143results about How to "Improve recovery" patented technology

A device is provided, in direct skin contact, surrounding an injured area for the light and heat treatment, reduction of joint inflammation, edema and excitation of neural and muscular stimulation associated with human and mammal tissues. This therapeutic light and heat source includes multiple tiers or layers, e.g., three or four layers and a multiplicity of light emitting diodes (LED's) found in the ranges of 250 nm to 20,000 nm and fiber optic connections. A neoprene type material or other non-allergenic material will be used to set the LED's and fiber optics in layers consisting of contact with the skin to a few centimeters from the skin tissue. (Distance between the layers of LED's will vary from contact or near contact with devices to several millimeters of separation.) Each LED array will be independently controlled allowing for optimal modulation of light frequencies and wavelengths. Technology will be integrated allowing for biomedical feedback of tissue temperature, biochemical changes in tissue and other statistical information. A low voltage, portable power supply, will be integrated into the device as well as an analog / digital, input / output connection device. The design will be created for continuous wear, flexibility and comfort. The tiers or layers can be individually programmed to turn “on” or “off” as required by the physiologic condition to be treated. A device for light and heat treatment is contemplated using polarized film or a light guide accepting white light.

The disclosure relates to the process of enhanced recovery from injury or body fatigue due to strenuous activity or strenuous conditions using a contemplated apparatus. Generally the apparatuses disclosed utilize two or more physiological properties and / or body interfaces selected from 1) thermoregulation enhancer via cooling or heating sources; 2) blood flow viscosity enhancer via electromagnetic forces; 3) a circulatory pull by creating a negative pressure or vacuum environment which draws more blood to the treatment area; 4) muscle release apparatus via pressure point applicators and / or electric stimulation devices, which enhance the bodies natural abilities to recover from stress, fatigue or injury; and 5) a fatigue stimulator may be utilized to accelerate the amount of inflammation, stress, and / or fatigue applied to an area of the body via a restrictive cuff which prevent the body from constantly experiencing enhanced recovery techniques and depriving the body of natural adaptation.

The invention relates to a gas-assisted SAGD method for exploiting super heavy oil; the selecting layer thickness is 530m, remaining oil saturation is more than 0.50, oil layer thickness is more than 10.0m, horizontal permeability is more than 250md, the ratio of the vertical permeability to the horizontal permeability is more than 0.1, the oil layer porosity is more than 0.20, continuous distributed impermeable clay and intercalated shale oil pools do not exist in the oil layer; a horizontal well is drilled between soaking vertical wells, the well spacing is 35m or a pair of horizontal wells are drilled at the bottom of the oil layer, the vertical distance is 6m; swallowing is carried out for 3 stages, when the hot communication is formed between the wells, the vertical wells is used to inject steam continuously, the production of horizontal wells is 3 years, then the vertical wells is used to inject nitrogen and steam until the underground volume ratio is 0.5 and the total injection rate of nitrogen is 0.10PV, then the steam is injected continuously, the steam injection rate is 1.4m / d.ha.m, the dryness of steam at the bottom of wells is 70%, the production-injection ratio is maintained at 1.2; the recovery percent is increased by 6.0-9.0% and the oil-steam ratio is improved by 0.02-0.05.

A system and method for performing modeling, prediction, optimization and control, which would permit what is, described herein as embedded alarm control. In the proposed method of embedding alarm control, the alarm limits are used to constrain the controlled variables dynamically such that the controller actions are affected to minimize and prevent alarm limit violations in addition to the constraints commonly included. It is proposed in the present invention that the alarm limits be incorporated as part of optimization and constrained control action calculation in a model predictive control. As an exemplary case, this method of incorporation of alarm limits within optimization and control is described and the results obtained from it are presented.The embedding of alarm control within optimization and control would not only directly minimize number of alarms from becoming active from improved control but also provide additional capabilities whereby selectively alarms limits violations can be tuned to reduce the number of alarms without compromising on either product quality control or safety violations.

The invention relates to a hyposmosis oil pool microbial oil recovery method, comprising the following steps: (1) fracturing production is carried out to the hyposmosis oil pool; (2) microbes and nutrients are filled in an oil layer from cracks formed by fracturing to carry out microbial oil recovery. Compared with the prior art, the oil pool fracturing and the microbial oil recovery are combined together, so as to increase the action range of the microbes in the hyposmosis oil pool on one hand, on the other hand, the metabolic action of the microbes is helpful to keeping seeping channels to be open at the fracturing position, thereby promoting stable output of oil wells and prolonging steady yield time of oil fields; therefore, the invention is a scientific, economic and effective hyposmosis oil pool microbial oil recovery method.

The invention relates to a later-period air injection exploitation method for super heavy oil reservoir using steam assisted gravity drainage (SAGD) exploitation. The method comprises the following steps of: newly drilling a straight well as an air injection well at a position where a steam cavity of the super heavy oil reservoir develops poorly; perforating on the upper part of the air injection well to complement a perforation section with the length of 2-3m; continuously injecting air by the air injection well at the speed of 20,000-80,000m<3> / day and firing to exploit; and stopping injecting the air when the volume percentage of the oxygen in the produced gas reaches 3 percent or the volume ratio of the volume of the injected air and the volume of the produced crude oil reaches over 3,000m<3> / m<3>. With the adoption of the method, the later-period heat loss is reduced by using the SAGD technology, and the stable production of the whole system is maintained by utilizing heat energy released by reacting substances in the oil reservoir.

The present invention involves a method and apparatus for enhanced recovery of petroleum fluids from the subsurface by injecting a hydrocarbon solvent vapor in contact with the oil sand formation and the heavy oil and bitumen in situ. Multiple propped vertical hydraulic fractures are constructed from the well bore into the oil sand formation. The hydrocarbon solvent vapor and a non-condensing diluent gas are injected into the well bore, fill the hydraulic fractures, and thus contact and diffuse into the in situ bitumen. The hydrocarbon solvent vapors diffuse into the bitumen from the vertical faces of the propped fractures. The bitumen softens and flows by gravity to the well bore, exposing fresh surface of bitumen for the process to progressively soften and mobilizes the bitumen in a predominantly circumferentially, i.e. orthogonal to the propped fracture, diffusion direction at a nearly uniform rate into the oil sand deposit. The mobile oil may be deasphalted by the condensed solvent, leaving the heavy asphaltenes behind in the oil sand pore space with little loss of inherent fluid mobility in the processed oil sands. The processed product is produced with the dissolved solvent along with a tail diluent gas. The tail diluent gas is enriched with hydrocarbon solvent and re-injected into the process zone and the cycle repeated.

The invention discloses handling method and device for a double-medium stacked supporting and hard top plate type mined-out area, and aims at solving the construction problem that the hard top plate of a thick coal mine seam is difficultly fallen. The method is that a base stack body fills in the mined-out area after the mining at the working face; the base stack body and the top plate are subjected to flexible roof contact by filling chemical materials; the spacing and arrangement distance of the filled stacks are influenced by the mining depth, height and lithology of the top plate and other factors, wherein the arrangement distance is 15 to 30m, and the spacing is 8 to 15m; the section of the filled stack can be circular, rectangular or quadrate; the effective section area is 0.8 to 1m<2>; the flexible roof contact medium is 1 / 10 to 1 / 8 of the mining height; the base stack can be filled by grouting concrete or gravels and other materials. The method and device are particularly suitable for continuous mining of shallow buried thin coal seam layers; the design that the working surface is frequently moved while supporting the mined-out area through tool posts is replaced, or the complex processes of softening the top plate by filling water and blasting and pre-cracking are decreased.

The invention discloses an energy increase type foam drainage gas recovery process. Firstly, a reagent A is fed into accumulated liquid in a gas well, then a reagent B is fed into the accumulated liquid in the gas well, wherein the reagent A comprises sodium nitrite A1 and ammonium chloride A2, and the reagent B comprises a catalyst and a foaming agent. According to the invention, by injecting the chemical agents in the well in batches and through different channels, chemical agents are in chemical reaction in the well to generate lots of gases and foam, under the action of gases generated by chemical reaction, foam moves upwards to drain accumulated liquid in a wellbore, and thus a conventional foam drainage gas recovery process is expanded to peripheral wells and flooded out wells with extremely low yields, and the recovery percent of the gas well is increased further.

The invention provides an experimental device and method for simulating gas reservoir water invasion. The experimental device comprises a gas supply device for inputting gas into a man-made rock core model, a liquid supply device for inputting liquid into the man-made rock core model, wherein the man-made rock core model comprises a body provided with a first end and a second end which turn their backs to each other, a first pipeline is arranged at the first end, and a second pipeline is arranged at the second end. A simulated fracture cave communicated with the second pipeline and the first pipeline is formed in the outer wall of the body. A first valve is arranged on a connecting pipeline between the gas supply device and the first pipeline. A second valve is arranged between the liquid supply device and the first pipeline. A third valve is arranged on the first pipeline, a first detecting part is used for detecting the pressure in the first pipeline, and a control device is used for controlling the first valve, the second valve and the third valve based on the first detecting part. The purpose of providing the experimental device capable of understanding distribution characteristics of residual gas after water invasion and simulating gas reservoir water invasion is achieved.

The invention provides a heavy oil reservoir cold recovery method adopting carbon dioxide energy storage and high pressure viscosity reduction. The heavy oil reservoir cold recovery method comprises the steps that carbon dioxide is injected into a heavy oil reservoir to accumulate energy for a stratum and initial viscosity reduction is carried out to crude oil; and a high-efficiency cold-recoveryviscosity-reducing agent is used to achieve further viscosity reduction of heavy oil in a carbon dioxide low-temperature effect environment, interfacial tension is reduced, colloids and asphaltene precipitated from the heavy oil are dissolved, thus mobility of underground heavy oil is improved, driving power of the crude oil is increased, and the degree of exploitation of the heavy oil reservoir is improved. According to the heavy oil reservoir cold recovery method adopting carbon dioxide energy storage and high pressure viscosity reduction, the improvement of the reservoir energy of heavy oilreservoirs and the improvement of the flowability of underground crude oil are realized, and the cold damage effect caused by the precipitation of the colloids and the asphaltene by the low-temperature effect during the heavy oil cold recovery process is reduced, thereby greatly improving the degree of reserve utilization of the heavy oil reservoirs.

The invention provides a CO2-injection asynchronous-throughput energy supplement method of ultralow-permeability compact oil reservoir horizontal wells. The method comprises that a horizontal well rowis arranged along the direction of the maximal principle stress, at least one local well and two adjacent wells are laid, and the reservoir stratum reconstruction by fracturing is carried out on thehorizontal wells; and a scheme that throughput of one well is asynchronous with that of the adjacent well but synchronous with that of the other well adjacent to the adjacent well is used, and the whole throughput period includes gas injection, soaking and oil extraction. CO2 can reduce the tension in a crude oil interface, the volume of crude oil is expanded, the density and viscosity of the crude oil are reduced, light components in the crude oil are extracted, and the permeability of regions near the wells are improved; stratum energy is supplemented, the problems that water injection exploitation of an unconventional stratum is low in spreading efficiency, easy to water channeling and hard to improve the final recovery efficiency are solved, and high and stable yield of an oil field isensured; and the asynchronous throughput method can alleviate the gas bypassing phenomenon of the local well, gas bypassing characteristic of the adjacent wells is used for displacement, and the total recovery degree is imporved.

The invention discloses an advanced treatment device for vitamin C production waste water and an application method thereof. The advanced treatment device for the vitamin C production waste comprises an anaerobic biofilter and is characterized by also comprising a coagulation and sedimentation system, a preoxidation system, an A / O biochemical system, a secondary sedimentation system and a disinfection system, wherein the outlet of the vitamin C production waste water is connected with the coagulation and sedimentation system; a water outlet of the coagulation and sedimentation system is connected with the preoxidation system through a pump; a water outlet of the preoxidation system is connected with the A / O biochemical system; a water outlet of the A / O biochemical system is connected with the secondary sedimentation system; a water outlet of the secondary sedimentation system is connected with the disinfection system; and a water outlet of the disinfection system is connected with the anaerobic biofilter. The combined process is effective and reasonable in treatment on vitamin pharmacy waste water; under the conditions of normal water quality and full-load water quality, the process has the obvious effect of removing the pollution items, such as chemical oxygen demand (COD), biochemical oxygen demand 5 (BOD5), NH3-N, TN, TP, chromaticity and the like, in the vitamin pharmacy waste water and the items can reach the standard stably; and under the condition of low temperature, the process has high impact resistance.

A method for improving oil recovery by using foam flooding assisting nitrogen soaking in a fault block oil reservoir comprises the steps that a developed reservoir is selected; injection well preformed foam injection is performed; production well nitrogen injection is performed; shut-in well oil-gas gravity differentiation is performed; and a production well is opened for production. By the adoption of the method, the property that the foam blocks the large and does not block small and blocks water and does not block oil is used, that is, the property that under the general condition, the foamhas the tendency to block pore passages with the larger permeability and pore passages with the higher oil saturation in the stratum is used, the swept volume of the foam near an injection well is expanded, and the problem of less movable oil in the late stage of huff and puff of the production well is alleviated to a certain degree. By the adoption of the method, the vertical fluctuation of thenitrogen can be strengthened when the nitrogen is injected into the production well, the longitudinal action radius of the nitrogen huff and puff can be expanded, and meanwhile the problem that the foam flooding is difficult to be effective near the production well is effectively alleviated due to the effect introduction during the huff and puff processes; and the foam flooding assisting can improve the effective cycle of nitrogen huff and puff, the recovery of nitrogen huff and puff is enhanced, and the development of fault block reservoirs is further improved.

The invention provides pharmaceutical compositions comprising TGF-β superfamily members and sugars, the compositions allowing improved recovery and / or increased biological activity of the TGF-β superfamily member incorporated therein. The invention also relates to uses of sugars to improve the recovery or increase the biological activity of TGF-β superfamily members in a pharmaceutical composition. Uses of the pharmaceutical compositions are also described, particularly with reference to wound healing and fibrosis. Furthermore, the invention discloses medicaments for the prevention or reduction of injection pain.

The invention discloses an auxiliary device used for health and medical rehabilitation, comprising a base with a cavity inside and a brace with a cavity inside, wherein a seat is arranged at the rightend of the top of the base, cylinders are arranged from left to right at the right end of the base vertically upwards, a piston rod at the top of the cylinder vertically runs through the top wall ofthe base and is vertically and fixedly connected with the bottom of the base, and the brace is in inverted L shape. According to the invention, by horizontally arranging a cross rod at the left end inthe base, arranging rubber spheres at the top of the right end of the cross rod, arranging a plurality of message semispheres at the top of a pedal, and arranging a feet exercising device on the basebetween the brace and the seat, when a patient performs arm exercise, the rubber spheres can be driven by the cross rod to perform extrusion vibration on the feet exercising device by gravity extrusion of a counter weight frame to a pressed plate, so as to drive the message semispheres to perform vibration extrusion on the feet of the patient to message the acupuncture points, and therefore, patient rehabilitation effect and progress are increased, and the auxiliary device is relatively practical and suitable for wide popularization and application.

The invention provides a perforating and fracturing method with an effect of increasing modification degree of a tight oil horizontal well. The method comprises steps as follows: the perforating position of each section is selected, perforating is performed on each section for N clusters, and length of a perforating section of each cluster and the number of perforations are optimized; a drift sizegauge tool is adopted to perform drifting to reach artificial well bottom of an operating well; a first section of the horizontal well is subjected to multi-cluster perforating, and fracturing construction is performed with a multi-cluster fracturing technology; first-stage prepad fluid and sand-carrying fluid are pumped, the number of effectively fractured perforated clusters at the well bottomis judged according to the characteristic of wellhead pressure, if part of the clusters are not fractured, degradable resin is pumped by the fracturing fluid, a temporary plugging effect is judged according to the pressure characteristic of the degradable resin entering a crack seam, and a corresponding measure is adopted; a bridge plug and a perforating tool are hydraulically pumped, and packingof an operated well section and perforating of a to-be-operated well section are realized; all sections of the operation well are fractured finally. According to the method, effectiveness of multi-cluster crack seams in the sections can be effectively improved, production and recovery percent per well are increased, and the method has broad application prospect in the aspect of yield increase andstabilization of an unconventional oil-gas horizontal well.

A method is disclosed that by correlating the network fault management, circuit provisioning data and cable inventory data, it can identify the most critical network elements that can be fixed in order to restore the services quickly in a network outage that involves high number of collapsed rings. This method can also be used for proactive network maintenance, to avoid chokepoints when provisioning circuits for mission critical facilities.

A spinal implant structure includes a hollow cylinder and a biodegradable polymer membrane. The hollow cylinder is implanted in a bone damaged part of human vertebra. The biodegradable polymer membrane is formed to a part of a surface of the hollow cylinder. Thus, the biodegradable polymer membrane blocks invasion of soft tissues, and then the bone fillers integrated with vertebra are maintained without loss.

There is provided a dielectric ceramic composition having a high relative permittivity, a high frequency-quality factor, a small absolute value temperature coefficient, a low sintering temperature, and unreactivity with an internal conductor material. The dielectric ceramic composition comprises a main component represented by general formula xZnOxNlb2O5yCaTiO3zCaO, wherein 37≦x≦50, 10≦y≦60, 3≦z≦40, and x+y+z=100, and a boron (B) oxide as an accessory component in an amount of 0.3 to 3.0 parts by weight in terms of B2O3 based on the main component.

The invention provides a hot exploitation method for exploiting gas-cap super-heavy oil reservoirs; the method comprises the steps of screening out an oil reservoir, deploying a well network, carrying out steam huff-puff, and combusting an oil layer and injecting air. According to the hot exploitation method for exploiting gas-cap super-heavy oil reservoirs, the techniques such as SAGD (steam-assisted gravity drainage), in-situ combustion of oil and gas-assisted SAGD are effectively combined and used in gas-cap heavy oil reservoirs, and low-cost high-benefit exploitation is achieved. The method has the advantages that steam usage can be reduced, crude oil quality can be improved, a gas drainage passage can be enlarged, crude oil can also be pressurized into a horizontal production well through gas-cap expansion, accelerated oil drainage and reduced production cost are achieved, and good economic benefit is provided.

A method, device and system for correcting errors in a group of received packets having a redundant packet. The method includes determining an inconsistent bit indicator for a bit position of the packets, determining a bit reliability indicator indicative of a potential bit error location in at least one packet, calculating a number of potential bit error locations for the bit position and identifying a correctable bit location accordingly. A method, device and system for correcting an error in a received packet. The method is adapted to calculate a checksum value of the received packet, verify if the checksum value is indicative of at least one bit error in the received packet, identify a predefined Checksum Pattern Type (CPT) according to the checksum value and determine at least one bit error event (BEE) accordingly. A method, device and system for decoding a plurality of received fountain encoded symbols.

The invention relates to a surfactant for changing surface wettability of compact sandstone as well as a preparation method and an application of the surfactant. An oil phase solution is added to a water phase solution, and a dispersed and uniform phase is realized after 1-2 h under the action of an emulsifier. An initiator is added, the mixture is stirred and heated to 60-75 DEG C and reacts at the temperature for 12-18 h, and a colorless and clear liquid, namely, a high-molecular polymer, is prepared. A fluorocarbon surfactant and a biosurfactant are added at the room temperature, the mixture is stirred continuously for 4 h, and the surfactant for changing surface wettability of the compact sandstone is obtained. By the aid of the surfactant, the oil-water interface tension can be reduced, an oil wetted surface can be changed into a water wetted surface, the adhesion of oil drops on sandstone surfaces can be reduced, the flowability of crude oil in an original stratum can be improved, and the recovery percent of low-permeability oil reservoirs can be increased.

A traditional Chinese medicine (TCM) pillow core capable of treating cervical spondylosis and lumbar spondylosis is prepared by the following raw material: ligusticum chuanxiong, carthamus tinctorius, Chinese Angelica, kudzuvine root, salvia miltiorrhiza, lycopodium clavatum, oriental wormwood, tartary buckwheat, chrysanthemum, aspidistra lurida, corn stigma and borneol. The preparation method of the TCM pillow core includes the following steps: the ligusticum chuanxiong, the carthamus tinctorius, the Chinese Angelica, the kudzuvine root, the salvia miltiorrhiza, the lycopodium clavatum, the oriental wormwood, the tartary buckwheat, the chrysanthemum, the corn stigma and the borneol are processed to be medicinal slices, and the medical slices are used as filler after being mixed; and after the aspidistra lurida is wrapped by the corn stigma, the aspidistra lurida is shaped to be a round block which is arranged on the right central position inside the pillow core, and then the TCM pillow core is made. The TCM pillow core capable of treating the cervical spondylosis and the lumbar spondylosis has the functions of activating blood and dissolving stasis, clearing and activating the channels and collaterals, and removing inflammation and relieving pain due to the fact that medicine directly permeates to local parts, and has a continuous traction effect on the cervical vertebra and the lumbar vertebra due to physical effects, and therefore various clinical symptoms are enabled to disappear or decrease. The invention further provides the preparation method of the TCM pillow core, and the method is simple in process and low in preparation cost.

The invention relates to a cyclical method for producing a nitrogen fraction, the purity of which is greater than or equal to 95 mol %, and a hydrocarbon-enriched fraction from a filler containing nitrogen and a hydrocarbon, said method using a specific class of porous hybrid solids as an adsorbent in a pressure-swing adsorption (PSA) process. The invention also relates to equipment for implementing said method.

The invention provides a gas-bearing coal seams U-shaped well drilling and exploiting method, and the method comprises the steps of (1) drilling the straight well of the U-shaped well and conducting cavern completion; (2) drilling the straight well segment of the horizontal well; (3) drilling the horizontal segment of the horizontal well; and (4) perforating and fracturing the horizontal well so as to communicate a multilayer object layer of the gas-bearing coal seams. According to the invention, a non-target reservoir is deflected and the horizontal segment is drilled, like a sandstone or a limestone; a borehole is prevented from collapsing, block is prevented from falling off and the well is prevented from leaking when a target reservoir of gas-bearing coal seams is drilled; drilling efficiency is raised; drilling fluid is prevented from soaking the reservoir of the gas-bearing coal seams for a long time, particularly the coalbed gas layer and the shale gas layer; damage of particles in solid phase and drilling cuttings in the drilling fluid to the reservoir of the gas-bearing coal seams is effectively reduced; by communication between the horizontal segment of U-shaped well and the reservoir of the gas-bearing coal seams by pressing crack in a large scope, exploitation swept area and deflation area are increased; multilayer commingled production of the gas-bearing coal seams is realized; the utilization rate of the gas-bearing coal seams is raised; area well drilling quantity and total cost of well drilling are reduced; and the yield of a single well, exploitation degree and economic benefit are greatly increased.

A class of non-sulfide, silicate gangue material depressants based on naturally-occurring galactomannans, having a galactose-to-mannose ratio of less than 1:2.1, exemplified by modified products of the seed gums: casia tora gum, sesbania gum, kalonji gum, Ceratonia siliqua gum and / or Tamarindus indica gum, and methods of making and using them.

The invention provides an exploitation method and an injection system for an oil reservoir of super heavy oil. The exploitation method includes that steps that an injection-production pattern is deployed; solvent and superheated steam are injected into an injection well simultaneously; after a steam chamber extends to the top of an oil layer, the solvent, non-condensate gas and the superheated steam are injected into the injection well simultaneously, when the solvent and the superheated steam are injected into a well simultaneously, a producing well extracts oil continuously until the production is finished. The injection system comprises hydrogen donor visbreaking in-place modification equipment, a superheated steam injection device and associated gas separation recovery equipment, which are connected with the injection well respectively; the superheated steam injection device comprises a sewage treatment station, membrane treatment equipment, an MVC water treatment station and a drum boiler, wherein the sewage treatment station, the membrane treatment equipment and the drum boiler are communicated with one another in sequence, and the MVC water treatment station is communicated with the membrane treatment equipment and the drum boiler. The exploitation method and the injection system for the super heavy oil reservoir can reduce heat losses, and the exploitation effect and the economic benefit of the super heavy oil reservoir are greatly improved.

The invention provides an experiment table and an experiment method for identifying a coal-gangue dynamic state. The experiment table is composed of a steel tabletop, a detector, a funnel, a flat plate cart, a blanking box, a lift, a motor, table legs, a base, a baffle and a hinge. The experiment method comprises the following steps that: a coal-gangue mixture is contained in the funnel and an inclined angle is adjusted by the lift; the detector is mounted on the flat plate cart; the detector and the blanking box are placed and the distance between the detector and a coal feed port of the experiment table is adjusted; then the baffle is pulled out in the lateral direction and the coal-gangue mixture in the funnel flows out and drops into the blanking box, so as to simulate a coal caving process of a top coal caving hydraulic bracket and measure the mixing degree of caved coal and gangues. According to the experiment table and the experiment method provided by the invention, when the coal-gangue mixture falls off, relative data is acquired by the detector; processing and experimental simulation for the data are used for determining a reasonable coal caving height and the inclined angle of a tail beam of the top coal caving hydraulic bracket, so as to reduce the gangue content of the caved top coal and improve the recovery coefficient; the experiment table and the experiment method provided by the invention have guidance meanings on optimization of field top coal caving technological parameters.