Patents by Inventor Dragan Stojkovic
Dragan Stojkovic has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20240084191Abstract: A slurry including a density-tunable aqueous heavy fracturing fluid and a method for completing a hydrocarbon well using such a slurry are provided herein. The slurry includes proppant particulates and the density-tunable aqueous heavy fracturing fluid, where the density-tunable aqueous heavy fracturing fluid includes a bromide-based compound. The density of the density-tunable aqueous heavy fracturing fluid is between 1 gram/cubic centimeter (g/cc) and 3.6 g/cc.Type: ApplicationFiled: August 17, 2023Publication date: March 14, 2024Inventors: Timothy J. NEDWED, Dragan STOJKOVIC, Lee J. HALL, P. Matthew SPIECKER
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Patent number: 11905813Abstract: A slurry including a density-tunable heavy fracturing fluid and a method for completing a hydrocarbon well using such a slurry are provided herein. The slurry includes a proppant and the density-tunable heavy fracturing fluid, where the density-tunable heavy fracturing fluid includes a pseudo heavy fluid suspension, a concentrated aqueous solution of a soluble heavy compound, and/or a high-density organic solution. The density of the density-tunable heavy fracturing fluid is between 1.25 grams/milliliter (g/ml) and 3.4 g/ml. Moreover, the density of the density-tunable heavy fracturing fluid is selected based on the density of the proppant. According to the method provided herein, the slurry is used to provide for more effective placement of the proppant within the fractures than can be achieved using only a slurry including conventional fracturing fluid and the proppant.Type: GrantFiled: November 14, 2022Date of Patent: February 20, 2024Assignee: ExxonMobil Technology and Engineering CompanyInventors: Timothy J. Nedwed, Dragan Stojkovic, Lee J. Hall
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Publication number: 20230286395Abstract: A method for controlling an electromotive drive of a motor vehicle. At least one of the motor vehicle wheels can be driven by an electric motor of the electromotive drive and the electromotive drive has at least one energy source for the electric motor. The method includes: identifying a request for applying a deceleration torque to the vehicle wheel, identifying status of the electromotive drive, selecting an operating mode of the electric motor according to the identified status, and controlling the electric motor in the selected operating mode for applying the deceleration torque. In a first operating mode, the electric motor is controlled such that the rotational energy of the vehicle wheel is converted at a first efficiency into electrical energy. In a second operating mode, the electric motor is controlled such that the rotational energy of the vehicle wheel is converted at a second efficiency into electrical energy.Type: ApplicationFiled: August 6, 2021Publication date: September 14, 2023Inventors: Olivier Frament, Jens Hoffmann, Martin Semsch, Matthias Töns, Martin Spornraft, Dragan Stojkovic, Vincent Vahee
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Publication number: 20230175377Abstract: A slurry including a density-tunable heavy fracturing fluid and a method for completing a hydrocarbon well using such a slurry are provided herein. The slurry includes a proppant and the density-tunable heavy fracturing fluid, where the density-tunable heavy fracturing fluid includes a pseudo heavy fluid suspension, a concentrated aqueous solution of a soluble heavy compound, and/or a high-density organic solution. The density of the density-tunable heavy fracturing fluid is between 1.25 grams/milliliter (g/ml) and 3.4 g/ml. Moreover, the density of the density-tunable heavy fracturing fluid is selected based on the density of the proppant. According to the method provided herein, the slurry is used to provide for more effective placement of the proppant within the fractures than can be achieved using only a slurry including conventional fracturing fluid and the proppant.Type: ApplicationFiled: November 14, 2022Publication date: June 8, 2023Inventors: Timothy J. NEDWED, Dragan STOJKOVIC, Lee J. HALL
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Publication number: 20230167354Abstract: Proppant particulates like sand are commonly used in hydraulic fracturing operations to maintain one or more fractures in an opened state following the release of hydraulic pressure. Fracturing fluids and methods of hydraulic fracturing may also use proppant particulates composed of high-flow polyolefin coated mineral particles (referred to as high-flow polyolefin coated mineral proppant particulates). In some instances, the high-flow polyolefin-coated mineral proppant particulates have a particle density of equal to or less than about 1.35 grams per cubic centimeter, and further may be prepared using a one-pot hot melt process.Type: ApplicationFiled: November 10, 2022Publication date: June 1, 2023Inventors: Dragan STOJKOVIC, Abdelhadi SAHNOUNE, Haiqing PENG, Lee J. HALL, Kendal K. DECKER
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Publication number: 20230134440Abstract: Proppant particulates like sand are commonly used in hydraulic fracturing operations to maintain one or more fractures in an opened state following the release of hydraulic pressure. Fracturing fluids and methods of hydraulic fracturing may also use proppant particulates composed of resin-coated petroleum coke (referred to as resin-coated petroleum coke proppant particulates). In some instances, the resin-coated petroleum coke proppant particulates have a particle density of equal to or less than about 1.7 grams per cubic centimeter and better resistance to creating fines when exposed to uniaxial stress.Type: ApplicationFiled: October 18, 2022Publication date: May 4, 2023Inventors: Kendal DECKER, Dragan STOJKOVIC, Lee J. HALL
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Publication number: 20230119075Abstract: Methods for completing hydrocarbon wells using variable rate fracturing are provided herein. One method includes positioning a perforation device within a tubular conduit of a downhole tubular, where the downhole tubular extends within a wellbore, and where the wellbore extends within a subsurface region, as well as perforating the downhole tubular using the perforation device to define perforations within the downhole tubular. The method also includes pumping a slurry including fracturing fluid and a lightweight proppant into the tubular conduit according to a variable pumping rate schedule to fracture zones of the subsurface region that are proximate to the perforations, forming corresponding fractures within the subsurface region. The method further includes flowing the slurry into the fractures, via the perforations, to prop the fractures with the lightweight proppant, where the lightweight proppant includes granules formed from a polyolefin, petroleum coke, and/or a polyaromatic hydrocarbon resin.Type: ApplicationFiled: October 12, 2022Publication date: April 20, 2023Inventors: Lee J. HALL, Dragan STOJKOVIC
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Patent number: 11555388Abstract: A self-adjusting gas lift system and corresponding self-adjusting gas lift valve (GLV) are described herein. The self-adjusting gas lift system includes a number of self-adjusting GLVs that fluidically couple an annulus of a well to an interior of a production tubing of the well. Each of the self-adjusting GLVs is configured to open to allow a compressed gas to flow from the annulus to the interior of the production tubing when a pressure differential between an injection pressure of the compressed gas within the annulus and a production pressure of fluids within the production tubing is within an engineered range. Each of the self-adjusting GLVs is also configured to close when the pressure differential is outside the engineered range.Type: GrantFiled: September 8, 2020Date of Patent: January 17, 2023Assignee: ExxonMobil Upstream Research CompanyInventors: Dragan Stojkovic, Michael C. Romer, Federico G. Gallo
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Patent number: 11506042Abstract: An oil-water fractionation system is positioned within a wellbore on a subsurface end of a production tubing proximate to a production region. The fractionation system includes a permeable hydrophobic media for preferentially conveying an oil-enriched stream (reduced water-cut presence) from the production region into the production tubing, and a permeable oleophobic media for preferentially conveying a water-enriched stream (reduced oil-cut presence) into a second flow path. The permeable hydrophobic media and the permeable oleophobic media are in simultaneous hydraulic communication with the production region. The permeable hydrophobic media is manufactured with a relatively high effective permeability to oil, allowing the oil-enriched stream to flow through the permeable hydrophobic media into the production tubing.Type: GrantFiled: October 22, 2020Date of Patent: November 22, 2022Assignee: ExxonMobil Upstream Research CompanyInventors: Mauro Lo Cascio, Andrey A. Troshko, Michael T. Hecker, Matthew S. Jackson, Dragan Stojkovic
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Patent number: 11414974Abstract: Hydrocarbon wells including crosslinked polymer granules as a proppant, methods of forming the hydrocarbon wells, and methods of operating the hydrocarbon wells. The hydrocarbon wells include a wellbore that extends within a subsurface region and a downhole tubular that extends within the wellbore and defines a tubular conduit. The hydrocarbon wells also include a plurality of perforations formed within the downhole tubular and a plurality of fractures formed within the subsurface region. The hydrocarbon wells further include the proppant positioned within the plurality of fractures. The proppant includes a plurality of crosslinked polymer granules, and each crosslinked polymer granule has a characteristic dimension of at least 100 micrometers and at most 2 millimeters.Type: GrantFiled: July 24, 2020Date of Patent: August 16, 2022Assignee: ExxonMobil Upstream Research CompanyInventors: Pavlin B. Entchev, Robert M. Shirley, Alan A. Galuska, William Handy, Dragan Stojkovic
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Patent number: 11293847Abstract: Test systems and methods for evaluating erosion of a test sample. The test systems include a particulate distribution structure configured to receive a supplied particulate stream and to discharge a distributed particulate stream. The test systems also include a particulate acceleration structure configured to receive the distributed particulate stream and to generate an accelerated particulate stream. The test systems further include a test sample fixture configured to hold the test sample at a test sample location positioned such that the accelerated particulate stream is incident upon the test sample location. The methods include methods of operating the test systems.Type: GrantFiled: April 14, 2020Date of Patent: April 5, 2022Assignee: ExxonMobil Upstream Research CompanyInventors: Matthew S. Jackson, Federico G. Gallo, Christian S. Mayer, Dragan Stojkovic, David Milton-Tayler, James Goddings
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Publication number: 20220098932Abstract: A capacitive cable, as well as a method for operating a downhole electro-hydraulic (EH) tool using the capacitive cable, are described herein. The capacitive cable includes at least one standard conductor and at least one capacitive conductor including integrated wire-shaped capacitors. The method includes inserting a tool string including the capacitive cable and an attached downhole EH tool into a wellbore and conducting power from the surface to the downhole EH tool via the standard conductor(s) of the capacitive cable. The method also includes storing electrical energy downhole within the capacitive conductor(s) of the capacitive cable, and activating the downhole EH tool to provide for the rapid release of the electrical energy from the capacitive conductor(s) into the downhole EH tool, initiating an electro-hydraulic event within the wellbore.Type: ApplicationFiled: April 13, 2021Publication date: March 31, 2022Inventors: ROMER MICHAEL C., P. MATTHEW SPIECKER, PETER A. GORDON, DRAGAN STOJKOVIC
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Publication number: 20210180440Abstract: An oil-water fractionation system for use in a wellbore is described herein. The fractionation system is positioned within a wellbore on a subsurface end of a production tubing proximate to a production region. The fractionation system includes a permeable hydrophobic media for preferentially conveying an oil-enriched stream (reduced water-cut presence) from the production region into the production tubing, and a permeable oleophobic media for preferentially conveying a water-enriched stream (reduced oil-cut presence) into a second flow path. The permeable hydrophobic media and the permeable oleophobic media are in simultaneous hydraulic communication with the production region. The permeable hydrophobic media is manufactured with a relatively high effective permeability to oil, allowing the oil-enriched stream to flow through the permeable hydrophobic media into the production tubing.Type: ApplicationFiled: October 22, 2020Publication date: June 17, 2021Inventors: Mauro Lo Cascio, Andrey A. Troshko, Michael T. Hecker, Matthew S. Jackson, Dragan Stojkovic
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Publication number: 20210131238Abstract: A self-adjusting gas lift system and corresponding self-adjusting gas lift valve (GLV) are described herein. The self-adjusting gas lift system includes a number of self-adjusting GLVs that fluidically couple an annulus of a well to an interior of a production tubing of the well. Each of the self-adjusting GLVs is configured to open to allow a compressed gas to flow from the annulus to the interior of the production tubing when a pressure differential between an injection pressure of the compressed gas within the annulus and a production pressure of fluids within the production tubing is within an engineered range. Each of the self-adjusting GLVs is also configured to close when the pressure differential is outside the to engineered range.Type: ApplicationFiled: September 8, 2020Publication date: May 6, 2021Inventors: Dragan Stojkovic, Michael C. Romer, Federico G. Gallo
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Publication number: 20210047906Abstract: Hydrocarbon wells including crosslinked polymer granules as a proppant, methods of forming the hydrocarbon wells, and methods of operating the hydrocarbon wells. The hydrocarbon wells include a wellbore that extends within a subsurface region and a downhole tubular that extends within the wellbore and defines a tubular conduit. The hydrocarbon wells also include a plurality of perforations formed within the downhole tubular and a plurality of fractures formed within the subsurface region. The hydrocarbon wells further include the proppant positioned within the plurality of fractures. The proppant includes a plurality of crosslinked polymer granules, and each crosslinked polymer granule has a characteristic dimension of at least 100 micrometers and at most 2 millimeters.Type: ApplicationFiled: July 24, 2020Publication date: February 18, 2021Inventors: Pavlin B. Entchev, Robert M. Shirley, Alan A. Galuska, William Handy, Dragan Stojkovic
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Publication number: 20200371007Abstract: Test systems and methods for evaluating erosion of a test sample. The test systems include a particulate distribution structure configured to receive a supplied particulate stream and to discharge a distributed particulate stream. The test systems also include a particulate acceleration structure configured to receive the distributed particulate stream and to generate an accelerated particulate stream. The test systems further include a test sample fixture configured to hold the test sample at a test sample location positioned such that the accelerated particulate stream is incident upon the test sample location. The methods include methods of operating the test systems.Type: ApplicationFiled: April 14, 2020Publication date: November 26, 2020Inventors: Matthew S. Jackson, Federico G. Gallo, Christian S. Mayer, Dragan Stojkovic, David Milton-Tayler, James Goddings
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Publication number: 20200095851Abstract: A subsurface autonomous inflow control device for a wellbore, the inflow control device comprising a tubular base pipe having one or more through-openings for receiving production fluids within a wellbore. The inflow control device further includes a housing residing along an outer diameter of the tubular base pipe and covering the one or more through-openings. The housing comprises a fluid inlet configured to receive production fluids from a subsurface formation, and a hydrophobic material positioned within the housing between the fluid inlet and the through-openings. The hydrophobic material provides a network of pores that permits a flow of hydrocarbon fluids there through en route to the through-openings, but the hydrophobic material blocks the passage of aqueous fluids there through. A method for completing a wellbore having the porous, hydrophobic inflow control device is also provided.Type: ApplicationFiled: July 11, 2019Publication date: March 26, 2020Inventors: Dragan Stojkovic, Matthew S. Jackson, Edward C. Wanat, Mauro Lo Cascio, Federico G. Gallo
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Patent number: 10427614Abstract: An article rack includes a base mountable to a top rail of a truck box, a carrier, and a linkage pivotally connected to the base and the carrier. A drive mechanism of the rack has a first wheel fixed to the base, a second wheel fixed to the carrier, and an endless loop trained around the wheels such that pivoting of the linkage about the base pivots the carrier about the linkage.Type: GrantFiled: December 8, 2017Date of Patent: October 1, 2019Assignee: FORD GLOBAL TECHNOLOGIES, LLCInventors: Jack Marchlewski, Joshua Robert Hemphill, Dragan Stojkovic, Robert Reiners, Jeffrey Gray
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Publication number: 20190176714Abstract: An article rack includes a base mountable to a top rail of a truck box, a carrier, and a linkage pivotally connected to the base and the carrier. A drive mechanism of the rack has a first wheel fixed to the base, a second wheel fixed to the carrier, and an endless loop trained around the wheels such that pivoting of the linkage about the base pivots the carrier about the linkage.Type: ApplicationFiled: December 8, 2017Publication date: June 13, 2019Inventors: Jack MARCHLEWSKI, Joshua Robert HEMPHILL, Dragan STOJKOVIC, Robert REINERS, Jeffrey GRAY
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Patent number: 9187129Abstract: A body frame for mounting to a base frame of a vehicle includes a body mount assembly including an aluminum, tubular cross member having an inner passage and an aluminum collar support received in the inner passage for supporting the tubular cross member once it is coupled to the base frame of the vehicle. The collar support member has a multi-hollows design including an inner and outer, cylindrically-shaped portions and a plurality of equi-angularly spaced, radially extending walls interconnecting the inner and outer portions for providing the body mount the required flexibility during assembly and the required structural support and performance during vehicle use.Type: GrantFiled: December 17, 2013Date of Patent: November 17, 2015Assignee: FORD GLOBAL TECHNOLOGIES, LLCInventor: Dragan Stojkovic