 in which said method further comprises the step of filling each of said annular cavities with an insulating cement or concrete.
Claim 22
Dependent Claim
28 words
The method as recited in claim 1 in which said method further comprises the step of continually applying a reversible, fixed pulse rate DC current to the electrodes.
Claim 23
Dependent Claim
20 words
The method as recited in claim 21 in which said method further comprising the step of applying a half-wave current.
Claim 24
Dependent Claim
22 words
The method as recited in claim 1 in which said step (e) of selective actuation includes the step of utilizing mechanical switches.
Claim 25
Dependent Claim
24 words
The method as recited in claim 1 in which said step (e) of selective actuation includes the step of using a relay or solenoid.
Claim 26
Dependent Claim
22 words
The method as recited in claim 1 in which said step (e) of selective actuation comprises the step of using a thyratron.
Claim 27
Dependent Claim
22 words
The method as recited in claim 1 in which said step (e) of selective actuation comprises the step of using an ignatron.
Claim 28
Dependent Claim
22 words
The method as recited in claim 1 in which said step (e) of selective actuation comprises the step of using an SCR.
Claim 29
Dependent Claim
29 words
The method as recited in claim 1 in which said step (e) of selective actuation comprises the step of using a gate turn-off (GTO or GTS) solid state device.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-17 | 1981-10-17 | 1982-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-17 | 1985-10-17 | 1986-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-17 | 1989-10-17 | 1990-04-18 | $7700.00 | Window Closed / Lapsed |