Abstract: An air conditioning system for an aircraft passenger compartment, the system including: an air supply circuit connecting at least one external air inlet to at least one air distribution outlet which opens into the compartment, an auxiliary power unit mounted in the supply circuit and configured to compress an air stream in the supply circuit, the supply circuit including a heating first branch that connects the auxiliary power unit to the air distribution outlet, and in which a heating mechanism is mounted, a cooling second branch that connects the auxiliary power unit to the air distribution outlet, and a switching mechanism configured to distribute the air stream between the heating first branch and the cooling second branch.

Abstract: Disclosed therein is an air conditioner for a vehicle, which includes an evaporator and a storage tank getting in surface contact with each other, thereby doubling a cold storage effect by directly transferring cold air of the evaporator to the storage tank in a cooling mode, maximizing the cold storage effect because condensate water generated from the surface of the evaporator additionally cools the surface of the storage tank, and effectively enhancing heat-exchanging performance without increasing capacity of the storage tank. The air conditioner further includes heat-exchanging means mounted inside the storage tank so as to enhance the heat exchange performance of a heat carrier more.

Abstract: A mobile heat dispersion system for preventing liquid conduits from freezing in cold environments, such as on frac pads, including a self-contained heating system formed of a forced air heater operatively connected to a fabric heat duct system and a heat entrapment cage enclosing both the liquid conduit to be protected and the fabric heat duct system, and a process for use thereof.

Abstract: Cooling systems and methods are provided which include a heat sink having a housing with a compartment, a coolant inlet, and a coolant outlet. The housing is configured for a coolant to flow from the coolant inlet through the compartment to the coolant outlet, wherein the coolant is transferring heat extracted from one or more electronic components. The heat sink further includes one or more heat pipes having a first portion disposed within the compartment of the housing and a second portion disposed outside the housing. The heat pipe(s) is configured to extract heat from the coolant flowing through the compartment, and to transfer the extracted heat to the second portion disposed outside the housing. The second portion outside the housing is disposed to facilitate conducting the extracted heat into the ground.

Abstract: Cooling methods are provided which include providing a heat sink having a housing with a compartment, a coolant inlet, and a coolant outlet. The housing is configured for a coolant to flow from the coolant inlet through the compartment to the coolant outlet, wherein the coolant is transferring heat extracted from one or more electronic components. The heat sink further includes one or more heat pipes having a first portion disposed within the compartment of the housing and a second portion disposed outside the housing. The heat pipe(s) is configured to extract heat from the coolant flowing through the compartment, and to transfer the extracted heat to the second portion disposed outside the housing. The second portion outside the housing is disposed to facilitate conducting the extracted heat into the ground.

Abstract: An air diffuser having a single air inlet has air outlets straddling a wall of a structure to distribute air to two or more rooms of the structure. The air diffuser includes an adjustable baffle that selectively directs air toward the first and second rooms. The air diffuser includes an acoustic dampener that prevents sound from moving through the air diffuser from one room to the next.

Abstract: A method of operating an air conditioning system includes cooling a selected space with the air conditioning system. The air conditioning system includes two or more compressors and two or more crank case heaters. Each crank case heater of the two or more crank case heaters is associated with a compressor of the two or more compressors. Operation of the two or more compressors is stopped, thus initiating operation of the two or more crank case heaters. The air conditioning system is switched to a conservation mode, including de-powering at least one compressor of the two or more compressors and an associated at least one crank case heater or the two or more crank case heaters thereby reducing energy consumption of the two or more crank case heaters.

Abstract: Cooling apparatuses and methods are provided for facilitating pumped immersion-cooling of electronic components. The cooling apparatus includes a housing forming a compartment about one or more components, a supply manifold, a return manifold, and a coolant loop coupling in fluid communication the supply and return manifolds and the housing. Coolant flowing through the coolant loop flows through the compartment of the housing and at least partially immersion-cools the component(s) by flow boiling. A pump facilitates circulation of coolant within the loop, and a coolant bypass line is coupled between the supply and return manifolds. The return manifold includes a mixed-phase manifold section, and the bypass line provides coolant from the supply manifold directly to the mixed-phase manifold section. Coolant flows from the coolant bypass line into the mixed-phase manifold section in a direction counter to the direction of any coolant vapor flow within that manifold section.

Abstract: A cooling system for a high performance computing system includes a closed-loop cooling cell having two compute racks and a cooling tower between the compute racks. Each compute rack includes at least one blade enclosure, and the cooling tower includes at least one water-cooled heat exchanger and one or more blowers configured to draw warm air from a side of the compute racks towards a back, across the water-cooled heat exchanger, and to circulate cooled air to a side of the compute racks towards a front. The cooling cell further includes a housing enclosing the compute racks and the cooling tower to provide a closed-loop air flow within the cooling cell. The cooling system further includes cooling plate(s) configured to be disposed between two computing boards within the computing blade, and a fluid connection coupled to the cooling plate and in fluid communication with the blade enclosure.

Abstract: A method and apparatus of cooling electronic components when replacing a cooling device in an information technology system are disclosed. The apparatus may include first and second cooling device trays that may be slidably mounted within an information technology system. The cooling device trays may include one or more cooling devices that are movably mounted to the cooling device trays. The apparatus may pivot one or more of the cooling devices when a pivot member contacts a fixed member with the chassis.

Abstract: The present invention relates to an integrated cooling system for a vehicle. The system includes an engine cooling loop having a first fluid configured for circulation through an engine of the vehicle and a power electronics cooling loop having a second fluid configured for circulation through at least one power electronics component of the vehicle. The engine cooling loop is fluidly isolated from, and in thermal communication with, the power electronics cooling loop.

Abstract: A heat exchanger adapted to transmit a first fluid through an interior, having a tubular body receptive of a second fluid, whereby heat transfer occurs between the fluids is provided, the tubular body extending longitudinally through the interior, having a non-circular cross-section, and being formed to define microchannels extending longitudinally along the tubular body through which the second fluid is transmitted.

Abstract: A flywheel is provided with an annular drive shaft and a stationary cooling member for directing a coolant into the drive shaft annulus. Coolant pumped through the cooling member will contact the wall of the annulus to cool the drive shaft and components thermally coupled to the drive shaft. Where the flywheel has an upright axis of rotation with the annulus opening downwardly, coolant falls from the annulus to a sump positioned below the drive shaft.

Abstract: A heat dissipating device includes a base, a heat pipe disposed on the base, and a plurality of first and second heat dissipating fins. Each first heat dissipating fin includes a fin body having a first through hole for extension of the heat pipe therethrough. The first and second heat dissipating fins are mounted on the heat pipe in a stack and in a spaced-apart alternating arrangement. Each second heat dissipating fin includes a fin body having a second through hole for extension of the heat pipe therethrough, two adjacent lateral edges, and a cut edge interconnecting the lateral edges such that each second heat dissipating fin has a smaller area than each first heat dissipating fin. Thus, the flow field resistance of the heat dissipating device can be reduced to increase the amount of airflow through the heat dissipating device for enhancing the heat dissipating efficiency.

Abstract: Cooling apparatuses and methods of fabrication thereof are provided to facilitate two-phase, immersion-cooling of one or more electronic components. The cooling apparatus includes a housing having a compartment within which dielectric fluid is disposed which facilitates immersion-cooling of the electronic component(s). A liquid-cooled heat sink is associated with the housing and cools a cooling surface exposed within the compartment. One or more pumps are disposed within the compartment and configured to pump dielectric fluid liquid within the compartment towards the cooling surface to facilitate cooling the liquid within the compartment below a saturation temperature of the dielectric fluid. The heat sink includes or is coupled to condensing and sub-cooling regions exposed within the compartment.

Abstract: An outdoor unit includes a casing having a side surface formed with an inlet port; an outdoor fan arranged above the inlet port in the casing and configured to upwardly blow air; and an outdoor heat exchanger arranged so as to face the inlet port. The outdoor fan includes a fan and a bell mouth provided so as to surround the outer periphery of the fan, and an electric component unit positioned at the periphery of the bell mouth is arranged in the casing.

Abstract: A heat dissipation system, comprising: (a) an electronic device comprising a heat source, wherein the heat source transmits heat to a second component or an external surface of the device; (b) a heat-conducting layer being positioned such that one of its major surfaces is in operative contact with the heat source such that it is interposed between the heat source and the second component or the external surface. The heat-conducting layer comprises at least one graphene oxide-coated graphitic foil laminate which thermally shields the second component or the external surface from heat generated by the heat source, and wherein the laminate is composed of a graphitic substrate/core layer with at least one primary surface coated with a graphene oxide coating layer. This graphene oxide-coated laminate exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface hardness, and scratch resistance, making this the most effective heat dissipation system.

Abstract: Heatshield with at least one hole, characterised in that an embossment pattern is arranged around the hole, whereby the embossment pattern comprises of a plurality of protruding elongated elements extending or radiating essentially perpendicular to the perimeter of the hole.

Abstract: Abstract: The Re-Corable Coaxial Hose System allows temperature control to be added around material-carrying tubing in both new and existing dispensing systems. The jacketing system seals around the material-carrying tube and allows a thermal transfer fluid to be circulated in the resulting annular space so as to change the temperature of the material being dispensed. Because the system is comprised of a series of tubing and hoses it is flexible and can be routed around corners and through wire tracks and can be used in both manual and robotic applications. Because the seals around the material-carrying tube can be released and subsequently re-sealed, the internal material-carrying tube can be replaced, defined as “re-coring” the hose assembly.

Abstract: A device for exchanging heat between first and second fluid streams is disclosed. The device includes a core housing configured to channel the first stream through heat exchange elements and out through a first half exhaust port. A shell housing encloses the core housing and is configured to channel the second stream past the heat exchange elements, the shell housing being isolated from the core housing by a space. A second half exhaust port is formed on the shell adjacent with the first half exhaust port, the first and second half exhaust ports being separated by a gap. An expansion joint couples the core housing to the shell housing, the expansion joint configured such that the expansion joint allows the core housing to float within the shell. The expansion joint includes a flexible ring flange having an inner edge mounted to the core housing adjacent the first half exhaust port and a peripheral edge mounted to the shell housing at a circular attachment point surrounding the second half exhaust port.

Abstract: A heat exchanger having a helix coil incorporated into a stainless steel elongated variable diameter cylindrical housing and a radial direct-firing burner and a blower-driven hot flue gas to heat water. A buffer tank is incorporated within the lumen of the helix coil. At least one rope seal is disposed between adjacent coil loops of a portion of the helix coil for enhancing heat transfer to the helix coil. In one embodiment, the heat exchanger further comprises a Stirling engine comprised of a free piston having hot and cold ends that is disposed within the cavity taken up the buffer tank, wherein the hot end receives heat from the burner and the cold end is cooled by the incoming cold water line to form an electric power generator.

Abstract: A heat exchanger having a helix coil incorporated into a stainless steel elongated variable diameter cylindrical housing and a radial direct-firing burner and a blower-driven hot flue gas to heat water. A buffer tank is incorporated within the lumen of the helix coil. At least one rope seal is disposed between adjacent coil loops of a portion of the helix coil for enhancing heat transfer to the helix coil. In one embodiment, the heat exchanger further comprises a Stirling engine comprised of a free piston having hot and cold ends that is disposed within the cavity taken up the buffer tank, wherein the hot end receives heat from the burner and the cold end is cooled by the incoming cold water line to form an electric power generator.

Abstract: Disclosed herein is a cooling system of a power semiconductor device. The cooling system of a power semiconductor device, which improves a cooling structure according to the related art to deprive heat generated from power devices while moving a working fluid introduced through an inlet to one direction and discharge the working fluid to an outlet, forms a branch inlet in a direction crossing a main inlet and additionally introduce the low-temperature working fluid through the branch inlet so as to be supplied to a channel to mix the working fluid supplied through the main inlet via the channel with the working fluid additionally introduced through the branch inlet around power devices, thereby improving a cooling effect.

Abstract: A heat exchanger for an air conditioner and an air conditioner having the same are provided. The heat exchanger may include at least one heat exchange device, the heat exchange device comprising a lower header provided therein with a lower flow path; an upper header provided therein with an upper flow path; and a plurality of flat tubes provided therein with a plurality of flow paths that communicates with the lower flow path and the upper flow path. The upper flow path may be partitioned into a first lower flow path with which a portion of the plurality of flat tubes may communicate, and a second lower flow path with which a remaining portion of the plurality of flat tubes may communicate. Each of an internal sectional area of the upper header and an internal sectional area of the lower header may be 0.7 times or more as large as a sum of sectional areas of flow paths in the plurality of flat tubes forming one path.

Abstract: The current invention provides a tube-grasping body for grasping an insert tube in a heat exchanger, and heat exchanger production methods and apparatuses utilizing the tube-grasping body, wherein said tube-grasping body enables to enlarge and connect an insert tube to a heat radiating fin for producing a heat exchanger, still keeping the total length of insert tubes at an almost same level even after the enlargement; and said tube-grasping body is connected at its exterior to the guide-pipe.

Abstract: A thermal energy transfer device attached to an object to dissipate thermal energy from the object is described. In one aspect, the device includes a non-metal base plate and first and second non-metal plate structures. The base plate includes at least one groove on one of its primary surfaces. An edge of the first plate structure is received in a first groove of the at least one groove of the base plate. An edge of the second plate structure is received in a second groove of the at least one groove of the base plate. At least the first groove or the second groove is a V-notch groove such that the edge of the first plate structure or the edge of the second plate structure that is received in the first groove or the second groove is interlockingly received in the V-notch groove.

Abstract: A radiation member includes a base material; and a composite plating layer, formed on the base material, that includes a metal layer and two or more kinds of carbon materials, having different diameters from each other, dispersed in the metal layer such that to be provided with a plurality of protruding portions, each of the protruding portions being composed by a part of each of the carbon materials that are protruded from a surface of the metal layer.

Abstract: The present invention relates to a multilayer fluid heat exchanger container comprising a thermo-conductive sheet, said sheet comprising at least a first layer comprising a metal foil and at least a second layer comprising a biocompatible plastic material, a multilayer sheet for the fluid container and systems for heating or cooling a fluid comprising the container and a fluid heating or cooling device for receiving the container. The present invention further relates to methods for heating or cooling a fluid comprising the step of circulating a fluid through the container and a process for the manufacture of the fluid container.

Abstract: The present invention provides a liquid cooling system and a method for preventing leakage thereof. The liquid cooling system comprises: an enclosed cooling liquid circulating assembly with cooling liquid flowing circularly and air above the cooling liquid provided therein; a vacuum pump leading to the air in the enclosed cooling liquid circulating assembly; and a vacuum gauge for measurement of a pressure of the air in the enclosed cooling liquid circulating assembly, wherein the vacuum pump is turned on when the measured pressure is higher than a predetermined pressure, and the vacuum pump is turned off when the measured pressure is not more than the predetermined pressure; wherein the predetermined pressure is set to ensure that the pressure of the cooling liquid is not higher than the atmospheric pressure.

Abstract: A coolant-conditioning unit is provided which includes a facility coolant path, having a facility coolant flow control valve, and a system coolant path accommodating a system coolant, and having a bypass line with a system coolant bypass valve. A heat exchanger is coupled to the facility and system coolant paths to facilitate transfer of heat from the system coolant to facility coolant in the facility coolant path, and the bypass line is disposed in the system coolant path in parallel with the heat exchanger. A controller automatically controls a regulation position of the coolant bypass valve and a regulation position of the facility coolant flow control valve based on a temperature of the system coolant, and automatically adjusts the regulation position of the system coolant bypass valve to facilitate maintaining the facility coolant flow control valve at or above a specified, partially open, minimum regulation position.

Abstract: A method is provided which includes providing a coolant-conditioning unit which includes a facility coolant path, having a facility coolant flow control valve, and a system coolant path accommodating a system coolant, and having a bypass line with a system coolant bypass valve. A heat exchanger is coupled to the facility and system coolant paths to facilitate transfer of heat from the system coolant to facility coolant in the facility coolant path, and the bypass line is disposed in the system coolant path in parallel with the heat exchanger. A controller automatically controls a regulation position of the coolant bypass valve and a regulation position of the facility coolant flow control valve based on a temperature of the system coolant, and automatically adjusts the regulation position of the system coolant bypass valve to facilitate maintaining the facility coolant flow control valve at or above a specified, partially open, minimum regulation position.

Abstract: The present invention relates to a downhole tubing cutter tool for submerging into a casing in a wellbore and separating an upper part of the casing from a lower part of the casing by cutting the casing from within, the tool extending in a longitudinal direction, comprising a tool housing having a first and a second housing part, 100 a cutting arm which is pivotably connected with the first housing part and has a cutting edge in a first end, said arm being movable between a retracted position and a projected position in relation to the tool housing, an arm activation assembly for moving the cutting arm between the retracted position and the projected position, and a rotatable shaft arranged in the second housing part and connected with the first housing part for rotating the cutting arm.

Abstract: A protective covering for use with a bottom hole assembly of a drilling rig to protect users from exposure to drilling fluid disposed within the assembly includes a sheet with a top face and a bottom face, a first set of fasteners affixed to the top face of the sheet along a longitudinal axis of the sheet and oriented substantially parallel to one another, and a second set of fasteners affixed to the bottom face of the sheet, the second set of fasteners being oriented substantially parallel to one another and perpendicular to the first set of fasteners. The user may dispose the bottom face of the sheet on the bottom hole assembly and wrap the sheet around the assembly such that the first set of fasteners engage the second set of fasteners, thereby securing the protective covering to the bottom hole assembly.

Abstract: A subterranean wellbore assembly includes an outer cylindrical wall and an inner cylindrical wall cooperatively defining an annular space. A seal assembly is disposed within the annular space. The seal assembly includes chevron seals. Each chevron seal includes a central portion and two axially and radially extending wing portions. Chevron seals may be of polymeric PEEK material or of nickel based material. Other seal assemblies may be arranged in the annular space in place of the seal assembly.

Abstract: Improved SAGD methods for recovering heavy oil from underground formations. In a first aspect a method is provided for drilling, using multi-lateral drilling techniques, a series of horizontal collector wells from a vertical shaft of a production well, below and parallel to an injection well. In a further alternative to the typical SAGD configuration having injector and producer well drilled from the same end of a region under development, the production well is instead drilled at an end of a region of development opposite to an end of such region at which an injector well is drilled. Lastly, in yet another aspect, the invention comprises a method for rejuvenating an existing SAGD well pair, comprising drilling a further production well or wells at an opposite end of said formation at which an existing injector well was drilled, preferably using multi-lateral drilling techniques.

Abstract: The present invention discloses a method and apparatus for remotely and selectively control fluid flow through tubular string disposed within a wellbore and further control fluid flow between the tubular string inner flow passage and the annular flow passage. The present invention further discloses a method of selectively and remotely receiving and interpreting a form of command or information at a desired apparatus within the wellbore caused by the operator on earth surface.

Abstract: A method of optimizing recovery of oil from a formation that includes injecting an oil tracer into an injection well in the formation and applying a tertiary oil recovery process for recovering the oil from the formation. A production well is monitored to detect the oil tracer in oil from the production wells within particular times. The method also includes modifying the tertiary oil recovery process based on the detection of the oil tracer in oil from the production well.

Abstract: A method for maneuvering a downhole tool in a well system includes: displacing a tool through a riser; detecting electromagnetic radiation from a source in real time using a detector coupled to the tool; and altering the velocity of the tool in response to detecting the electromagnetic radiation.

Abstract: A wellbore y-block junction comprises a first bore channel, a second bore channel, a deflector selectable to a neutral position, to a first bore channel selected position, and to a second bore channel selected position, a radio receiver, and a controller, wherein the controller is configured to command the deflector position to one of the neutral position, the first bore channel selected position, or the second bore channel selected position based on an input from the radio receiver.

Abstract: A tubular assembly is disclosed for use in a wellbore (5) of an oil, gas or water well, typically for landing a downhole device in the wellbore. The assembly has a sleeve (1) adapted to receive the body of the downhole device. The sleeve is deployed into a conduit in the wellbore and expanded, so that the outer circumferential surface of the sleeve is radially expanded against the inner surface of the conduit. The sleeve has a bore with an inner circumferential surface comprising an inwardly facing formation adapted to engage with an outwardly facing formation on the body of the downhole device when the body of the downhole device is disposed in the bore of the sleeve. The sleeve is typically deployed in the wellbore at the desired location and is radially expanded by an expander device (2) that is deployed within the bore of the sleeve. The expanded sleeve plastically deforms and retains its expanded configuration after the radial expansion force is removed from the sleeve.

Abstract: Proppant particles coated with an arylolic resin/silicone resin copolymer, wherein the silicon resin contains D units and T units, are suitable for fracturing operations in geological formations and retain their deformability over time without becoming excessively brittle.

Abstract: A downhole hydraulic tool employing multiple nozzles in a selectable fashion from an oilfield surface. At least one of the nozzles of the tool is equipped with a burst disk such that fluid pressure directed from the surface may be utilized in activating the nozzle. The pressure may be driven to exceed a predetermined level for sake of the activating by way of sealing off access to other nozzle(s) therebelow, for example, by way of standard ball drop techniques. Thus, nozzle selectivity may be taken advantage of when a first nozzle wears out without requiring time consuming removal of the tool from the well for sake of remedial repairs or replacement.

Abstract: Tools and methods for cutting multiple, co-extending casings in oil and gas wells are provided. The tools comprise a cylindrical body and first and second sets of cutting blades. Each set of cutting blades is mounted to the body for actuation from a retracted, run-in position to an extended, cutting position. The cylindrical body is rotated and the first set of cutting blades is actuated to cut the co-extending casings within a first sweep diameter. The second set of cutting blades then is actuated to cut the co-extending casings beyond the first sweep diameter and within a second sweep diameter.

Abstract: Superheated steam from a generator (10) proximate a well (14) is delivered through an output pipe (12) that communicates through a dual entry wellhead (17) with downhole steam piping (18) extending into the well (14). Steam is delivered at approximately 50 PSIG over the frictional and other losses encountered from the surface to the steam piping outlet (19). Oil is extracted through production tubing (20) passing through wellhead (17). Production tubing (20) and steam delivery piping (18) are secured in parallel relationship by clamps (46). The production tubing (20) communicates with a lift pump, and the steam piping (18) is terminated generally at a midpoint of the production tubing (20), several feet above the lift pump. A thermocouple (43) is placed approximately two feet below the end of the steam piping (18).

Abstract: Systems and methods are provided for low emission (in-situ) heavy oil production, using a compound heat medium, comprising products of combustion of a fuel mixture with an oxidant and a moderator, mixed with steam generated from direct contact of hot combustion products with water, under pressure. The compound heat medium, comprising mainly CO2 and steam, is injected at pressure into a hydrocarbon reservoir, where steam condenses out of the compound heat medium releasing heat to the reservoir. The condensate is produced with the hydrocarbon as a hydrocarbon/water mixture or emulsion. Non-condensable gases, primarily CO2, from the compound heat medium may remain in the reservoir through void replacement, leakage to adjacent geological strata. Beneficially, any CO2 produced is recovered at pressure, for use in other processes, or for disposal by sequestration. Produced water is recovered and recycled as a moderator and steam generating medium.

Abstract: The present invention relates to a process for fracturing a subterranean formation comprising a step of fracturing the formation and a step of introducing a treatment fluid containing glutamic acid N,N-diacetic acid or a salt thereof (GLDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA) and/or N-hydroxyethyl ethylenediamine N,N?,N?-triacetic acid or a salt thereof (HEDTA) into the formation, wherein the fracturing step can take place before introducing the treatment fluid into the formation, while introducing the treatment fluid into the formation or subsequent to introducing the treatment fluid into the formation.

Abstract: Methods and fluids are provided that include, but are not limited to, a drilling fluid comprising an aqueous base fluid and a fluid loss control additive that comprises at least one polymeric micro gel and a method comprising: providing an aqueous based treatment fluid comprising a fluid loss control additive that comprises at least one polymeric micro gel; placing the aqueous based treatment fluid in a subterranean formation via a well bore penetrating the subterranean formation; allowing the fluid loss control additive to become incorporated into a filter cake located on a surface within the subterranean formation; allowing the filter cake to be degraded; and producing hydrocarbons from the formation. Additional methods are also provided.

Abstract: Wellbores are fractured by setting open hole packers on a string with access through valves on the string between the set packers. Setting the packers creates wellbore stress so that fractures tend to preferentially form near the packers regardless of the orientation of the borehole. When the fracturing is done and the well is put on production some of the proppant comes back into the wellbore and packs around the packers with solids that can be produced from the formation carried by flowing fluids. An annular passage is created near the packer to allow produced fluids to bypass the packed proppant and other solids to get into the production string. A screen protects the passage from clogging so that production is enhanced.

Abstract: A fracturing system for a well, in which a stream of LPG, a mixture of propane and butane, is injected into the well at frac pressure. Proppant is supplied into the LPG stream, and carried by the LPG mix into the formation. Inert gas such as nitrogen is used for purging system components of LPG, and to help protect against risk of explosion. Nitrogen may also be added to the LPG mix during a frac of shale gas or coal gas formations.

Abstract: The invention provides a gate valve for control of production of petroleum, distinctive in that the valve comprises a coating or hard facing on the internal bore surface exposed to flow of petroleum and associated fluids and solids.