70results about How to "High drag reduction rate" patented technology

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.

A drag reduction superhydrophobic coating and a preparation method thereof belong to the technical field of functional nanometer material application. A base of the drag reduction superhydrophobic coating adopts electroless metal deposition technique, a precious metal micro-nanometer binary grading composite structure is constructed on the base and decorated by a low surface energy material, a water static contact angle of the coating is larger than 150 degrees, and a rolling angle is smaller than 5 degrees. The drag reduction superhydrophobic coating is used for a model with motive power by itself, running speed of the model is obviously increased, and drag reduction rate is as high as 20%. The drag reduction superhydrophobic coating has good corrosivity resistance and can resist corrosion of strong acid and strong base solutions. The drag reduction superhydrophobic coating has repairability, and the preparation method can enable hydrophobicity of damaged areas to be rapidly recovered in a short period. The preparation method of the drag reduction superhydrophobic coating is simple, short in preparation period, and high in drag reduction rate.

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 an acrylamide copolymer, and a preparation method and an application thereof. The acrylamide copolymer contains a constitutional unit A, a constitutional unit B, a constitutional unit C and a constitutional unit D, wherein the constitutional unit A is a constitutional unit represented by formula (1) and / or a constitutional unit represented by formula (2), the constitutional unit B is one or more of constitutional units represented by formula (3), formula (4), formula (5) and formula (6) respectively, the constitutional unit C is a constitutional unit represented by formula (7) and / or a constitutional unit represented by formula (8), and the constitutional unit D is a constitutional unit represented by formula (9) and / or a constitutional unit represented by formula (10); and the viscosity average molecular weight of the acrylamide copolymer is 2,000,000-25,000,000. The acrylamide copolymer has the advantages of high drag reduction rate, high heat and salt resistance, good high-shear resistance, good water solubility, good compatibleness with clay inhibitors (alcohol), and small damages to the stratum.

The invention relates to the preparation of organic macromolecule compounds and the technical field of pipeline systems, in particular to a method for preparing a poly alpha-olefin drag reduction agent suspension. A solvent comprises 15-45 percent of poly alpha olefin particles, 5-15 percent of long carbon chain amide, 50-60 percent of solvent, 1-5 percent of surface active agent, 0.1-2 percent of thickening agent, and 10-20 percent of suspending agent and stabilizing agent according to the proportion when the total weight of the solvent is 100, and long carbon chain amide powder particles are fully contacted in the solvent containing at least one surface active agent and emulsified at a certain temperature, and the alpha-olefin drag reduction agent suspension is obtained by adding ground poly alpha-olefin particles with super high molecular weight and at least one of a surface active agent, a suspending agent, a stabilizing agent and a dispersing agent into the emulsified solvent. The suspension prepared by the method has long storage cycle, high content of poly alpha-olefin particles, large drag reduction rate, and low transportation and preparation costs.

The invention discloses an efficient salt-resistant dual-purpose thickening agent, a preparation method and application thereof. The preparation method of the thickening agent comprises the followingsteps of: S1, preparing a water phase; S2, preparing an oil phase; S3, performing emulsifying; S4, conducting polymerization; and S5, carrying out aftertreatment. A hydrophobic monomer, a functional monomer and a salt-resistant monomer are introduced into the thickening agent to form a compact and complex spatial network structure in an aqueous solution, so that the thermal stability and the saltresistance of the thickening agent are improved, and the aqueous solution of the thickening agent can keep relatively high viscosity under a hypersalinity condition. Due to the addition of a chain extender, the molecular chain of the polymer is longer, and the viscosity is greatly improved. A cosolvent is introduced, so that the dissolving speed of a polymer emulsion is further increased, the polymer emulsion can be completely dissolved in 30 seconds, the requirement on water quality is low, and the polymer emulsion can be prepared from oilfield reinjection water and oilfield wastewater. Due to the addition of a suspending agent, the emulsion system is more stable, and the emulsion is not layered within two years. The thickening agent also has the characteristic of dual purposes, and can be used as a fracturing fluid slickwater drag reducer and a fracturing fluid thickening agent.

The invention discloses a preparation method for oil soluble drag reducer, which is characterized in that high purity an alpha-olefin material is obtained through implementing absorption and distillation pretreatment on alpha-olefin mixture; a Ziegler-Natta catalyst is added for prepolymerization to lead the viscosity of a liquid to be capable of preventing the catalyst from sinking; then polymerization reaction is implemented under a lower temperature between 10 DEG C between zero and 0 DEG C and finished until a conversion rate of monomer reaches 95 percent; then a drag reducing polymer is cut and a dispersing agent is added; then the drag reducing polymer is frozen by liquid nitrogen and is crushed to a granularity of 129 meshes under a low temperature; then the dispersing agent is dispersed, and the drag reducing polymer is mixed with a thickening agent and an aqueous surfactant liquid to prepare a finished product of stable drag reducer suspension. The drag reducing polymer copolymerized through the preparation method has high molecular weight, is easy to crush under low temperature, has fast solution velocity, is not adhered on the wall of an oil pipeline and has high drag reducing rate.

The invention discloses an acrylamide copolymer, and a preparation method and an application thereof. The acrylamide copolymer contains a constitutional unit A, a constitutional unit B, a constitutional unit C and a constitutional unit D, wherein the constitutional unit A is a constitutional unit represented by formula (1) and / or a constitutional unit represented by formula (2), the constitutional unit B is at least one of constitutional units represented by formula (3), formula (4), formula (5) and formula (6) respectively, the constitutional unit C is a constitutional unit represented by formula (7), and the constitutional unit D is a constitutional unit represented by formula (5) and / or a constitutional unit represented by formula (9); and the viscosity average molecular weight of the acrylamide copolymer is 5,000,000-18,000,000. The acrylamide copolymer has the advantages of high drag reduction rate, high heat and salt resistance, good high-shear resistance, good water solubility, good compatibleness with clay inhibitors (alcohol), and low damages to the stratum.

The invention relates to the technical field of drag reduction agents, and provides a poly-alpha-olefin drag reduction agent and a preparation method thereof. The poly-alpha-olefin drag reduction agent comprises alpha-olefin, solvent, a Ziegler-Natta catalyst and gas, wherein the gas is ethylene or propylene gas. The preparation method comprises the following steps: adding the Ziegler-Natta catalyst into the alpha-olefin and solvent in a nitrogen gas protective atmosphere, performing polymerization reaction on the long-chain olefin part, then introducing the ethylene or propylene gas, and performing binary copolymerization reaction to obtain the poly-alpha-olefin drag reduction agent. Thus, the poly-alpha-olefin drag reduction agent has the characteristics that the ethylene or propylene gas raw material is less prone to self polymerization in the reaction and is cheap and accessible, and the obtained poly-alpha-olefin drag reduction agent is high in drag reduction rate; and the production cost is lowered, and the shearing resistance is improved.

The invention relates to a low-temperature-resistant online variable-viscosity agent and a preparation method thereof. The method comprises the following steps: fully and uniformly mixing a water-phase solution, an oil-phase solution, an azo initiator and an oxidizing agent, emulsifying, pumping a reducing agent to initiate polymerization, adding a long-chain flexible monomer in the polymerization process, adding a hydrolytic agent for hydrolysis after the reaction is finished, adding a phase inversion agent after the hydrolysis is finished, and uniformly stirring to obtain the variable-viscosity agent. The aqueous phase solution is prepared from acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, methacryloyloxyethyl-N, N-dimethyl propanesulfonate, sodium hydroxide, a structure regulator, a pour point depressant and water; the oil phase solution comprises an oily solvent, an emulsifier, a suspending aid and a penetrant. The variable-viscosity agent prepared by the invention has the characteristic of dual purposes, has an extremely high drag reduction effect under the condition of a low-concentration polymer solution, and has an extremely good thickening and sand-carrying effect after the concentration of the polymer is properly increased.

The invention provides a bionic centrifugal pump blade. A bionic structure is arranged on the back side of the blade and comprises a plurality of lines of spherical pits. Each line of spherical pits are arranged in the width direction of the blade. The start position of the bionic structure is arranged at the position 1 / 3L away from the inlet edge of the blade, wherein L is the length of the blade. When the bionic centrifugal pump blade works, low-speed fluid forms vortexes, and the vortexes accumulate in the spherical pits. The bionic centrifugal pump blade lowers the corresponding flow losscaused by wall shear stress, improves the work efficiency of an impeller and prolongs the service life of the blade. Meanwhile, it is only needed to arrange the bionic structure in the middle of the back face of the blade, the shaping area of the bionic structure is small, so that the machining amount is reduced, machining is facilitated, and cost is lowered.

The invention discloses an efficient imbibition and drag-reducing water system applicable to an atmospheric pressure shale gas reservoir. The efficient imbibition and drag-reducing water system applicable to the atmospheric pressure shale gas reservoir comprises the following components: 0.04-0.1 percent of a high-molecular polymer drag reducer, 0.05-0.2 percent of a moisture regulator, 0.1-0.3 percent of an efficient shale inhibitor, 0.01-0.03 percent of an environment-friendly fungicide, 0.05-0.1 percent of an imbibition conditioner and the balance of water. The efficient imbibition and drag-reducing water system applicable to the atmospheric pressure shale gas reservoir has the advantages that the efficient imbibition and drag-reducing water system is prepared by using a low molecular weight high-molecular polymer as a drag reducer and introducing the moisture regulator, the imbibition conditioner, the efficient shale inhibitor and the environment-friendly fungicide. Therefore, therock core spontaneous imbibition amount can be effectively increased, the imbibition of a fracturing fluid to a deep ground mass can be promoted; smoothness of a spontaneous imbibition passage can bekept; the desorption of adsorbed gas can be promoted; effects of water soluble replacement of the adsorbed gas, energy increasing and drainage are achieved; atmospheric pressure shale fracking construction requirements are satisfied; the drainage of atmospheric pressure shale gas drag-reducing water fracturing fluid flow-back fluid is reduced; and the development of economic benefits of an atmospheric pressure shale gas field is realized.

The invention relates to a water-soluble drag reducer as well as a preparation method and application thereof. The preparation method is characterized by adding an emulsifier and solvent oil to a reactor to form an oil phase, adding a lipophilic propenyl monomer to the oil phase, dissolving a hydrophilic propenyl monomer in water, regulating the pH value to 8-9 to form an aqueous phase, slowly dropping the aqueous phase into the oil phase, carrying out emulsification while stirring, adding an initiator by times under the condition of introducing nitrogen, reacting at 30 DEG C for 48 hours, cooling, adding a polymerization inhibitor so as to obtain an inverse microemulsion system, and mixing the prepared inverse microemulsion system with a surfactant so as to obtain the water-soluble drag reducer. The water-soluble drag reducer is used in quick water fracturing fluid to reduce the friction drag of pipelines, reduces the pump power, improves the sand-carrying capacity of the construction fluid, is suitable for oil and gas exploitation of unconventional low permeability reservoirs, has good dissolving property and obvious drag reduction effect which can reach 50-70% compared with that of the clear water, and is convenient to use.

The invention relates to an acrylamide series terpolymer, a preparation method, and applications thereof. The acrylamide series terpolymer comprises a structural unit A, a structural unit B, and a structural unit C, wherein the structural unit A comprises a structural unit represented by the formula (1), the structural unit B comprises a structural unit represented by the formula (2), and the structural unit C comprises a structural unit represented by the formula (3). The acrylamide series terpolymer improves the solubility of the terpolymer in alcohol and clay inhibitor, has high drag reduction efficiency under a high salinity condition when the terpolymer is used as a drag reducer, and has a very good drag reducing effect in a pH range from 4 to 10.

The invention discloses an acrylamide copolymer and a preparation method and application thereof. The acrylamide copolymer contains a structural unit A and a structural unit B, wherein the structural unit A is a structural unit shown as a formula (1) and / or a structural unit shown as a formula (2); the structural unit B is a structural unit shown as a formula (3) and / or a formula (4); the viscosity-average molecular weight of the acrylamide copolymer is 4,000,000-20,000,000. The acrylamide copolymer provided by the invention has high drag reduction efficiency, high shear resistance, high salt tolerance and high compatibility with clay inhibitors and bactericides. The formula (1), the formula (2), the formula (3) and the formula (4) are shown in the specification.

The invention relates to the technical field of fracturing fluids, and discloses a drag reducer and a preparation method thereof as well as a slickwater fracturing fluid and application. The drag reducer contains a structural unit as shown in a formula (1) and a structural unit as shown in a formula (2) or a formula (3), m ranges from 20000 to 28000, n1 ranges from 90 to 130, and n2 ranges from 50 to 80; and the weight-average molecular weight of the drag reducer is 1.5 million to 2 million. The slickwater fracturing fluid has good temperature resistance and shear resistance, and has a better drag reduction effect.

The invention discloses a drag reducer for fracturing and a preparation method thereof. The drag reducer for fracturing consists of, in percentage by mass, 10%-30% of a water-soluble monomer, 5%-35% of water, 30%-65% of base oil, 5%-30% of an emulsifier, 1%-3% of an electrolyte with a salting-out effect and 0.001%-0.1% of an initiator. Under the initiation of the initiator, a water-in-oil system formed by an aqueous phase solution and an oil phase solution is subjected to a reversed-phase microemulsion polymerization reaction. According to the invention, the drag reducer for a fracturing fluidis synthesized by adopting a reversed-phase emulsion polymerization mode; the fracturing fluid is a water-soluble polymer with a small amount of hydrophobic groups on a hydrophilic macromolecular chain, and the solution has special thickening and shearing-resistant effects due to the specific amphiphilic molecular structure of the fracturing fluid; and the drag reducer has the advantages of highdrag reduction rate, strong compatibility, shearing resistance, low friction resistance, low damage and wide application range.

The invention relates to the field of oilfield chemistry, and discloses nano-silica, a nano-composite slick water fracturing fluid and a preparation method and application thereof.The preparation method of the nano-silica comprises the steps that 1, silicate ester, ethyl alcohol and water are subjected to a first reaction in the presence of acid, and an intermediate product system is obtained; and (2) carrying out a second reaction on the intermediate product system and dicarboxyl polyethylene glycol, and freeze-drying the obtained product to obtain the nano silicon dioxide. The nano-silica, a drag reducer, a discharge aiding agent, an anti-swelling agent and water are prepared into the nano-composite slickwater fracturing fluid with a specific formula, and the slickwater fracturing fluid has fracturing sand-carrying performance and imbibition oil discharge performance, and is high in drag reduction rate and excellent in temperature resistance and shear resistance.

The invention relates to a microbubble generating device which comprises a shell, a gas flow channel and a cover body. The upper end of the shell is sealed and the lower end is a bubble nozzle; the gas flow channel comprises a variable-diameter wall surface and an equal-diameter wall surface, a gas inlet is formed in the top end of the variable-diameter wall surface, N groups of exhaust holes areuniformly formed in the equal-diameter wall surface in the circumferential direction, N is an even number, and the diameters of the two groups of exhaust holes symmetrical about the circle center aredifferent; the gas-liquid mixing wall surface of the cover body is arranged outside the gas flow channel, the upper end and the lower end of the gas-liquid mixing wall surface are sealed, and a liquidflow channel which is gradually shrunk and then gradually expanded is formed between the gas-liquid mixing wall surface and the shell; the gas-liquid mixing wall face is provided with two openings symmetrical about the circle center at the same height of the exhaust holes, each opening corresponds to one set of exhaust holes, and when the gas flow channel rotates to a certain angle, the two openings correspond to the two sets of exhaust holes with different diameters respectively. High-quality microbubbles with smaller diameters can be generated through simultaneous gas injection of the two sets of exhaust holes, and the drag reduction rate is further increased.

The invention relates to the technical field of ship transportation stowage optimization, in particular to an intelligent stowage drag reduction system and method for ship navigation. The system comprises a sliding table stowage container, a lead screw motor and a conveying belt used for driving the sliding table stowage container, double guide rails used for supporting the sliding table stowage container to slide, a liquid level information reading device used for detecting the liquid level, reading the liquid level information and determining the displacement and the front and back draught difference, and a main controller used for controlling the navigation of the ship, receiving the liquid level information reading device and sending an instruction to control the movement action and the movement position of the sliding table stowage container. The self-adaptive adjustable mobile stowage control platform is used, the optimal trim angle is found through a neural algorithm, energy consumption is low, and the drag reduction rate is remarkable.

The invention discloses a salt-resistant drag-reduction agent polymer, and synthetic technology thereof. The salt-resistant drag-reduction agent polymer comprises, by weight, 320-360 parts of pure water, 0.1-0.3 part of Edta-2Na, 35-45 parts of sodium bicarbonate, 18-22 parts of acrylic acid, 8-12 parts of AMPS, 75-85 parts of acrylamide, and 14-18 parts of urea. The synthetic technology is simplein operation; product quality is stable; and environment pollution influence is extremely low. The salt-resistant drag-reduction agent polymer possesses advantages such as high dissolving speed, temperature resistance, salt resistance, shearing resistance, excellent compatibleness, and high drag reduction rate, is mainly used for reduction of conveying resistance force in shale hydrocarbon reservoir and compact sandstone hydrocarbon reservoir pressing crack construction and other fluid pipelines, enlarging discharge amount, and reducing power consumption.

The invention provides a novel drag reducer for fracturing and particularly relates to a drag reducer for fracturing fluid in petroleum fracturing construction. Adding a small quantity of novel drag reducer for fracturing in the fluid can reduce flow resistance in the turbulence state. A drag reduction rate can be up to 79.5% and can still keep at 79.4% after 5 hours' high-strength shearing. The novel drag reducer for fracturing is suitable for long-distance transportation.

The invention discloses an integrated piezoelectric vibration resistance reducer capable of being embedded in the wall face, and belongs to the technical field of fluid vibration resistance reducing. The problems that an existing resistance reducer is complex in structure, large in occupied space, difficult in control and poor in universality are solved. The integrated piezoelectric vibration resistance reducer is technically characterized in that the head and the tail of an underwater vehicle are in a conical shape, the middle portion is in a cylindrical shape, piezoelectric vibration resistance reducer bodies are specifically embedded in the middle portion and the tail of the underwater vehicle and each comprises a resistance reducer cavity and a piezoelectric vibrator; the piezoelectric vibrator of each piezoelectric vibration resistance reducer body comprises a copper sheet, a piezoelectric plate or a piezoelectric stack I or a piezoelectric stack II and a wire, wherein the copper sheet is placed in the middle of the corresponding resistance reducer cavity, the copper sheet and the corresponding resistance reducer cavity are installed in a sealed manner, and the top end of the piezoelectric plate or the piezoelectric stack I or the piezoelectric stack II is in glue joint with the copper sheet and located below the copper sheet; and an auxiliary hole is formed in each resistance reducer cavity and used for guiding-out of the wire of the corresponding piezoelectric vibrator. The integrated piezoelectric vibration resistance reducer is used for reducing the fluid contact wall face friction resistance and delaying boundary layer separation during sailing of the underwater vehicle, and pressure difference resistance is reduced.

The invention provides a fracturing fluid sand-carrying agent and a slickwater drag reducer based on a thermal tackifying emulsion polymer, and the thermal tackifying emulsion polymer is applied to the process of increasing the yield of petroleum and natural gas through hydraulic fracturing and is used for preparing the fracturing fluid sand-carrying agent or the slickwater drag reducer on site. The thermal tackifying emulsion polymer is obtained by polymerizing a temperature-sensitive macromolecule, an anionic monomer and an acrylamide monomer, and the temperature-sensitive macromolecule is apolyoxyethylene-polyoxypropylene-polyoxyethylene triblock polymer. According to the invention, the defects that a conventional fracturing fluid system needs to be dissolved and crosslinked in advance, and the fluid preparation process is tedious are overcome, and meanwhile, the defect that the sand carrying performance or the drag reduction efficiency of a traditional fracturing fluid or the slickwater drag reducer becomes poor due to thermal thinning is overcome.

The invention discloses an emulsion type anti-wear and anti-drag thickening agent for fracturing and a preparation method thereof, and the preparation method comprises the following steps: 1, preparation of a water phase: successively adding acrylamide and triethanolamine oleic soap into water, and uniformly mixing; step 2, preparing an oil phase, namely adding span 80 into white oil, and then uniformly stirring and mixing; step 3, preparing an emulsion, slowly adding the water phase in the step 1 into the oil phase in the step 2 in a stirring state, and circularly emulsifying for 1-3 times by using a homogeneous emulsification pump after the water phase in the step 1 is completely added into the oil phase in the step 2; and 4, polymerization reaction: putting the emulsion prepared in the step 3 into a reaction kettle with a stirrer, stirring, filling nitrogen for more than 20 minutes, adding an oxidant, heating, and slowly dropwise adding a reducing agent. When the emulsion type anti-wear and anti-drag thickening agent for fracturing is used for preparing a fracturing fluid, the thickening property is good, and the construction friction resistance is low; when used for preparing coiled tubing construction liquid, the lubricating oil has good lubricating property and strong wear resistance.

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 provides a drag reducer with a pour-point depression function and a preparation method of the drag reducer. The drag reducer comprises components in parts by weight as follows: 147-150 parts of 1-butylene hydrocarbon, 180-185 parts of vinyl acetate, 0.5-1 part of titanium tetrachloride-triethylaluminium, 570-575 parts of n-butyl alcohol and 90-100 parts of an emulsifier OP. According to the drag reducer with the pour-point depression function, the condensation point of crude oil can be effectively reduced, the energy loss in the crude oil flowing process is reduced, energy consumption can be greatly reduced, the pour point of the crude oil is reduced by 10 DEG C, the drag reduction rate is increased by 47.6%, the throughput increase rate is increased by 43.7%, the throughput can be improved, the flow speed is increased, and energy consumption is reduced.

The invention discloses an acrylamide copolymer, a preparation method and an application. The acrylamide copolymer contains a constitutional unit A, a structural unit B, a structural unit C and a structural unit D, wherein, the structural unit A is the structural unit shown in a formula (1), the structural unit B is the structural unit shown in a formula (2), structural unit C is the structural unit shown in a formula (3), and structural unit D is the structural unit shown in a formula (4), and the viscosity average molecular weight of the acrylamide copolymer is 5-15 million. The provided acrylamide copolymer has the advantages of high drag reduction efficiency, high salt tolerance, good high shear-resistance performance, good water solubility, good compatibleness with a clay stabilizing agent and low damage to stratum.

The invention belongs to the technical field of drag-reduction film composition for oil field production increase, and particularly discloses drag-reduction film composition. The drag-reduction film composition is prepared from raw materials as follows: water, acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, polyene amine, dimethyl diallyl ammonium chloride and an initiator. The drag-reduction film composition in the scheme has excellent drag-reduction performance, a propping agent is coated with a drag-reduction film by the prepared drag-reduction film composition, and after the propping agent is added to clear water, the drag-reduction film can be rapidly dissolved in the clear water and performs drag-reduction on the clear water.

The invention discloses an acrylamide copolymer, and a preparation method and an application thereof. The acrylamide copolymer contains a constitutional unit A, a constitutional unit B, a constitutional unit C and a constitutional unit D, wherein the constitutional unit A is a constitutional unit represented by formula (1) and / or a constitutional unit represented by formula (2), the constitutional unit B is one or more of constitutional units represented by formula (3), formula (4), formula (5) and formula (6) respectively, the constitutional unit C is a constitutional unit represented by formula (7) and / or a constitutional unit represented by formula (8), and the constitutional unit D is a constitutional unit represented by formula (9) and / or a constitutional unit represented by formula (10); and the viscosity average molecular weight of the acrylamide copolymer is 2,000,000-25,000,000. The acrylamide copolymer has the advantages of high drag reduction rate, high heat and salt resistance, good high-shear resistance, good water solubility, good compatibleness with clay inhibitors (alcohol), and small damages to the stratum.