167results about How to "Improve sand carrying capacity" patented technology

The invention discloses a high-temperature-resistant polymer thickening agent for an oil field fracturing fluid as well as a preparation method and application of the thickening agent. The preparation method of the thickening agent comprises the following step: polymerizing acrylamide, other olefin monomers, an initiating agent and a chain transfer agent in an aqueous solution by virtue of a solution process, wherein the weight ratio of acrylamide to the other olefin monomers to water is (10-20):(6-18):(62-84); and the other olefin monomers are selected from one or more, preferably two or three, of anionic olefin monomers, cationic olefin monomers or non-ionic olefin monomers. According to the high-temperature-resistant polymer thickening agent disclosed by the invention, free radicals are generated by using an aqueous solution catalyst process so as to ensure that the monomers are subjected to ternary polymerization or quaternary polymerization to form the anionic high molecular polyacrylamide polymer with the molecular weight of 4,000,000-8,500,000. After the thickening agent is crosslinked with a crosslinking agent, the thickening agent can be used for tolerating high temperature of more than 210 DEG C, and has the advantages of good crosslinked gel elasticity, strong sand carrying capacity, anti-shearing performance, salt resistance, no residues and the like.

The invention relates to an inverse emulsion polymer thickener for a fracturing fluid and a preparation method thereof. The thickener is polymerized by water, 2-acrylamidyl-2-methyl sodium proparesulfonic acid liquid with mass fraction of 50%, alkyl acrylamide, acrylamide, a cationic monomer, N, N-methylene bisacrylamide, a tween-80 emulsifier, ethylene diamine tetraacetic acid disodium salt, 30% sodium hydroxide, white oil, acrylic ester, a span-80 emulsifier, sulfite, a peroxysulphate initiator, a water-soluble azo initiator and OP-15. According to the invention, raw materials are industrial products, and purification is not needed before reaction; polymerization is initiated by initiators by adding a complexing agent, and the preparation process is simple; the thickener provided by the invention is fast in dispersing, easy to prepare, free from pollution and harm, small in use level and good in stability, in particular resists high temperature of 220 DEG C, and is suitable for fracturing a high-temperature stratum; and the thickener is higher in shear resistance, can meet the fracturing construction of high flow, has high sand carrying performance, and is free from residue and is not harmful to the reservoir.

The invention relates to an amphoteric ionic polymer water base fracturing fluid thickening agent and a preparation method of the amphoteric ionic polymer water base fracturing fluid thickening agent, and belongs to the technical field of propping agent fracturing fluid used for oil and gas reservoir volume increase and injection increasing measures. The amphoteric ionic polymer water base fracturing fluid thickening agent is prepared through copolymerization of alkyl group acrylic amide, acrylic amide, 2-acrylic amide group-2-methyl propane sulfonic acid sodium aqueous solution, cationic monomers, vinyl monomers and polymerizable surface active agent monomers. The amphoteric ionic polymer water base fracturing fluid thickening agent and the preparation method of the amphoteric ionic polymer water base fracturing fluid thickening agent have the advantages that raw materials used for the amphoteric ionic polymer water base fracturing fluid thickening agent are all industrial products, purification treatment is not needed before a reaction, a complexing agent is added so that polymerization of the complexing agent and an initiating agent can be initiated at an appropriate temperature, and the preparation technology is simple; due to the fact that the surface active agent monomers are added, an obtained polymer has a hydrophobic association function and is higher in shearing stability, easy to dissolve, free of pollution and harm and good in sand carrying performance; and the amphoteric ionic polymer water base fracturing fluid thickening agent can be resistant to the high temperature of 180 DEG C, is suitable for fracturing of high temperature strata, has high shearing-resistant performance to meet the requirement of high-flow fracturing construction, has high sand carrying performance and no-residue performance, and causes no harm to reservoir strata.

The invention provides a fracturing method capable of improving the sand-carrying performance of fracturing liquid. The method comprises the following steps: dispersing degradable fibers by virtue of a dispersion device, and uniformly dissolving the dispersed degradable fibers in a fracturing liquid base solution; pumping into a fracturing blender truck, and mixing with a propping agent for fracturing so as to form sand-carrying fluid; then pumping the sand-carrying fluid dissolved with the fibers into a strata so as to support a formed fracture geometry. When the degradable fibers added into the fracturing liquid are uniformly dispersed in the fracturing liquid, the fibers and a guanidine gum chain with a network structure form a tangled structure, so that the strength of the cross-linked network structure is enhanced, the sedimentation rate of the propping agent is reduced, the sand-carrying capacity of the fracturing liquid is improved, the propping agent is uniformly distributed in a whole crack, a supporting effect is fully realized, the crack is prevented from being closed and thus the fracturing period of validity is increased; furthermore, the added fibers are capable of effectively preventing the propping agent from flowing back and preventing formation sand flow; an oil gas flow passage is additionally increased, so that the fracturing yield-increasing effect is finally realized.

The invention discloses fracturing fluid directly prepared from seawater. The fracturing fluid consists of the following components in part by weight: 0.3 to 2.0 parts of thickening agent, 1.0 to 8.0 parts of organic metal composite crosslinking agent, 0.2 to 0.6 part of discharge aiding agent, 0.01 to 0.3 part of gel breaker and 100 parts of seawater. The fracturing fluid is directly prepared from the seawater without fresh water, so the problem of water source for marine platform fracturing construction is solved; the seawater mineralization degree is high, so clay swelling of a storage layer can be effectively inhibited; and an encapsulated gel breaker is adopted, so high viscoelasticity of the fracturing fluid in the fracturing construction period is guaranteed, the gel of the fracturing fluid is broken completely after construction, the fracturing fluid flows back timely, damage to the storage layer is reduced, and an expectant yield-increasing effect is achieved.

The invention relates to an oil-gas well fiber assisted water control fracturing method, and belongs to the technical field of petroleum extraction. The method comprises the following steps of: (1) adding a thickening agent with water control function into water with stirring, and then adding additive to obtain fracturing prepared fluid; (2) mixing a part of the fracturing prepared fluid preparedin the step (1) and fiber uniformly to obtain fracturing sand-carrying fluid; (3) adding a propping agent into the fracturing sand-carrying fluid prepared in the step (2) to obtain sand mixing fluid;and (4) pumping the rest fracturing prepared fluid prepared in the step (1) into a destination layer in an oil-gas well, and then pumping the sand mixing fluid prepared in the step (3). According to the method, the thickening agent is adopted, so functions of seam forming and sand carrying of the conventional thickening agent are obtained, and the oil (gas) water ratio in the oil-gas layer can bechanged and the permeability of the aqueous phase is greatly reduced.

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 discloses a seawater-based fracturing fluid for fracturing a sea high-temperature oil-gas reservoir and relates to the technical field of cross-linked gel fracturing fluid. The seawater-based fracturing fluid comprises a base solution, a cross-linking agent and a thickening agent, wherein the base solution comprises the components (in percentage by weight) in terms of the weight of the prepared seawater-based fracturing fluid total solution as follows: 0.3%-0.8% of thickening agent, 0.1%-0.3% of pH regulating agent, 0.1%-0.5% of discharge aiding agent and the balance being seawater; relative to the mass fraction of the base solution, the cross-linking agent is 0.4%-0.6%; and the thickening agent refers to guar gum, carboxy-methyl hydroxypropyl guar gum, hydroxypropyl guar gum, fenugreek gum or sesbania gum. The seawater-based fracturing fluid is adopted, so that the dissolving speed of the thickening agent is quick, and therefore, direct mixing and continuous constructing can be realized, and therefore, the seawater-based fracturing fluid is in particular suitable for the fracturing construction of the sea high-temperature oil-gas reservoir. Meanwhile, the fracturing fluid can be continuously sheared for 90 minutes under the conditions of 150 DEG C and 170s<-1>, so that the viscosity is kept to be 70mPa.s or more.

The invention discloses a foam-like fracturing system, which comprises a base liquid, an acid liquid and a gel breaker, wherein a weight ratio of the base liquid to the acid liquid to the gel breaker is 10:0.8-1.5:0.002-0.006. The invention further discloses a foam-like fracturing liquid preparation method, which comprises the following steps: S1, preparing a cross-linking agent, S2, preparing a base liquid, and S3, preparing an acid liquid. The invention further discloses a foam-like fracturing liquid filling method. According to the present invention, functions similar to the conventional foam fracturing liquid are provided, heat and gas can be automatically generated under a stratum condition, integration of automatic gas generation, acid cross-linking and the foam-like structure is achieved, the structure viscosity is stable, sand carrying capacity of the fracturing liquid can further be enhanced, filtration loss resistance is strong, intrusion damage on the stratum can be effectively reduced, a water lock effect can be effectively reduced, the guar gum use amount and the fracturing liquid base liquid preparation difficulty are effectively reduced, and effects of excellent sand carrying, gel breaking, low damage and cleanup are provided.

The invention belongs to the field of chemical engineering, and particularly relates to a water-based fracturing fluid thickening agent and a synthetic method thereof. The thickening agent comprises substances in parts by weight as follows: acrylamide, methacrylamide, undecylenic acid, 2-acrylamide-2-methylpropane sulfonate, methacryloyloxyethyl trimethyl ammonium chloride, dodecafluoroheptyl methacrylate, vinyl pyrrolidone, modified corn starch, an initiator and water. The synthetic method of the thickening agent comprises steps as follows: various co-monomers and modified starch are prepared in deionized water in proportion; the PH value and the temperature of the solution are adjusted; high-purity nitrogen is fed for oxygen removal; the compound initiator is added to initiate a reaction. The thickening agent is a multifunctional high-molecular polymer which is easily soluble, free of pollution and damage, good in sand carrying property and particularly good in temperature resistance and anti-shearing sand carrying property. The thickening agent has main characteristics of wide use temperature range as well as high temperature resistance and shearing resistance, has characteristics that the thickening agent is high in sand carrying property, free of residues, causes no damage to reservoir and the like, and can be used as an excellent substitute for guanidine gum.

The invention discloses a thickening agent for liquid carbon dioxide fracturing and a preparation method thereof, relates to a thickening agent formula for the liquid carbon dioxide fracturing, and belongs to the technical field of oilfield chemistry. The thickening agent for the liquid carbon dioxide fracturing and the preparation method thereof are provided for solving the deficiency that existing liquid carbon dioxide fracturing viscosity is low. The thickening agent for the liquid carbon dioxide fracturing consists of constituents of, by weight percentage, 20-30% of long-chain alkyl trimethyl quaternary ammonium salt, 10-20% of long-chain alkyl dihydroxy ethyl methyl quaternary ammonium salt, 5-15% of organic acid, 10-20% of small molecular alcohol and the balance clear water. The thickening agent for the liquid carbon dioxide fracturing is made of raw material which is low in cost and easy to obtain, can substantially improve liquid carbon dioxide fracturing viscosity, reduces filtration loss of liquid carbon dioxide in the fracturing, and improves sand carrying capacity of the liquid carbon dioxide.

The invention provides a water-in-oil associated non-crosslinked fracturing fluid concentrating and thickening agent, which is prepared from the following components in percentage by mass: 25-50wt% of a dispersion medium, 18-40wt% of a disperse phase, 20-40wt% of a hydrophobic associated polymer fracturing fluid thickening agent and 2.5-6wt% of a compound emulsifier, wherein the dispersion medium is an organic solvent incompatible with water; the disperse phase is water; the compound emulsifier is the compound emulsifier compounded by an emulsifier of which the HLB value is 3-7 and an emulsifier of which the HLB value is 8-10; and the sum of the content of various components is 100wt%. The stabilization time of the prepared concentrating and thickening agent is greater than 120d and the dissolution time is smaller than 1min. The solution property of the fracturing fluid prepared from the concentrating and thickening agent is superior to that of the fracturing fluid which is directly prepared from corresponding fracturing fluid thickening agent dry powder.

The invention discloses a liquid-phase CO2 fracturing fluid including a tackifying agent, an auxiliary solvent, nano coating fibers and liquid CO2, wherein the nano coating fibers particularly comprise polymer / inorganic ion nano composite fibers, polymer / carbon nano tube composite fibers, polymer / lamellar filling material composite fibers, polymer / montmorillonite nano composite fibers or polymer / graphite nano composite fibers. In the embodiment above, by means of addition of the nano coating fibers to the liquid-phase CO2 fracturing fluid, friction resistance in a constructed tubular column is reduced. In addition, the nano coating fibers can form a fiber network in the liquid-phase CO2 fracturing fluid, thereby improving sand carrying performance of the fracturing fluid, changing sedimentation manner and reducing sedimentation rate of a propping agent.

The invention relates to a preparation method of a fracturing supercritical carbon dioxide thickener containing a siloxane polymer. The method comprises the steps: carrying out a reflux reaction on anaminopropyl alkoxy silane hydrolysis product, tetravinyl tetramethylcyelo tetrasiloxane and other cyclosiloxane under the catalysis of an alkali to prepare aminopropyl-terminated vinyl side chain modified polydimethylsiloxane; then, carrying out an acylchloride reaction on the aminopropyl-terminated vinyl side chain modified polydimethylsiloxane and aroyl chloride to prepare an aroylamino-terminated side chain modified siloxane polymer; dropwise adding an organic solvent solution of chloroplatinic acid to make the aroylamino-terminated side chain modified siloxane polymer react with hydrosiloxane to obtain a product. The preparation method is high in monomer synthesis efficiency, the siloxane polymer serving as phenyl and acylamino in the fracturing supercritical carbon dioxide thickenerproduct is capable of improving the thickening effect, and when the dosage of the product is relatively low, the thickening performance is good, and the pollution to underground water and surface water of a stratum is reduced.

The invention provides water base guanidine gum fracturing fluid, and belongs to the field of oil field fracturing technologies. The water base guanidine gum fracturing fluid comprises the following ingredients: guanidine gum derivative, cross-linking agents, gel breakers, thickening agents, PH value adjusting agents and water. The invention further provides a water base guanidine gum fracturing fluid preparation method. The method includes the following steps of (1) dissolving gelatinizing agents in the water, evenly mixing, and obtaining thickened water; (2) dissolving the cross-linking agents in the water, evenly mixing and obtaining cross-linking agent water solution; (3) adjusting the PH value of the thickened water to 9-10, then slowly adding the cross-linking agent water solution into the thickened water to obtain jelly solution; (4) and adding the thickening agents into the jelly solution, and finally adding the gel breakers to obtain the water base guanidine gum fracturing fluid. The water base guanidine gum fracturing fluid is low in sludge content after gel breaking, and meanwhile the cost of the water base guanidine gum fracturing fluid is greatly reduced.

The invention provides a carbon dioxide anhydrous sand fracturing method. The method comprises the following steps that (1) a gas well and a reservoir which are subjected to carbon dioxide anhydrous sand fracturing are selected; (2) fracturing for fracture forming is carried out, specifically, carbon dioxide is injected into an oil pipe and oil sleeve annulus at the same time, wherein the injection displacement of carbon dioxide prepad is greater than the injection displacement of carbon dioxide in the oil pipe; (3) a gap of a fracturing crack is filled, specifically, a carbon dioxide sand-carrying solution and a viscosity increasing agent are injected into the oil sleeve annulus; and (4) sand stopping and displacing are carried out. Carbon dioxide is simultaneously injected into the oil pipe and the oil sleeve annulus, and pressure balance is achieved; the viscosity increasing agent is added, so that the viscosity and the sand carrying performance of the carbon dioxide are improved, carbon dioxide anhydrous sand fracturing is realized, and the method has the characteristics of small damage to the reservoir, crack filling with a propping agent, and good crack morphology and stability. According to the method, few additives are used, so that the damage and pollution to the environment and the stratum are reduced, and the cost of fracturing fluid is greatly reduced; and carbon dioxide can adsorb and replace natural gas on rock walls, so that the yield of natural gas is improved.

The invention relates to an anionic clean fracturing fluid applicable to oilfield fracturing yield increase operation and a preparation method thereof, belonging to the technical field of oil-gas field exploitation application. The anionic clean fracturing fluid comprises the following components in percentage by mass: 2-8% of long-carbon-chain natural fatty acid salt anionic surfactant, 0.5-6% of Bola type counter ion quaternary ammonium salt, 0.1-2% of nano stabilizer and the balance of water. The preparation method is simple and quick. The preparation method comprises the following steps: dissolving the Bola type counter ion quaternary ammonium salt in water at room temperature by stirring, and slowly adding the fatty acid salt and nano stabilizer to obtain the transparent viscous fluid. The anionic clean fracturing fluid has the advantages of low formation damage, high sand carrying capacity, no need of any gel breaker, low adsorptivity and environmental protection. The anionic clean fracturing fluid has huge potential value in oil-gas field fracturing exploitation application.

A high-temperature resistant seawater-based polymer fracturing fluid capable of continuous blending and a preparing method thereof are disclosed. The fracturing fluid includes 0.4-0.8 wt% of a thickening agent, 0.3-0.6 wt% of an auxiliary synergist, 0.2-0.4 wt% of an activating agent, 0.2-0.4 wt% of a metal ion stabilizer, and 0.3-0.4 wt% of a temperature stabilizer, with the balance being seawater. Beneficial effects of the fracturing fluid are that: a water-soluble multi-component copolymer is adopted as the thickening agent of the fracturing fluid system so that the fracturing fluid can rapidly swell in seawater having a high degree of mineralization; a low-viscosity high-elasticity fluid having a high space structure is formed through synergistic effects (non-crosslinking functions) with the auxiliary synergist; a sand-carrying property is good when the apparent viscosity is greater than 20 mPa.s; the prepared fracturing fluid is not eroded by bacteria, has characteristics of salt resistance, good temperature resistance and shearing resistance, low harm, no residue after cleaning, and the like, and can be prepared in batch or mixed continuously by adopting sea water; and the fracturing fluid can significantly reduce offshore fracturing construction costs and can increase fracturing construction efficiencies and reservoir yield-increasing effects.

The invention provides a crosslinking agent system, a low-concentration polymer crosslinked fracturing fluid and preparation methods of the crosslinking agent system and the low-concentration polymercrosslinked fracturing fluid. The low-concentration polymer crosslinked fracturing fluid has both high viscoelasticity of the existing polymer fracturing fluid and low damage of a clean fracturing fluid. The economical efficiency of the fracturing fluid is improved by means of low concentration, and accordingly, the low-concentration polymer crosslinked fracturing fluid is more popular with oilfields on the premise of cost decreasing, benefit increasing and reservoir protecting. A prepared base fluid has the viscosity range of 10-24 mPa.s, and is easy to prepare and pump. Delayed crosslinkingtime is 30-120 s, gel can be formed after crosslinking, viscosity is enhanced three times or more, sand carrying is facilitated, and a supporting agent can be delivered to the far end of a fracture. Therefore, the low-concentration polymer crosslinked fracturing fluid inherits various advantages of the traditional fracturing fluid, and further, the sand carrying capability and fracture conductivity of the fracturing fluid can be improved effectively.

The invention discloses a low-damage and ultralow-concentration guar gum fracturing fluid system, a preparation method and an application of the guar gum fracturing fluid system and belongs to the technical field of reservoir reforming for oil-gas field development. In order to solve the problems that the existing conventional fracturing fluid systems hardly give attention to the lowering of concentration of a thickener, the prolonging of crosslinking time, the improving of gel strength and gelout capability and being environmentally friendly, a SITAR-11 powerful delayed crosslinker is selected, so that formed gel is endowed with a relatively high delayed crosslinking effect while heat resistance, shearing resistance and solid carrying capacity for the formed gel are guaranteed, and the concentration of the thickener is greatly lowered; and on one hand, the reduction of cost and the increase of economic benefit are facilitated, and on the other hand, the amount of gelout residues is reduced after the concentration of the thickener is lowered. Further, FANTA-05 and FANTA-06fracturing gelout enzymes, which are thorough in gelout and controllable in gelout time, and a ZITHE-34 efficient discharge aiding agent are added in a matched manner, so that the fracturing fluid system, which has a delayed crosslinking effect, is high in heat resistance and salt tolerance, excellent in solid carrying behavior, controllable in gelout time and thorough in gelout and is green, environmentally friendly and efficient, can be formed.

The invention discloses a dual-cycle relay coal bed well drilling method. The method comprises the following steps: (1) drilling and extracting: carrying out well cementation and enlarging a cave in a coal bed after drilling and completion twice and running casing; (2) drilling a horizontal multilateral well: through drilling and completion twice, after the second drilling and completion, running dual-casing to suspend and center an internal casing in an external casing, and placing the terminal of an internal casing on a place which is 0.5-10m far away from the casing shoe of the external casing; bypassing an extraction well while the third drilling is carried out, disconnecting the extraction wheel, and then drilling the extraction wheel after the construction of a horizontal multilateral well is finished; and (3) shutting in the well and putting into production in commission: cementing a plug, sealing the well head of the horizontal multilateral well, and pumping, draining and producing coal gas by using the extraction well. According to the drilling method, the double circulation above the casing shoe is formed, and coal dust at a horizontal naked eye section accelerates upward movement by virtue of the dual-circulation effect after the coal dust reaches the casing shoe, so that the stability and return flow of the drilling returning fluid can be improved, the sand-carrying capacity can be improved, and pipe-sticking accidents can be reduced or eliminated.

The present invention provides a fiber-reactive aqueous fracturing fluid for compact reservoir transformation, and a use method thereof, wherein the raw materials comprise, by weight, 0.05-0.1% of a friction-reducing agent, 0.5-2.0% of a composite synergist, 0.1-0.3% of water-soluble fibers, and the balance of water. The use method of the fiber-reactive aqueous fracturing fluid comprises: during the fracturing construction process, uniformly mixing the friction-reducing agent, the composite synergist, the water-soluble fibers and the water, and pumping into the stratum. According to the present invention, the fiber-reactive aqueous fracturing fluid has characteristics of no thickener, low damage, low friction, simple formula, easy preparation, strong operability and the like; and the thickener is not used and the residue is less, such that the reservoir damage can be reduced at a maximum, and the fiber-reactive aqueous fracturing fluid is especially suitable for the compact reservoir fracturing transformation.

A gas injection type of slurry pipeline transportation method relates to a novel method which injects the gas into the sediment fluid to reduce the transportation resistance of the slurry and the sedimentation of the sediment and improve the transportation efficiency of the slurry. The transportation method comprises that the transportation pipelines which contain the gas injection channels are prepared; the gas injection type of transportation pipelines are connected according to the traditional pipeline connection method; a gas supply device is connected with the gas injection channels; during the transportation process of the slurry, the gas is injected into the sediment fluid continuously; the gas supply pressure is adjusted until the best sediment transportation efficiency is attained; after the transportation of the sediment, the gas continues to be injected into the transportation pipeline until the cleaning of the pipeline is completed. The invention has simple implementation technology and low sediment transportation cost. The invention can not only reduce the sedimentation of coarse sediment in the transportation pipeline, improve the transportation efficiency of the sediment and produce great transportation effect under the working conditions of wide sediment gradation and coarse grain size, but also improve the transportation distance and slurry concentration, reduce the post-processing dehydration working load of the dredging and reclamation and decrease the environmental pollution.

The invention relates to the technical field of unbalanced drilling, and particularly relates to high-temperature ebonite foam for unbalanced drilling and a preparation method thereof. The high-temperature ebonite foam for unbalanced drilling comprises the following components in percentage by weight: 1-3% of bentonite, 3-6% of composite foaming agent, 0.3-0.6% of foam stabilizer and the balance of water. Through the synergistic effect of the composite foaming agent and the foam stabilizer, the high-temperature ebonite foam provided by the invention has the characteristics of dense foam, temperature resistance, salt resistance, strong oil resistance and stable foam performance; and the sand carrying ability is enhanced, and the requirements for drilling construction are met better.

The invention relates to preparation and application of a low-hydrocarbon anhydrous fracturing fluid crosslinking agent for unconventional reservoirs. The crosslinking agent is mainly composed of the following substances in parts by mass: 15-35 parts of main agent, 2-4 parts of phase-transfer catalyst, 7-12 parts of crosslinking accelerator and 40-58 parts of deionized water. The preparation of the crosslinking agent comprises the following steps: adding a certain proportion of deionized water into a reaction vessel, and heating to 60-70 DEG C; adding the phase-transfer catalyst and main agent, and stirring to perform homogeneous reaction; and cooling to room temperature, finally adding the crosslinking accelerator, and stirring to react for 15 minutes. The anhydrous fracturing fluid crosslinking agent has the advantages of high crosslinking speed with the gelatinizer and high gel stability; and the fracturing fluid system has high temperature resistance and shear resistance, and has ideal fracturing effects on high-temperature reservoirs.

The invention belongs to the field of oil field fracturing fluid, and particularly relates to an alcohol-containing fracturing fluid and a preparation method and application thereof. The alcohol-containing fracturing fluid comprises ethanol, ethylene glycol, water, a thickening agent and a cross-linking agent. By adding ethanol, the phenomenon that part of properties become poor due to addition ofethylene glycol into the fracturing fluid can be improved, and along with increasing of the content of ethanol, the viscosity of the ethanol-ethylene glycol-water mixed solvent fracturing fluid is increased, the temperature resistance is good, the sand carrying capacity is enhanced, the viscosity of the gel breaking fluid is reduced, and the content of residues is reduced.

The invention discloses a high-viscosity mortar cutting process for cutting a silicon chip and belongs to the technical field of cutting of a solar cell silicon chip. The high-viscosity mortar cutting process comprises the following steps: a, preparing mortar by adopting cutting fluid and green silicon carbide sand particles and continuously stirring to prevent sedimentation; b, separating high-density mortar and low-density mortar out of the mortar by a centrifugal separator and continuously stirring the separated high-density mortar and low-density mortar to prevent sedimentation; c, feeding the high-density mortar into a cutting seam to participate in cutting for single crystal cutting and using the low-density mortar for jetting chips in a knife edge after cutting so as to solve the problem of an adhesion phenomenon; d, recovering the high-density mortar and the low-density mortar which are used in the step c together and feeding the recovered high-density mortar and low-density mortar into centrifugal separator again for repeated use. According to the high-viscosity mortar cutting process, high-viscosity mortar can be used in the cutting of the silicon chip so as to promote cutting capacity of the silicon chip and improve a finished product ratio of products and working efficiency.

The invention belongs to the technical field of organic polymer materials, and discloses a preparation method of a low-friction drag composite nano-proppant. The preparation method comprises the following steps: (1) using a styrene derivative, an acrylic acid derivative and divinylbenzene as copolymerization monomers, adding a modified nano-filler, and performing suspension polymerization to obtain a high-molecular polymer in order to obtain composite nano-aggregates; (2) performing suction filtration on the composite nano-aggregates until the water content is less than 20%; (3) preparing a drag reducer; and (4) adding polyacrylamide, the drag reducer and a surfactant to the dried composite nano-aggregates, uniformly mixing the above obtained mixture, and drying and solidifying the mixture. The proppant prepared by the method rapidly releases a water-soluble substance which reduces the friction drag in the clean water, so the friction drag in fracturing construction using clear water containing the proppant as a fracturing sand-carrying liquid is lower than the friction drag in fracturing construction using the pure clear water as the fracturing the sand-carrying liquid, a conventional fracturing fluid construction fracturing technology is further simplified, and the use cost of the fracturing fluid is low.

The invention relates to a foam-assisted hydraulic sandblasting perforating technique pipe string and a method. The technique pipe string comprises an outer oil pipe tripping in a shaft and a sandblasting pipe string penetratingly arranged in the outer oil pipe. The sandblasting pipe string is composed of an inner oil pipe, a centering device, a hydraulic ejector, a one-way valve, a screen pipe and a plug in sequential connection form top to bottom, and the hydraulic ejector is located at a perforating position of an oil layer. A hydraulic sandblasting perforating technology and a foam sandblasting technology are combined, hydraulic sandblasting perforating is performed while foam fluid is injected from the outer oil pipe, fluid column pressure of the shaft is decreased by the aid of the foam fluid, and ambient pressure of hydraulic sandblasting perforating is decreased; sand carrying capability is improved, abrasives and debris accumulated around a nozzle of the hydraulic ejector are cleaned, and accordingly depth of perforating is increased; and further, 'negative pressure' of the shaft can be formed by the foam fluid, fluid penetrating into the formation is reduced, and damages to reservoirs during perforating are reduced.

The invention relates to the technical fields of oilfield chemistry, reservoir reconstruction and fracturing production increase and particularly relates to multifunctional reservoir reconstruction liquid and a preparation method therefor. The weakly-acidic multifunctional reservoir reconstruction liquid provided by the invention contains a base solution for the reservoir reconstruction liquid, a structure reinforcing agent for the reservoir reconstruction liquid and ammonium persulfate, wherein the base solution for the reservoir reconstruction liquid is prepared from the following ingredients in percentage by weight: 0.3-0.6% of thickening agent for the reservoir reconstruction liquid, 0.3-0.4% of regulator for the reservoir reconstruction liquid, 1% of potassium chloride and the balance of water. The multifunctional reservoir reconstruction liquid and the preparation method therefor have the following advantages that the multifunctional reservoir reconstruction liquid has efficient swelling resistance and a precipitate generation preventing function, and damage caused by the action between reservoirs and reservoir fluid can be effectively lowered; the viscosity is relatively low, so that seam height is effectively controlled; the viscous elasticity is excellent, so that the sand carrying performance of a system is improved; and the multifunctional reservoir reconstruction liquid has the characteristics that the damage is low, no residue is caused, and flowback fluid can be recovered and reused.