74results about How to "Completely broken glue" patented technology

The invention relates to crosslinked acid sand fracturing acid liquor, comprising the following components in percentage by weight: 0.7% of thickening agent, 1.5% of cross-linking agent, 1.5% of corrosion inhibitor, 0.5% of surfactant, 0.15% of stabilizing agent, 20% of hydrochloric acid and 75.65% of water, wherein the thickening agent consists of the following components by weight percent: 6.61% of methacrylamidoethyltrimethylamine hydrochloride, 3.22% of acrylamide, 1.25% of acrylic acid, 9.52% of 2-acrylamide-2-methylpropanesulfonic acid, 6.15% of sodium hydroxide and 73.25% of deionized water; and the cross-linking agent consists of the following components in percentage by weight: 1% of zirconium oxychloride, 80% of formaldehyde and 19% of glyoxal. The crosslinked acid sand fracturing acid liquor can be cross-linked in 20% hydrochloric acid, the temperature resistance reaches 100 DEG C, the constant of reaction rate of acid-rock is 1.3744*10-6 (mol / cm<3>)(1-m)*(cm / s), and the viscosity of the gel-breaking liquid is less than 10 mPa.s.

The invention relates to a low-friction recyclable slickwater fracturing fluid system suitable for compact oil and gas reservoirs and a preparation method thereof. Every tonnage of water is added with 0.06-0.25% of a water soluble drag reducer by mass, 0.2-0.5% of a demulsification cleanup additive by mass and 0.5% of a clay stabilizer by mass for evenly mixing to obtain a slickwater fracturing fluid; the prepared slickwater fracturing fluid is a reverse phase micro-emulsion system, and has the characteristics such as low viscosity, thorough gum breaking, easy flowing back, good expansion prevention performance and low friction; the resistance reducing effect is obvious; compared with clear water, the resistance reducing effect can achieve 50-70%; in the scene hydraulic fracturing operation, the resistance reducing rate of the water soluble drag reducer is 42.5% higher than that of the traditional guanidine gum slickwater in the case that the construction displacement is 3.5 m<3> / min.

The invention relates to a novel organic boron cross linking agent for fracturing and fracturing fluid for deferring cross bonding vegetable glue, wherein the preparation method comprises the steps of, reacting sodium borate with multicomponent aldehydes (e.g. ethanedial), adding polyvalent alcohol amine (e.g. triethanolamine) for complete reaction, forming component an of organic boron cross linking agent, and organic boron component B of 20-30% caustic soda liquor solution, mixing component an and B in the proportion of 100:5-100:15 to form the organic boron cross linking agent. While the organic boron deferring cross bonding vegetable glue fracturing fluid comprises vegetable glue polymer, pH regulator, glue breaking agent and organic boron cross linking agent.

The invention relates to a high temperature resistant cleansing emulsion or microemulsion fracturing fluid and a preparation method thereof. The emulsion fracturing fluid is composed of a continuous oil phase, a polymer (I)-containing dispersed water phase and an emulsifier. The preparation method of the emulsion fracturing fluid includes: preparing a mixed solution of the oil phase and the emulsifier, preparing a four-monomer containing water phase, conducting a polymerization reaction in the presence of an initiating agent, and other steps. The product provided in the invention has low apparent viscosity, and can dissolve rapidly. When the emulsion dissolves into gel, the emulsifier can have a synergistic effect with an association polymer, thus further improving and maintaining the viscosity, and helping to prevent leak-off and help flowback. An oxidation gel breaking way is employed for gel breaking, the gel can be completely broken, and the gel breaking solution has low viscosity and contains no residue. The emulsion fracturing fluid is easy to undergo flowback, and has low damage to the stratum.

The invention discloses a slippery water fracturing fluid with ultra-low interfacial tension with crude oil after degradation. The slippery water fracturing fluid is prepared from an ultra-low interfacial tension drag reducer, a demulsify-cleanup additive, a clay stabilizer and a degrading agent. A preparation method of the slippery water fracturing fluid comprises steps as follows: 0.02%-0.10% in percentage by mass of the ultra-low interfacial tension drag reducer, 0.1%-0.2% in percentage by mass of the demulsify-cleanup additive and 0.3% in percentage by mass of the clay stabilizer are added to every ton of water, the agents are mixed to form a homogeneous solution, and 0.08% of the degradation agent is added from a mixing tank of blending equipment during construction. Additives of the slippery water fracturing fluid are all liquid phase, and the slippery water fracturing fluid can be quickly dispersed in water, have good salt tolerance, are not easily affected by the content of bacteria in a fluid preparation solution and have a stable drag reduction effect under the construction displacement of 6-20 m<3> / min; when applied to improvement of low-permeability oil and gas reservoirs, the slippery water fracturing fluid can reduce the interfacial tension between a gel breaking liquid and crude oil and reduce string and construction friction, helps production of the crude oil, increases of the yield of the crude oil and can be prepared repeatedly from backflow fracturing fluids.

The invention relates to a fracturing fluid capable of resisting high salinity water quality. The fracturing fluid is characterized by being composed of a base fluid and a cross-linking fluid which are fully mixed in proportion. The base fluid contains a chelate cosolvent and a chelate stabilizer, wherein the chelate cosolvent can restrain high salinity of water quality and promote swelling of guanidine gum. The base fluid comprises 98.2-98.65 parts of high salinity surface water, 0.1-0.15 part of the chelate cosolvent,0.3-0.4 part of thickener, 0.1-0.15 part of bactericide, 0.3-0.5 part of clay stabilizer, 0.5 part of demulsifying cleanup agent and 0.05-0.1 part of the chelate stabilizer; the cross-linking fluid comprises 50 parts of water, 50 parts of organic cross-linking agents and 0.35 part of gel breaker; and the fracturing fluid comprises 99.2-99.5 parts of the base fluid and 0.5-0.8 part of the cross-linking fluid. By aid of the fracturing fluid, water resources can be saved effectively, and the success rate for fracturing construction can be improved.

The invention discloses a cationic viscoelastic surfactant and preparation and application thereof. The preparation method of the cationic viscoelastic surfactant comprises the following steps: firstly, mixing long-chain fatty acid with dimethylaminopropylamine according to a certain proportion, adding a catalyst solution to obtain a required amide product intermediate A by a series of reaction; allowing reflux condensation reaction of epoxy chloropropane and water at a certain proportion to be carried out in oil bath of 100 DEG C to obtain colourless and transparent 3-chloro-1,2-propylene glycol aqueous solution, namely an intermediate B; heating the intermediate A in oil bath for melting, and dropwise adding an aqueous solution B to obtain the required viscoelastic surfactant by a series of reaction; the surfactant can be mixed with a potassium chloride solution according to a certain proportion to obtain clean fracturing fluid which is low in cost and excellent in performance, besides, the clean fracturing fluid has excellent high-temperature resistance, shearing resistance, and excellent solid-carrying performance, is automatic and thorough in gel breaking, causes little damage to the reservoir stratum and has the characteristic of wide application range.

The invention relates to a composition used for preparing a temperature-resistant salt-resistant fracturing fluid thickening agent, the temperature-resistant salt-resistant fracturing fluid thickeningagent prepared from the composition, and a preparation method thereof. The composition comprises following components: acrylamide, acrylic acid, a hydrophobic monomer, 2-acrylamido-2-methylpropane sulfonic acid, a rigid monomer, a surfactant, and a shielding reagent. According to the temperature-resistant salt-resistant fracturing fluid thickening agent, excellent sand suspension effect can be achieved without crosslinking with a crosslinking agent, the temperature resistance and salt resistance are better; after 2h of aging in a simulated brine with total mineralization degree of 50000mg / L at 160 DEG C, the viscosity retention rate of the temperature-resistant salt-resistant fracturing fluid thickening agent is equal to or larger than 80%. Solution gel breaking of the temperature-resistant salt-resistant fracturing fluid thickening agent is complete, no water insoluble substance is left, flowback is complete, the ground is not destroyed, and no oil layer pollution is caused.

The present invention relates to an improvement on oil-field water base fracture fluid formula. Said water base fracture liquid is composed of base fluid and cross-linking liquor according to a certain ratio. Said base fluid is formed from (by wt%) 0.25-0.40% of thickness agent, 0.15-0.30% of cleanup additive, 0.10-0.20% of emulsion-breaking emulsion preventer, 1.0-2.0% of antiswelling agent, 0.10-0.20% of clay stabilizing agent, 0.1-0.15% of vegetable gun stabilizing agent and 96.65-98.3% of water, and the cross-linking liquor is formed from 3.0-6.0% of cross-linking agent, 0.4-1.2% of breaking agent and 92.8-96.6% of water, and the volume ratio of base fluid and cross-linking liquor is 20-50:1. Said invention can effectively improve fracture fluid properties, and its damage to reservoir permeability and fracture conductivity can be minimum.

The invention relates to compound type temperature-resisting viscoelastic self-diverting acid as well as a preparation method and application thereof. The self-diverting acid is prepared from 1.0 to 7.5 weight percent of thickening agent A, 1.0 to 7.5 weight percent of thickening agent B, 32.2 to 75.5 weight percent of concentrated hydrochloric acid, 1.0 to 4.0 weight percent of corrosion inhibitor, 1.5 to 5.0 weight percent of ferric ion stabilizer, 1.5 to 4.0 weight percent of clay stabilizer and the balance of water; the thickening agent A is prepared from one or more of cocamidopropyl betaine, octadecyl dimethyl hydroxypropyl betaine and lauramidopropyl betaine; the thickening agent B is prepared from one or more of erucamide propyl betaine, docosyl dimethyl betaine and erucamide propylsulfobetaine. The self-diverting acid disclosed by the invention is suitable for a carbonate reservoir with the temperature of 80 to 120 DEG C.

The invention discloses fracturing fluid and a preparation method thereof. The fracturing fluid is formed by mixing base fluid and crosslinked fluid according to the crosslinking ratio of 100 to 5; the base fluid consists of the following compositions according to mass percentage: 03 to 0.5 percent of hydroxypropyl guanidine gum HPG-1, 0.4 to 0.5 percent of a temperature stabilizer for the fracturing fluid, 0.05 to 0.15 percent of a low temperature evocating agent for the fracturing fluid, 0.2 to 0.3 percent of a cleanup additive and the balance being sewage water from a crude oil layer; and the crosslinked fluid consists of the following compositions according to mass percentage: 0.5 to 1.5 percent of borax, 0.5 to 1.5 percent of ammonium persulfate and the balance being clear water. The method for preparing the fracturing fluid comprises the following steps: the prepared base fluid and the prepared fracturing fluid are respectively placed for 100 to 120 minutes and are mixed according to the crosslinking rate of 100 to 5 to form the fracturing fluid. The method adopts the sewage water for matching the fracturing fluid, saves cost, has small pollution to the environment and improves the wave and volume of a water-driven reservoir and the oil-sweeping efficiency.

The invention discloses a method for preparing a guanidine-gum fracturing-liquid nanometer cross-linking agent.The method includes the steps that sodium silicate serves as a silicon source to be hydrolyzed, surface modification is carried out with an organic silicon modifier, reactive nanometer silicon dioxide is prepared, and boric acid is loaded on the surface of the reactive nanometer silicon dioxide.According to the method, the raw materials are low in cost, the preparation technology is simple, and the cross-linking time can be controlled by adjusting the content of surface amido and the loading capacity of the boric acid; as cross-linking time is delayed, frictional resistance between fracturing liquid and a conveying pipe in the construction process can be reduced, and effective time is bought for construction while energy consumption is reduced; meanwhile, as the spatial size of the boric acid is increased, the cross-linking efficiency can be improved, the fracturing liquid has the good temperature resistance and the good shearing resistance accordingly, and gum breaking is complete.

The invention provides a fracturing fluid prepared by utilizing a fracturing flow-back fluid and a preparation method thereof. The fracturing flow-back fluid is not processed or subjected to simple processing and then is directly used to prepare the fracturing fluid. The fracturing fluid is composed of a thickening agent and other auxiliary agents, and employs a crosslinking agent compatible with a guar gum thickening agent used for the flow-back fluid and a crosslinking promoter. The formula crosslinking time 1-3 min is adjustable, the temperature resistance is 120 DEG C or more, and the system frictional resistance is reduced by 20% or more compared with a common hydroxypropyl guar gum fracturing liquid. The fracturing liquid preparation method realizes cyclic utilization of the fracturing flow-back fluid, and the prepared fracturing liquid possesses good performances.

The invention provides a small-molecular clean fracturing fluid and a preparation method and an application thereof. The fracturing fluid includes a thickening agent, an auxiliary agent, a co-solvent, an activator, an inorganic salt and water, wherein the thickening agent, the auxiliary agent, the co-solvent, the activator and the inorganic salt are each composed of a substance with the molecular weight of less than 500 and the molecular dynamics diameter of less than 60 nm, and the mass ratio of the thickening agent to the auxiliary agent to the co-solvent to the activator to the inorganic salt to water is (0.8-3.5) to (0.01-0.05) to (1.0-3.0) to (0.4-1.5) to (0.1-0.8) to 100. The invention also provides a preparation method for the fracturing fluid. The method comprises the steps: dissolving the inorganic salt in water; mixing the thickening agent, the auxiliary agent and the co-solvent; and adding the thickening agent solution into the salt solution, cooling the mixed solution to room temperature, adding the activator to the mixed solution, aging at room temperature, and thus obtaining the small-molecular clean fracturing fluid. The fracturing fluid provided by the invention has the advantages of wide range of temperature resistance, good shearing property, low cost and simple preparation.

The invention discloses a novel polymeric visco-elastic surfactant, and a preparation method and an application thereof. The method comprises the following steps: 1, preparing an amide product intermediate A from fatty acid and dimethylaminopropylamine; 2, placing dichloroethane, diethanolamine, NaOH and ethanol in a reaction container, carrying out a reflux reaction for 20-24 h, cooling the obtained reaction product to room temperature, and removing ethanol to obtain an intermediate B; and 3, adding the amide product intermediate A and the intermediate B into the reaction container, adding ethanol, mixing the intermediates and ethanol, and carrying out a reflux reaction for 10-12 h to obtain the novel polymeric visco-elastic surfactant. The novel polymeric visco-elastic surfactant prepared through the method can be used for preparing a low-cost high temperature-resistant clean fracturing fluid to improve the high temperature resistance, the shear resistance and the suspended sand performance of the fracturing fluid.

The invention discloses a fracturing fluid additive with emulsion breaking capability, which belongs to a fracturing fluid technology and mainly solves the problem that the conventional fracturing fluid cannot meet the environmental requirements easily. The fracturing fluid additive with emulsion breaking capability is characterized by comprising the following components in percentage by mass: 6 percent of emulsifying agent, 4 percent of thickening agent, 3 percent of cross linking agent, 50 percent of fluid loss additive, 1-3 percent of gel breaker, 1-1.5 percent of cleanup additive, 30 percent of clay stabilizer and 4.5 percent of emulsion splitter. The using effect of the fracturing fluid can be enhanced to a great extent, complete gel breaking is achieved by the fracturing fluid, and bonding capability is enhanced.

The invention discloses a gelled fracturing fluid being applicable to coalbed methane reservoir, which consists of 0.3 to 0.5 percent of non-ionic polyacrylamide and 0.014 to 0.04 percent of zirconium oxychloride (ZrOCl12) which are used as cross-linking agent, 0.01 to 0.12 percent of hydrochloric acid which is used as pH adjusting agent, 0.06 to 0.12 percent of gelbreaker and surplus water, wherein the gelbreaker is of a redox system which is formed by ammonium persulfate and sodium sulfite according to the mass ratio of (1.0 to 3.0): 1. With the gelbreaker, the gel can be broken under the low-temperature condition. The gelation time and the gel-breaking time of the gelled fracturing fluid are adjustable. The gelled fracturing fluid has the advantages of fast low-temperature cross-linking sped, large viscosity, low filter loss, thorough breaking, no residual slag of gelled fracturing liquid and easy flowback, and can effectively improve the yield of the coalbed methane.

The invention discloses a quick gel breaking process for intermediate and low temperate oil gas well fracturing fluid, and the process at least comprises the following steps: 1) adding a sufficient amount of gel breaking agent in a pre-loading liquid stage; 2) lowering the use concentration of a crosslinking agent in the construction field to form weak crosslinking or under crosslinking fracturing fluid gel; and 3) in the later stage of a sand-carrying agent step, i.e., when a sand adding step is about to finish, adding a gel breaking agent into well fracturing fluid in a tail chase wedge shape. The quick gel breaking process has the following advantages: (1) the water base fracturing fluid is quick, the gel is thoroughly broken, and the flowback rate is high; (2) the gel breaking process is simple, is easy to master and is convenient to operate on site; (3) the gel breaking process is wide in applicable range, is suitable for the common guar gum fracturing fluid system and is also suitable for the water base polymer fracturing fluid system of other gel breaking agents; and (4) the gel breaking process can be used for intermediate and low temperate oil gas well fracturing at the temperature of 20-60DEG C.

The invention relates to the technical field of fracturing reformation of oil and gas reservoirs, in particular to multifunctional emulsion-type salt-tolerant fracturing fluid and a production methodthereof. The multifunctional emulsion-type salt-tolerant fracturing fluid comprises the following raw materials in parts by weight: 0.1-2 parts of an emulsion drag reducer, 0.1-0.3 part of a cleanup additive, 0.2-0.5 part of a clay stabilizer, 0-0.6 part of cross-linking agents, 0-0.08 part of polymer breakers, 0-0.08 part of polymer breaking assistants and 100 parts of water, wherein the emulsiondrag reducer is hyperbranched amphoteric polyacrylamide and a derivative of the hyperbranched amphoteric polyacrylamide. According to the multifunctional emulsion-type salt-tolerant fracturing fluidand the production method thereof, through synergism of the emulsion drag reducer and the components, the fracturing fluid with excellent comprehensive performance of temperature resistance, salt tolerance, shear resistance, anti-swelling performance and the like is obtained so that different requirements of a reservoir can be met.

The invention discloses a preparation method and the application of unified clean fracturing fluid. The method comprises the steps of adding a solvent into a reaction kettle, and controlling the reaction temperature to be 60 DEG C; starting a mixer, sequentially adding a scale inhibitor, and carrying out reaction for 10-30min; adding a clay stabilizer, and carrying out reaction for 10-30min; adding a non-emulsifier and carrying out reaction for 10min; adding reversed phase ions and carrying out reaction for 20-30min; adding a micro-package agent and carrying out reaction for 20-50min; adding a cationic surface active agent into the reaction kettle, and carrying out reaction for 30-60min. According to the method, the reversed phase ions and the cationic surface active agent which influence each other are combined together, so that micelle can not be formed under the condition of high concentration, and the characteristics of viscoelastic clean fracturing fluid can be formed; the reversed phase ions can be released under the condition of low concentration to form micelle together with the cationic surface active agent, so that the performance characteristic of viscoelasticity can be generated; the fracturing sand-carrying property is stable, gel can be thoroughly broken when the unified clean fracturing fluid comes across the oil gas; the product contains the components which are supplementary, so no liquid preparation device is neededand the good effect of preventing an oil layer from being damaged can be achieved.

An emphasized fracturing liquid formula consists of water 500 proportion, emphasizing agent 180-483 proportion, gelatinizer hydroxypropyl guar gum 2-3 proportion, pH value adjuster sodium carbonate 0.8-1 proportion, pH value adjuster sodium hydrate 0.15-0.27 proportion, auxiliary 3.0-3.3 proportion, and emphasized fracturing liquid density is between 1.25-1.5g / cm3. It can be used to increase liquid column pressure in well and decrease construction pressure on well opening and finish oil-well fracture of deep well, super-deep well, abnormal high-pressure well and realize storage-layer transformation.

The invention provides a weighted fracturing fluid. The weighted fracturing fluid is a liquid system prepared by using the following raw materials, by weight, 29-70.5 parts of a weighting agent, 0.2-0.8 parts of a vegetable glue thickener, 0.1-0.8 parts of a cleanup additive, 0.02-0.15 parts of a bactericide, 0.05-0.3 parts of a pH value adjusting agent, 0.1-0.7 parts of a cross-linking agent, 0.03-0.2 parts of a gel breaker and 29.5-71 parts of water. The density of the fracturing fluid at room temperature is 1.22-1.62g / cm<3> or more; the temperature resistance capability of the fracturing fluid can reach above 200DEG C; and the fracturing fluid has the characteristics of cross-linking delaying, low frictional resistance, good cross-linking performance, strong temperature and shear resistance, low filter loss, thorough gel breaking, low residue content, good expansion resistance and the like.

The invention relates to a medium-high temperature oil reservoir phenolic gel self-degradation temporary plugging agent and a preparation method thereof. The temporary plugging agent is prepared fromthe following components in percentage by mass: 2 to 2.5 percent of low molecular weight polymer, 0.2 to 0.25 percent of phenolic cross-linking agent, 0.2 to 0.6 percent of aldehyde cross-linking agent, 0.05 percent of stabilizer, 0.1 percent of catalyst, 0.5 to 2 percent of gel breaker and the balance of water, wherein the sum of the mass percent of all the components is 100 percent. The gel temporary plugging agent provided by the invention can meet the requirements that the oil reservoir temperature is 60-100 DEG C, the plugging time is adjustable within 120-168h, and the gel breaking timeis adjustable within 168-240h; the plugging rate of a rock core reaches 98% or above, the permeability damage rate after gel breaking is 10% or below, a high-permeability layer of a target stratum canbe effectively plugged, flowback is easy after automatic gel breaking, damage to the stratum is extremely small, and the plugging agent can be suitable for most conventional oil reservoirs and has good field application value.

The invention provides anionic clean fracturing fluid and a preparing method thereof. The anionic clean fracturing fluid is prepared from, by weight, 1-3.5% of oleic acid, 1-3.5% of erucic acid, 1-2% of auxiliaries, 0.6-1.3% of potassium hydroxide, 2-5% of cosolvent, 3-7% of potassium chloride and the balance water. The anionic clean fracturing fluid can resist medium and high temperature, gel breaking can be achieved completely, no residue is left basically, apparent viscosity is quite high, sand carrying is achieved, the anionic clean fracturing fluid belongs to clean fracturing fluid and is highly compatible with stratums, and the requirement of an oil and gas field site for fracturing fluid is met.

A method for additionally adding the degelating agent in hydraulic fracturing well in order to decrease the damage of hydraulic fracturing liquid to oil stratum and increasing the hydraulic fracturing effect features that the concenhtration of degelating agent is different for different phases. An equation for calculating the concentration of degelating agent is also disclosed.

The invention discloses a gel temporary plugging agent. The gel temporary plugging agent is prepared from, by mass, 0.3-0.4% of partially hydrolyzed polyacrylamide, 0.03-0.08% of phenol crosslinking agent, 0.03-0.08% of aldehyde crosslinking agent, 0.05-0.2% of water soluble polyvinyl alcohol, 0.05-0.5% of hydrochloric acid or acetic acid, 0.2-0.5% of antioxidant and the balance water, and the sum of the mass percents of all the components is 100%, wherein the phenol crosslinking agent is one of combination of resorcinol and hydroquinone, the aldehyde crosslinking agent is urotropin, and the antioxidant is one or combination of diphenylamine, p-phenylenediamine and sodium fluoborate. The gelling time of the gel temporary plugging agent is adjustable in the range of 5-50 h, the gel breaking time is adjustable in the range of 120-240 h, after gel breaking, the viscosity is measured by a rotational viscometer at the shear rate of 70 / s to be 5-10 mPa.s, which indicates thorough gel breakage, and therefore the gel temporary plugging agent can be suitable for most conventional oil deposit.

The invention discloses a self-heating gas generation foam fracturing fluid and a preparation method thereof. The fracturing fluid is prepared from the following raw materials in percentage by mass: 0.2%-0.5% of a thickening agent, 0.2%-0.5% of a cross-linking agent, 6%-8% of sodium nitrite, 6%-8% of ammonium chloride, 0.7%-1% of a heating catalyst, 0.1%-0.3% of a breaking aid, 0.1%-0.3% of a gelbreaker, and the balance of water. The thickening agent is acid-resistant modified guanidine gum. The fracturing fluid has good gel breaking performance, can automatically generate heat, generate gasand increase pressure, is foamed on site, greatly reduces requirements for ground equipment, has plugging and profile control effects higher than those of conventional foam, has low filtration loss and good sand carrying performance, achieves gel breaking through the low-temperature gel breaker, can promote flowback of the gel breaking fluid, and has good application prospects. The fracturing fluid is suitable for fracturing transformation of middle-shallow-layer high-condensation-point oil, thick crude oil and low-temperature low-pressure low-permeability oil and gas reservoirs.

The invention relates to the technical field of treatment on oil field fracturing recovery fluid, and in particular relates to a fracturing recovery fluid gel breaker and a preparation method thereof. The gel breaker is prepared from the following components in parts by weight: 10-15 parts of oxygen chloride chemical gel breaker, 8-12 parts of guanidine gum polysaccharide linkage-specific hydrolase biological gel breaker, 1-3 parts of metal salt initiator with reducing agent, and 90-110 parts of deionized water; the oxygen chloride chemical gel breaker is prepared from chlorine dioxide, sodium hypochlorite and calcium hypochlorite in mass proportion of 1: 1-2: 2-3; the metal salt initiator with the reducing agent is prepared from ferrous chloride, ferrous sulfate and cuprous chloride in mass proportion of 1: 2-3: 1-2. The fracturing recovery fluid gel breaker disclosed by the invention is high in gel breaking speed and high in gel breaking water yield, so that the water, petroleum and suspended matters can be easily separated, the treatment effects of subsequent flocculation, sedimentation and filtering processes of the fracturing recovery fluid are improved. Therefore, the gel breaker can be extensively applied to the technical field of gel breaking treatment of the fracturing recovery fluid.

The invention discloses a temperature-resistant salt-resistant quick-dissolving thickening agent used for a seawater-based fracturing fluid and a preparation method thereof. The temperature-resistant salt-resistant quick-dissolving thickening agent comprises the following components in percentages by mass: 6% to 8% of acrylic acid, 5% to 6% of sodium hydroxide, 18% to 23% of acrylamide, 1% to 2% of an isolation monomer, 3% to 4% of a functional anion monomer, 3% to 5% of a functional cationic monomer, 4% to 6% of an association intermediate, and 0.4% to 0.8% of an ammonium persulfate-sodium bisulfite redox system or 0.6% to 1.0% of azobisisobutyronitrile which is used as an initiator, with the balance being deionized water. The preparation method for the temperature-resistant salt-resistant quick-dissolving thickening agent comprises the following steps: 1, synthesis of the association intermediate; 2, synthesis of a thickener colloid; and 3, colloid postprocessing. The thickening agent provided by the invention has the following advantages: salt resistance is excellent; the degree of mineralization of a solution has little influence on the rate of swelling; the viscosity-increasing capacity in seawater is strong; antibacterial stability of the solution is strong; the solution has excellent temperature resistance and shearing resistance; and the content of an insoluble substance is extremely small and can not be measured with a conventional method, so the damage of residues on reservoir strata is almost eliminated.

The invention discloses an acid polymer weighted fracture fluid and a preparation method thereof, wherein the acid polymer weighted fracture fluid comprises a base fluid and a crosslinked fluid, the base fluid comprises components with percentage by quality: weighting agents 20%-50%, polymer thickening agent 0.8%-1.20% and discharge aiding agent 0.2%-0.5%, and the allowance is water. The crosslinked fluid comprises an acid polymer delayed crosslinked agent and an acid polymer crosslinked agent, wherein the weight radio of the acid polymer delayed crosslinked agent and the acid polymer crosslinked agent is (1.5-2.5): (3.5-5), and the quality of the crosslinked fluid is 0.6%-0.8% of the quality of the base fluid. The acid polymer weighted fracture fluid achieves to adjust density in 1.10g / cm3-1.50g / cm3, meets the density demands for the scene, improves pressure of fluid columns in shafts, reduces construction pressure of wellheads, and is suitable to remould fracture reservoirs of deep wells, superdeep wells, abnormal high pressure wells and dense wells.