Process and apparatus for electrohydraulic recovery of crude oil
First Claim
1. A process for stimulating recovery of crude oil from oil bearing earth formations wherein such oil is incapable of migrating through the formation in commercially producing quantity, said process comprising:
- locating a pair of electrodes within a well bore, said electrodes being in spaced relation and defining a spark gap therebetween;
developing first and second electrical charges substantially at the level of the oil bearing earth formation;
releasing said first electrical charge into said spark gap to render said spark gap conductive;
releasing said second electrical charge into said conductive spark gap to generate said explosive spark;
said explosive spark introducing intense shock waves into said oil bearing formation at the level of said formation, said electrical spark generated shock waves being of sufficient magnitude to modify the oil retention quality of said formation sufficiently to release a substantial quantity of oil from the adhesion thereof to the formation;
introducing hydraulic waves into said oil bearing formation at the level of said formation, said hydraulic waves being generated by said electrical spark simultaneously with said shock waves and traveling through said formation at a rate of speed that is slower as compared to the speed of said shock waves;
said hydraulic waves inducing released oil to migrate forcibly away from the point of energy introduction of said shock waves and hydraulic waves; and
producing the migrating oil from adjacent collection wells positioned in spaced, surrounding relation with said point of energy introduction into said formation.
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Accused Products
Abstract
Process and apparatus for electrohydraulic recovery of crude oil wherein an explosive, ablative electric spark is generated at or near a subsurface oil bearing formation and which generates shock waves and hydraulic waves that radiate or propogate outwardly into the formation and cause forcible migration of oil toward adjacent collection wells. Electrical energy, which is well within the load-carrying capacity of an electrical service cable extending into the well, is stored at or near the level of the oil bearing formation by a capacitor bank. A spark gap across electrodes is broken down by discharging current from an injector capacitor bank after which a current of substantial magnitude is discharged from a main capacitor bank into the broken down spark gap, thus generating the explosive spark.
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Citations
21 Claims
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1. A process for stimulating recovery of crude oil from oil bearing earth formations wherein such oil is incapable of migrating through the formation in commercially producing quantity, said process comprising:
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locating a pair of electrodes within a well bore, said electrodes being in spaced relation and defining a spark gap therebetween; developing first and second electrical charges substantially at the level of the oil bearing earth formation; releasing said first electrical charge into said spark gap to render said spark gap conductive; releasing said second electrical charge into said conductive spark gap to generate said explosive spark; said explosive spark introducing intense shock waves into said oil bearing formation at the level of said formation, said electrical spark generated shock waves being of sufficient magnitude to modify the oil retention quality of said formation sufficiently to release a substantial quantity of oil from the adhesion thereof to the formation; introducing hydraulic waves into said oil bearing formation at the level of said formation, said hydraulic waves being generated by said electrical spark simultaneously with said shock waves and traveling through said formation at a rate of speed that is slower as compared to the speed of said shock waves;
said hydraulic waves inducing released oil to migrate forcibly away from the point of energy introduction of said shock waves and hydraulic waves; andproducing the migrating oil from adjacent collection wells positioned in spaced, surrounding relation with said point of energy introduction into said formation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. Apparatus for generating electrohydraulic waves and shock waves in an oil bearing formation, said apparatus comprising:
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elongated housing means of sufficiently limited external diameter to allow easy insertion of said housing means into the well pipe of an oil well intersecting an oil bearing earth formation; adapter means defined at the upper extremity of said housing means for supporting connection of said housing means with housing support means; a pair of electrodes being supported by said housing means with the extremities of said electrodes positioned in spaced relation to one another and defining a spark gap; a main capacitor bank circuit being contained within said housing means and being electrically interconnected with said electrodes said main capacitor bank circuit incorporating a plurality of parallel related capacitors; an injector capacitor bank being coupled with said main capacitor bank and increasing the voltage of said main capacitor bank to an injector level for breaking down the resistance of said spark gap; and an ignitron switch being coupled with one of said electrodes and said main capacitor bank, said ignition switch firing upon breaking down of the resistance of said spark gap by said voltage of said injector capacitor bank and conducting the stored electrical energy of said main capacitor bank into said spark gap to cause spark detonation; and means controlling charging and discharging of said injector and main capacitor banks in accordance with the characteristics of said oil bearing formation and the viscosity of crude oil contained therein and developing a controlled spark detonation at said spark gap, which spark detonation develops shock waves and hydraulic waves in said oil bearing formation of controlled frequency and amplitude for releasing oil from the adhesion thereof with said formation and causing said oil to flow in a direction away from said spark gap. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A method of developing shock and hydraulic waves by explosive-like ablative electrical spark across a spark gap defined by electrodes positioned in a well bore near a subsurface earth formation from which crude oil is to be produced, said method comprising:
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providing a source of electrical energy at the earth'"'"'s surface; transmitting electrical energy through a service cable extending from the earth'"'"'s surface to a location near said subsurface earth formation, said energy transmission being at a rate within the transmission capability of said service cable; storing electrical energy in a main capacitor bank at said location and developing an electrical charge of high magnitude; storing electrical energy in an injector capacitor bank at said location at a maximum injector voltage level exceeding the voltage level of said main capacitor bank and being sufficient to render said spark gap conductive; selectively discharging said stored electrical energy of said injector capacitor bank across said spark gap to render said spark gap conductive; and suddenly discharging said electrical charge across said spark gap defined by spaced electrodes with the rate of energy transmission of said discharging greatly exceeding the energy transmission capability of said service cable. - View Dependent Claims (17, 18, 19, 20)
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21. A process for stimulating recovery of crude oil from oil bearing earth formations wherein such oil is incapable of migrating through the formation in commercially producing quantity, said process comprising:
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locating a pair of electrodes within a well bore, said electrodes being in spaced relation and defining a spark gap therebetween; developing a main capacitor bank voltage substantially at the level of said oil bearing earth formation and providing said main capacitor bank voltage at said spark gap; developing an injector capacitor bank voltage in the immediate vicinity of said main capacitor bank voltage; increasing said main capacitor bank voltage to an injector level by means of said injector capacitor bank voltage to initially break down the resistance of said spark gap and render said spark gap conductive; discharging said main capacitor bank voltage into said conductive spark gap to generate said explosive spark; said explosive spark introducing intense spark generated shock waves into said oil bearing formation at the level of said formation, said electrical spark generated shock waves being of sufficient magnitude to modify the oil retention quality of said formation sufficiently to release a substantial quantity of oil from the adhesion thereof to the formation; introducing hydraulic waves into said oil bearing formation at the level of said formation, said hydraulic waves being generated by said electrical spark simultaneously with said shock waves and traveling through said formation at a rate of speed that is slower as compared to the speed of said shock waves;
said hydraulic waves inducing released oil to migrate forcibly away from the point of energy introduction of said shock waves and hydraulic waves; andproducing the migrating oil from adjacent collection wells positioned in spaced, surrounding relation with said point of energy introduction into said formation.
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Specification