203 results about "Drag reducing agent" patented technology

The invention provides a cement paste system with high strength, elasticity and toughness and application of the cement paste system in deep coal bed gas horizontal well cementation, and the cement paste system is prepared from the following raw materials in parts by mass: 40-70 parts of oil well cement, 13-40 parts of fly ash, 15-45 parts of slag, 5.0-20.0 parts of water-based organic silicon resin, 0.1-0.5 part of ultra-high performance polyethylene fiber, 3.0-8.0 parts of calcium oxide and 2.0-5.0 parts of calcium sulfate whisker. 1.0-8.0 parts of nano silicon dioxide, 1.0-6.0 parts of a fluid loss agent, 0.5-2.0 parts of a drag reducer, 0.2-1 part of a defoaming agent and 50-80 parts of water. The cement paste system disclosed by the invention has the characteristics of remarkable low-temperature quick setting and high early strength, also has the advantages of low water loss, controllable thickening, simple preparation operation and the like, and set cement is high in compressive strength, high in breaking strength and very excellent in elastic and tough mechanical properties.

The invention relates to the technical field of oil and gas field exploitation, and discloses a drag reducer for a multifunctional fracturing fluid and a preparation method thereof.The preparation method of the drag reducer for the multifunctional fracturing fluid comprises the steps that acrylic acid, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and modified itaconic acid are added into deionized water, stirring and mixing are conducted, and the drag reducer for the multifunctional fracturing fluid is obtained. Nitrogen is introduced for 30-40 min to remove oxygen, then azobis (isobutylamidine) hydrochloride is added, the mixture is stirred to react for 48-72 h at the temperature of 45-50 DEG C, and a polymer solution is obtained; and directly and uniformly mixing the polymer solution, the compatilizer and the modified nano silicon dioxide, and reacting in a magnetic stirrer at 60-70 DEG C for 1.5-2 hours to obtain the drag reducer for the multifunctional fracturing fluid. The drag reducer has a good drag reduction effect, and the hydrophobicity, the temperature resistance, the salt resistance and the shear resistance are improved.

The invention provides a dry powder drag reducer for fracturing fluid and a preparation method of the dry powder drag reducer, and belongs to the technical field of fracturing materials for well drilling, and the preparation method comprises the following steps: dissolving 4-bromobutyryl chloride and N-dodecyl methylamine in acetonitrile, heating and stirring for reaction, adding polyethylene glycol monomethyl ether acrylate and dichloromethane, stirring and purifying in a nitrogen atmosphere to obtain a dry powder drag reducer; a double-tailed hydrophobic monomer is obtained; uniformly mixing the core-shell SiO2 / Fe3O4 composite nanoparticles, an ethanol water solution, KH570 and an ammonia solution, stirring, and purifying to obtain modified SiO2 / Fe3O4; the preparation method comprises the following steps: adding acrylamide, acrylic acid, sodium 2-acrylamido-2-methylpropanesulfonate, a double-tailed hydrophobic monomer and modified SiO2 / Fe3O4 into water, uniformly mixing, adjusting the pH value, introducing nitrogen, mixing and stirring, adding an azo initiator, stirring, cooling, purifying, carrying out vacuum drying, and crushing into powder, thereby obtaining the dry powder drag reducer for the fracturing fluid. The drag reducer has certain heat resistance while achieving good drag reduction performance, and can be better applied to fracturing operation in the well drilling process.

The invention discloses deep coal bed gas well cementation cement paste and a preparation method thereof, and the deep coal bed gas well cementation cement paste is prepared from the following raw materials in parts by weight: 100 parts of G-grade oil well cement, 5-15 parts of water-borne epoxy resin, 1.5-3 parts of a nano silicon dioxide solution, 0.5-1.8 parts of calcium sulfate whiskers, 0.2-0.6 part of composite coating fibers, 1.2-1.8 parts of a fluid loss agent and 0.5-1.8 parts of a retarder. 0.3 to 0.5 part of a drag reducer, 0.2 to 0.5 part of a defoaming agent and 38 to 42 parts of water; wherein the composite coating fiber is hydrophilic epoxy resin modified polyethylene fiber. The cement paste can improve the well cementation cementing packing quality of a coal seam, and has good filtration property.

A treatment fluid for oilfield applications, such as matrix acidizing and acid fracturing. The treatment fluid is a two-phase fluid with an hydrophobic continuous phase and an at least partially dispersed water phase. The hydrophobic continuous phase can contain 1 ppm to 10 wt %, based on the total weight of the treatment fluid, of one or more types of oil-soluble DRAs having a weight average molecular weight greater than 200,000. The at least partially dispersed water phase can contain water and one or more reactive acids having a pH of 4 or less than 4.

The invention provides an environment-friendly efficient energizing flushing fluid. The flushing fluid comprises hydrochloric acid, a base fluid A, an energizing capsule B and a catalytic capsule C, the base solution A is prepared from the following components in parts by mass: 100 parts of water serving as a dispersion medium, 0.5 to 1 part of an emulsifier, 0.5 to 1 part of a surfactant, 1 to 2 parts of a cosurfactant, 5 to 10 parts of a mutual solvent, 0.03 to 0.08 part of a drag reducer, 25 to 45 parts of an organic solvent, 0.05 to 0.1 part of a bactericide and 0.3 to 0.5 part of a scale inhibitor; an energy increasing agent CO (NH2) 2 and an energy increasing agent NH4Cl; the energizing capsule B comprises a capsule core and a capsule wall; the capsule wall is paraffin and the like; the capsule core is prepared from NaNO2 and NaHCO3; the catalytic capsule C comprises a capsule core and a capsule wall; the capsule core is oxalic acid and the like; the capsule wall is paraffin and the like. The flushing fluid has the characteristics of small flow resistance, viscosity reduction, obvious energy increase, strong chip carrying capacity, high dynamic paraffin dissolving rate, high paraffin inhibition rate, safety and environmental protection, and can realize multiple effects.

The application relates to a dry powder drag reducer for fracturing fluid and a preparation method thereof, and belongs to the technical field of drag reducers; the dry powder drag reducer is copolymerized and modified by preparing a polymerizable modifier, aromatic rings and sulfonic acid ion structures are introduced into the dry powder drag reducer, the high-temperature resistance and salt resistance of the dry powder drag reducer are effectively improved, in addition, the modified dry powder drag reducer structure also has a catechol structure, can form a stable five-membered ring borate with a boron crosslinking agent, and the dry powder drag reducer can be mixed with a guar gum drag reducer when the boron drag reducer is used, so that the problem of poor sand carrying capacity of the dry powder drag reducer is effectively solved.

The present disclosure provides a drag reducing agent. In an embodiment, the drag reducing agent includes a polymer and a liquid carrier. The polymer is composed of one or more C6-C14 α-olefin monomers. The polymer includes a residual amount of zirconium. The polymer has an absolute weight average molecular weight (Mw(Abs)) greater than 1,300,000 g / mol and a (Mw(Abs) / Mn(Abs) from 1.3 to 3.0.

The invention relates to a dry powder drag reducer for fracturing fluid and a preparation method thereof, and belongs to the technical field of drag reducers. The dry powder drag reducer is subjected to copolymerization modification by preparing the polymerizable modifier, an aromatic ring and sulfonic acid ion structure is introduced into the dry powder drag reducer, the high temperature resistance and salt resistance of the dry powder drag reducer are effectively improved, in addition, the modified dry powder drag reducer structure further has a catechol structure, and the modified dry powder drag reducer has a good application prospect. The dry powder drag reducer can form stable five-membered ring boric acid ester with a boron cross-linking agent, when the boron drag reducer is used, the dry powder drag reducer can be mixed with a guar gum drag reducer for use, and the problem that the dry powder drag reducer is poor in sand carrying capacity is effectively solved.

The invention belongs to the technical field of oil exploitation, and relates to a drag reducer for fracturing and a preparation method thereof. The preparation method comprises the following steps: adding 1, 5-hexadiene-3, 4-diol and a catalyst into a high-pressure reactor, raising the temperature, introducing ethylene oxide, raising the temperature, carrying out a heat preservation reaction, stopping heating, and cooling to 50 DEG C or below; adjusting the pH value to 2-3 by using phosphoric acid, adding sulfamic acid, heating, preserving heat and reacting, and cooling to below 40 DEG C; the preparation method comprises the following steps: adding deionized water, 2-(trifluoromethyl) acrylic acid and methacryloylethyl sulphobetaine, stirring and dissolving, adjusting the pH value to 7-8, adding an initiator, heating and carrying out a heat preservation reaction to obtain a viscous liquid; and settling, centrifuging, cleaning and drying to obtain the product drag reducer. The drag reducer has the characteristics of high viscosity and high drag reduction rate.

This invention provides a dry powder drag-reducing agent for fracturing fluids and its preparation method, belonging to the technical field of fracturing materials for drilling. The method includes the following steps: dissolving 4-bromobutyryl chloride and N-dodecylmethylamine in acetonitrile, heating and stirring to react; adding polyethylene glycol monomethyl ether acrylate and dichloromethane; stirring under a nitrogen atmosphere; purifying to obtain a double-tailed hydrophobic monomer; mixing core-shell Fe3O4 / SiO2 composite nanoparticles, ethanol aqueous solution, KH570, and ammonia solution; stirring; purifying to obtain modified SiO2 / Fe3O4; adding acrylamide, acrylic acid, sodium 2-acrylamido-2-methylpropanesulfonate, the double-tailed hydrophobic monomer, and modified SiO2 / Fe3O4 to water; adjusting the pH value; mixing and stirring with nitrogen gas; adding an azo initiator; stirring; cooling; purifying; vacuum drying; and pulverizing into powder to obtain the dry powder drag-reducing agent for fracturing fluids. This invention achieves good drag-reducing performance while also possessing certain heat resistance, making it better suited for fracturing operations in drilling processes.

This invention discloses a gradient pore self-assembled drag-reducing agent for nano-fracturing fluids and its preparation method. The drag-reducing agent comprises nanoparticles with a three-layer gradient self-assembled structure, the particle size of which is no greater than 50 nm. The three-layer gradient self-assembled structure comprises, from the inside out, a hydrophobic core layer, a middle viscoelastic layer, and an outer hydrophilic layer, and is composed of the following by mass percentage: hydrophobic core layer: 25–35% nonionic surfactant, 15–20% organic solvent; middle viscoelastic layer: 30–40% polymer; outer hydrophilic layer: 15–20% zwitterionic surfactant. This invention, through its three-layer gradient self-assembled structure design, integrates multiple functions such as high-efficiency drag reduction, strong proppant carrying capacity, reservoir modification, deep penetration, and temperature and salt resistance. It comprehensively solves the technical bottlenecks of existing technologies, such as low drag reduction efficiency, high reservoir damage, single function, and poor environmental adaptability, providing a novel fracturing fluid additive with superior performance for the efficient development of unconventional oil and gas resources.

The application discloses a polymer drag-reducing agent injection type hydrofoil, and belongs to the technical field of polymer drag-reducing agents of underwater vehicles. The application solves the problem that there is no drag-reducing agent injection structure capable of stably outputting polymer drag-reducing agents and capable of adhering to the surface of a drag-reducing part of an underwater vehicle. One end of a steady flow cavity is communicated with a solution storage box in the underwater vehicle through a discharge channel, a cover plate is parallel and slidingly inserted on a main body of the hydrofoil, the lower surface of the cover plate is adhered to the upper surfaces of a plurality of fairing plates, and the outer surface of one end of the cover plate and the inner wall surface of one end of the steady flow cavity form an injection channel. The steady flow cavity has a steady flow effect on the solution, so that the stable output of the polymer solution is realized; the flow state of the polymer solution is adjusted through the fairing plates, so that the polymer solution flows stably; the polymer solution flows out to the surface of the hydrofoil through the injection channel, the frictional resistance generated during sailing is reduced, and the sailing performance of the underwater vehicle is improved.

The invention discloses a preparation method of a self-degradation fracturing drag reducer, and relates to the technical field of drag reducer preparation.The self-degradation fracturing drag reducer is prepared by mixing acrylamide, acrylic acid, methyl methacrylate, a modified additive and a modified filler to react, a molecular chain segment of the drag reducer contains a cyclodextrin structure, and the molecular chain segment of the drag reducer contains a cyclodextrin structure; the drag reducer can be self-degraded, cyclodextrin has a hydrophilic outside and a hydrophobic inside cavity ring structure, and can interact with hydrophobic groups in drag reducer polymer molecules through a host-guest inclusion effect, so that hydrophobic aggregation is destroyed, and drag reducer chains are easier to stretch and dissolve in water; meanwhile, the thermal motion of a polymer molecular chain can be limited, the drag reducer is kept stable in a high-temperature stratum, the flowing resistance of fracturing fluid in pipelines and cracks can be effectively reduced due to the self-lubricating characteristic of the modified filler, and the anti-shearing effect of the drag reducer can be improved due to the cooperation of the modified filler and a cyclodextrin structure on the molecular chain.

The invention relates to a natural gas drag reduction evaluation device under the synergistic effect of a pipe wall interface layer and turbulent flow drag reduction. The device comprises a nitrogen purging system, a natural gas turbulence circulating system, a drag reducer quantitative injection system, a PIV imaging and testing system and a drag reducer filtering and recycling system. The nitrogen purging system is used for cleaning an experimental loop, the natural gas turbulence circulating system is used for simulating turbulence states under different working conditions, and the duplex organic glass transparent test pipe section group can test flow characteristics under different pipe diameters and inner wall conditions; the drag reducer quantitative injection system adopts a plunger pump and an atomization device to ensure that the drag reducer is uniformly dispersed; the PIV imaging and testing system is used for accurately capturing a turbulent flow microstructure. Through macroscopic flow and microscopic turbulence structure observation, the drag reduction performance under the synergistic effect of the inner coating and the drag reducer and the influence of factors such as the pipe diameter, the position, the concentration and the variety of the drag reducer on the drag reduction effect are evaluated, and experimental data and a theoretical basis can be provided for engineering application of the natural gas drag reduction technology.

The invention discloses a shear-resistant, high-drag-reducing, high-viscosity slickwater drag reducing agent and a preparation method therefor. The drag reducing agent is polymerized from acrylamide, sodium acrylate, a sulfonate ion-containing hydrophobic monomer, a hydrophobic unit microblock regulator, a molecular weight modifier, and a composite initiator. Through the special sulfonate ion-containing hydrophobic monomer, the hydrophobic unit microblock regulator matched with a hydrophobic monomer and the control of a polymer molecular weight, the solubility and viscosity-increasing performances of the polymer can be significantly improved, the shear-resistant and degradation-resistant performance of the drag reducing agent is improved, with excellent sand carrying performance and drag reducing performance, and the shortcomings of existing slickwater drag reducing agents such as weak shear resistance, rapid decline in drag reduction rate and poor sand carrying performance are overcome, thereby meeting the special requirements of deep / ultra-deep oil and gas reservoir fracturing on fracturing fluid rheology.

The application relates to the field of turbulent flow control in fluid mechanics and discloses a natural gas drag-reducing agent atomization injection indoor circulation system. The system is composed of a natural gas drag-reducing agent atomization device and an indoor circulation pipeline; the natural gas drag-reducing agent atomization device comprises a shell, a conical jet cylinder and a gas-liquid mixing cavity; a conical jet cylinder and a nozzle are arranged in the shell; the nozzle can be automatically adjusted within an angle range of 20-80 degrees according to the natural gas conveying flow; a blade support plate cuts the mixed drag-reducing agent to atomize the drag-reducing agent again; the particle size of the atomized drag-reducing agent ranges from 20 to 40 microns; square magnet blocks are evenly arranged on the outer wall of the indoor circulation pipeline; the number of the square magnet blocks is 114; the length of each square magnet block is 200 mm, the width is 80 mm, and the thickness is 50 mm. The application utilizes the comprehensive effect of jet flow, cutting and electromagnetic field to enhance the atomization and adhesion effect of the drag-reducing agent; the drag-reducing effect of the drag-reducing agent atomization injection is evaluated based on control variables; and the result can be applied to the drag-reducing conveying of a natural gas long-distance pipeline.

This invention relates to the field of cement slurry technology for oil and gas field cementing, and discloses a low-friction, salt-resistant, high-density oil well cement slurry and its preparation method. The low-friction, salt-resistant, high-density oil well cement slurry comprises the following components, added per 100 parts by weight of cement: 35-110 parts weighting agent, 0-15 parts fine aggregate, 1.5-5 parts fluid loss reducing agent, 0-1 part retarder, 0.5-3 parts drag reducing agent, and 0.2-0.6 parts defoamer; the density is 2.0-2.10 g / cm³. 3 The salt-resistant, low-temperature, anti-channeling, and tough cement slurry provided by this invention is based on a low-friction, high-density cement slurry system with iron ore powder weighting. The thickening time is adjustable, and the overall performance is good. It can maintain good performance under high temperature, high pressure, and high salt conditions.

The application provides a preparation method and application of a polymer intercalation composite oil product drag reducer. The preparation method adopts polymer solution intercalation: under the action of an interfacial compatibilizer, layered silicate particles are soaked in a polymer solution and heated and stirred, the polymer is directly inserted into the interlayer from the solution to form a nanocomposite. The application obtains an intercalation type nanocomposite oil product drag reducer based on the intercalation composite process of the polymer intercalation type, the product has high strength and high toughness, and has good shear resistance; the drag reduction and transportation increase effect is good.

The present invention discloses a latex matrix conveying resistance reducer, which is installed between the mixer of the mixing truck and the conveying hose. It is composed of components such as an outer casing, a core body, a rotating rotor, an inner core, and a shunt valve. Its working principle is as follows: The concentrated drag reducer and water are respectively pumped out by a high-pressure pump and shunted at the shunt valve. 15% of the solution is injected into the first mixing zone, and the drag reducer diluted in proportion is ejected from the axial through groove at the front end of the inner core under the action of pressure to form an extremely thin first drag reduction ring, completing the primary drag reduction; the remaining 85% of the concentrated drag reducer and water are injected into the second mixing zone, and the drag reducer diluted in proportion is ejected from the axial through groove at the front end of the core body under the action of pressure to form a drag reduction ring column, which wraps the first drag reduction ring to form the second drag reduction. The existence of the two drag reductions ensures that during the process of conveying the latex matrix to the end of the hose, the latex matrix is always wrapped by the drag reducer, blocking the contact between the latex matrix and the pipe wall and reducing the conveying resistance.

The invention discloses a biodegradable drag reducer for fracturing as well as a preparation method and application thereof, and the drag reducer is prepared from the following raw materials in parts by weight: 8 to 12 parts of acrylamide, 5 to 8 parts of 2-acrylamido-2-methylpropanesulfonic acid, 2 to 4 parts of dimethyl itaconate, 1.5 to 3 parts of methacrylic acid-beta-cyclodextrin, 0.1 to 0.3 part of cross-linking agent and 0.04 to 0.08 part of initiator. And 70 to 90 parts of deionized water. The drag reducer can be quickly degraded into small molecules in a specific environment, so that the problem of permanent damage of a synthetic drag reducer to a reservoir is fundamentally solved, and the damage rate of a rock core is reduced compared with that of a traditional product; and the drag reduction agent also has excellent self-repairing capability, and after high-speed shearing, the retention rate of the drag reduction rate can still reach 80% or above, so that the long-term stability and effectiveness of the fracturing process are ensured.

The utility model provides a drying and dehumidifying device for producing a solid drag reducer for fracturing, belongs to the technical field of petroleum and natural gas exploitation, and solves the problems that an existing solid drag reducer is low in drying and dehumidifying efficiency and poor in drying and dehumidifying effect, and the solid drag reducer cannot be prepared on an assembly line easily. The drying and dehumidifying device for producing the solid drag reducer for fracturing comprises a drying conveying chain, a vibration conveying mechanism is arranged at the feeding end of the drying conveying chain, a material crushing mechanism is arranged at the discharging end of the vibration conveying mechanism, a hot air mechanism and a hot oil circulating mechanism are arranged on the drying conveying chain, and an ash removal scraping roller is further arranged at the feeding end of the drying conveying chain. According to the utility model, wet slag charge is uniformly spread for three times, the spreading is more uniform, the temperature in the drying oven forms hot air heat exchange, and the wet slag charge is quickly dried; and the dried materials are beaten and crushed through the material crushing mechanism, adhesion and caking of the materials are avoided, and the functions of effective crushing and stable conveying of the materials are achieved.

The invention discloses a method for preparing a sintered hollow batten from high-doping-amount graphite tailings, pretreated graphite tailings are used as a main raw material, coal gangue and functional auxiliaries are matched, the use amount of the graphite tailings is 40%-65%, the use amount of the coal gangue is 30%-50%, and the functional auxiliaries comprise mullite powder, rice hull ash and a polycarboxylic acid drag reducer. The preparation method comprises the following steps: burdening raw materials, adding water, mixing, aging, carrying out vacuum extrusion molding to obtain a green body, and sintering by a segmented drying and programmed roasting process to obtain a finished product. By optimizing the raw material ratio and process parameters, the problems of poor plasticity and difficult forming of high-doping-amount graphite tailings are solved, the prepared sintered hollow batten has the advantages of light weight, high strength and low water absorption rate, the compressive strength exceeds 10 MPa, the dry density is lower than 800 kg / m < 3 >, all performance indexes meet the standard requirements of light partition battens for buildings, and the sintered hollow batten is suitable for large-scale popularization and application. And an effective technical approach is provided for large-scale high-value utilization of the graphite tailings.

The application provides a hydrothermal geothermal composite salt cement slurry system and a preparation method, and solves the problems of poor corrosion resistance, insufficient heat preservation and weak permeability resistance of a traditional cement slurry in a geothermal well. The system is composed of 40%-60% of base material cement, 4%-8% of metakaolin, 12%-18% of microsilica, 0.1%-0.3% of nanometer SiO 2 1%-3%, 0.5%-1.5% of foam stabilizer, 1.2%-1.8% of fluid loss additive, 0.2%-0.5% of drag reducing agent and 0.1%-0.3% of corrosion inhibitor. The corrosion inhibitor is a nanometer silicon shell slow-release unit. The preparation method comprises the following steps: multi-scale synergistic modification (three-stage treatment to construct a dense gel network), mechanical aeration foaming, functional treatment (step-by-step addition of the fluid loss additive / corrosion inhibitor), gradient heat preservation regulation (closed porosity≥85%). The system performance is as follows: permeability≤0.0028mD, thermal conductivity≤0.07W / (m·K), strength decay rate after 28-day CO2 corrosion≤5%, and the geothermal well cementing service life is significantly improved.

The utility model relates to the technical field of inverse emulsion, and discloses an integrated reactor for preparing an inverse emulsion resistance reducing agent, which comprises a reaction kettle body, and an acrylamide water feeding pipe, a motor and an emulsifier feeding pipe are sequentially arranged at the top end of the reaction kettle body from left to right. An output shaft of the motor penetrates into the reaction kettle body and is fixedly connected with a stirring shaft rod through a coupling, and a notch is formed in the top end of the reaction kettle body. According to the technical scheme, the heating rod can be mounted through the notch, so that the heating rod is directly inserted into the reaction kettle body, the limiting block can limit the downward moving range of the heating rod and prevent the whole heating rod from falling into the reaction kettle body, then the limiting block is fixed through the bolt, meanwhile, the heating rod is stabilized, and the heating rod is prevented from falling into the reaction kettle body. During replacement, only the bolts need to be screwed off, and the heating rods are pulled out from the interior of the reaction kettle body through the limiting blocks, so that replacement is convenient and simple.

The invention discloses a preparation method of a porous wall capable of controlling a slow release rate by temperature, and belongs to the technical field of porous medium slow release. The method comprises the following steps: constructing a three-dimensional skeleton with a three-dimensional network structure and a plurality of reserved cavities by adopting a water-soluble solid material; respectively placing closed gas units in a plurality of reserved cavities of the three-dimensional skeleton; immersing the three-dimensional skeleton with the closed gas unit in an uncured organic silicon flexible material precursor, filling network gaps in the three-dimensional skeleton with the organic silicon flexible material precursor and coating the closed gas unit with the organic silicon flexible material precursor, and then curing; after curing, dissolving the overall structure in a solvent, and removing the three-dimensional skeleton to form a flexible porous wall; the rigid shell covers the outer surface of the flexible porous wall to form the porous wall with the rigid shell, namely the porous wall with the temperature-controlled slow release rate. According to the invention, the self-adaptive matching between the release rate of the drag reducer and the temperature can be realized, and finally, the purposes of ensuring the drag reduction effect and extremely saving chemicals are achieved.

The invention discloses a drag reducer for brine-resistant well cementation. The drag reducer comprises 45-60 parts by weight of a polycarboxylic acid polymer, 35-45 parts by weight of an aliphatic polymer and 5-10 parts by weight of a naphthalene sulfonic acid dispersant. The brine-resistant well cementation drag reducer provided by the invention is formed by mixing a plurality of polycarboxylic acid drag reducers, aliphatic drag reducers and naphthalene drag reducers which have dispersion effects, has the advantage of good dispersion at both high temperature and low temperature, and has a good salt-resistant effect; compared with the conventional drag reducer, the drag reducer provided by the invention has the advantages that the addition amount is greatly reduced, the efficiency is high, and the dispersing performance of a system is excellent; meanwhile, the rheological property is good, and the characteristic of sodium chloride brine resistance is also achieved; the drag reducer provided by the invention has broad spectrum performance and can be applied to conventional cement slurry, salt-containing cement slurry and high-density cement slurry systems.

The invention discloses a dry powder drag reducer for fracturing fluid and a preparation method of the dry powder drag reducer, and relates to the technical field of fracturing fluid additives for gas field exploitation. The invention relates to an anionic polymer, which is prepared from the following raw materials in parts by weight through copolymerization: 25 to 35 parts of N-acryloyl morpholine, 5 to 8 parts of 2-methacryloyloxyethyl phosphorylcholine, 3 to 5 parts of 2-vinyl-4, 5-dihydrooxazole, 40 to 50 parts of anionic monomer, 0.1 to 0.5 part of initiator, 0.05 to 0.2 part of chain transfer agent and 0.5 to 2 parts of dispersing agent. The drag reducer is remarkable in drag reduction effect, excellent in temperature resistance and salt resistance and rapid in dissolution.

The invention provides fracturing fluid for coal seam roof fracturing and a preparation method and application thereof. The fracturing fluid for coal seam roof fracturing is prepared from, by mass concentration, 2-4 g / L of drag reducer, 30-50 g / L of temporary plugging agent, 0.05-0.1 g / L of cross-linking agent, 2-10 g / L of pH regulator and the balance water. The fracturing fluid for fracturing the coal seam roof meets the fracturing and plugging requirements on the coal seam roof during fracturing, the stress of the coal seam roof is released, and the safe mining effect of a coal mine is guaranteed.

A composition for use in well stimulation operations, the composition comprising a saline fluid, the saline fluid comprising between 50,000 ppm and 70,000 ppm; a polymer, the polymer operable to hydrate in the saline fluid such that it increases the viscosity of the saline fluid react with a chelating agent, the chelating agent comprises L-glutamic acid N, N diacetic acid (GLDA), wherein the GLDA is present in an amount between 1 wt % and 20 wt %.