60 results about "Repeated fractures" patented technology

The invention provides a low permeability gas reservoir turning repeated fracturing technological method. The specific technological method comprises the following steps of gas well initial fracturing failure or low-efficiency reason analyzing, reservoir stratum evaluating conducted before turning repeated fracturing, turning repeated fracturing well selection and stratum selection decision making, rock mechanical parameter and ground stress testing, turning repeated fracturing ground stress field changing simulating, fracture geometrical parameter and flow conductivity optimizing, turning repeated fracturing technology optimizing, fracturing liquid and turning agent studying, repeated fracturing constructing and evaluating conducted after repeated fracturing. The well selection and stratum selection decision making and residual gas detecting serve as verification systems of each other, fracturing design and fracture detecting serve as verification systems of each other, and a novel fracture turning agent is used in the low permeability gas reservoir turning repeated fracturing technological method. The integrated design of the low permeability gas reservoir turning repeated fracturing is achieved, and the low permeability gas reservoir turning repeated fracturing technological method has the advantages that the design links are macroscopically integrated, local innovation is achieved, linkage is close, mutual verification is achieved, the design is advanced, and the technological advantage is obvious.

The invention discloses an evaluation method for low permeability heterogeneous oil reservoir horizontal well repeated fracturing yield increasing potential. The evaluation method sequentially comprises the following steps that (1), a crack expansion model is built by utilizing Meyer software, and inversion of first-time fracturing hydraulic crack parameters is conducted; (2), an oil reservoir heterogeneous geological model is built by utilizing oil reservoir numerical value simulation software Eclipse, the first-time fracturing hydraulic crack parameters are planted into the heterogeneous geological model to conduct production dynamic history fitting, and remaining oil saturation field and stratum pressure field distribution is obtained; and (3), quantitative evaluation is conducted on the horizontal well repeated fracturing yield increasing potential according to the remaining oil saturation field and stratum pressure field distribution, first-time fracturing hydraulic cracks are classified, and pertinence repeated fracturing modes are proposed. The problems of the stress sensitivity phenomenon and poor pertinence of the repeated fracturing modes and the like existing in evaluation of the low permeability heterogeneous oil reservoir horizontal well repeated fracturing yield increasing potential are effectively solved, the effect of repeated fracturing transformation is improved, the risk of engineering construction is reduced, and the evaluation method has wide market application prospects.

The present invention relates to a method for implementing repeated fracturing treatment to make new fracture for low permeability oil field. Said invention utilizes elliptic fracture to described primary fractured artificial fracture, and combines tensional breaking criterion and shear breaking criterion so as to obtain the theoretical basis for repeatedly-fracturing to make new fracture. Said invention utilizes this theoretical basis to provide various fracturing processes for implementing the invented method.

The invention belongs to the technical field of unconventional oil and gas production increasing and transformation, and particularly relates to an optimization design method for hydraulic fracture parameters of repeated fracturing of shale gas horizontal wells. The optimization design method comprises the following steps that (a) a numerical model for predicting the productivity of repeated fracturing of the shale gas wells is established; (b) the established numerical model for capacity prediction is numerically solved and integrally coupled; (c) based on the established numerical model forpredicting the productivity of repeated fracturing , the production of the shale gas wells after repeated fracturing under the different hydraulic fracture parameters is simulated by considering two modes of repeated fracturing and re-perforating repeated fracturing of an original fracture system; and (d) a simulation result of the shale gas horizontal well production is evaluated and analyzed, the optimal hydraulic fracture parameters of the corresponding repeated fracturing mode are obtained. The optimization design method can consider the complex fracture morphology and flow behavior of a shale reservoir, simulate the hydraulic fracture parameters to influence the productivity of the shale gas wells under different repeated fracturing modes, and guide the optimization design of the hydraulic fracture parameters for repeated fracturing of the shale reservoir.

The invention discloses a method for judging temporary plugging and fracture initiation in a repeated fracturing well crack. The method specifically comprises the following steps that basic parameters are collected; a hydraulic fracture filled with temporary plugging agents is divided into two hydraulic fractures, and the stress of all points on the fracture face is calculated; a judging criterion of the temporary plugging, fracture initiation and diversion the fracture wall face after the temporary plugging agents are added into the hydraulic fractures is established by the force analysis of the fracture wall face; and the effects of different fracture length, net fluid pressure in the fracture, the temporary plugging agents, the pressure and the sealing blocking length of the temporary plugging agents on the temporary plugging and fracture initiation of the fracture wall face are analyzed quantitatively. According to the method for judging temporary plugging and fracture initiation in the repeated fracturing well crack, the organic combination of the parameters of induced stress fields produced by the extension of the hydraulic fractures and pressure changing of stratum hole fluid, the performance parameters of the temporary plugging agents, the sealing blocking length of the temporary plugging agents and the like is fully considered, the location and orientation of the fracture initiation of the temporary plugging fracture in the repeated fracturing well fracture can be effectively predicted, and the effect of repeated fracturing temporary plugging diversion transforming can be effectively improved.

The invention discloses a repeated fracturing method for a low-yielding and low-efficiency old oil well, and relates to the technical field of repeated fracturing and production-increasing. The method comprises the steps that numerical simulation is conducted to obtain the reservoir remaining oil distribution characteristic according to the reservoir microscopic characteristic, the production performance analysis and the site parameter obtained by testing; a crustal stress field prediction model is established under the development condition of a single well or a well net to obtain the crustal stress field state before repeated fracturing is conducted; a reconstructed reservoir is obtained based on the reservoir remaining oil distribution characteristic; a reconstructed crustal stress field is obtained according to the crustal stress field state before repeated fracturing is conducted; the penetration of artificial fractures of the reservoir is optimized to promote generation of the stress interference between the fractures, and the spreading directions and the complexity of the fractures are changed to obtain a reconstructed underground seepage field; artificial complex fracture net seepage channels are established under the reconstructed reservoir, the reconstructed crustal stress field and the reconstructed underground seepage field to form a fracture control matrix unit; and full-scale water injection is conducted on the reservoir to improve the driving pressure difference of seepage of fluid in the fracture control matrix unit to the fractures.

The invention relates to a method for maintaining flow conductivity of multi-slit fracturing seams in a horizontal well section. The method comprises the steps of firstly, preparing a temporary plugging steering working solution, wherein the temporary plugging steering working solution comprises degradable temporary plugging agents, degradable fiber, an equidensity proppant and a low-viscosity carrying liquid; carrying out staged fracturing, wherein the pump injection sequence is a prepad fluid, a sand-carrying fluid and the temporary plugging steering working solution; and after complete fracturing, waiting till the temporary plugging steering working solution is degraded, carrying out fluid drainage, and ensuring that the proppant remains at the seams and forms a seepage channel. According to the method, the plugging efficiency is improved and the seepage loss of liquids among the seams is reduced through adopting the multi-scale degradable temporary plugging agents; after construction, the degradable temporary plugging agents and the degradable fiber in the temporary plugging steering working solution are completely degraded under the action of the bottom hole temperature; the proppant maintains the flow conductivity of a near mineshaft; and the method is applicable to conventional hydraulic fracturing staged reconstruction, unconventional staged fracturing reconstruction, uncrushed perforation cluster reconstruction of a new well, repeated fracturing reconstruction of an old well, and various technologies of staged reconstruction of a horizontal well.

The invention discloses a testing method of the breakthrough pressure of a repeated fracturing plugging agent. The testing method comprises the following steps: (a) preparing the repeated fracturing plugging agent for future use; (b) selecting a plurality of rock core samples for future use; (c) respectively weighing rock cores and measuring lengths; (d) cutting each rock core along an axial direction and making an artificial crack; (e) paving one layer of particle substances on a crack surface and simulating a fracturing crack; (f) injecting the repeated fracturing plugging agent into the simulated fracturing crack and standing for a period of time; and (g) after the repeated fracturing plugging agent is gelled, testing the breakthrough pressure of the repeated fracturing plugging agent. According to the testing method disclosed by the invention, the breakthrough pressure of the repeated fracturing plugging agent can be rapidly detected; and the testing process is simple, the tested result is accurate, and the testing method provides data support to the utilization of the repeated fracturing plugging agent.

The invention discloses a horizontal well crack plugging and wellbore reconstruction repeated-fracturing method. The horizontal well crack plugging wellbore reconstruction repeated-fracturing method comprises the steps that liquid is injected into a formation until the wellhead injection pressure is greater than the well formation closing pressure; crack plugging particles are injected into original cracks; cement is injected into the formation; then drillable plugging materials are injected; after the cement and the crack plugging particles are stable, a drilling and grinding tool is trippedin to drill and grind the drillable plugging materials, and the drillable plugging materials are circulated out of the ground through the liquid; a first drillable bridge plug and a perforating gun pump are tripped into the first new crack position, a perforating gun is controlled to conduct perforating, meanwhile, the perforating gun is separated from the first drillable bridge plug, the first drillable bridge plug completes setting, then the perforating gun is tripped out, sleeve injection fracturing is conducted, and the drillable bridge plug and the perforating gun pump are tripped in repeatedly to complete all layer sections needing to be transformed. By plugging old cracks and conducting plugging agent and cement filling on the previous well-cementation-unqualified layer sections, abrand new wellbore is manufactured, and thus tool sand-burying caused by communication of upper and lower layers outside a sleeve due to poor well-cementation quality is effectively prevented.

The invention relates to a repeated fracturing temporary blocking agent and a preparation method and application thereof. The repeated fracturing temporary blocking agent is prepared from acrylamide,bone glue, an initiator, a cross-linking agent and a chain transfer agent; the mass ratio of the bone glue to the acrylamide is 1:(1-2); the mass of the initiator is 0.5-1% of that of the acrylamide,the mass of the cross-linking agent is 0.1-0.2% of that of the acrylamide, and the mass of the chain transfer agent is 1.5-2% of that of the acrylamide. The repeated fracturing temporary blocking agent further comprises an admixture, and the mass of the admixture is 0.6-1.2% of that of the acrylamide. The temporary blocking agent has the maximum breakthrough pressure of 16 MPa and the adjustable dissolution time of 16-72 h and has the advantages of high-strength blocking and dissolubility in the stratum.

The invention relates to a method for dealing repeated fracture of an industrial pipeline caused by thermal stress. The method comprises the following steps of: judging a stress trend of the pipeline and quantifying a stress level thereof by testing an original deformation degree formed in a pipeline construction process; judging a limit expansion and contraction rate epsilon of an involved pipeline section according to a maximal temperature difference interval of a service environment of the pipeline; respectively quantifying various stress values borne by the involved pipeline section and a maximal cumulative stress intensity sigma respectively by using a linear rule of an elastic modulus E of a material; judging whether the involved pipeline section is safe by comparing the maximal cumulative stress intensity sigma with a usable intensity [sigma] of a pipeline material; and finally providing a measurable reinforcement scheme or a stress compensation scheme. The method has the advantages that: the analysis and the judgment of a pipeline fracture phenomenon in the field is converted into a quantitative analysis and judgment mode in a data form from a conventional experience judgment mode; and a practical solution is proposed.

The invention provides a gas well re-fracturing well selection and layer selection method. The gas well re-fracturing well selection and layer selection method comprises the following steps: (1) calculating a porous elastic stress steering coefficient Piporo; (2) taking a well selected according to step (1) as an alternative target well for repeated fracturing, calculating the deflation volume Vdof the target well; (3) calculating the instantaneous recovery percent IRR; (4) calculating the yield decreasing coefficient Di by taking the well selected according to step (3) as an alternative target well for repeated fracturing; (5) calculating a gas reservoir attenuation coefficient RDep by taking the well selected according to step (4) as an alternative target well for repeated fracturing; (6) calculating each single-layer reserve abundance omegai of the target well, and selecting a layer with the air layer reserve abundance greater than 0.2 as an alternative air layer for repeated fracturing. According to the gas well re-fracturing well selection and layer selection method, a judgment algorithm is determined by application of mathematical statistics and the dynamic analysis of the gas reservoir engineering, and the calculation is simple. In the method, factors affecting the repeated fracturing are considered comprehensively, the repeated fracturing well and layer are optimized,the implementation accuracy is high, the method has high transplantability, and the application is wide.

The invention discloses a fracturing technique for achieving a complex crack through multiple particle class differential temporary blocking, which is fracturing technique that a primary artificial crack is temporarily blocked through rigid temporary plugging agent composition with particle size class differential carried by a fracturing fluid, net pressure in the crack is improved, and a new sidecrack is opened. The fracturing technique comprises the steps that the rigid temporary blocking agent carried by a biodegradable polylactic acid resin-like fiber fracturing fluid with four kinds of particle size class differential combination is fast injected according to the sand mulling concentration of 350-500-650g / cm3, and crack deep part temporary blocking is carried out; the net pressure inthe crack is improved, and the side natural crack is opened, and side remaining oil is effective used; and the oil well single well production and final recovery ratio are improved. The fracturing technique has the advantages that the operability of the construction technique is high, a complex fracture system is fractured to be formed, the using degree of the oil well side remaining oil is improved, the cost is low, and the oilfield development benefit is greatly improved, and solves the difficult problem of the poor repeated fracturing effect of low-permeability reservoirs.

The invention provides a pressure testing method for a segmented oil pool and a segmented trial-squeezing tubing string. The segmented trial-squeezing tubing string comprises a hydraulic anchor, a Y111 type packer, an oil pipe adjusting short section, a pressure guiding sand blower, a Y211 type packer and a guider which are sequentially connected in series. The hydraulic anchor is connected with an oil pipe through a safety joint. A wellbore and a blocked reservoir stratum nearby cracks are cleaned through blockage removing fluid, the initial transformation situation is judged to serve as a subsequently conducted repeated fracturing design basis, the average time of single-segment trial-squeezing pressure testing is 3 h, the testing period is effectively shortened, and the construction efficiency is improved; the calculation method is simple and rapid, and no special interpretation software is needed; and the problems that direct segmented oil pool pressure testing conducted on a horizontal well is long in consumed time, high in cost and the like, and the segmented oil pool pressure of the horizontal well cannot use the vertical well testing method are solved, so that the testing period is shortened.

The invention relates to a horizontal well repeated fracturing device and method based on open-hole preset tubular column well completion. Firstly, an original fracturing sliding sleeve ball seat in apreset pipe column is grinded and milled to achieve the full diameter of a well shaft and provide a passage for a repeated fracturing device to enter; impurities such as steel slag and the like remained in the grinded and milled ball seat on the sleeve wall are cleaned through two well passing procedures, and the resistance risk of a repeated fracturing device is reduced; because the sand blasting port in the sleeve is in an open state after the primary fracturing, the gap between an oil pipe and a tail pipe is blocked by an oil pipe packer, the tail pipe is blocked by a sealing piece, and the oil pipe packer and the sealing piece are respectively positioned at two sides of the same nozzle, the liquid outlet of the oil pipe is positioned in the sealed space, and after the packer is set and sealed, the repeated fracturing transformation is finished according to the pump injection procedure; and then the tool is released when the internal pressure difference and the external pressure difference are consistent, and the pipe column is lifted. The method achieves the purpose of repeated fracturing modification under the condition of open-hole prefabricated tubular column well completion, prolongs the service life of an oil well and increases the yield.

The invention discloses a repeated fracturing indoor test device and an operation method thereof. The repeated fracturing indoor test device comprises a triaxial test platform, a triaxial stress loading system, a triaxial servo control system and a computer system. The triaxial test platform is used for placing a rock test piece, and is connected with the triaxial stress loading system and the triaxial servo control system; the triaxial stress loading system is used for providing axial pressure, confining pressure and hydraulic pressure; and the triaxial servo control system can accurately carry out servo control on the axial pressure, confining pressure and hydraulic and can transmit the acquired data to the computer system. According to the repeated fracturing indoor test device, the structure is simple, the operation is convenient, the test efficiency is high, and the modular design is adopted, so that the device is relatively high in pertinence and capable of effectively simulatingthe repeated fracturing process of the shale gas well, and intuitively observing the geometrical morphology of the hydraulic fracture, expansion, interaction and other phenomena, so that the shale gas well repeated fracturing theory and technical analysis are carried out, and guidance is provided for scientific research and engineering practice.

The invention relates to the technical field of re-fracturing well selection, in particular to a shale gas well re-fracturing well selection evaluation method. The shale gas well re-fracturing well selection evaluation method comprises the following steps that S1, a near pressure transporting well is selected to be a re-fracturing target well from all production wells in a shale gas field; S2, shale gas well re-fracturing well selection evaluation indicators are optimized, S3, quantitative evaluation indicators are carried out to a single well one by one, and a target well is optimized; and S4, a well with a high yield-increasing potential is optimized to be subjected to repeated fracturing. The shale gas well re-fracturing well selection evaluation method can achieve a goal that the re-fracturing target well with the high yield-increasing potential can be quickly and reasonably optimized from hundreds of shale gas wells, so that the efficiency of single well repeated fracturing is improved, and the technical reference is provided for developing the shale gas reservoir reasonably and effectively.

The invention discloses a testing method of a substrate permeation rate of a repeated fracturing plugging agent. The testing method comprises the following steps: (a) preparing the repeated fracturing plugging agent for future use; (b) selecting a plurality of rock core samples for future use; (c) cutting a selected rock core and making an artificial crack; (d) paving one layer of particle substances on a crack surface and simulating a fracturing crack; (e) injecting the repeated fracturing plugging agent into the simulated fracturing crack and standing for a period of time; (f) injecting liquid, determining the permeation rate and calculating the plugging rate; and (g) cleaning sand in the rock core and then firmly sticking the rack to determine the substrate permeation rate. According to the testing method disclosed by the invention, the substrate permeation rate of the repeated fracturing plugging agent can be rapidly detected; and the testing process is simple, the tested result is accurate, and the testing method provides data support to the utilization of the repeated fracturing plugging agent.

The invention discloses an energizing re-fracturing process method for an old well. The energizing re-fracturing process method comprises the steps of: injecting nano-liquid into a formation with highdisplacement, and injecting pressure lower than the splitting pressure of the formation; injecting a temporary plugging agent into the formation to plug old cracks in the formation; injecting a fracturing fluid and a proppant into the formation to form a new crack network of the formation, and then carrying out repeated fracturing operations; closing the well after the repeated fracturing operations are completed, and opening the well for production after bottom hole pressure drops. By adopting the method, a large amount of nano liquid is firstly injected into the formation during repeated fracturing, then the original old cracks are plugged, the liquid return rate is reduced, the water storage rate of the formation is improved, then formation energy is supplemented, and the yield is increased.

The invention discloses a method for preparing a repeated fracturing blocking agent based on a selective gel breaker. The method comprises the following steps of: (a) preparing polyacrylamide; (b) dissolving the prepared polyacrylamide; (c) adding a pre-crosslinker into the solution; (d) adding a second crosslinker into the solution; (e) adding the gel breaker into the solution, wherein the gel breaker is ammonium persulfate; and (f) reacting the mixed solution in an incubator, and thus obtaining a target product. By adopting the method, the repeated fracturing blocking agent required by the conventional oilfields can be successfully prepared; the method is simple and facilitates artificial operation; various performance parameters of the prepared repeated fracturing blocking agent are superior to those of the conventional pressure blocking agent, and a foundation is laid for the exploitation of the oilfields; and by selecting the proper gel breaker, the gel breaking performance of the product is improved.

The invention relates to a yield-increasing potential evaluation method aiming at typical fracture failure wells in a hydraulic fracturing process in the field of petroleum engineering. Single wells are classified according to the single well control reservoir stratum coefficient; evaluation indexes of the fracture failure wells are built; and typical failure wells are selected. The single well control reserves are calculated by a volume method and a geologic model method; and the recovery percent of reserves of the current single well is calculated by combining current production data of thetypical failure wells. Finally, by referring to the final recovery rate of oil and gas fields, the yield-increasing potential factor of oil gas wells is defined, and the yield-increasing potential ofthe typical failure wells is quantitatively analyzed. The yield-increasing potential evaluation method has the advantages that the earlier-period fracture failure wells are finely selected; the yield-increasing potential of the typical fracture failure wells is accurately evaluated; the theory is reliable; the practical operability is high; guidance and suggestion are provided for the later-periodrepeated fracturing process; and the repeated fracturing risk is greatly reduced.

The invention relates to a volumetric fracturing process for repeated reconstruction of old wells, which is characterized in that it mainly includes the following steps: performing initial fracturing analysis, pre-fracture evaluation and well selection decision-making on the wells to be refractured with mining potential, and determining the Excavate potential wells to be refractured; screen fracturing fibers and particle temporary plugging agents: screen out stored and refractured fracturing fibers and temporary plugging agents according to reservoir temperature, pressure, water production rate, salinity, and fracturing fluid type Evaluate the static and dynamic performance of the selected fracturing fiber and particle temporary plugging agent, determine the final required fracturing fiber and particle temporary plugging agent; determine the construction parameters; fracturing construction: complete the transformation of the reservoir construction; Obtain a larger volume of reservoir stimulation, and maintain a high conductivity of the main fractures near the wellbore. A larger volume of reservoir stimulation can be obtained, and the main fractures near the wellbore can maintain a high conductivity.

The invention provides a method for production increasing through repeated transformation based on a complex crack network. Formation wax and inorganic scale are removed by means of the method that plug removal liquid is injected into a target layer section, then repeated fracturing construction is conducted in a support-free mode, the reservoir transforming volume is enlarged, formation energy isreplenished, fracturing liquid does not flow back after fracturing construction is completed, and by shutting in a well for pressure enlarging, old-well production increasing is achieved. According to the method for production increasing through repeated transformation based on the complex crack network, firstly, by adopting the large-displacement, low-frictional-resistance-slickwater, and support-free modes, repeated fracturing construction is conducted, based on the original complex crack network, the reservoir transforming volume is further enlarged, and the stratum energy is replenished;and secondly, by shutting in the well, under the pressure effect of capillarity tubes, low-frictional-resistance slickwater and remaining oil in medium and small pore throats or matrixes are subjectedto dialysis replacement, and thus the oil well yield and the final recovery percent are increased.

The invention relates to an oil and gas well production increasing method. The method comprises the steps that firstly, mining is stopped, and the reason that the flow conductivity of old cracks is lowered is analyzed and determined; secondly, according to the reason obtained in the first step, a method for repairing the old cracks is selected; thirdly, construction parameters are determined according to the method selected in the second step, and the flow conductivity of the old cracks is recovered; and fourthly, an oil and gas well continues to be mined, specifically, the old cracks are supporting cracks formed after fracturing of the first time. According to the method provided by the invention, the cost is low, operation is easy, the flow conductivity of the old cracks formed through fracturing of the first time can be recovered to a great extent without repeated fracturing, and accordingly the yield is increased.

The invention discloses a method for testing matrix damage rate applied to a plugging agent. The method comprises the steps of: (a) preparing a repeated fracturing blocking agent and selecting a plurality of cores for later use; (b) respectively splitting the selected cores, and manufacturing an artificial fracture; (c) paving a layer of particulate matter inside a fracture, and simulating a fracturing fracture; (d) injecting the repeated fracturing blocking agent into an analogue fracturing fracture to stew for a period of time; (e) cleaning sand in each core after injecting the liquid, firmly bonding the fracture and determining the matrix permeability, and (f) obtaining the matrix damage rate through the measured matrix permeability. The matrix damage rate of the repeated fracturing blocking agent can be rapidly tested by the method; the method is simple in test process and accurate in test result, and the data support is provided for use of the repeated fracturing blocking agent.

The invention discloses a computer intelligent diagnosis system for hereditary bone diseases, namely osteogenesis imperfecta, which cause repeated fracture and severe harm. According to early researchon clinical phenotype and pathogenic gene mutation of a large sample patient, the computer intelligent diagnosis system comprising a data acquisition module, a feature extraction module, a data processing and diagnosis module and a data output module is established; the data acquisition module comprises a medical record information unit, a medical image information unit and an experimental examination information unit; and the feature extraction module comprises a text extraction unit, an image extraction unit and a gene extraction unit. The invention also discloses a construction method of the osteogenesis imperfecta risk assessment model and the osteogenesis imperfecta risk assessment model, and the computer intelligent diagnosis system is helpful for improving the diagnosis level of diseases and promoting the early effective prevention and treatment of the diseases.

The invention discloses an evaluation method for low permeability heterogeneous oil reservoir horizontal well repeated fracturing yield increasing potential. The evaluation method sequentially comprises the following steps that (1), a crack expansion model is built by utilizing Meyer software, and inversion of first-time fracturing hydraulic crack parameters is conducted; (2), an oil reservoir heterogeneous geological model is built by utilizing oil reservoir numerical value simulation software Eclipse, the first-time fracturing hydraulic crack parameters are planted into the heterogeneous geological model to conduct production dynamic history fitting, and remaining oil saturation field and stratum pressure field distribution is obtained; and (3), quantitative evaluation is conducted on the horizontal well repeated fracturing yield increasing potential according to the remaining oil saturation field and stratum pressure field distribution, first-time fracturing hydraulic cracks are classified, and pertinence repeated fracturing modes are proposed. The problems of the stress sensitivity phenomenon and poor pertinence of the repeated fracturing modes and the like existing in evaluation of the low permeability heterogeneous oil reservoir horizontal well repeated fracturing yield increasing potential are effectively solved, the effect of repeated fracturing transformation is improved, the risk of engineering construction is reduced, and the evaluation method has wide market application prospects.

The invention discloses a fracturing technique for achieving a complex crack through multiple particle class differential temporary blocking, which is fracturing technique that a primary artificial crack is temporarily blocked through rigid temporary plugging agent composition with particle size class differential carried by a fracturing fluid, net pressure in the crack is improved, and a new sidecrack is opened. The fracturing technique comprises the steps that the rigid temporary blocking agent carried by a biodegradable polylactic acid resin-like fiber fracturing fluid with four kinds of particle size class differential combination is fast injected according to the sand mulling concentration of 350-500-650g / cm3, and crack deep part temporary blocking is carried out; the net pressure inthe crack is improved, and the side natural crack is opened, and side remaining oil is effective used; and the oil well single well production and final recovery ratio are improved. The fracturing technique has the advantages that the operability of the construction technique is high, a complex fracture system is fractured to be formed, the using degree of the oil well side remaining oil is improved, the cost is low, and the oilfield development benefit is greatly improved, and solves the difficult problem of the poor repeated fracturing effect of low-permeability reservoirs.

The invention discloses a repairing method of a badminton racket frame, and belongs to the technical field of repairing of rackets. Specifically, the repairing method comprises the following steps: S1, cleaning internal filler in fractures of the racket frame, and implementing fracture surface and inner wall grinding; S2, mixing a steel bar planted adhesive; S3, making a pre-filling carbon fiber sheet provided with middle holes, and placing the pre-filling carbon fiber sheet on a tool cone; S4, winding a carbon fiber bundle on the surface of the carbon fiber sheet, and sticking the carbon fiber bundle with the steel bar planted adhesive, so that the carbon fiber filler (the carbon fiber sheet), which is wound, adapts to a to-be-filled space; S5, applying adhesives to the inner wall and fracture surface of the cleaned racket frame, filling the racket frame with the carbon fiber filler which is prepared in the step S4, and perforating the carbon fiber filler in the locations of two sideholes of the fracture after curing and binding; and S6, pulling out the tool cone, and inserting a wire inserting pipe for conducting threading. According to the repairing method provided by the invention, by filling the fracture of the racket frame in a mode of winding the carbon fiber bundles outside the carbon fiber sheets and by perforating the middle holes in the carbon fiber sheet, the repaired badminton racket frame is firm and high in intensity, and repeated fracture, which can occur easily, can be prevented.