|Número de publicación||US3679264 A|
|Tipo de publicación||Concesión|
|Fecha de publicación||25 Jul 1972|
|Fecha de presentación||22 Oct 1969|
|Fecha de prioridad||22 Oct 1969|
|Número de publicación||US 3679264 A, US 3679264A, US-A-3679264, US3679264 A, US3679264A|
|Inventores||Huisen Allen T Van|
|Cesionario original||Huisen Allen T Van|
|Exportar cita||BiBTeX, EndNote, RefMan|
|Citas de patentes (9), Citada por (48), Clasificaciones (13), Eventos legales (4)|
|Enlaces externos: USPTO, Cesión de USPTO, Espacenet|
United States Patent Van Huisen  GEOTHERMAL IN SITU MINING AND RETORTING SYSTEM  Inventor: Allen T. Van llulsen, 1516 Granvia Altamira, Palos Verdes Estates, Calif. 90274  Filed: Oct. 22, 1969  Appl. No.: 868,395
[ 51 July 25,1972
3,430,700 3/1969 Satter et al 166/263 X 3,432,205 3/1969 l-lottman et al. ..166/272 X FOREIGN PATENTS OR APPLICATIONS 1,414,837 9/1965 France ..166/302 Primary Examiner-Jan A. Calvert Attorney-Marvin E. Jacobs [5 7] ABSTRACT The following disclosure relates to a system for the recovery of minerals, metals, and chemicals in situ by the utilization of geothermal heat energy which is transferred from one stratum or zone within the interior depths of the earth into another stratum or zone in the earth's interior, which contains minerals, oil, metals, or chemicals whose recovery is enhanced by coming in contact with the invading heat energy, and is accomplished by a closed system which permits the escape of high pressure geothermally heated gas or fluid from the one subsurface zone within the earth into the other subsurface zone within the earth. Alternatively a fluid may be injected into the geothermal zone, heated therein, transferred into the other zone, and the fluidized body of material from the other zone recovered through a second well.
5 Claims, 3 Drawing Figures PATENTEDJULZB 1912 3.679 .264- sum 1 0F 3 INVENTOR.
ALLEN T. VAN HUISEN FIGI PATENTEDJULZS I912 3.679.264
sum 2 or 3 INVENTOR.
ALLEN T. VAN HUISEN FIG. 2
PATENTEDJHL 25 m2 SHEEI 3 OF 3 INVENTOR.
ALLEN T. VAN HUISEN FIG. 5
GEOTIIERMAL IN SITU MINING AND RETORTING SYSTEM BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to the utilization of geothermal heat energy for the recovery of oil, minerals, metals, and chemicals which can be more efiiciently mined or produced by coming in contact with increased temperatures and pressures that serve to increase viscosities, create solutions, and enhance recovery.
Brief Summary of the Invention The present invention relies upon the geothermal zones which exist within the interior depths of the earth and contains vast sources of heat energy resulting from the earths calorific production which is housed in formations at various depths within the earth. In one of its aspects, the present inventive system provides for the direct utilization of steam or hot liquid contained within the geothermal stratum under suflicient pressures to allow it to enter a perforated or slotted well casing, which has been enclosed in cement and inserted in a well bore drilled into the geothermal stratum from which steam and heated fluid can flow through the well casing to and into another stratum penetrated by the same well bore and casing where entry is permitted through perforations or slots at such stratum. In another aspect, the present inventive system utilizes geothermally heated zones or formations which do not contain moisture or gas sufficient to effect the desired heat transfer from one stratum to another by employing a system through which water or other suitable fluids or materials can be injected into the geothermal stratum through this inventive system and after it is geothermally heatedcan return into the well casing through perforations or slots in the well casing and thence into the desired stratum for in situ mining or retort utilization. In another aspect, this inventive system embodies the utilization of the bottom portion of the well casing which has been submerged into a geothermal stratum and into which fluid is injected which will absorb heat energy from the surrounding geothermal stratum and after it has attained sufficient heat and pressure will flow through the well casing into the stratum which surrounds the perforations or slots made for its escape into the desired zone. The top portion of the well casing being closed at the surface of the well restrains the flow of the geothermally heated gas or fluids and thus permits the guaging of volumes and pressures rising within the inventive system by recording guages at the well head and permits escaping into the stratum selected for in situ retorting. This aspect of the inventive system also permits a controlled escape of geothermal fluids or geothermally heated fluids through control valves located at the well head which, when open, will tend to encourage flow from the geothermal stratum and also permit utilization of the geothermal energy at the wells surface when desired.
The geothermal in situ mining and retorting system of the invention is peculiarly adaptable to a novel method of oil and gas recovery where pressures are required and where oil is waxy and/or viscous, and flows with difficulty at ambient formation temperatures.
The present invention proposes to exploit many important mineral deposits in the United States that are too deeply buried to pennit open-pit mining or exist in a state of viscosity and in an environment of low ambient temperatures which prohibit their economical production with present-day technology.
Prior to recent conservation methods employed in the oil and gas producing industry, many oil fields were improperly produced to secure maximum potential production, with the result that only a fraction of the oil in place was produced and the remaining oil lacked sufficient gas pressure, ambient temperature, or viscosity to permit recovery by the then-existing production methods. As oil consumption increased and overtook new discovery replacement reserves, the oil producing industry returned to the dormant oil fields where in situ reserves challenged its ingenuity for innovation. To release in situ oil from such depleted oi] strata, a system of water-flooding was commenced that entailed the injection of water from the surface into the oil stratum where the oil rising above the injected water became available for pumping to the surface. Another method in this so-called secondary recovery method of producing depleted oil wells is a method of steam-flooding, wherein water is heated to steam at a well's surface and then injected into the oil stratum to create the increased oil production. This method involved the consumption of one energyproducing substance in order to. produce another. Other methods attempted to promote secondary oil recovery included the emplacement of heating elements within well bores adjacent to oil strata, injection of chemical solutions, fireflooding, and more recently, the explosion of nuclear devices.
Many of the methods devised for secondary oil recovery have economical or technological limitations that have become apparent by their application. In contrast, the present invention proposes the capture and utilization of the earth's native heat energy for such vital projects as oil recovery, mineral recovery, chemical recovery, metal recovery, and in situ water recovery. The system of this invention permits the capture of heat energy from the depths within the earth and the'removal of such captured heat energy into preselected strata or zones where its heat will serve to assist the recovery of oil, minerals, chemicals, metals, or water that may be contained in the preselected stratum or zone. One distinct advantage of this invention is the unlimited quantity of heat that exists within the depths of the earth, reachable by present-day oil drilling technology. Another distinct advantage is that geothermal strata within the earth contain sufiicient heat volumes and pressures to permit the invasion of most oil, mineral, chemical, metal, and water strata when communication between a geothermal zone and such product-containing zone is permitted as described herein (in the specification and drawings).
The advantages of the system, as compared to the prior art of mining, are apparent. Secondary recovery methods for depleting oil and gas fields have devised elaborate systems for steam-flooding to increase production and yield from depleting oil fields. In most cases, they consume the very product they are seeking to produce to create the steam for injection into the stratum. Pollutants that result from the consumption of fossil fuels which are used to create steam for such steamflooding projects, will not result from the use of this inventive system. Also, certain minerals, chemicals, and metals that are soluble in water and. temperature but are located too deep within the earth for conventional mining methods may become economical to extract with the use of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS These and many other attendant advantages of the inventive system will readily be appreciated as they become better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which:
FIG. I is a schematic view showing how communication is established between two zones in a well where steam and/or hot water from one zone can escape from its habitat through perforations made through the well casing and into the stratum formation and after entering the well casing the steam or hot water is able to flow to another zone where similar perforations allow its entry to promote in situ mining or retorting of minerals, chemicals, or metals which may be contained therein.
FIG. 2 is a cross-sectional view of a well similar to FIG. 1 but adds the potential for injecting water or other fluids through a pipe conducted through the well casing and into the geothermal stratum which may contain sufiicient heat but lacks sufficient moisture.
FIG. 3 is a cross-sectional view of a well similar to FIG. 1 and FIG. 2 and contains no perforations in that portion of the well which extends into a geothermal stratum but uses that portion of the well as a fluid reservoir which will absorb heat energy by exchange from the surrounding formation and after attaining sufficient pressure will flow into the perforated mineral, metal, or chemical zone.
Referring now to FIG. 1, the system of this embodiment includes a metal well casing 2 which has been inserted into a well drilled into the earth into a geothermal stratum 11 and the well casing 2 has been surrounded with cement l and sealed with a plug 3 at the bottom.
Above the plug 3 located at the lower extremity in the well casing 2, perforations 4 have been made through the well casing 2 and the surrounding cement l and penetrating the adjacent geothermal stratum 11 which will permit the escape of steam and/or hot water from the geothermal stratum 11 through the perforations 4 and into the well casing 2.
The heated geothermal fluids which have entered the well casing 2 will now rise up the well casing 2 filling the entire well casing 2 and pass through pipe 9 and valve 8 until a continuous strong production is maintained from the geothermal stratum 11 into the well casing 2 as measured by gauge 7 for temperature and pressure, located above the well 's cap 6.
After the desired temperature and pressure have been attained at gauge 7 the valve 8 is partially or completely closed to permit the heated gas or fluids from the geothermal stratum 11 to enter perforations and the formation 10 where in situ mining or retorting of contained oil, gas, other minerals, chemicals, and metals may occur. Through other wells not shown which penetrate the formation 10, the oil, gas, and other products are subsequently recovered.
FIG. 2 illustrates the preferred closed system with auxiliary equipment such as the fluid injection pipe 12 and a bottomhole plug 3 which surrounds the fluid injection pipe 12 completely sealing the metal well casing 2 at the wells bottom. This embodiment of the inventive system contains a pump 13 to inject fluid under pressure into the geothermal stratum 11 as required.
Referring now to the top of the well auxiliary equipment as shown in FIG. 2, there is both a fluid injection pipe 12 and a fluid withdrawal pipe 9 which permits adequate testing of gas or fluid in the well casing 2 prior to partial or complete closing of valve 8 located on the fluid withdrawal pipe 9.
Referring now to the fluid circuit as illustrated in FIG. 2, fluid enters the injection pipe 12, from a source not shown, passing through valve 8 and into pump 13 which controls the pressure of the fluid injected into the geothermal stratum 11. After being heated in the geothermal stratum 11 the steam or hot water enters the well casing 12 through perforations 4 and rises in the well casing 2 to invade the mineralized stratum 10 by passing through the perforations 5 made through the well casing 2, the cement l, and penetrating the mineralized stratum 10. Pressure and temperature of the steam or hot fluid within the well casing 2 is measured by gauge 7. The valve 8 in line 9 maintains a high pressure within casing 2 when the valve is partially or completely closed.
To initiate recovery of the oil, gas, minerals, chemicals, or metals after in situ retorting has been accomplished in the mineralized stratum 10, other conventional wells, such as a producing well extending from the surface into the stratum 10, would produce the products.
Referring now to FIG. 3, this method of in situ retorting within a mineralized stratum 10 would serve to utilize geothermal stratum 11 which may contain excessive contaminants or lack moisture but possess sufficient heat. This method excludes the perforations 4 and depends upon a sufiicient heat exchange to be accomplished to effect heating of the fluid 14 to sufficient temperature to effect its rise and entry into perforations 5 and the mineralized stratum l0. 1
Recent technology in drilling large diameter wells into the earth provides a means to effect large reservoirs of fluids l4 and large areas of heat exchange surfaces on the well casing 2 which is submerged into geothermal stratum ll.
With respect to the drilling of wells for in situ retorting of gas, oil, minerals, chemicals, or metals, temperatures within the earth increase with depth at a rate of approximately 3 C. for each 328 feet of depth. However, abnormal increases over this mean occur in many instances because of faulting, volcanism, metamorphosis, chemical, and radiological activities. All oil and gas fields are related to entrapments which are related to faults and such faults are rich sources of geothermal heat energy. It has also been noted in many deep wells drilled into the earth that deep-seated faults contain excessive temperatures. At some depth beneath every square mile of the earth's surface lies a vast store of geothermal heat energy which can, in many instances, be put to work for in situ mining or retortmg.
When it is desirable to discontinue the flow of geothermal gases or fluids into a preselected zone, it can easily be accomplished by employing conventional well remedial methods such as inserting packers, squeezing off zones, or cementing of well bores.
It is recognized that various, more extensive communication methods between geothermal zones and other zones may become obvious, such as mining the geothermal fluids from one well and returning it into another well and into a different zone.
The possibilities of utilization of this inventive system are infinite, and grandiose schemes are envisioned, such as repres surizing entire oil and gas fields, mining minerals, chemicals, and metals which have heretofore existed too deep for economic mining and opening new vistas of mining procedures by the controlled displacement of geothermal temperatures from one stratum or zone within the earth into other preselected strata or zones.
Whereas the invention has been described with reference to recovery of oil, gas, chemicals and minerals, it is within the scope of the invention to employ the system described hereinbefore to retort impure, salty or brackish waters within strata beneath the surface of the earth in order to recover pure water therefrom.
What is claimed is:
l. A system for producing a material selected from oil, gas, chemicals, minerals, metals and the like from a geological formation including a subsurface stratum containing at least one of said materials overlying a dry, subsurface geothermal zone having an abundant supply of naturally occurring heat and having a naturally occurring temperature substantially greater than said stratum, comprising in combination:
means for injecting heated fluid into said material containing stratum comprising a first well bore extending from said surface and through said stratum into said lower zone, a metal casing lining said bore containing a cap at a first end above said surface and a sealing plug received in the lower end of the casing within said zone and containing a first series of perforations above said plug and within said zone and a second series of perforations within the portion of the casing traversing the stratum; a fluid injection pipe disposed within said casing and having a first upper end extending through said cap and a second lower end extending sealingly through said plug and into said zone below said plug; a source of liquid; pump means for pumping said liquid from said source into the first end of said pipe and through said second end and into said zone to form a body of pressurized, heated fluid within said zone for entering said casing through said first series of perforations and for injecting said pressurized, heated fluid into said stratum through said second series of perforations to form a fluidized body of said liquid and material; and
a producing well spaced laterally from said first well bore having a lower, open end disposed within said stratum and an upper end communicating with the surface for transferring said fluidized body to the surface for recovery of said material.
2. A system according to claim 1 further including outlet means containing a valve connected to said casing above the surface for flowing said well at the surface of the earth.
3. A system according to claim 1 further comprising a cement layer surrounding and engaging said plug and the exterior of the casing below the surface of the earth and said layer containing said perforations and an aperture for receiving said pipe.
4. A method for recovering a material selected from oil, gas, minerals, chemicals, metals and the like from a geological formation including a subsurface stratum containing at least one of said materials and a lower, dry, geothermal zone having an abundant reservoir of heat and a natural temperature substantially above the temperature of the stratum comprising the steps of:
drilling a well bore through said formation having an upper end communicating with the surface of the earth and a lower end terminating within said zone;
lining said bore with a metal casing having a first series of perforations within said zone above the lower end of the casing and a second series of perforations within the portion of the casing traversing the stratum;
capping the upper end of the casing;
plugging the lower end of the casing within said zone and below said second perforations;
disposing a pipe within said casing having an upper end penetrating said cap and a lower end penetrating said plug and extending into said zone;
injecting liquid under pressure through said pipe into said zone to form a body of heated liquid;
transferring said heated liquid through said first perforations into said casing and from said casing through said second perforations into said stratum in sufficient volume to form a fluidized body of said heated liquid and said material within said stratum;
drilling at least one second well, laterally spaced from said first well and extending from the surface into said stratum and in communication with said fluidized body; and
recovering said fluidized body of material from said second well.
5. A method according to claim 4 in which said injected liquid is water.
* l i I I
|Patente citada||Fecha de presentación||Fecha de publicación||Solicitante||Título|
|US2856000 *||20 Jul 1954||14 Oct 1958||Texaco Development Corp||Production of hydrocarbons from subsurface reservoirs|
|US2871945 *||21 Sep 1956||3 Feb 1959||Ralph Spearow||Single casing multiple horizon oil production method|
|US3258069 *||7 Feb 1963||28 Jun 1966||Shell Oil Co||Method for producing a source of energy from an overpressured formation|
|US3274769 *||5 May 1964||27 Sep 1966||J B Reynolds Inc||Ground heat steam generator|
|US3294167 *||13 Abr 1964||27 Dic 1966||Shell Oil Co||Thermal oil recovery|
|US3379247 *||8 Nov 1965||23 Abr 1968||Phillips Petroleum Co||Oil recovery process using hot fluids|
|US3430700 *||16 Dic 1966||4 Mar 1969||Pan American Petroleum Corp||Recovery of petroleum by thermal methods involving transfer of heat from one section of an oil-bearing formation to another|
|US3432205 *||8 Dic 1966||11 Mar 1969||Shell Oil Co||Sulfur steam drive|
|FR1414837A *||Título no disponible|
|Patente citante||Fecha de presentación||Fecha de publicación||Solicitante||Título|
|US3830305 *||21 Feb 1974||20 Ago 1974||Atlantic Richfield Co||Method of well production in permafrost|
|US3830317 *||21 Feb 1974||20 Ago 1974||Atlantic Richfield Co||Well drilling in permafrost|
|US3878884 *||2 Abr 1973||22 Abr 1975||Cecil B Raleigh||Formation fracturing method|
|US3889473 *||8 Mar 1974||17 Jun 1975||Van Huisen Allen T||Geothermal channel and harbor ice control system|
|US4074754 *||27 Sep 1976||21 Feb 1978||Exxon Production Research Company||Method for producing geothermal energy and minerals|
|US4078608 *||23 Mar 1977||14 Mar 1978||Texaco Inc.||Thermal oil recovery method|
|US4105252 *||20 Dic 1976||8 Ago 1978||Atlantic Richfield Company||Solution mining of minerals from vertically spaced zones|
|US4199028 *||22 Nov 1978||22 Abr 1980||Conoco, Inc.||Enhanced recovery with geopressured water resource|
|US4211613 *||28 Nov 1977||8 Jul 1980||Milton Meckler||Geothermal mineral extraction system|
|US4248306 *||2 Abr 1979||3 Feb 1981||Huisen Allan T Van||Geothermal petroleum refining|
|US4319635 *||29 Feb 1980||16 Mar 1982||P. H. Jones Hydrogeology, Inc.||Method for enhanced oil recovery by geopressured waterflood|
|US4387016 *||10 Nov 1980||7 Jun 1983||Gagon Hugh W||Method for extraction of bituminous material|
|US5322115 *||4 Jul 1989||21 Jun 1994||Hans Hildebrand||Installation for energy exchange between the ground and an energy exchanger|
|US5622450 *||24 Mar 1995||22 Abr 1997||Grant, Jr.; Richard P.||Pressure extraction process for removing soil and groundwater contaminants|
|US7490657 *||19 Sep 2007||17 Feb 2009||Hiroaki Ueyama||Double-pipe geothermal water circulating apparatus|
|US7673681||19 Oct 2007||9 Mar 2010||Shell Oil Company||Treating tar sands formations with karsted zones|
|US7677310||19 Oct 2007||16 Mar 2010||Shell Oil Company||Creating and maintaining a gas cap in tar sands formations|
|US7677314||19 Oct 2007||16 Mar 2010||Shell Oil Company||Method of condensing vaporized water in situ to treat tar sands formations|
|US7681647||19 Oct 2007||23 Mar 2010||Shell Oil Company||Method of producing drive fluid in situ in tar sands formations|
|US7717171||19 Oct 2007||18 May 2010||Shell Oil Company||Moving hydrocarbons through portions of tar sands formations with a fluid|
|US7730945 *||19 Oct 2007||8 Jun 2010||Shell Oil Company||Using geothermal energy to heat a portion of a formation for an in situ heat treatment process|
|US7730946||19 Oct 2007||8 Jun 2010||Shell Oil Company||Treating tar sands formations with dolomite|
|US7730947||19 Oct 2007||8 Jun 2010||Shell Oil Company||Creating fluid injectivity in tar sands formations|
|US7798220||18 Abr 2008||21 Sep 2010||Shell Oil Company||In situ heat treatment of a tar sands formation after drive process treatment|
|US7798221||31 May 2007||21 Sep 2010||Shell Oil Company||In situ recovery from a hydrocarbon containing formation|
|US7841401||19 Oct 2007||30 Nov 2010||Shell Oil Company||Gas injection to inhibit migration during an in situ heat treatment process|
|US7841408||18 Abr 2008||30 Nov 2010||Shell Oil Company||In situ heat treatment from multiple layers of a tar sands formation|
|US7845406 *||30 Ago 2007||7 Dic 2010||George Nitschke||Enhanced oil recovery system for use with a geopressured-geothermal conversion system|
|US7849922||18 Abr 2008||14 Dic 2010||Shell Oil Company||In situ recovery from residually heated sections in a hydrocarbon containing formation|
|US7866385||20 Abr 2007||11 Ene 2011||Shell Oil Company||Power systems utilizing the heat of produced formation fluid|
|US7866386||13 Oct 2008||11 Ene 2011||Shell Oil Company||In situ oxidation of subsurface formations|
|US8191630||28 Abr 2010||5 Jun 2012||Shell Oil Company||Creating fluid injectivity in tar sands formations|
|US8196658||13 Oct 2008||12 Jun 2012||Shell Oil Company||Irregular spacing of heat sources for treating hydrocarbon containing formations|
|US8381815||18 Abr 2008||26 Feb 2013||Shell Oil Company||Production from multiple zones of a tar sands formation|
|US8555971||31 May 2012||15 Oct 2013||Shell Oil Company||Treating tar sands formations with dolomite|
|US8627887||8 Dic 2008||14 Ene 2014||Shell Oil Company||In situ recovery from a hydrocarbon containing formation|
|US8662175||18 Abr 2008||4 Mar 2014||Shell Oil Company||Varying properties of in situ heat treatment of a tar sands formation based on assessed viscosities|
|US9181780||18 Abr 2008||10 Nov 2015||Shell Oil Company||Controlling and assessing pressure conditions during treatment of tar sands formations|
|US9518787||1 Nov 2013||13 Dic 2016||Skanska Svergie Ab||Thermal energy storage system comprising a combined heating and cooling machine and a method for using the thermal energy storage system|
|US9657998||1 Nov 2013||23 May 2017||Skanska Sverige Ab||Method for operating an arrangement for storing thermal energy|
|US9791217||1 Nov 2013||17 Oct 2017||Skanska Sverige Ab||Energy storage arrangement having tunnels configured as an inner helix and as an outer helix|
|US20080073058 *||19 Sep 2007||27 Mar 2008||Hiroaki Ueyama||Double-Pipe geothermal water circulating apparatus|
|US20080142217 *||19 Oct 2007||19 Jun 2008||Roelof Pieterson||Using geothermal energy to heat a portion of a formation for an in situ heat treatment process|
|US20090056944 *||30 Ago 2007||5 Mar 2009||George Nitschke||Enhanced oil recovery system for use with a geopressured-geothermal conversion system|
|US20090080979 *||22 Sep 2008||26 Mar 2009||Fruits & Associates, Inc.||System and method for decontaminating soil and groundwater|
|US20150354903 *||1 Nov 2013||10 Dic 2015||Skanska Sverige Ab||Thermal energy storage comprising an expansion space|
|WO1994021889A2 *||15 Mar 1994||29 Sep 1994||John North||Improvements in or relating to drilling and to the extraction of fluids|
|WO1994021889A3 *||15 Mar 1994||8 Dic 1994||John North||Improvements in or relating to drilling and to the extraction of fluids|
|Clasificación de EE.UU.||299/4, 166/401, 165/45, 166/52, 166/269|
|Clasificación internacional||E21B43/16, E21B43/00, E21B43/28, E21B43/24|
|Clasificación cooperativa||E21B43/281, E21B43/24|
|Clasificación europea||E21B43/24, E21B43/28B|
|16 Dic 1982||AS02||Assignment of assignor's interest|
Owner name: IMPERIAL ENERGY CORPORATION, 2049 CENTURY PARK EAS
Effective date: 19821115
Owner name: VAN HUISEN, ALLEN T.
|16 Dic 1982||AS||Assignment|
Owner name: IMPERIAL ENERGY CORPORATION, 2049 CENTURY PARK EAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:VAN HUISEN, ALLEN T.;REEL/FRAME:004076/0842
Effective date: 19821115
|17 Ago 1981||AS||Assignment|
Owner name: ROSS, KENNETH A., JR.
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:BRIGGS, GEORGE L.;BRIGGS, RAMONA M.;REEL/FRAME:003887/0065
Effective date: 19810807
|17 Ago 1981||AS02||Assignment of assignor's interest|
Owner name: BRIGGS, GEORGE L.
Owner name: BRIGGS, RAMONA M.
Effective date: 19810807
Owner name: ROSS, KENNETH A., JR.