Abstract: A method and apparatus for initiating and propagating a vertical hydraulic fracture in unconsolidated and weakly cemented sediments from a single bore hole to control the fracture initiation plane and propagation of the hydraulic fracture, enabling greater yield and recovery of petroleum fluids from the formation. An injection casing with multiple fracture initiation sections is inserted and grouted into a bore hole. A foam fracture fluid carrying a proppant is injected into the injection casing and opens the fracture initiation sections to dilate the formation in a direction orthogonal to the required fracture azimuth plane. Propagation of the fracture is controlled by limiting the fracture fluid form to that of a stable foam fracturing fluid during the fracturing process. The injection casing initiation section remains open after fracturing providing direct hydraulic connection between the production well bore, the permeable proppant filled fracture and the formation.

Abstract: The present invention involves a method and apparatus for enhanced recovery of petroleum fluids from the subsurface by convective heating of the oil sand formation and the heavy oil and bitumen in situ by a downhole electric heater. Multiple propped vertical hydraulic fractures are constructed from the well bore into the oil sand formation and filled with a diluent. The heater and downhole pump force thermal convective flow of the heated diluent to flow upward and outward into the propped fractures and circulating back down and back towards the well bore heating the oil sands and in situ bitumen on the vertical faces of the propped fractures. The diluent now mixed with produced products from the oil sand re-enters the bottom of the well bore and passes over the heater element and is reheated to continue to flow in the convective cell. Thus the heating and diluting of the in place bitumen occurs predominantly circumferentially, i.e.

Abstract: The present invention involves a method and apparatus for enhanced recovery of petroleum fluids from the subsurface by injecting a hydrocarbon solvent vapor in contact with the oil sand formation and the heavy oil and bitumen in situ. Multiple propped vertical hydraulic fractures are constructed from the well bore into the oil sand formation. The hydrocarbon solvent vapor and a non-condensing diluent gas are injected into the well bore, fill the hydraulic fractures, and thus contact and diffuse into the in situ bitumen. The hydrocarbon solvent vapors diffuse into the bitumen from the vertical faces of the propped fractures. The bitumen softens and flows by gravity to the well bore, exposing fresh surface of bitumen for the process to progressively soften and mobilizes the bitumen in a predominantly circumferentially, i.e. orthogonal to the propped fracture, diffusion direction at a nearly uniform rate into the oil sand deposit.

Abstract: Methods of increasing the permeability of a portion of a subterranean formation may comprise providing a remediation fluid capable of decreasing the tackiness of a tackifying agent, the remediation fluid comprising a surfactant; introducing the remediation fluid into the portion of the subterranean formation, wherein a plurality of tackified particulates at least partially coated with formation fines are located within the portion; and allowing at least a substantial portion of the formation fines to detach from the plurality of tackified particulates.

Abstract: Methods are provided that include a method of creating a stable slurry of coated particulates wherein the slurry is capable of being stored for at least 2 hours before use comprising the steps of: providing resin coated particulates wherein the resin comprises a resin that does not completely cure unless it is at least one of exposed to a temperature above about 175° F. or exposed to an external catalyst; and, substantially suspending the resin coated particulates in a servicing fluid to create a stable resin coated particulate slurry. Methods are provided that include a method of creating a stable slurry of coated particulates wherein the slurry is capable of being stored for at least 2 hours before use comprising the steps of: providing tackifier coated particulates; and, substantially suspending the tackifier coated particulates in a servicing fluid to create a tackifier coated particulate slurry.

Abstract: Methods of initiating a fracture tip screenout, that comprise pumping an annulus fluid into an annulus, between the subterranean formation and a work string disposed within a wellbore penetrating the subterranean formation, at an annulus flow rate; and reducing the annulus flow rate below a fracture initiation flow point so that the fracture tip screenout is initiated in the one or more fractures in the subterranean formation, are provided. Also provided are methods of fracturing a portion of a subterranean formation and methods of estimating a fracture initiation flow point.

Abstract: The invention relates to enhancing the conductivity of fractures in a subterranean formation so as to enhance fluid flow therethrough. In one embodiment, the present invention provides a method comprising: providing a proppant matrix composition, the proppant matrix composition comprising at least a plurality of proppant particulates and at least a plurality of composite particles, the composite particles comprising a degradable material and a filler material; introducing the proppant matrix composition to the fracture so as to form a proppant matrix in the fracture; and allowing the degradable material of the composite particles to degrade so as to form at least one void in the proppant matrix.

Abstract: The present invention is directed to a method of isolating hydrajet stimulated zones from subsequent well operations. The method includes the step of drilling a wellbore into the subterranean formation of interest. Next, the wellbore may or may not be cased depending upon a number of factors including the nature and structure of the subterranean formation. Next, the casing, if one is installed, and wellbore are perforated using a high pressure fluid being ejected from a hydrajetting tool. A first zone of the subterranean formation is then fractured and stimulated. Next, the first zone is temporarily plugged or partially sealed by installing an isolation fluid into the wellbore adjacent to the one or more fractures and/or in the openings thereof, so that subsequent zones can be fractured and additional well operations can be performed.

Abstract: A method is given for treating a subterranean formation penetrated by a wellbore with a viscosified fluid. The fluid contains a solid hydrolysable polyacid that upon dissolution and hydrolysis releases an acid that is a breaker for the viscosifying system. Suitable solid hydrolysable polyacids include polylactic acid and polyglycolic acid. The fluid also contains a pH control agent, present in an amount sufficient to neutralize any acid present in the solid hydrolysable polyacid before the injection and to neutralize any acid generated by the solid hydrolysable polyacid during the injection, so that the acid breaker is not available to break the fluid during the injection. In one embodiment the viscosifier is a viscoelastic surfactant fluid system and the solid hydrolysable polyacid is of a size selected to be a fluid loss additive, for example in fracturing or gravel packing.

Abstract: Among the methods provided are methods of treating a subterranean formation comprising placing a solid treatment chemical and a tacky polymer onto a solid substrate to create a coated solid substrate; placing the coated solid substrate into a portion of a subterranean formation; and, allowing the tacky polymer to degrade and allowing the solid treatment chemical to be released into the portion of the subterranean formation. Also provided are methods of creating a particulate pack comprising a treatment chemical in a subterranean formation comprising placing a solid treatment chemical and a tacky polymer onto a particulate to create a coated particulate; creating a slurry comprising the coated particulates slurried into a treatment fluid; placing the slurry into a portion of a subterranean formation so as to create a particulate pack; and, allowing the tacky polymer to degrade and allowing the solid treatment chemical to be released into the portion of the subterranean formation.

Abstract: A method of hydraulically fracturing a hydrocarbon-bearing subterranean formation ensures that the conductivity of water inflow below the productive zone of the subterranean formation is reduced. The method consists of two principal steps. In the first step, a fracture in and below the productive zone of the formation is initiated by introducing into the subterranean formation a fluid, free of a proppant, such as salt water, fresh water, brine, liquid hydrocarbon, and/or nitrogen or other gases. The proppant-free fluid may further be weighted. In the second step, a proppant laden slurry is introduced into the subterranean formation which contains a relatively lightweight density proppant. Either the fluid density of the proppant-free fluid is greater than the fluid density of the proppant laden slurry or the viscosity of the proppant-free fluid is greater than the viscosity of the proppant laden slurry.

Abstract: The present invention provides compositions and methods for enhancing subterranean well productivity by enhancing fracture conductivity. A method of increasing the conductivity of a fracture in a portion of a subterranean formation comprising providing a slurry comprising a fracturing fluid, a degradable material, and proppant particulates coated with a tackifying agent; allowing the degradable material to become at least temporarily attached to the tackifying agent coated onto the proppant particulates so as to avoid substantial segregation of the degradable material from the proppant particulates within the slurry; introducing the slurry to the fracture and allowing the proppant particulates and degradable material to form a substantially uniform particulate pack; and, allowing the degradable material to degrade and produce a particulate pack having voids therein.

Abstract: Propped fractures in formations from which fluids are produced are described that have wormholes extending out into the formations from the faces of the fractures at locations distant from boreholes. Methods are given for creating such propped fractures having wormholes in which either a closed propped fracture is formed and then the wormholes are formed, or the entire fracture and channel system is formed before the closure occurs.

Abstract: Small spheres, commonly referred to as proppants, are manufactured from sol-gel ceramics, preferably aluminosilicates or phosphates, and include chemical composites termed geopolymers. In the preferred manufacturing process, the required chemical components are blended, and the proppant particles are shaped and cured at low temperatures. The proppant particles have high compressive strength, are chemically inert, and a low specific gravity, making them particularly suited for hydraulic fracturing.

Abstract: Reduced friction fluids comprising an aqueous liquid, carbon dioxide, and a polymer comprising acrylamide and an acrylamide copolymer derivative. And methods of treating a subterranean formation comprising the steps of providing a reduced friction fluid comprising an aqueous liquid, carbon dioxide, and a polymer comprising acrylamide and an acrylamide copolymer derivative; and, introducing the reduced friction fluid to a subterranean formation.

Abstract: Propped fractures in formations from which fluids are produced are described that have wormholes extending out into the formations from the faces of the fractures at locations distant from boreholes. Methods are given for creating such propped fractures having wormholes in which either a closed propped fracture is formed and then the wormholes are formed, or the entire fracture and channel system is formed before the closure occurs.

Abstract: Method and apparatus for fracturing different levels of a completion interval in a well. A workstring lowers a fracturing string which, in turn, is comprised of a base pipe which is blank except for perforated sections spaced along its length. Screen may be provided over said sections to block the flow of sand into the base pipe. An alternate flow path (e.g. shunt tubes) extends along the base pipe and has one or more outlets spaced along its length. A slurry is flowed into the annulus surrounding the fracturing string. As liquid is lost from the slurry, sand from the slurry will form bridges at said perforated sections thereby isolating portions of the annulus. Slurry then flows through the shunts tube(s) and out into the isolated portions to fracture the different levels in the completion interval.

Abstract: The present invention relates to substantially hydrated cement particulates. More particularly, the present invention relates to compositions comprising substantially hydrated cement particulates and associated methods of use in drilling and subterranean applications. These substantially hydrated cement particulates may be included in drilling and subterranean treatment fluids, inter alia, as carrier particles for admixtures, lost circulation materials, density-varying additives, proppants, and the like.

Abstract: Some embodiments provide methods of obtaining data from a portion of a subterranean formation comprising providing proppant particulates wherein at least a portion of the proppant particulates are coated with an electroconductive resin that comprises a resin and a conductive material; placing the proppant particulates into a portion of a fracture so as to form an electroconductive proppant pack; providing a transmitter capable of sending an electric current into the electroconductive proppant pack; sending an electric current into the electroconductive proppant pack with the transmitter; providing a receiver capable of deflecting a reflected or conducted electric signal from the electroconductive proppant pack; and, receiving a reflected electric signal with the receiver.

Abstract: Method for hydraulic fracturing of wells by transporting a cross-linked polymer containing a proppant down a wellbore in a carrier fluid, allowing the cross-linked polymer to coalesce into a polymer phase and squeezing the cross-linked polymer as a fracturing fluid is provided. Composition of the cross-linked polymer solution and the selection of additives may be varied to adjust the viscosity, degradation time and other properties of the fracturing fluid.

Abstract: Methods are presented to induce a screenout during a subterranean formation fracturing or combined fracturing and gravel packing treatment having a viscoelastic surfactant-based carrier fluid by laying down a filter cake at least a portion of which is a base-soluble material, injecting proppant slurry, and causing hydrolysis and dissolution of the solid base-soluble material by adding base so that leak-off increases, the concentration of proppant in the fracture increases, and the proppant screens out. A method of gravel packing with a viscoelastic surfactant-based carrier fluid by laying down a filter cake at least a portion of which is a base-soluble material, injecting gravel, and causing hydrolysis and dissolution of the solid base-soluble material by adding base. Methods of slowing or accelerating the hydrolysis and dissolution are given, and addition of bridging-promoting materials is included.

Abstract: The present invention relates to enhancing fluid flow from subterranean formations. More particularly, this invention relates to providing improved proppant matrixes within fractures in a subterranean formation. An example of the methods of increasing the conductivity of a fracture in a subterranean formation comprises the steps of providing a fracturing treatment fluid comprising a proppant composition, the proppant composition comprising proppant particulates and a degradable material capable of undergoing an irreversible degradation downhole; introducing the proppant composition to the fracture; and allowing the proppant composition to form a proppant matrix having voids in the fracture.

Abstract: The present invention discloses two stage subterranean zone fracturing fluids and methods. A two stage subterranean zone fracturing fluid of the invention comprises a first stage fluid comprising a foamed liquid containing a water soluble gel breaker and a second stage fluid that comprises a viscous liquid containing a metal cross-linked gelling agent. Another two stage subterranean zone fracturing fluid comprises a first stage fluid comprising a foamed liquid containing a water soluble gel breaker and a second stage fluid comprising a viscous liquid containing a borate cross-linked gelling agent.

Abstract: The present invention provides methods for fracturing and for reducing the production of both water and particulates from subterranean formations. The methods are particularly useful in conjunction with subterranean formations surrounding wellbores and fractures. The methods comprise the steps of applying to a subterranean formation gelled fluid that contains a gelling agent and a water resistant polymer, applying aqueous surfactant fluid, applying a low-viscosity consolidating fluid, and applying an after-flush fluid, and (in some embodiments) a crosslinked gel fluid.

Abstract: A method for retaining a treatment chemical in a subterranean formation containing hydrocarbons is disclosed. The method includes first preparing an emulsion. The emulsion contains an oil continuous phase and first and second aqueous phases. The first aqueous phase includes a treatment chemical, such as a scale inhibitor. The second aqueous phase comprises a retention enhancing chemical which is to be reacted with the treatment chemical in the subterranean formation. Preferably, the first and second aqueous phases remain generally separately dispersed and stable within the oil continuous phase prior to being introduced into the subterranean formation. The emulsion is then placed down a well bore and into the subterranean formation.

Abstract: Methods of treating subterranean zones and high density viscous aqueous treating fluids are provided. A high density viscous aqueous treating fluid of the invention comprises salt water comprising water and one or more oxidation resistant salts; a gelling agent; and a delayed oxidizing gel breaker.

Abstract: Methods of fracturing a subterranean formation include providing a fracturing fluid having a first pH. The fracturing fluid may be made by combining a gelling agent, a surfactant, and a proppant. The surfactant is capable of facilitating foaming of the fracturing fluid at the first pH and defoaming of the fracturing fluid when its pH is changed to a second pH. The methods of fracturing the subterranean formation further include foaming the fracturing fluid having the first pH and subsequently pumping it to the subterranean formation to fracture the formation. The pH of the fracturing fluid changes to a second pH, for example via in situ contact with an acidic material, causing the level of foam in the fracturing fluid to be reduced. As a result of the reduction of the foam, the fracturing fluid deposits the proppant into the fractures formed in the subterranean formation.

Abstract: Methods are presented to induce a screenout during a subterranean formation fracturing or combined fracturing and gravel packing treatment by laying down a filter cake early in the treatment, then injecting proppant slurry, and then while proppant slurry injection continues chemically damaging the filter cake with one or more filter cake degradation agents so that leak-off increases, the concentration of proppant in the fracture increases, and the proppant screens out. The additional use of filter cake degradation agent aids and bridging-promoting materials is included.

Abstract: A method of fracturing subterranean zones at temperature below about 200° F. wherein the fracturing fluid comprises water, a viscosity increasing gelling agent, a particulate proppant material, a delayed viscosity breaker for causing the fracturing fluid to revert to a thin fluid and a breaker activator comprising a mixture selected from the group of a mixture of cobaltous acetate and the sodium salt of ethylenediaminetetraacetic acid and a mixture of thioglycolic acid and sodium molybdate.

Abstract: Improved methods of preventing the flow-back of particulates deposited in subterranean formations with produced formation fluids are provided. The methods include extruding or injecting a solution or mixture of a particulate solid polymer through a plurality of small diameter ports into an aqueous carrier fluid containing suspended particulate material whereby polymer fibers and strands are formed in the carrier fluid. The polymer fibers and strands mix with the particulate material suspended in the carrier fluid as the carrier fluid is pumped into the subterranean formation. The mixture of the particulate material and the polymer fibers and strands is deposited in the subterranean formation so that the mixture forms at least one permeable pack that prevents the production of formation fines with fluids produced from the formation and prevents the flow-back of the deposited particulate solids, fibers or strands.

Abstract: The current invention provides improved methods of completing wellbores penetrating unconsolidated and poorly consolidated subterranean zones. The methods basically comprise the steps of placing a coated proppant in fractures penetrating the subterranean zone, allowing the coated proppant to cure or set as a fluid permeable barrier to particulate matter and expanding an expandable well screen located adjacent to the fractures.

Abstract: The present invention relates to a method of determining the proppant friction generated in a fracture of a subterranean formation during a hydraulic fracturing treatment involving injection stages of pad and of proppant-laden fluids. This method is based on close monitoring of surface pressure to define a “net pressure rate” which defines an increase or decrease of net pressure while the job is being pumped, and then relates it with the pressure changes observed with the onset of proppant stages of varying concentrations.

Abstract: A method for predicting the secondary porosity system (SPS) porosity, and thereby permeability, of a coal bed involves determining an initial condition in the coal bed, including an initial SPS pressure and an initial sorbed gas composition, determining a pressure strain effect due to increasing the SPS pressure to a value greater than the initial SPS pressure, and determining a sorption strain effect due to changes in the sorbed gas composition resulting from decreasing the methane content and increasing the content of a stronger adsorbing fluid (SAG) relative to the initial sorbed gas composition. Preferably, the method uses data from test injections of water and/or a weaker adsorbing fluid (WAG) and a SAG. The data is used in the inventors' model to compute a SPS porosity and an absolute permeability at a reference SPS pressure and a reference sorbed gas composition. Preferably, the reference pressure is atmospheric pressure.

Abstract: The present invention provides a method for enhancing the production of hydrocarbons from a subterranean formation. A hydrocarbon bearing formation, surrounding a well bore, is fractured with a fracturing fluid to create one or more fractures in the formation. The formation includes a higher permeability zone and a lower permeability zone with the fractures extending across both the higher and lower permeability zones. The lower permeability zone may contain a substantially higher concentration of hydrocarbons, oil and gas, than does the higher permeability zone which may generally be depleted of hydrocarbons. Proppant is then selectively positioned, such as by allowing the proppant to “float” in a carrier fluid to the top of the fracture, with a majority of the proppant being positioned in the lower permeability zone. The fracture is allowed to close about the proppant to create at least one high conductivity channel in the lower permeability zone.

Abstract: Methods of reducing or preventing particulate flow-back in subterranean zones. In accordance with the methods, a treating fluid having a mixture of reticulated foam fragments and particulate solids are suspended therein. The treating fluid is introduced into a subterranean zone and the mixture of the reticulated foam fragments and the particulate solids are deposited in the subterranean zone whereby the reticulated foam fragments retard or prevent the flow-back of the particulate solids and the transport of formation fines from the subterranean zone upon the flowing-back of fluid from the zone.

Abstract: According to the invention, a method of treating a subterranean formation is provided comprising the steps of: (a) forming a mixture comprising: (i) a particulate, (ii) an elastomer-forming component in a liquid form or in a solvent solution, and (iii) a fluid for carrying the particulate through the well into the subterranean formation; and (b) introducing the mixture into the subterranean formation. The elastomer-forming component has the following characteristics under laboratory testing: (a) the component, by itself or with a curing agent, is capable of being cured to form an elastomeric material, and (b) the component, at a test level of 2 percent by weight over the particulate alone and under conditions of sufficient stress loading, is capable of forming the particulate into a flexible and coherent mass.

Abstract: A method of consolidating particulates comprising providing a slurry comprising a carrier fluid, a first portion of particulates, and a second portion of particulates wherein the first portion of particulates is at least partially coated with resin or tackifying agent and wherein the second portion of particulates is substantially free of resin or tackifying agent; introducing the slurry into a portion of a subterranean formation such that the first portion of particulates and second portion of particulates to form a particulate pack in the portion of the subterranean formation; and, allowing the resin to substantially consolidate the particulate pack. A particulate slurry for use in subterranean formations comprising a carrier fluid, a first portion of particulates, and a second portion of particulates wherein the first portion of particulates is at least partially coated with resin or tackifying agent and wherein the second portion of particulates is substantially free of resin or tackifying agent.

Abstract: A method of the preparation and utilization of polymerized alpha-hydroxycarboxylic-acid-coated proppants for gravel pack and removal of filter cake that was deposited by reservoir drilling fluid. In a preferred example, polyglycolic-acid-coated sand is used to replace conventional gravel pack sand typically used for gravel packing. Under downhole conditions, the acidic by-product generated from the hydration of polyglycolic-acid-coated sand can break down acid-soluble and/or acid-breakable components embedded in the filter cake. This reaction enhances the filter cake removal and the flow of hydrocarbon from the producing formation. The polyglycolic-acid-coated sand may be produced by polymerizing a glycolic acid with a natural or synthetic proppant like 20-40 mesh commercial sand, at temperatures of about 210° F. or higher.

Abstract: The present invention provides improved methods of fracturing subterranean zones penetrated by well bores and improved fracturing fluids. The fracturing fluids are basically comprised of water, a terpolymer of 2-acrylamido-2-methylpropane sulfonic acid, acrylamide and acrylic acid, or its salts, a cross-linking agent for the terpolymer and a delayed viscosity breaker for effecting a controlled reduction in the viscosity of the fracturing fluid.

Abstract: The present invention provides a method for enhancing the production of hydrocarbons from a subterranean formation. A hydrocarbon bearing formation, surrounding a well bore, is fractured with a fracturing fluid to create one or more fractures in the formation. The formation includes a higher permeability zone and a lower permeability zone with the fractures extending across both the higher and lower permeability zones. The lower permeability zone may contain a substantially higher concentration of hydrocarbons, oil and gas, than does the higher permeability zone which may generally be depleted of hydrocarbons. Proppant is then selectively positioned in the fractures using a carrier fluid with a majority of the proppant being positioned in the lower permeability zone. The fracture is allowed to close about the proppant to create at least one high conductivity channel in the lower permeability zone.

Abstract: A formation fracturing method with which to mitigate risk to hydrocarbon productivity includes pumping fracturing fluid, during at least part of a fracturing job time period, into a well to fracture a formation; generating signals, within the fracturing job time period, in response to at least one dimension of the fracture; and further pumping fracturing fluid, within the fracturing job time period, into the well in response to the generated signals. Further pumping includes controlling at least one of a pump rate of the further pumping and a viscosity (either fluid viscosity or particulate concentration) of the further pumped fracturing fluid. Control can include comparing a measured magnitude of at least one dimension of the fracture represented by the generated signals with a predetermined modeled magnitude of the same dimension. Tiltmeters can be used to sense fracture height and width, for example.

Abstract: Improved methods of treating subterranean formations using solid particles and other larger solid materials are provided. The methods are basically comprised of the steps of introducing a carrier fluid containing suspended solid particles which have been coated with a non-hardening tackifying agent into a subterranean formation, mixing a solid material of larger size with the tackifying compound coated solid particles whereby the solid particles stick to the larger solid material and the solid particles and larger solid material are uniformly suspended in the carrier fluid and depositing the larger solid material and the tackifying compound coated smaller solid particles in the subterranean formation.

Abstract: Propped fractures in formations from which fluids are produced are described that have wormholes extending out into the formations from the faces of the fractures at locations distant from boreholes. Methods are given for creating such propped fractures having wormholes in which either a closed propped fracture is formed and then the wormholes are formed, or the entire fracture and channel system is formed before the closure occurs.

Abstract: A multi-zone packing system having unique features that allow for remote operation, thereby eliminating the need to raise and lower a work string and crossover tool to various zones of interest during a frac pack, gravel pack or related completion procedure. The squeeze pack system has a crossover tool or port collocated with each zone of interest and remotely operated closing devices to allow for the setting of each packer and the packing job to be performed with minimal or no movement of the work string.

Abstract: Methods and compositions for preventing fracture proppant particle flowback from subterranean zones penetrated by well bores are provided. The methods basically comprise the following steps. One or more fractures are formed in a subterranean zone and proppant particles coated with a curable liquid composition for consolidating the proppant particles into resilient permeable masses are deposited in the fractures. The curable liquid composition is a mixture of a tackifying compound liquid and a curable resin. After the coated proppant particles have been deposited, the curable liquid composition is allowed to cure.

Abstract: Methods of reducing proppant flowback during production of fluids form subterranean formations are provided. Compressed sieves made from a shape memory material are introduced into hydraulic fracturing opera into hydraulic fractures in subterranean formations during hydraulic fracturing operations or subsequent thereto. The heat of the formation, or introduced heat, triggers the return of the sieves to their previous uncompressed shape and size. The sieves thereby wedge themselves into position within the fractures and serve to filter proppant and formation fines from produced fluids.

Abstract: Methods are presented to induce a screenout during a subterranean formation fracturing or combined fracturing and gravel packing treatment having a viscoelastic surfactant-based carrier fluid by laying down a filter cake at least a portion of which is a base-soluble material, injecting proppant slurry, and causing hydrolysis and dissolution of the solid base-soluble material by adding base so that leak-off increases, the concentration of proppant in the fracture increases, and the proppant screens out. A method of gravel packing with a viscoelastic surfactant-based carrier fluid by laying down a filter cake at least a portion of which is a base-soluble material, injecting gravel, and causing hydrolysis and dissolution of the solid base-soluble material by adding base. Methods of slowing or accelerating the hydrolysis and dissolution are given, and addition of bridging-promoting materials is included.

Abstract: A low density, spherical proppant made from kaolin clay having an alumina content distributed homogeneously throughout the pellets, an apparent specific gravity of from about 1.60 to about 2.10 g/cc, and a bulk density of from about 0.95 to about 1.30 g/cc. The low density is achieved by controlling the time and temperature of the firing process to be from about 1200 to about 1350° C. This low density proppant is useful in hydraulic fracturing of shallow oil and gas wells.

Abstract: Methods and compositions useful for subterranean formation treatments, such as hydraulic fracturing treatments and sand control that include porous materials. Such porous materials may be selectively configured porous material particles manufactured and/or treated with selected glazing materials, coating materials and/or penetrating materials to have desired strength and/or apparent density to fit particular downhole conditions for well treating such as hydraulic fracturing treatments and sand control treatments. Porous materials may also be employed in selected combinations to optimize fracture or sand control performance, and/or may be employed as relatively lightweight materials in liquid carbon dioxide-based well treatment systems.