5484 results about "Filter cake" patented technology

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.

The present invention relates to methods and compositions for treating subterranean formations, and more specifically, to improved methods and compositions for degrading filter cake deposited on a subterranean formation. One embodiment of the present invention provides a method of creating particulates coated with acid-releasing degradable material on-the-fly comprising the step of: combining an acid-releasing degradable material with a solvent or a plasticizer to create a coating solution; and, coating the coating solution onto a particulate on-the-fly to create coated particulates. Another embodiment of the present invention provides a gravel pack comprising gravel particles coated on-the-fly with an acid-releasing degradable material.

Aphron-containing spotting fluids and their use in releasing pipe or tools stuck in the filter cake on the sides of a borehole are disclosed. The spotting fluids comprise a liquid, either aqueous, oleaginous, or mixtures thereof, a viscosifier which imparts a low shear rate viscosity to the fluids of at least 10,000 centipoise, an aphron-generating surfactant, and aphrons. The spotting fluids are used in a conventional method of releasing pipes or tools stuck in the filter cake on the sides of a borehole during conventional drilling or well servicing operations.

A flow conduit having at least one orifice is placed in the vicinity of a flow source, which in one non-limiting embodiment may be a hydrocarbon reservoir. The flow pathway between the orifice and the source is temporarily blocked with a degradable barrier. Once the flow pathway is physically placed, the degradable barrier is removed under the influence of an acid, a solvent, time and/or temperature. The flow source and the flow pathways are at least partially covered (and flow blocked by) a temporary coating such as a pseudo-filter cake formed by a viscoelastic surfactant-gelled aqueous drill-in fluid, and the flow conduit is extended to the flow source. The pseudo-filter cake is removed when viscosity is reduced by an internal breaker, and flow is then allowed. The method is useful in one context of recovering hydrocarbons where the flow conduit is a telescoping sleeve or tube that contacts the borehole wall.

This invention proposes a method for completing an interval of an open-hole injection wellbore penetrating a subterranean formation, said wellbore being communicating with the formation by way of an interface that comprises at least a filter cake invaded zone comprising bridging materials and other embedded solid materials, said method comprising the steps of injecting a clean-up fluid and contacting it with the filtercake for a period of time sufficient to loose some of the other solids embedded in the filter cake; removing the loosened solids by a high-rate displacement fluid comprising suspending additives; and then injecting a dissolving fluid comprising a diverter and an effective amount of a salt or acid capable of dissolving the bridging material.

Well treatment is disclosed that includes injecting a well treatment fluid with insoluble polyol polymer such as polyvinyl alcohol (PVOH) dispersed therein, depositing the insoluble polymer in the wellbore or an adjacent formation, and thereafter dissolving the polymer by reducing salinity and/or increasing temperature conditions in the environment of the polymer deposit. The method is disclosed for filter cake formation, fluid loss control, drilling, hydraulic fracturing and fiber assisted transport, where removal of the polyol at the end of treatment or after treatment is desired. The method is also disclosed for providing dissolved polyol as a delayed breaker in crosslinked polymer viscosified systems and viscoelastic surfactant systems. Also disclosed are well treatment fluids containing insoluble amorphous or at least partially crystalline polyol, and a PVOH fiber composition wherein the fibers are stabilized from dissolution by salinity.

A method for well construction and completion is disclosed. First, a productive section of a well is drilled in the presence of a fluid system that controls fluid losses, is substantially non-damaging to the formation and includes particles in a particle size distribution sufficient to form a low permeability filter cake on a formation face and to allow the majority of the filter cake particles to flow back into the borehole after well completion. after drilling, a casing includes at least one and preferably a plurality of extendable permeable elements or member is run in the well so that the elements are positioned and aligned with sites in the producing formation and once extended form production conduits between the formation and an interior of the casing. A completed borehole is also disclosed including a casing having production conduits formed from the extendable members or elements.

Methods of drilling and completing open hole well bores and methods of removing filter cake comprised of a gelling agent and calcium carbonate are provided. A method of the invention for removing filter cake comprised of a gelling agent and calcium carbonate from the walls of an open hole well bore is basically comprised of the steps of contacting the filter cake with a delayed clean-up solution comprised of water and a formate ester and removing the clean-up solution from the well bore.

A method and apparatus for purifying crude terephthalic acid from a liquid dispersion thereof also containing impurities selected from unreacted starting materials, solvents, products of side reactions and/or other undesired materials is provided. The method comprises the steps of filtering the dispersion to form a crude terephthalic acid filter cake, dissolving the filter cake in a selective crystallization solvent at an elevated temperature to form a solution, crystallizing purified terephthalic acid from the solution in the crystallization solvent by reducing the pressure and temperature of the solution, and separating the crystallized purified terephthalic acid from the solution. According to the invention, the selective crystallization solvent is non-aqueous, non-corrosive and essentially non-reactive with terephthalic acid. Preferably, the selective crystallization solvent is N-methyl pyrrolidone. The method and apparatus produces purified terephthalic acid having a purity desired for use in forming polyester resin and other products at an economically attractive rate and at operating conditions of reduced severity which require a lower capital investment and simplified processing.

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.

A flow conduit may have at least one orifice, which conduit is in the vicinity of a flow source. The source is at least partially covered (and flow blocked by) an optional temporary coating or barrier (e.g. filter cake). The flow pathway between the orifice and the source is temporarily blocked with a degradable material. A delayed degradation material layer is present over or covering the degradable material. The delayed degradation material layer degrades at a rate slower than the degradable barrier. The degradable material and delayed degradation material layer disintegrate (e.g. via time, temperature, a solvent). The degradable material optionally produces a product that removes the temporary coating. The method is useful in one context of recovering hydrocarbons where the flow conduit is the casing or liner of the well and the flow source is a subterranean reservoir where the coating is filter cake.

The present invention involves methods and compositions for treating subterranean formations, and more specifically, relates to improved methods and compositions for degrading filter cake deposited in a subterranean formation by effecting a uniform distribution of a filter cake breaker. One embodiment of the present invention provides a weighted encapsulated breaker comprising a breaker material; and, a coating material comprising a polymer material and a filler material having a specific gravity of at least about 6.5.

A method of cleaning a wellbore prior to the production of oil or gas is disclosed, wherein the wellbore has been drilled with an invert emulsion drilling mud that forms an invert emulsion filter cake. The method may include the steps of circulating a breaker fluid into the wellbore, where the breaker fluid includes an aqueous fluid, and imino diacetic acid or salt thereof. Optionally an acid buffering agent, and a weighting age are also included. The breaker fluid is formulated such that after a predetermined period of time and the filter cake present in the wellbore or on the wellbore face is substantially degraded. Other methods may also include drilling the wellbore with a water-based drilling mud that forms a water-based filter cake, wherein the method may include the steps of circulating a breaker fluid into the wellbore, where the breaker fluid may include an aqueous fluid, and an iminodiacetic acid or a salt thereof.

The invention discloses a process for producing vanadic anhydride by vanadium slag. The steps of the process comprise as follows: a, adding alkali metal salt in the vanadium slag, and mixing with each other uniformly, a mixture is obtained. b, laying the mixture obtained by step a into a calcining furnace to oxidize and calcine, vanadium slag grog is obtained. c, the calcined vanadium slag is discharged out of the furnace, fast cooling and performing water immersion. d, filtering the mixture obtained by step c, filter liquor is obtained. e, removing impurities in the filter liquor. f, adjusting the pH value of the filter liquor obtained by step e, adding ammonium salt to precipitate vanadium and filtering the filter liquor, then, ammonium peroxovanadate filter cake and ammonium metavanadate filter cake are obtained. g, calcining the filter cake after vanadium precipitation obtained by step f, and vanadic anhydride is obtained, wherein the content of the vanadic anhydride in the vanadium slag used in step a is 2.0%-8.0%. The invention has the advantages of simple and easy, low facility request, convenient operation and low cost, further, the residual quantity of the vanadic anhydride in waste slag is 0.55%-1.0%, which has fine economic benefit and social benefit.

A composition and method for improving the fluid efficiency of many oilfield treatments is given. The composition is a solid additive, in a viscosified fluid, in a size range small enough that it enters formation pores; it optionally bridges there to form an internal filter cake, and then decomposes to provide a breaker for the viscosifying system for the fluid. Examples of suitable additives include waxes, polyesters, polycarbonates, polyacetals, polymelamines, polyvinyl chlorides, and polyvinyl acetates. Degradation of the additive may be accelerated or delayed.

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.

Viscoelastic surfactant (VES) gelled aqueous fluids containing water, a VES, an internal breaker, a VES stabilizer, a fluid loss control agent and a viscosity enhancer are useful as treating fluids and particularly as fracturing fluids for subterranean formations. These VES-based fluids have faster and more complete clean-up than polymer-based fracturing fluids. The use of an internal breaker permits ready removal of the unique VES micelle based pseudo-filter cake with several advantages including reducing the typical VES loading and total fluid volume since more VES fluid stays within the fracture, generating a more optimum fracture geometry for enhanced reservoir productivity, and treating reservoirs with permeability above the present VES limit of approximately 400 md to at least 2000 md.

The invention discloses a method for recycling molecular sieve crystallization mother solution, which comprises the following steps of: (1) preparing a material for synthesizing a molecular sieve, gelatinizing, crystallizing, filtering, and collecting all molecular sieve crystallization mother solution; (2) using the obtained all molecular sieve crystallization mother solution for synthesis of the molecular sieve directly, mixing with a solid silicon source, an aluminum source and alkali, and adding or not adding molecular sieve seed crystals and a template agent to obtain a reaction mixture; and (3) crystallizing the obtained reaction mixture according to the conventional hydrothermal method, obtaining a filter cake, namely a molecular sieve product, and filtering and collecting all molecular sieve crystallization mother solution, wherein the obtained all molecular sieve crystallization mother solution can be circularly utilized according to the sequence of steps (2) and (3). In the synthesis of the molecular sieve, alkaline waste liquor is not discharged basically, the total silicon utilization rate is more than or equal to 90 percent, and the yield of the molecular sieve product is over 90 percent.

The invention provides a preparation method of dispersible silane functionalized graphene. The method comprises the steps of: conducting ultrasonic dispersion to graphene oxide in absolute ethyl alcohol so as to form a uniform graphene oxide dispersion solution, then adjusting the pH value to 3-4, or under the protection of an inert atmosphere, adding silane into the dispersing solution for modification, with silane and graphene oxide in a mass ratio of 0.1:1-5:1, continuing the reaction for 12h-48h at a temperature ranging from normal temperature to 78DEG C, carrying out centrifugation, then adding hydrazine hydrate to the obtained solid, performing heating reduction, and filtering the reaction solution, then washing and drying the filter cake, thus obtaining dispersible silane functionalized grapheme. The method of the invention is simple and practicable, and the obtained silane functionalized grapheme has good dispersibility in solvents like absolute ethyl alcohol, acetone, toluene, ethyl acetate, butyl acetate, and tetrahydrofuran (THF), etc.

Disclosed are systems and methods for monitoring wellbore servicing fluids. One system includes a flow path fluidly coupled to a borehole and containing a wellbore servicing fluid that is exiting the borehole, the wellbore servicing fluid being configured to chemically react with and remove filter cake from the borehole, an optical computing device arranged in the flow path and having at least one integrated computational element configured to optically interact with the wellbore servicing fluid and thereby generate optically interacted light, and at least one detector arranged to receive the optically interacted light and generate an output signal corresponding to a characteristic of the wellbore servicing fluid, the characteristic of the wellbore servicing fluid corresponding to a concentration of a filter cake chemical constituent.

Single phase microemulsions improve the removal of filter cakes formed during drilling with oil-based muds (OBMs). The single phase microemulsion removes oil and solids from the deposited filter cake. Optionally, an acid capable of solubilizing the filter cake bridging particles may also be used with the microemulsion. In one non-limiting embodiment the acid may be a polyamino carboxylic acid. Skin damage removal from internal and external filter cake deposition can be reduced. In another optional embodiment, the single phase microemulsion may contain a filtration control additive for delaying the filter cake removal, destruction or conversion.

The invention provides a preparation method for core-shell type silicon dioxide-coated nanometer calcium carbonate, which comprises following steps: adding silicate in calcium carbonate suspension pulp; stirring and mixing using emulsion pump; introducing kiln gas with CO2 for carbonization until the pH is 6.5 to 7.0; heating to 60 to 90 DEG C; adding coating agent for coating treatment; the product is obtained after the coated pulp is filtered and the filter cake is dried. The preparation method for core-shell type silicon dioxide-coated nanometer calcium carbonate has the advantages of improving the acid resistance of nanometer calcium carbonate since silica sol precipitated through hydrolysis is coated on the surface of nanometer calcium carbonate, improving dispersion of the product in polymer due to surface treatment using coupling agent and organic acid, good acid resistance and dispersion, greatly improving physical and chemical properties, and felicitating industrial production with simple operation.

The invention discloses a preparation method of an alumina porous microsphere. The preparation method comprises the following steps: 1) dissolving a surfactant in deionized water, stirring the solution, and using the solution as a water phase; 2) mixing a chelating agent, an alumina precursor and octanol, stirring the materials, and using the mixture as an oil phase; 3) adding Span80 and a pore-forming agent to the oil phase, and stirring the materials; 4) pouring the clear oil phase obtained in the step 3) into the water phase, and continuously stirring and emulsifying the materials; 5) carrying out vacuum filtration on the product obtained in the step 4), and washing and then drying the obtained filter cake, thus obtaining the alumina porous microsphere. The microsphere has an internally closed macroporous structure and has a microsphere dimension of 1-100mu m and an internally closed pore diameter of 50nm-5mu m.

The invention relates to a method for recycling titanium dioxide in a waste SCR (Selective Catalytic Reduction) denitration catalyst. The method comprises the following steps of: firstly removing dust from the waste denitration catalyst, pulverizing, then adding concentrated sulfuric acid so as to carry out acid hydrolysis on the waste denitration catalyst to obtain a concentrated titanyl sulfate solution, and adding water for dilution; adding a non-ionic emulsifier serving as a flocculating agent and a sulfonate surface active agent or a polycarboxylate surface active agent as a coagulant aid, and adding water-solubility methyl silicone oil; pumping into a plate-and-frame filter press for filter pressing, carrying out vacuum concentration on filtrate, then heating to 90 DEG C to 98 DEG C, and maintaining for 5.5 hours so as to hydrolyze the filtrate; cooling a hydrolysis product to 40 DEG C, and carrying out vacuum filtration so as to sediment out metatitanic acid; rinsing with sand-filtered water and deionized water, and adding potassium carbonate or phosphorous acid to obtain metatitanic acid filter cakes; and drying the filter cakes, calcining at 500-800 DEG C, and then pulverizing to obtain a titanium dioxide finished product. The method has the advantages of being capable of reducing disposal amount of the waste denitration catalyst, recycling the waste denitration catalyst and reducing the production cost of the waste denitration catalyst.

Presented herein are improved bridging agents comprising a degradable material, improved subterranean treatment fluids comprising such improved bridging agents, and methods of using such improved subterranean treatment fluids in subterranean formations. An example of a method presented is a method of drilling a well bore in a subterranean formation. Another example of a method presented is a method of forming a self-degrading filter cake in a subterranean formation. Another example of a method presented is a method of degrading a filter cake in a subterranean formation. An example of a composition of the present invention is a treatment fluid including a viscosifier, a fluid loss control additive, and a bridging agent comprising a degradable material. Another example of a composition presented is a bridging agent comprising a degradable material.

The invention relates to a method for preparing graphene oxide by chemical peeling, belonging to the field of graphene oxide preparation. The method comprises the following steps: (1) graphite oxide preparation: selecting expanded graphite, strong acid, oxidant and distilled water according to the proportion of (0.1-0.8g):(10-90ml):(0.6-12g):(40-300ml); mixing the expanded graphite with the strong acid evenly, adding oxidant and then carrying out a reaction on the mixture for 0.25-4 hours in a condition of 30-45 DEG C; adding distilled water to react for 0.5-2.5 hours and washing the filter cake to neutral with distilled water; rinsing the filter cake with absolute ethyl alcohol, drying the cake in a condition of 30-45 DEG C to obtain the graphite oxide. (2) graphene oxide preparation: selecting the graphite oxide and organic solvent according to the proportion of (0.02-0.1g):(15-70ml); adding the graphite oxide to the solvent and dispersing with a 40-50kHz ultrasonic sound for 0.5-10 hours; centrifugating at a rate of 3000-5000r/min for 20-90 minutes; taking the suspension solution and drying in a condition of 30-45DEG C to obtain the graphene oxide. The method in the invention is safe in operation and has low costs.

The invention discloses a method for preparing concavo-convex rod soil/zinc oxide nanometer composite materials, which comprises the following steps: purifying and dispersing the concavo-convex rod soil in water to prepare concavo-convex rod soil dispersion liquid; then adjusting the temperature of the concavo-convex rod soil dispersion liquid to 30 to 100 DEG C; agitating the concavo-convex rod soil dispersion liquid dispersion liquid and while adding zinc salt aqueous solution with the concentration of 0.3 to 3 mol.L<-1> and carbonate aqueous solution with the concentration of 0.3 to 2 mol.L<-1> to the concavo-convex rod soil dispersion liquid dispersion liquid; and keeping the pH value of mixed liquid within the range of 6.0 to 8.0. The prepared mixed serous fluid comprising the prepared nanometer concavo-convex rod soil and basic zinc carbonate is filtered; and a filter cake is washed by deionized water; when the electrical conductivity of filtrate is less than 300 MuS.cm<-1>, the washing is finished; and the filter bake obtained is dried at the temperature of below 100 DEG C, then baked for 1 to 10 hours at the temperature of 300 to 600 DEG C, and finally crushed. The invention is simple and has the advantages of low energy consumption and high safety; the load of the adsorbing material prepared is uniform and has good dispersibility, strong adsorbability and remarkable photo-catalyzed degradation property.

The invention relates to a manganese-based low-temperature denitration catalyst and a preparation method thereof. The preparation method comprises the following steps of: 1, dissolving manganous nitrate, ferric nitrate, crystal tin tetrachloride and cerous nitrate in water at normal temperature, and stirring the mixture to form transparent solution; 2, preparing solution of ammonium carbonate, dripping the solution of ammonium carbonate into the solution prepared by the step 1, and heating and stirring the mixture to obtain slurry; 3, ultrasonically immersing the slurry, leaching the slurry to obtain a filter cake, and then washing the filter cake with deionized water; and 4, drying and roasting the filter cake to obtain the manganese-based low-temperature denitration catalyst MnFeSnCeOx, wherein the molar ratio of Mn: Fe: Sn: Ce in the prepared catalyst is equal to (35-39):(2-5):(9-35):(54-21). The purification efficiency of nitric oxides reaches 71 to 100 percent when the metallic oxide catalyst is at the temperature of between 80 and 250 DEG C. The composite oxide catalyst has high sulfur resistance.

A method of cleaning a wellbore prior to the production of oil or gas, wherein the wellbore has been drilled with an invert emulsion drilling mud that forms an invert emulsion filter cake is disclosed. The method may include circulating a breaker fluid into the wellbore, where the breaker fluid includes a non-oleaginous internal phase and an oleaginous external phase, where the non-oleaginous phase includes a water soluble polar organic solvent, a hydrolysable ester of a carboxylic acid, and a weighting agent, and the oleaginous external phase includes an oleaginous fluid and an emulsifier, and where the hydrolysable ester is selected so that upon hydrolysis an organic acid is released and the invert emulsion of the filter cake breaks.

The invention relates to a preparation method of a reduction graphene oxide heat-conducting film. The preparation method comprises the following steps of: firstly weighing graphite oxide, adding the graphite oxide to deionized water, and carrying out ultrasonography, centrifugalizing at low speed for impurity removal, drying and grinding to obtain graphene oxide; dissolving the graphene oxide into a solvent, and carrying out the ultrasonography to prepare a graphene oxide dispersion solution; carrying out vacuum filtration on the graphene oxide dispersion solution by adopting a microporous filtering film, drying an obtained filter cake and the filtering film together, and then stripping the filter cake from the filtering film to obtain a graphene oxide film; acquiring the reduction graphene oxide heat-conducting film by adopting a high-temperature heat treatment or hydriodic acid reduction method in a restricted space. The preparation method disclosed by the invention effectively solves the technical problems of easiness for breakage and difficulty in large-area integrity keeping in preparing the reduction graphene oxide heat-conducting film from the graphene oxide film and is simple and higher in film heat conductivity; the prepared reduction graphene oxide heat-conducting film achieves potential practical application value in the field of heat radiation of a microelectronic device.