146 results about "Acid fracturing" patented technology

A hydraulic pulse-type soluble segmented acid fracturing slide sleeve and a pulse acid fracturing construction method. The slide sleeve comprises a slide sleeve outer cylinder (1) and a rotary valve assembly, and flow-passing holes (101) are formed on the slide sleeve outer cylinder (1); the rotary valve assembly comprises a valve core (2) and a valve ball (13), and the valve ball (13) can block a passage (203); a flow guide channel (206) and flow splitting channels (207) are formed between the outer wall of the valve core (2) and the inner wall of the slide sleeve outer cylinder (1); the slide sleeve outer cylinder (1) has a first position and a second position in the axial direction; when the valve core (2) is located at the first position, the outer wall of the valve core (2) blocks the flow-passing holes (101); an acid fracturing working fluid flowing through the flow guide channel (206) can push the valve core (2) to move from the first position to the second position along the slide sleeve outer cylinder (1), and push the valve core (2) to continuously rotate at the second position, so that the flow splitting channels (207) are alternately communicated with the flow-passing holes (101), the acid fracturing working fluid is discharged from the flow-passing holes as hydraulic pulses, hydraulic pulses with a proper frequency can be excited at the bottom of a well, energy attenuation is reduced, and the formation of a complex fracture network is promoted in a stratum.

The invention provides a coal seam collaborative anti-reflection method and a cave forming device. The coal seam cave forming device comprises a mounting main body and a blade mechanism for rotationally forming a cave. The collaborative permeability increasing method for the coal seam comprises the following steps that a coal seam sample is collected, experimental analysis is conducted, and the optimal acidizing fracturing fluid proportion is determined; fracturing drill holes and gas extraction drill holes are constructed; acid fracturing operation is carried out, and then gas extraction is carried out; gas extraction data are continuously monitored, and the extraction effect and abnormal conditions are analyzed; early warning is conducted on the extraction abnormal area, the extraction abnormal area is marked as a potential blank zone, rechecking is conducted through the micro-seismic monitoring technology, and the range and characteristics of the blank zone are determined; according to the geological conditions of the coal seam of the blank zone area, hydraulic punching or mechanical hole making is carried out to supplement pressure relief and permeability increasing measures; and gas extraction is recovered, and monitoring is enhanced. According to the method, a blank zone is effectively eliminated, efficient, uniform and long-term extraction of coal seam gas is guaranteed, and double optimization of the extraction effect in time and space is achieved.

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 relates to an integral vulcanization type acid fracturing hose connector assembly and a preparation method thereof. The hose connector assembly comprises a connector and a hose. Wherein the joint comprises an outer connector, an outer protective sleeve, a steel wire rope fixing table and a steel wire rope fixing pressing block, and the hose comprises a steel wire rope winding layer; wherein a steel wire rope in the steel wire rope winding layer is fixed on the steel wire rope fixing table, the steel wire rope fixing pressing block is arranged above the steel wire rope fixing table, the steel wire rope fixing pressing block is fixedly connected with the steel wire rope fixing table, and contact surfaces between the steel wire rope fixing pressing block and the steel wire rope fixing table are complementary special-shaped contact surfaces; the outer connector is in threaded connection with the front end of the steel wire rope fixing table, the outer protective sleeve is arranged above the outer connector and the steel wire rope fixing pressing block, the outer protective sleeve is in threaded connection with the outer connector, and the contact face of the outer protective sleeve and the steel wire rope fixing pressing block is an inclined face with the same slope; compared with the prior art, according to the technical scheme, the connection stability of the hose connector can be improved.

The invention belongs to the technical field of petroleum and natural gas yield increase transformation, and provides a visual proppant migration experiment device used in a sand-carrying acid fracturing fracture, which comprises a plunger pump, a liquid supply tank, a liquid supply tank heater, a sand mixing tank, a gas supply bottle, a visual fracture system, a waste liquid tank, a computer data acquisition system and a high-speed camera. Two micropore plates of the visual crack system are arranged between a front cover plate and a rear cover plate in parallel at intervals, micropores are evenly distributed in the micropore plates, gas in the space between the front cover plate and the rear cover plate and the micropore plates can enter a crack space, and meanwhile the injection direction of the gas is changed into the transverse direction relative to the crack space from the vertical direction. The device can effectively simulate the influence of different sand-carrying fluid viscosities, gas volume proportions, sand ratios, particle sizes, tracing proppant proportions and temperatures on the migration of the proppant in the acid sand-carrying fracturing crack and the distribution form of the sand bank.

The invention provides a thickening agent as well as a preparation method and application thereof. The thickening agent is prepared from acrylamide, acrylic acid long-chain ester and dichloromethyl (1-methyl ethylene) benzene, the thickening agent can be self-crosslinked under the acidic condition, the use of a cross-linking agent can be avoided, and the thickening agent can be self-crosslinked in the stratum under the acidic condition, so that the thickening effect can be achieved in the stratum, and the thickening effect is good. And the acidizing fracturing fluid can be prevented from being reduced along with the rise of the temperature in the stratum.

The invention discloses a high-temperature-resistant self-degradation type composite acid fracturing fluid system and a preparation method thereof, and relates to the technical field of acid fracturing fluids, the high-temperature-resistant self-degradation type composite acid fracturing fluid system comprises a base fluid, a thickening agent, a complexing agent, a cleanup additive, a corrosion inhibitor and a solvent; the base liquid is citric acid-tartaric acid-hydrochloric acid composite acid liquid, the thickening agent is AM / DMC / AA / AMPS / NVP quinary copolymer, the complexing agent is dihydroxyethyl glycine, the cleanup additive is a fluorocarbon surfactant, the corrosion inhibitor is an imidazoline and pyridine compound corrosion inhibitor, and the solvent is deionized water. The high-temperature-resistant self-degradable composite acid fracturing fluid system has the advantages of high-temperature retardance, self-degradation property, environmental protection property, salt resistance, shear resistance and temperature resistance.

The invention provides a natural fracture acid fracturing process parameter optimization method and device, equipment and a medium, and the optimization method comprises the steps: obtaining geological and engineering data of a target block, carrying out the fitting of the geological and engineering data to obtain a natural fracture fitting model, determining the natural fracture fitting parameters according to the natural fracture fitting model, and carrying out the acid fracturing process parameter optimization of the target block. Further establishing a pressure drop characteristic parameter model and a natural fracture characteristic parameter model by using actually measured pressure data, and further establishing a productivity prediction model; and according to the productivity prediction model and the natural fracture fitting model, optimizing the acid fracturing process parameters of the natural fractures. According to the method, the condition of natural fractures encountered by underground hydraulic fractures is innovatively and dynamically judged according to the wellhead pressure change rule in the multi-stage alternate acid fracturing process, parameters can be dynamically adjusted on this basis to achieve dynamic optimization of a pump injection program, and a basis is provided for whether the natural fractures are transformed or not in real time in the construction process; and a new thought and a new method are provided for acid fracturing parameter design and optimization.

The invention discloses a high-voltage electric pulse synergistic acidizing fracturing coal seam anti-reflection device and method.The high-voltage electric pulse synergistic acidizing fracturing coal seam anti-reflection device comprises a hole packer, the hole packer comprises a high-pressure acid injection pipeline, the middle of the high-pressure acid injection pipeline is sleeved with an expansion capsule, the two ends of the expansion capsule are each provided with a fixing end, and a connecting pipe is arranged at the rear end of the high-pressure acid injection pipeline; each high-voltage electrode comprises a high-voltage electrode A section and a high-voltage electrode B section, mounting holes are formed in the two sides of the fixed end at the front end in the radial direction, springs are fixedly arranged at the bottoms in the mounting holes, the two high-voltage electrode A sections penetrate through the expansion capsule, and the front ends of the two high-voltage electrode A sections abut against the high-voltage electrode B sections to achieve electric connection. And the rear end of the high-voltage electrode section A is connected with the pulse circuit. Mineral substances can be corroded through the acidizing fracturing fluid, a coal seam hole fracture network can be dredged, the subsequent high-voltage electric pulse discharging difficulty is reduced, then high-voltage electric pulse discharging is carried out for fracturing, and the coal rock fracturing efficiency is guaranteed.

The application provides a compact dolomite reservoir composite acid fracturing process parameter evaluation system and method, which comprises a simulated fracture device, an acid injection device and a circulating water injection device. The acid injection device comprises an acid storage container, an acid injection pipeline and an acid discharge pipeline. The acid injection pipeline is connected to the acid storage container and the acid injection liquid inlet hole of the simulated fracture device at both ends. The acid discharge pipeline is connected to the acid injection liquid outlet hole of the simulated fracture device. The circulating water injection device comprises a water storage container, a water inlet pipeline and a circulating water discharge pipeline. The water inlet pipeline is connected to the water storage container and the water injection liquid inlet hole of the simulated fracture device at both ends. The circulating water discharge pipeline is connected to the water injection liquid outlet hole of the simulated fracture device and the water storage container at both ends. The application adopts reverse thinking to evaluate the composite acid fracturing process parameters such as the preflush / acid viscosity ratio, the pump injection displacement and the alternating series by taking the fractal dimension, the acid volume, the flow conductivity and the acid fluid loss as the targets, and is more specific and systematic.

The invention discloses a hydrogen sulfide scavenger for acid fracturing and a preparation method thereof, and relates to the technical field of hydrogen sulfide scavengers, the hydrogen sulfide scavenger comprises the following raw materials by weight: 30-45 parts of an aldehyde compound, 30-45 parts of an alcohol amine compound, 10-18 parts of a diamine bridging agent, 2-6 parts of a solubilizing compounding agent, 20-30 parts of a solvent and 1-3 parts of a catalyst; the aldehyde compound is divided into a component A and a component B, the mass ratio of the component A to the component B is 2: 1-3: 1, the component A is paraformaldehyde, and the component B is at least one of glyoxal or glutaraldehyde. By optimizing a molecular skeleton and introducing a hydrophilic group, the sulfur removal capacity and chemical stability in a strong acid environment are improved, compatibility with acid liquor is good, generation of acid sludge and insoluble precipitates is effectively inhibited, secondary damage to a stratum is avoided, and the high efficiency and mass transfer performance of a product are guaranteed through the preparation process.

The invention discloses an acid fracturing sand adding composite flow conductivity optimization method considering nonlinear characteristics, and belongs to the technical field of oil and gas field development, and the method comprises the following steps: S1, determining a flow conductivity calculation model of a work area target layer through an experiment; s2, constructing a reservoir geologic model; s3, giving variables including the proportion of a supporting section and the proportion of an acid etching section, determining the flow conductivity of the fracture area through the flow conductivity calculation model, taking the permeability corresponding to the flow conductivity as the initial permeability of the grid of the fracture area, substituting the initial permeability into the reservoir model, and simulating the productivity change of the gas reservoir; and S4, adjusting variables, simulating the productivity change of the gas reservoir under different conditions, and comparing the cumulative yields under different combination conditions to determine the optimal flow conductivity distribution mode. According to the method, a new flow conductivity calculation model is designed, the design parameters of the acid fracturing and sand adding composite process are determined through numerical values by taking the productivity as an evaluation index, a theoretical basis is provided for the design of a field acid fracturing and sand adding technical scheme, and the field trial and error cost is reduced.

The invention discloses an oil and gas well yield increase monitoring method and system based on an acid fracturing technology, and relates to the technical field of oil and gas monitoring. The oil and gas well yield increase monitoring method based on the acid fracturing technology comprises the steps that stress change uniformity is evaluated; carrying out acidification data transmission interference assessment; and evaluating acidification accuracy. According to the method, stress change uniformity evaluation is performed on stress change between sandstones, whether stress change uniformity evaluation optimization is performed or not is judged on the basis of a quantitative evaluation result, then acidification data transmission interference evaluation is performed, and whether acidification data transmission interference evaluation optimization is performed or not is judged on the basis of the quantitative evaluation result. Finally, acidification accuracy evaluation is executed, whether acidification accuracy and qualification optimization is conducted or not is judged based on the quantitative evaluation result, the effect of improving the acidification data accuracy in the oil and gas well yield increase monitoring process is achieved, and the problem that in the prior art, the acidification data accuracy is low in the oil and gas well yield increase monitoring process is solved.

The application provides a method and system for calculating the conductivity of a sand-acid fracturing reservoir simulation system, which comprises the following steps: constructing a simulation parameter combination set around sand-acid fracturing operation parameters for reservoir types with sand-acid fracturing requirements; analyzing fracture acid erosion data of different reservoirs by using a preset fracture acid erosion calculation model, and analyzing the embedding depth and deformation data of the proppant in combination with the injection rate parameters and the proppant data; further analyzing the sand concentration of sand-acid fracturing, and setting a rough body simulation distribution coefficient in combination with the injection rate, so as to form a reservoir fracture model that presents a real fracturing state; analyzing the permeability state of the reservoir fracture model after fracturing based on the rough body simulation distribution coefficient and the reservoir closure pressure; and further calculating the corresponding conductivity in combination with the fracture width calculated according to the fracture acid erosion data, the embedding depth and deformation data of the proppant. The method solves the problem that the sand-acid fracturing conductivity cannot be quantitatively analyzed, and provides support for field acid fracturing design and productivity prediction.

The invention discloses a high-temperature and high-pressure corrosion on-line porosity and permeability testing method. According to the method, an integrated process of triple dynamic correction-multistage self-cleaning filtration-AI self-adaptive collaborative testing is constructed, and high-precision online continuous testing of the porosity and the permeability in the corrosion process is achieved under the conditions of the confining pressure of 0-120 MPa, the pore pressure of 0.1-50 MPa, the temperature range of 25-220 DEG C and the multi-medium supercritical corrosion working condition; the problems that in an existing high-temperature and high-pressure corrosion test, pressure-temperature-concentration coupling correction is not comprehensive, corrosion products are accumulated for a long time and are prone to blockage, the fluid stability under the supercritical working condition is poor, and the test frequency adaptability is insufficient are solved. The method can accurately capture the instantaneous evolution law of rock physical properties in a complex corrosion environment, is suitable for extreme scenes such as deep CO2-EOR sealing, ultra-deep oil and gas reservoir acid fracturing transformation and high-temperature geothermal reservoir long-term operation, and provides data support with higher fidelity for engineering scheme optimization.

The invention discloses a deep cloud-ash interaction reservoir acid fracturing fracture extension rule simulation method, and relates to the technical field of carbonate rock oil-gas exploration and development acid fracturing engineering, and the method comprises the following steps: based on the related data of a target block, through single well geological statistics, indoor test and theoretical calculation analysis, obtaining the extension rule of the acid fracturing fracture of the target block; searching the relationship between the lithology and the geomechanical parameters; based on a single well geological parameter statistical result, a Petrel platform is utilized to construct a geological attribute, geomechanics and natural fracture distribution mechanism model, and a model foundation is laid for cloud ash interaction reservoir fracture extension rule simulation; based on the acid killing well geological attribute model, simulating and analyzing the influence of construction parameters on a crack extension rule by taking the cloud rock section acid etching crack area as a target, and performing parameter optimization; and on the basis of cloud-ash interaction reservoir acid fracturing fracture extension mechanism analysis and based on a cloud-ash interaction reservoir acid fracturing construction parameter optimization result, cloud-ash interaction reservoir fracture extension main control factor analysis and fine regulation and control parameter chart construction are carried out.

This invention discloses a method, equipment, and medium for calculating construction parameters of sand-added acid fracturing stimulation, relating to the field of carbonate reservoir stimulation. Based on the single-well production requirements of the oilfield development plan, it determines the target artificial fracture length and conductivity; determines the fracturing fluid volume required to achieve the target artificial fracture length; determines the proppant volume required for sand-added acid fracturing stimulation according to the principle that permeability is supported by the filler; establishes a flow reaction model and temperature field model within the acid fracture to determine the concentration field, velocity field, and temperature field within the fracture during acid injection; and determines the actual permeability formed by acid dissolution and the acid volume required for sand-added acid fracturing stimulation based on the acid concentration and flow rate at different times in the fracture. This invention accurately determines the construction parameters of the pre-fracturing acid, proppant, and acid for sand-added acid fracturing stimulation, providing a basis for the design and optimization of acid fracturing processes in carbonate reservoirs.

The invention provides a salt-sensitive self-thickening weighted acid fracturing system as well as a preparation method and application thereof, and belongs to the technical field of acid fracturing of oil fields. The salt-sensitive self-thickening weighted acid fracturing system comprises the following components in parts by weight: 27-40.5 parts of a hydrochloric acid aqueous solution, 10-50 parts of a weighting agent, 1-4 parts of a thickening agent, 1-4 parts of a corrosion inhibitor and 1.5-55 parts of water. The acid fracturing system has the characteristics of high density, low corrosion rate, good high-temperature stability, excellent compatibility and the like, and is suitable for acid fracturing transformation of deep high-temperature and high-pressure carbonate reservoirs.

This utility model discloses an acid fracturing fluid mixing device, relating to the field of oil and gas field equipment technology. The device includes a mixing cylinder with a cap at its top. A first motor is fixedly mounted on the top of the cap, and the output end of the first motor passes through the cap and is fixedly connected to a stirring shaft. Stirring blades are fixedly mounted on the circumferential wall of the stirring shaft. A feed branch pipe is fixedly mounted through the top of the mixing cylinder on one side of the first motor. By driving the first and second motors to rotate, the stirring shaft and stirring frame rotate in opposite directions, preventing the raw materials inside the mixing cylinder from flowing in one direction. This allows for faster and more thorough mixing of the raw materials, improving the mixing effect of the acid fracturing fluid. Brake wheels facilitate movement of the mixing device. Clockwise rotation of the screw moves the support base plate downwards, causing the damping pad to contact the ground, ensuring stable parking of the mixing device.

The invention provides a resveratrol fermentation broth separation method, which comprises: (1) carrying out filter pressing treatment on a resveratrol fermentation broth to obtain a second filter residue, the filter pressing treatment comprising carrying out acid pressing on the fermentation broth first and then carrying out alkali pressing, or carrying out alkali pressing on the fermentation broth first and then carrying out acid pressing; (2) carrying out extraction treatment on the second filter residue by adopting an organic solvent to obtain extract liquor; (3) washing the extract to obtain a washing solution; wherein the washing treatment comprises the following steps: sequentially carrying out alkali washing treatment and acid washing treatment on the extracting solution, or sequentially carrying out acid washing treatment and alkali washing treatment on the extracting solution to obtain a washing solution; (4) decoloring and dehydrating the washing solution, and concentrating to obtain a concentrated solution; and (5) carrying out crystallization treatment on the concentrated solution to obtain resveratrol. According to the method, the resveratrol extraction period can be shortened under the condition that a chromatographic method is not used, the cost is reduced, and the purity and the yield of resveratrol are improved.

The present application relates to the field of horizontal well coalbed methane production, in particular to a method for increasing the yield of coalbed methane by deep foam displacement in horizontal well, which is suitable for coalbed methane well with long horizontal section, difficult to discharge residual acid slag and poor deep acid washing effect. The method comprises the following steps: running the well flushing pipe column to the deepest part of the horizontal well, continuously injecting acid liquid and foam stabilizer compound solution into the oil pipe, using the retreating type well flushing technology to flush acid in sections until the last acid washing well section, shutting down the well to maintain acid pressure after the pump pressure is stable, carrying out acid immersion operation for 8 hours, running the oil pipe to inject sodium bicarbonate solution, and then carrying out sectional alkali injection after the pump pressure is stable. The alkali water reacts with the residual acid liquid to generate carbon dioxide gas and release heat, the foam stabilizer reduces the gas-liquid surface tension, a large amount of foam is generated to carry the residual slag out of the oil jacket annulus and the wellbore passage, and the generated inorganic salt is beneficial to the wetting and solution stability of the residual slag. The method solves the problem of difficult discharge of residual acid slag in deep acid washing of horizontal well, makes the acid washing effect more thorough, and the flowback efficiency is higher.

The invention discloses a resistance-reducing retarded acid thickening agent suitable for high-temperature deep well acid fracturing as well as a preparation method and application thereof, and belongs to the technical field of oil field reservoir transformation. The resistance-reducing retarded acid thickening agent is prepared by copolymerizing the following monomers in parts by weight: 3-6 parts of acrylamide, 18-20 parts of a cationic functional monomer, 2-5 parts of a rigid functional monomer and 0.5-1 part of a supramolecular long-chain functional monomer. The drilling fluid can be suitable for well depth and high-temperature characteristics of carbonatite gas reservoirs in Sichuan and Chongqing regions, has the characteristics of good temperature resistance, friction resistance and retarding performance, and can remarkably improve the deep acidification transformation effect of the reservoirs in acidification construction of the carbonatite reservoirs.

This invention provides a micro-acidification downhole formation testing device and a micro-acidification method based thereon. The device includes a hydraulic power module, a compartmentalized acid-carrying unit, an acid injection / discharge pump unit, a probe module, a downhole observation chamber for acid-formation reaction, a pipeline system, and a control circuit. The hydraulic module is configured to drive tool movements and control the testing process via hydraulic power. The acid injection / discharge unit is configured to control fluid flow, circulation, and pressure regulation. The injection probe of the probe module is seated at the target acidification or acid fracturing test injection point, connecting the device to the formation. The downhole observation chamber for acid-formation reaction is configured to monitor the physical / chemical parameters during injection / discharge. This invention effectively solves the problems of acid system and acid formulation screening, optimization, and process optimization in real-world acid environments within formations.

Described herein are methods for treating a subterranean formation penetrated by a wellbore with a retarded acidizing fluid containing an acid and an acid retarding agent, the concentrations of which are adjusted based on measured parameter values of the formation. Also described is a method for treating a subterranean formation by introducing an acid to the formation following the introduction of an acid retarding agent to the formation. Also described is a method for acid fracturing a subterranean formation including reducing the concentration of an acid retarding agent contained in a retarded acidizing fluid over the course of the acid fracturing operation.

The present invention discloses a dual-pulsation acidic fracturing and permeability-enhanced low-permeability coal seam gas extraction system, comprising a pressure overshoot protection mechanism, a fracturing fluid transmission line, a gas extraction line, a mixing liquid box, a pressure regulating and monitoring mechanism, and a frequency regulating and monitoring mechanism; the present invention also discloses a dual-pulsation acidic fracturing and permeability-enhanced low-permeability coal seam gas extraction method, comprising the following steps: step S1, investigating the target coal seam and obtaining fracturing fluid; step S2, installing the above-mentioned system; step S3, adjusting the fracturing pressure and pulsating frequency of the fracturing fluid, and performing continuous cyclic fracturing on the fracturing borehole; step S4, adjusting the fracturing pressure and pulsating frequency of the fracturing fluid to, and performing continuous cyclic fracturing on the fracturing borehole; step S5, repeating steps S3-S4 five times, and extracting and detecting gas concentration to generate data. The present invention has the advantages of increasing the connectivity of the internal fracture-pore structure of the coal body, improving the permeability enhancement effect of the coal seam, improving the coal seam gas extraction efficiency, and having an interlocking structure.

The present application relates to a kind of acid liquid fingering quantitative evaluation method for carbonate rock geothermal reservoir preflush acid fracturing, belong to the technical field of enhanced geothermal system reservoir stimulation.Establish three-dimensional model and multi-field coupling numerical model considering fingering effect, using numerical simulation method can obtain the three-dimensional morphological change of fracture surface, by calculating etching front fingering coefficient, the acid liquid fingering effect in the process of carbonate rock heat reservoir preflush acid fracturing is quantitatively evaluated, and the sensitivity of rock plate temperature, preflush viscosity, acid injection displacement and other parameters to fingering effect is also analyzed, which provides theoretical basis and technical support for geothermal reservoir depth acid fracturing technology.

The invention provides a coal seam composite anti-reflection method and a coal seam composite anti-reflection device for acidification presplitting and mechanical and hydraulic synergistic cave building. The coal seam composite anti-reflection device for acidification presplitting and mechanical and hydraulic synergistic cave building comprises a mounting main body and a cave building mechanism. The coal seam composite anti-reflection method based on acidification presplitting and mechanical-hydraulic synergistic cave building comprises the following steps that samples are collected at a coal seam, and the optimal acid fracturing fluid ratio is obtained through theoretical analysis and experimental research; starting the drilling machine, and operating the coal seam composite anti-reflection device for acidizing presplitting and mechanical hydraulic synergistic cave building to construct a drill hole in a coal seam; carrying out acid fracturing; mechanical-hydraulic synergistic cave-building pressure-relief permeability-increasing operation is implemented; and flushing the acidizing and fracturing pipeline system. According to the invention, the gas desorption can be promoted, the pressure relief range is extended, and the pressure relief and permeability increasing effects are enhanced, so that the gas extraction efficiency is improved.

This invention belongs to the field of oil and gas field development technology, and specifically relates to an acid tank preparation and filtration device. It includes a first installation pipe, a second installation pipe, and an acid preparation and circulation pipeline fixedly installed between the first and second installation pipes. The first and second installation pipes are connected to the acid preparation and circulation pipeline via unions. A first valve and a second valve are respectively installed on the first and second installation pipes. A filter screen is installed inside the acid preparation and circulation pipeline. This invention utilizes the circulation time of the prepared acid solution to filter difficult-to-dissolve chemical materials and other solid particles in the acid tank, saving water used for cleaning the acid tank, reducing the safety risks of cleaning the acid tank, lowering the probability of fracturing trucks running dry, improving the first-time success rate of acid fracturing operations, greatly simplifying the acid tank cleaning process, and providing convenient maintenance and safe filtration operations.

This invention relates to the field of oil and gas field enhancement and stimulation technology, and discloses a method for screening coupling agents for acid fracturing in carbonate rocks based on interfacial film formation to regulate acid-rock reactions. The method first conducts basic physical property tests on different types of coupling agents to evaluate their wettability and spreading ability on carbonate rock surfaces; then, it characterizes the adsorption and film-forming behavior of the coupling agents on the rock surface; it evaluates the compatibility of the coupling agents with different fracturing fluid systems; it analyzes the influence of coupling agent concentration and stirring conditions on the acid-rock reaction rate through acid-rock reaction experiments, and establishes an evaluation index for acid-rock reaction rate control; finally, it conducts reservoir adaptability evaluation under different temperature, mineral composition, and porosity conditions, and comprehensively screens out target coupling agents suitable for acid fracturing operations in carbonate rocks. This invention establishes a systematic coupling agent screening process, which can effectively reduce the acid-rock reaction rate, increase the acid interaction distance, and thus improve the acid fracturing stimulation effect of carbonate reservoirs.

The application discloses a hydrogen sulfide scavenger for acid fracturing and a preparation method thereof, and relates to the technical field of hydrogen sulfide scavengers, and comprises the following raw materials in parts by weight: 30-45 parts of aldehyde compounds, 30-45 parts of alcohol amine compounds, 10-18 parts of diamine bridging agents, 2-6 parts of solubilizing complexing agents, 20-30 parts of solvents and 1-3 parts of catalysts; the aldehyde compounds are divided into A component and B component, wherein the mass ratio of the A component to the B component is 2:1-3:1, the A component is paraformaldehyde, and the B component is at least one of glyoxal or glutaraldehyde. Through optimization of a molecular skeleton and introduction of a hydrophilic group, the hydrogen sulfide scavenger improves sulfur removal capacity and chemical stability in a strong acid environment, has good compatibility with acid liquid, effectively inhibits the generation of acid residues and insoluble precipitates, avoids secondary damage to a formation, and ensures high efficiency and mass transfer performance of the product through a preparation process.