Abstract: A frac truck is provided for the portable metering and dispensing of sand into a fractionation fluid system. Hopper vessels for powder, sand or other aggregate have a discharge vent for releasing air that is displaced during the filling of the hoppers. Venting is required to prevent over pressurization; conventionally, this vented gas entrains a significant amount of solids that would subsequently be released into the atmosphere. A dust collector is mounted for receiving the vented air displaced when powdered material is loaded into the hoppers. The dust collector is connected through a vent tube communicating between the hoppers and the dust collector. Air vented from the hoppers is drawn though the dust collector and past and through a filter media, where clean air is discharged and solids collected. A low profile rotary airlock is used to discharge solids from the bottom of the dust collector.

Abstract: Well treatment agents containing a particulate substrate are coated with a polyelectrolyte bilayer to provide a well treatment composite for use in well treatment operations. Each layer of the polyelectrolyte bilayer is composed of oppositely charged polyionic material. The well treatment composite may further contain a succession of polyelectrolyte bilayers, each polyelectrolyte bilayer containing layers of oppositely charged polyionic materials.

Abstract: A method of permeating and infusing a formation around the borehole with wax by heating a formation surrounding a borehole and pumping molten wax into the formation, wherein the molten wax flows into and fills voids the formation without disrupting the formation is described. Also, a method of permeating and infusing a formation around the borehole with wax by heating a formation surrounding a borehole, pumping molten wax into the borehole, heating and circulating the molten wax vertically within the borehole for an extended period using a heater and pump attached to a circulation pipe extended to the bottom of a zone of the borehole to be heated, and recovering molten wax from the borehole by displacing it back to the surface with another material of different density is described.

Abstract: A method for fracturing a subterranean formation penetrated by a well bore comprises formulating a fracturing fluid useful in hydrocarbon drilling having the properties of both a dispersing fracture solution and an aggregating fracture solution. In particular, the dispersing properties of the stabilizing fracture solution are able to act as a dispersing fracture fluid in the clay and earthen materials discharged from the pay zone in the flow-back fluids during hydraulic fracturing. At the same time, aggregating properties of the stabilizing solution stabilize the pay zone. This stabilization property allows the flow of hydrocarbon through the fractures for a significantly longer time than with prior art fluids.

Abstract: The present invention is directed to a method of hydrocarbon production from a hydrocarbon reservoir. The method includes providing a substantially horizontal wellbore having at least one productive interval within a hydrocarbon reservoir and forming at least one non-conductive transverse fracture in the reservoir along the substantially horizontal wellbore. An injection well is also provided. A fluid is injected into the reservoir through the injection well to displace hydrocarbons within the reservoir toward a production portion of the substantially horizontal wellbore. Fluid production from the at least one production interval into the substantially horizontal wellbore flows through an inflow control device that can restrict the fluid flow. A non-conductive transverse fracture can form a barrier within the reservoir to divert injected fluids to increase sweep efficiency and reduce the influx of injected fluids into the production interval.

Abstract: A system and method for increasing hydrocarbon production from a subsurface reservoir by utilizing an intersection of two well bores and a flexible linear cutting device, such as a segmented diamond wire saw, to form a fissure beginning at the intersection of the well bores and extending along a specified the length of the well bores. The ends of the cutting device can be actuated above ground. The shape of the fissure can be a substantially ruled surface defined between the two bores between which the fissure is formed. Configurations for the well bores include both bores extending from the surface and, alternatively, a first bore extending from the surface and a second bore extending from a whipstock in the first bore. The fissure may be located and oriented to maximize the extent of the fissure formed within the hydrocarbon bearing horizon and to intersect with a maximum number of natural and/or previously formed fractures.

Abstract: A method for controlling the influx of fluids into a multizone well in which each inflow zone is provided with an inflow control device, comprises: assessing the flux of oil, gas, water and other effluents from the well; monitoring production variables, including ICD position and/or fluid pressure in each inflow zone upstream of each ICD and/or downstream of each ICD; sequentially adjusting the position of each of the ICDs and assessing the flux of crude oil, natural gas and/or other well effluents; monitoring production variables; deriving a zonal production estimation model for each inflow zone of the well; and adjusting each ICD to control the influx of crude oil, natural gas and/or other effluents into each inflow zone on the basis of data derived from the zonal production estimation model for each inflow zone of the well.

Abstract: A system and method for increasing hydrocarbon production from a subsurface reservoir and/or sequestering waste material such as carbon dioxide by utilizing a connection between two well bores and a flexible linear cutting device, such as a segmented diamond wire saw, to form a fissure beginning at the connection of the well bores and extending along a specified the length of the well bores. Methods and systems relate to hydrocarbon production and/or waste sequestration, including for extracting or recovering oil or gas from coal beds or tar sands.

Abstract: A process is disclosed for using heavy petroleum fraction as a drive fluid in the recovery of hydrocarbons from a subterranean formation. The hydrocarbons may be in the form of bitumen or heavy oil. The heavy petroleum fraction may be injected into at least one injection well and hydrocarbons produced out of at least one distinct production well. The heavy petroleum fraction may be co-injected together with steam and/or hot water and/or solvent. The heavy petroleum fraction may be a heavy fraction of a process used to upgrade crude oil, such as a heavy asphaltene fraction produced from solvent deasphalting crude oil produced by this recovery process.

Abstract: Methods including providing a substantially horizontal wellbore having at least one productive interval within a hydrocarbon reservoir and forming at least one non-conductive transverse fracture in the reservoir along the substantially horizontal wellbore. An injection well is also provided. A fluid is injected into the reservoir through the injection well to displace hydrocarbons within the reservoir toward a production portion of the substantially horizontal wellbore. Hydrocarbons are drained from the reservoir into at least one production interval of the substantially horizontal wellbore. Fluid production from the at least one production interval into the substantially horizontal wellbore flows through an inflow control device that can restrict the fluid flow. A non-conductive transverse fracture can form a barrier within the reservoir to divert injected fluids to increase sweep efficiency and reduce the influx of injected fluids into the production interval.

Abstract: A mechanical vessel may effectively and simultaneously displace a first undesired gas from within water with a second desired gas, and remove at least one alkaline species and oily matter from the water. The vessel raises the pH of the water and reduces the lime requirement for subsequent lime softening. The vessel receives the water containing the first gas and passes the water through a series of gasification chambers. Each gasification chamber may have a mechanism that ingests and mixes a second gas into the water thereby physically displacing at least a portion of the first gas into a vapor space at the top of each gasification chamber from which it is subsequently removed. There is an absence of communication between the vapor spaces of adjacent chambers. An acid is added to remove the alkaline species, where the first gas is an optional by-product that is also removed.

Abstract: Systems and methods for drainage of a heavy oil reservoir via a horizontal wellbore. A method of improving production of fluid from a subterranean formation includes the step of propagating a generally vertical inclusion into the formation from a generally horizontal wellbore intersecting the formation. The inclusion is propagated into a portion of the formation having a bulk modulus of less than approximately 750,000 psi. A well system includes a generally vertical inclusion propagated into a subterranean formation from a generally horizontal wellbore which intersects the formation. The formation comprises weakly cemented sediment.

Abstract: An erosion migration arrangement includes a tubular having a window therein. A body positioned within a portion of the window is configured to sacrificially erode in response to a slurry flowing through the window to thereby migrate a location of impact on a member positioned downstream of the window.

Abstract: The present invention is directed to a method of hydrocarbon production from a hydrocarbon reservoir. The method includes providing a substantially horizontal wellbore having at least one productive interval within a hydrocarbon reservoir and forming at least one non-conductive transverse fracture in the reservoir along the substantially horizontal wellbore. An injection well is also provided. A fluid is injected into the reservoir through the injection well to displace hydrocarbons within the reservoir toward a production portion of the substantially horizontal wellbore. Hydrocarbons are drained from the reservoir into at least one production interval of the substantially horizontal wellbore. Fluid production from the at least one production interval into the substantially horizontal wellbore flows through an inflow control device that can restrict the fluid flow.

Abstract: A method of lowering the temperature of a subsurface formation, e.g., comprising oil shale, includes injecting a cooling fluid under pressure into a wellbore. The wellbore is completed at or below a depth of the subsurface formation, and the wellbore includes a bore formed through the subsurface formation defining a diameter. The cooling fluid comprises a slurry having particles of frozen material. The cooling fluid is circulated across the formation in order to lower the temperature of at least a portion of the formation to a point that is at or below the freezing point of water.

Abstract: A plume of combined gases are infused into hydrocarbon-bearing formations, “inert” as the major gas and “reactive” as the minor gas, where the minor gas reacts with hydrocarbons to fully saturate hydrocarbons with supercritical fluid, which migrate hydrocarbons out of formations, even at great distances from the regulated fuel cell source. Coal, tar sands, petroleum-contaminated soil, and/or oil wells that have lost gas pressure can also be desorbed by this in-situ method.

Abstract: A fractionation system is disclosed, the system having a fractionation manifold with a plurality of connectors in fluid communication with one another and a plurality of valves disposed adjacent the connectors for selectively flowing fluid through the manifold. The connectors define a plurality of exterior ports for communication with wellstrings and fracturing fluid sources. A primary choke in communication with a tubing string and a secondary choke in communication with a casing string can be engaged with exterior ports, the secondary choke useable as a backup choke and for inducing sandouts. The present system can achieve a flow rate of up to 80 barrels per minute, or more, using only a single manifold and single power unit, and can be wirelessly operated. System components can incorporate self-aligning, self-positioning skids, or alternatively, the system can be transported using a single skid to facilitate portability and installation.

Abstract: A method for drilling and completing multiple wellbores in a subsurface rock formation includes drilling a first wellbore along a first selected trajectory through the rock formation. The first wellbore is fracture treated and then abandoned. A second wellbore is drilled along a second selected trajectory through the rock formation. The second trajectory is laterally spaced from the first trajectory. The second wellbore is then fracture treated and abandoned. A third wellbore is drilled along a third selected trajectory through the rock formation. The third trajectory is disposed between the first and second trajectories. The third wellbore is fractured treated such that a fracture network extending therefrom hydraulically connects to fracture networks extending from the first and second wellbores.

Abstract: The invention provides a method for fracturing a subterranean formation penetrated by a well bore, by formulating a fracturing fluid useful in hydrocarbon drilling having the properties of both a dispersing fracture solution and an aggregating fracture solution. In particular, the dispersing properties of the stabilizing fracture solution are able to act as a dispersing fracture fluid in the clay and earthen materials discharged from the pay zone, in the flow-back fluids during hydraulic fracturing. At the same time, aggregating properties of the stabilizing solution stabilizes the pay zone. This stabilization property allows the flow of hydrocarbon through the fractures for a significantly longer time than with prior art fluids.

Abstract: A method of servicing a subterranean formation comprising positioning a wellbore servicing tool comprising an axial flowbore within a wellbore, making a first application of pressure to the axial flowbore of the wellbore servicing tool; wherein the pressure within the wellbore servicing tool is at least a first upper threshold during the first application of pressure, allowing the pressure within the axial flowbore following the first application of pressure to fall below a first lower threshold, making a second application of pressure to the axial flowbore of the wellbore servicing tool, wherein the pressure within the wellbore servicing tool is at least a second upper threshold during the second application of pressure, allowing a second subsiding of pressure within the axial flowbore following the second application of pressure to fall a second lower threshold, and communicating a fluid to the wellbore, the subterranean formation, or both via one or more ports of the wellbore servicing tool.

Abstract: A hydraulic fracturing process consisting essentially of drilling a wellbore through at least one reservoir formation, installing in said wellbore at least one conduit, ensuring pressure communication between said wellbore and said reservoir formation, at a higher effective stress formation, selecting the location of the pressure communication between the wellbore and the reservoir formation for control of said hydraulic fracturing process and pumping a hydraulic fracturing treatment comprising a fracturing fluid and a proppant, at a sufficient pressure via said conduit to create at least one fracture in the higher effective stress formation. In addition, processes for increasing conductivity near a wellbore and producing fluids from a lower effective stress permeable formation via a fracture extending from the higher effective stress fracture formation into the lower effective stress permeable formation may include applying several approaches to packing or filling fractures with proppant.

Abstract: A method for completing an oil and gas well completion is provided. The perforators (10, 11) may be selected from any known or commonly used perforators and are typically deployed in a perforation gun. The perforators are aligned such that the cutting jets (12, 13) and their associated shockwaves converge towards each other such that their interaction causes increased fracturing of the rock strata. The cutting jets may be also be aligned such that the cutting jets are deliberately caused to collide causing further fracturing of the rock strata. In Ian alternative embodiment of the invention there is provided a shaped charge liner with at least two concave regions, whose geometry is selected such that upon the forced collapse of the liner a plurality of cutting jets is formed which jets are convergent or are capable of colliding in the rock strata.

Abstract: The present invention is directed to a method of hydrocarbon production from a hydrocarbon reservoir. The method includes providing a substantially horizontal wellbore having at least one productive interval within a hydrocarbon reservoir and forming at least one non-conductive transverse fracture in the reservoir along the substantially horizontal wellbore. An injection well is also provided. A fluid is injected into the reservoir through the injection well to displace hydrocarbons within the reservoir toward a production portion of the substantially horizontal wellbore. Hydrocarbons are drained from the reservoir into at least one production interval of the substantially horizontal wellbore. Fluid production from the at least one production interval into the substantially horizontal wellbore flows through an inflow control device that can restrict the fluid flow.

Abstract: Disclosed herein are methods of making free flowing coated particles and low temperature including a step of curing the coating with UV light or electron beam. Each particle has a precured coating disposed upon a substrate. Methods of using the particles are also disclosed.

Abstract: A hydraulic fracturing fluid includes a hydrocarbon fluid and viscosifying agent, wherein the viscosified fluid is a Newtonian fluid; a hydrocarbon fluid and gelling agent, wherein the viscosified fluid is a power law fluid; a hydrocarbon fluid, a gelling agent, and a rheological additive, wherein the viscosified fluid is a yield power law fluid; or a hydrocarbon fluid, a gelling agent, a rheological additive, and solvent for the rheological additive, wherein the viscosified fluid is a yield power law fluid. The hydrocarbon fluid is preferably weighted with nano-scale or self suspending weighting agents. The hydraulic fracturing fluids are prepared for use in fracturing a subterranean petroliferous formation. A weighted (preferably with nano-scale weighting agent), oil-based hydraulic fracture fluid breaker is also disclosed.

Abstract: The present invention is directed to methods for extracting a kerogen-based product from subsurface (oil) shale formations, wherein such methods rely on fracturing and/or rubblizing portions of said formations so as to enhance their fluid permeability, and wherein such methods further rely on chemically modifying the shale-bound kerogen so as to render it mobile. The present invention is also directed at systems for implementing at least some of the foregoing methods. Additionally, the present invention is also directed to methods of fracturing and/or rubblizing subsurface shale formations and to methods of chemically modifying kerogen in situ so as to render it mobile.

Abstract: There is a method for enhancing the recovery of oil from a reservoir. The method has the step of a) introducing a flooding fluid into the reservoir and b) extracting the oil through a wellbore at a location different than the point of introduction of the flooding fluid into the reservoir. The flooding fluid has water and an amount of one or more non-polymeric viscoelastic surfactants sufficient to provide an interfacial surface tension of about 1 mNm or less and a viscosity of about 10 cps or more. The one or more surfactants is selected from the group of one or more cationic surfactants, one or more zwitterionic surfactants, one or more amphoteric surfactants, one or more anionic surfactants, and combinations thereof.

Abstract: The present invention relates to aqueous oilfield treatment fluids containing a gas component and fibers, wherein the fluids may further include a viscosifying agent and/or proppant. The fluids have good proppant suspension and transport properties as well as excellent gas phase stability. Use of fluids comprising an aqueous medium, a gas component, viscosifying agent, and fibers for hydraulically fracturing a subterranean formation, cleanup operations, and gravel packing a wellbore, are also disclosed.

Abstract: A process for fracturing a subterraneous formation in the production of an oil well is described. The process steps include injecting an initial charge of a mixture, the mixture being formed from at least a water-insoluble adsorbent and at least one well treatment agent, into a well bore formed in the subterraneous formation so as to form a downhole matrix within the formation; injecting a solution comprised of an additional amount of the well treatment agent into the formation after the initial charge of the at least one well treatment agent has been substantially depleted; and then pressurizing the well bore for a time and under conditions sufficient to reactivate the downhole matrix in the formation, so that the treatment agent activity of the matrix is increased relative to the treatment agent activity of the matrix just prior to injecting the solution.

Abstract: A method and apparatus for treating a subterranean formation with a fluid, including forming a fluid including a organosilane and a particulate and introducing the fluid into a subterranean formation with exposed surfaces, wherein the organosilane modifies the particulate or surfaces or both. Also, a method and apparatus for treating a subterranean formation with a fluid, including forming a fluid including an organosilane and introducing the fluid into a subterranean formation with exposed surfaces, wherein the organosilane modifies the surfaces with a first functional group.

Abstract: A method of increasing the recovery of hydrocarbons from a highly fractured reservoir is described using the steps of injecting into the reservoir a membrane-forming fluid to form a membrane over the surface of at least part of exposed formation, injecting into the reservoir a fluid to establish a chemical potential gradient across the membrane and letting fluid enter the formation across the membrane to increase the pressure inside the formation and to force additional hydrocarbon from the formation.

Abstract: An engineered, scalable underground containment system and method for storing compressed gases or liquids in permeable rock formations using conventional drilling techniques. The porosity and permeability of the formation may be enhanced to maximize reservoir capacity and increase the rate at which gases and liquids can be introduced into and removed from the reservoir. In some embodiments, layers of cap rock in the formation are utilized as containment barriers, and in some, containment barriers are constructed around the storage zones.

Abstract: Systems and methods for drainage of a heavy oil reservoir via a horizontal wellbore. A method of improving production of fluid from a subterranean formation includes the step of propagating a generally vertical inclusion into the formation from a generally horizontal wellbore intersecting the formation. The inclusion is propagated into a portion of the formation having a bulk modulus of less than approximately 750,000 psi. A well system includes a generally vertical inclusion propagated into a subterranean formation from a generally horizontal wellbore which intersects the formation. The formation comprises weakly cemented sediment.

Abstract: Methods and compositions of acid fracturing formations are provided. The fracturing fluid includes a liquid breaker that decreases the viscosity of the fracturing fluid over time. The liquid breaker can also be produced in situ. The liquid breaker includes fluoroboric acid.

Abstract: Particles, including proppants, comprising a fluorinated siloxane. The particles are useful as proppants in fractured a subterranean geological formation comprising hydrocarbons.

Abstract: Methods and aqueous acid solutions for acidizing wells containing sludging and emulsifying oil are disclosed. An aqueous acid solution of the invention comprises water, hydrochloric acid, a cationic hydrochloric acid corrosion inhibitor and a conjugate ion pair of a cationic amine oxide surfactant and an anionic surfactant that does not react with the cationic hydrochloric acid corrosion inhibitor.

Abstract: A system and method for increasing hydrocarbon production from a subsurface reservoir by utilizing an intersection of two well bores and a flexible linear cutting device, such as a segmented diamond wire saw, to form a fissure beginning at the intersection of the well bores and extending along a specified the length of the well bores. The ends of the cutting device can be actuated above ground. The shape of the fissure can be a substantially ruled surface defined between the two bores between which the fissure is formed. Configurations for the well bores include both bores extending from the surface and, alternatively, a first bore extending from the surface and a second bore extending from a whipstock in the first bore. The fissure may be located and oriented to maximize the extent of the fissure formed within the hydrocarbon bearing horizon and to intersect with a maximum number of natural and/or previously formed fractures.

Abstract: Systems and methods for drainage of a heavy oil reservoir via a horizontal wellbore. A method of improving production of fluid from a subterranean formation includes the step of propagating a generally vertical inclusion into the formation from a generally horizontal wellbore intersecting the formation. The inclusion is propagated into a portion of the formation having a bulk modulus of less than approximately 750,000 psi. A well system includes a generally vertical inclusion propagated into a subterranean formation from a generally horizontal wellbore which intersects the formation. The formation comprises weakly cemented sediment.

Abstract: An aqueous oilfield treatment fluid containing a chelating agent and an HF source is described. This fluid is effective at dissolving siliceous materials such as clays and keeping the dissolved materials in solution. In particular it is effective at preventing re-precipitation of initially-dissolved silicon as silica and therefore reduces damage to sandstones with which it is contacted. Methods are given for using this fluid for sandstone matrix stimulation, removal of clay-containing drilling fluid components and filter cakes from wellbores, sandstone acid fracturing, and gravel pack and proppant pack cleaning.

Abstract: Multiple formations are isolated in the wellbore and fractured and gravel packed together. The bottom hole assembly can have a series of screens that are separated with packers in between and above and below the screen stack. The assembly is positioned where needed in the borehole and the topmost and lowermost packers (if used) are set. The bottom of the interval can alternatively be the hole bottom. With multiple intervals isolated a fracturing operation can take place for the entire isolated interval that can encompass multiple producing zones. The interval can also be gravel packed in a single operation. After the gravel pack of the interval, packers that are on the bottom hole assembly between screens that are aligned with perforations for different zones can be set into the gravel pack and get an effective seal against the casing to isolate the various producing zones from each other.

Abstract: Processes for effecting biocidal activity in subterranean oil and gas wells being drilled, completed, worked over or produced are described. In general the process comprises blending with aqueous well fluid a biocidally-effective amount of a sulfamate stabilized, bromine-based biocide. Compositions comprised of aqueous well fluid blended with such aqueous biocides are also described.

Abstract: A method for treating an oil shale formation comprising dawsonite includes providing heat from one or more heaters to the formation to heat the formation. Hydrocarbon fluids are produced from the formation. At least some dawsonite in the formation is decomposed with the provided heat. A chelating agent is provided to the formation to dissolve at least some dawsonite decomposition products. The dissolved dawsonite decomposition products are produced from the formation.

Abstract: A method for treating an oil shale formation comprising nahcolite includes providing a first fluid to a portion of the formation. A second fluid is produced from the portion. The second fluid includes at least some nahcolite dissolved in the first fluid. A controlled amount of oxidant is provided to the portion of the formation. Hydrocarbon fluids are produced from the formation.

Abstract: The present invention relates to emulsion compositions and associated methods. More particularly, the present invention relates to gelled invert emulsion compositions and their associated methods of use and preparation. In one embodiment, the present invention provides a method of treating a portion of a subterranean formation comprising the steps of: providing a gelled invert emulsion composition that comprises an oleaginous continuous phase, a discontinuous phase, and a gelling agent; and treating a portion of the subterranean formation. The present invention also provides methods of increasing the viscosity of an invert emulsion composition, methods of making gelled invert emulsion compositions, methods of providing some degree of sand control to portions of subterranean formations, methods of fracturing a portion of a subterranean formation, and gelled invert emulsion compositions.

Abstract: A method for lowering the temperature of a portion of a subsurface formation is provided. Preferably, the formation is an oil shale formation. The method includes the step of injecting a cooling fluid under pressure into a wellbore, with the wellbore having been completed at or below a depth of the subsurface formation. The wellbore has an elongated tubular member for receiving the cooling fluid and for conveying it downhole to the subsurface formation. The wellbore also has an expansion valve in fluid communication with the tubular member through which the cooling fluid flows. The method then includes the steps of injecting a cooling fluid under pressure into the wellbore, and expanding the cooling fluid across the first expansion valve. In this way, the temperature of the cooling fluid is reduced. The temperature of the surrounding formation is likewise reduced through thermal conduction and convection.

Abstract: A well treating composition of a composite containing a scale inhibitor adsorbed onto a water-insoluble adsorbent is useful in the control, formation and treatment of inorganic scales in a subterranean formation or wellbore. In addition, the well treating composition is useful in controlling the rate of release of scale inhibitor in the wellbore. The water-insoluble adsorbent may be activated carbon, silica particulate, precipitated silica, zeolite, diatomaceous earth, ground walnut shells, fuller's earth and organic synthetic high molecular weight water-insoluble adsorbents. The composite may be introduced into an oil or gas well with a carrier fluid.

Abstract: There is a method for enhancing the recovery of oil from a reservoir. The method has the step of a) introducing a flooding fluid into the reservoir and b) extracting the oil through a wellbore at a location different than the point of introduction of the flooding fluid into the reservoir. The flooding fluid has water and an amount of one or more non-polymeric viscoelastic surfactants sufficient to provide an interfacial surface tension of about 1 mNm or less and a viscosity of about 10 cps or more. The one or more surfactants is selected from the group of one or more cationic surfactants, one or more zwitterionic surfactants, one or more amphoteric surfactants, one or more anionic surfactants, and combinations thereof.

Abstract: The invention relates to methods and apparatus for creating multiple fractures in subterranean formations. The apparatus is a jetting tool having a plurality of sets of jetting nozzles so that the sets of nozzles are substantially parallel to one another such that parallel cavities may be formed substantially simultaneously in the formation. The jetting nozzles may be adapted to provide a fluid jet that flares outwardly from the nozzle. The nozzles also may be aligned such that cavities in the formation overlap to form a single cavity. The nozzles may be further adapted so that holes jetted into the casing thereby are still spaced from one another. Methods of fracturing subterranean formations using the apparatus are also disclosed.

Abstract: An apparatus for fracturing wells employs a propellant charge and an ignition cord wrapped around the outer surface of the propellant charge to rapidly ignite the outer surface of the propellant charge.

Abstract: The invention concerns an aqueous viscoelastic fluid for use in the recovery of hydrocarbons. According to the invention, the aqueous viscoelastic fluid comprises a monomer, a dimer or an oligomer of a viscoelastic surfactant able to form a viscoelastic gel under downhole conditions, said surfactant comprising a hydrophobic tail and a hydrophilic head, and being of the following formulae: R—X—Y-Z where R is the hydrophobic tail of the surfactant, Z is the hydrophilic head of the surfactant, said hydrophilic head being charged, X is a stabilising group and Y chain is a linear, saturated or unsaturated, hydrocarbon chain of 1, 2 or 3 carbon atoms or a branched, saturated or unsaturated hydrocarbon chain wherein the main chain is of 1, 2 or 3 carbon atoms, possibly incorporating an aromatic ring.