47results about How to "Avoid Downhole Accidents" patented technology

The invention discloses a deep hole pre-grouting top plate reinforcement method for a large-mining height working face under special geological conditions. By the method, the phenomenon that local inbreak accidents of a top plate of the large-mining height working face are easy to cause due to the special geological conditions can be avoided, and the problems of poor effect of the conventional cement grout advanced reinforcement of the special geological conditions and high cost of high-polymer shallow part grouting can be solved. The method comprises the following steps of: distributing three lines of drilled holes on a laneway's side from top to bottom in a crossed shape, adjusting the angles of all the drilled holes, and controlling the positions of end holes, so that the effect of multi-point multi-face effective distance reinforcement can be achieved; after each drilled hole is opened, inserting a 108 sleeve pipe into the drilled hole, and solidifying by using grout; when each hole is drilled forward 5 meters, grouting once; after initial setting, cleaning, and drilling the next section continuously, wherein during construction, a short circle is finished after the drilling depth reaches 5 meters; and after solidification, cleaning and continuously drilling until the hole depth reaches the designed depth. The method has the advantages of good reinforcement effect, reasonable parameter, simplicity in construction, low cost and safety and reliability, and is particularly suitable for reinforcing the large-mining height working face under the special geological conditions.

The invention provides a curable low-density leaking stoppage working fluid and a preparation method. The curable low-density leaking stoppage working fluid is prepared from, by weight, 100 parts of G-grade oil well cement, 44-60 parts of slag, 23-67 parts of lightening admixture, 8-12 parts of micro silicon, 0.4-1.2 parts of dispersant, 4-5 parts of fluid loss agent, 0.4 part of retarder, 1 part of fiber, 131-214 parts of water and 0.5 part of foaming agent. The density of the curable low-density leaking stoppage working fluid is 1.20-1.50 g / cm<3>, the curable low-density leaking stoppage working fluid is high in early strength and thixotropy, free of free water and good in system stability, and the technical problem that a curing body cannot be formed due to bridge plug leaking stoppage in a conventional leaking stoppage method and the cement leaking stoppage cutting body difficultly stays at a leaking layer is solved. After leaking stoppage is carried out, the formation pressure bearing capacity at the leaking layer can be improved, and the technical defects of the existing conventional leaking stoppage method are overcome.

The invention provides a hydrate / ice-containing low-temperature stratum well cementation simulation experiment reaction kettle which comprises a kettle barrel, a kettle cover, a bracket, a data processing system, a gas / liquid pressurized injection system and a cement paste injection system, wherein the inner cavity of the kettle barrel is divided into a sound wave detection cavity, a cement paste cavity and a simulated stratum cavity which are coaxial with one another through a first cavity wall and a sieving pipe which are arranged in sequence from inside to outside; a second cavity wall is inserted into the sieving pipe; a first liquid discharging opening is formed in the bottom of the cement paste cavity; a gas inlet and a second liquid discharging opening are formed in the bottom of the simulated stratum cavity; the kettle cover comprises a first circular kettle cover, a second annular kettle cover and a third annular kettle cover which are respectively matched with the tops of the sound wave detection cavity, the cement paste cavity and the simulated stratum cavity; the gas / liquid pressurized injection system is connected with an inlet in the bottom of the simulated stratum cavity; the cement paste injection system is connected with an inlet in the top of the cement paste cavity; the data processing system comprises a data detection device, a data receiving processing device and a computer image processor. The hydrate / ice-containing low-temperature stratum well cementation simulation experiment reaction kettle is simple in structure, reliable in operation and low in cost.

The invention specifically relates to an additive composition applicable to viscosity reduction of an oil-based drilling fluid and application thereof, and the oil-based drilling fluid and application thereof. The additive composition is a double block copolymer which is composed of a block A and a block B, wherein the block A is composed of a constitutional unit as shown in a formula (1) which is described in the specification and has a number-average molecular weight of 1500 to 10000, and the block B is composed of a constitutional unit as shown in a formula (2) which is described in the specification. The double block copolymer can be used as a viscosity reducer for the oil-based drilling fluid, especially as a viscosity reducer for a high-density clay-free oil-based drilling fluid; and the double block copolymer can greatly reduce the apparent viscosity and plastic viscosity of the oil-based drilling fluid in high-temperature high-pressure strata while guaranteeing proper shearing force, so drilling speed can be conveniently accelerated and difficulty in well drilling can be reduced.

The invention discloses a metal mine downhole microseismic monitoring system which comprises at least one downhole network multi-channel collector arranged in a roadway of a downhole monitored section. Every downhole network multi-channel collector comprises a plurality of difference input channels for analog signal collection, every difference input channel is respectively connected with a microseismic signal collecting device, every microseismic signal collecting device is fixedly distributed on downhole roadway side walls in different directions, and output ends of the downhole network multi-channel collectors are connected with a ground data receiving processing platform sequentially through a transmission local area network and a concentrator local area network. The metal mine downhole microseismic monitoring system has the advantages of performing microseismic real-time on-line monitoring and analysis, preventing downhole accidents, optimizing blasting and ore falling effect in the recovery process and mastering vibration conditions of surrounding device systems and the like and is suitable for being widely applied to the technical field of microseismic monitoring.

The invention relates to a multi-layer sleeve tube cutter. The cutter comprises an upper joint, a piston, a central pipe, a piston sleeve, a cutter seat body, a cutter, a lower central pipe and a lower joint, the upper joint, the piston sleeve, the cutter seat body and the lower joint are sequentially in threaded connection, the piston is in threaded connection with the central pipe, the piston isinstalled on the upper end part of the central pipe, the central pipe penetrates through the upper joint, the piston and the interior of the cutter seat body, an upper spring is arranged on the central pipe, one end of the upper spring is limited through the end face of the piston, the other end of the upper spring is limited through the end face of the cutter seat body, the lower central pipe isarranged in the cutter seat body, three long hole grooves are uniformly formed in the cutter seat body, cutting knives are arranged in the long hole grooves, the cutting knives are connected with thecutter seat body through pin shafts, cutting teeth are arranged on the cutting knives, liquid holes used for cleaning and cooling the cutting knives are formed in the lower central pipe, and a lowerspring is arranged on the lower central pipe. By means of the cutter, the cutting of multiple layers of sleeve tubes can be completed by one underground operation, the replacement of the cutter is notneeded, and the construction efficiency is improved.

The invention discloses fully dissolvable slips and belongs to the technical field of downhole tools, and is suitable for tool design needing deblocking anchoring structure such as a packer and a bridge plug. A preparation method of the fully dissolvable slips comprises coating a 0.5-1 mm thick nickel-based alloy thin layer which is high in wear resistance and coefficient of friction on a specially designed and processed water soluble magnesium aluminum alloy by means of a special process method. An application method of the fully dissolvable slips comprises the steps of matched with a slips cone and a slips back ring, in a tool sealing process, stretching the fully dissolvable slips uniformly and attaching the same to a bushing; and enabling the tool to be anchored to the bushing withoutmovement, and unblocking the tool automatically after the fully dissolvable slips is dissolved. Compared with conventional slips, the fully dissolvable slips does not damage the busing and is free ofimpurities in the bushing after being dissolved, so that follow-up construction is not affected and a construction flow is simplified.

The invention relates to an intelligent real-time early warning system for coal mine safety and belongs to the technical field of coal mine underground communication. The intelligent real-time early warning system is characterized in that a sensor group is installed in an underground roadway and is capable of collecting underground personnel behavior characteristics, underground environment characteristics, underground equipment operating state characteristics and mine disaster characteristics and transmitting the collected information to intelligent node equipment installed in the same roadway; the intelligent node equipment collects, analyzes, measures and credibly judges the received information, performs early warning on dangerous factors and sends alarm information to the undergroundroadway and a well surface control center; the well surface control center is a collective body for performing clustering, fusion and feature extraction on the received multiple types of data information, establishing a credible decision mechanism and loading and embedding decision methods into the intelligent node equipment; there are wired or wireless communication between the multi-source sensor group and the intelligence node equipment and between the intelligent node equipment and the well surface control center. The intelligent real-time early warning system has the advantages of timelycollection, analysis and judgment of various characteristic information in the mine roadway, real-time early warning of risk information factors, and effective prevention of coal mine accidents.

The invention discloses a rectorite saturated brine drilling fluid for drilling under a rock salt deep stratum and belongs to the technical field of drilling and oil exploitation. The drilling fluid is prepared from an auxiliary agent, NaCl and water according to a certain proportion, wherein the auxiliary agent at least comprises 1 to 8 percent of sodium base rectorite, 0.2 to 14 percent of main fluid loss agent, 0.1 to 5 percent of auxiliary fluid loss agent, 0.1 to 1 percent of coating agent, 1 to 5 percent of wall protective agent, 1 to 5 percent of lubricant, 0.1 to 0.5 percent of antifoaming agent and 0.1 to 0.5 percent of NaOH, wherein the NaCl is in a saturated state in the drilling fluid. The drilling fluid of the invention can still keep good rheological property, prop-carrying capacity and filtration property resistance at the highest temperature of 200 DEG C, can quickly and safely drill in a salt layer, guarantees the smooth drilling operation under the deep stratum salt layer and is particularly suitable for drilling under the rock salt deep stratum and extracting rock cores.

The invention discloses a self-rotating drillable reaming float shoe which comprises a shell body and a transmission structural part arranged in the lower end of the shell body in a sleeved manner. The transmission structural part is rotationally connected with the shell body, and a self-rotating guide head, the shell body, the transmission structural part and a rolling structural part are combined in a pairwise manner, so that a guide head which does not have the rotating function originally can freely rotate by 360 degrees, and the function that the tool automatically rotates to guide a casing pipe to be tripped in is achieved; by arranging a cutting and righting assembly, when a barrier is encountered in the casing pipe tripping-in process, cutting and reaming can be carried out on a necking-down well wall section by using a metal cutting block, the well diameter of the necking-down well wall section is enlarged to the normal size, and follow-up smooth casing pipe tripping-in is facilitated; and centralizing strips are used for centralizing the casing pipe, ensuring the local centrality of the casing pipe and improving the well cementation quality, the problems that an existing product is only suitable for a specific tripping-in tool and is small in application range are solved, the application range of the self-rotating drillable reaming float shoe is widened, and the self-rotating drillable reaming float shoe is not limited by the tripping-in tool.

The invention discloses a continuous natural gamma logging while drilling instrument and a logging method thereof. The continuous natural gamma logging while drilling instrument is mainly composed of four parts, i.e., a rock debris collector, a natural gamma sensor, an access integrated logging instrument and natural gamma signal acquisition software, wherein the rock debris collector is designed according to onsite well conditions and project design requirements and realizes rock debris quantitative continuous collection and automatic updating functions so as to enable the natural gamma sensor to perform continuous measurement on underground rock debris. According to the invention, real-time detection is performed through the natural gamma sensor, detection signals are input to the integrated logging instrument, lag depth correction and data acquisition processing are carried out, a real-time curve and real-time data can be output, a reference basis is provided for geological technical personnel in lithology identification, stratum comparison and horizon sticking work, and the exploration efficiency is improved.

The invention discloses a casing scraper. The casing scraper is characterized in that the middle of the inner side of an upper connector is fixedly connected with the upper end of the outer side of a body; the middle of the inner side of a lower connector is fixedly connected with the lower end of the outer side of the body; a radially retractable scraping pipe sleeves the body and is positioned between the upper connector and the lower connector, and scraping teeth are arranged on the scraping pipe; the scraping pipe comprises an upper connecting head, a lower connecting head and at least two elastic scraping sheets; the axially retractable elastic scraping sheets which are circumferentially distributed are arranged between the upper connecting head and the lower connecting head in a fixedly connected manner, and each elastic scraping sheet is in the shape of an arch with a high middle and two low sides. The casing scraper has the advantages that the casing scraper comprises a drop-proof connector, the upper portion of the casing scraper is mounted on the lower portion of the lower connector in a threaded manner when the casing scraper is used, a first lower connector with the casing scraper can idle when strings reversely rotate in repeated scraping and string tripping procedures, threaded connection between the first lower connector and the casing scraper can be prevented from being loosened, the casing scraper can be prevented from dropping in service procedures, and the problem of downhole accidents due to the fact that existing scrapers are released and fall into wells can be solved.

The invention relates to a jacket structure of a flame-retardant cable, comprising an inner jacket and an outer jacket; wherein, the outer jacket is sleeved on the outer surface of the inner jacket; the jacket structure has the advantages that the outer jacket can be connected with the outer surface of the inner jacket in a sliding manner, the outer jacket and the inner jacket are flame-retardant chlorinated polyethylene rubber jacket, flame-retardant chloroprene rubber jacket or flame-retardant chlorosulfonated polyethylene rubber jacket, and the flame-retardant chlorinated polyethylene rubber jacket adopts the flame-retardant chlorinated polyethylene rubber jacket with a oxygen index more than 35; the jacket structure of the flame-retardant cable has ingenious design and simple structure, effectively prevents that when using cables, too many mechanical damages are generated on cables so that cables are damaged completely, avoids the frequent happening of underground accidents and is applicable to the jacket structure of mine cables.

The invention relates to a marine drift diameter gauge type drill rod or oil pipe leakage flux detection device and method. The marine drift diameter gauge type drill rod or oil pipe leakage flux detection device is provided with a fishing head and a drift diameter gauge, wherein the drift diameter gauge comprises an excitation coil and a signal acquisition and emission device; the excitation coil is electrified by a lithium battery; the excitation coil is electrically connected to the signal acquisition and emission device; a permanent magnet is arranged between the fishing head and the drift diameter gauge; the magnetic field of the permanent magnet is contrary to the magnetic field of the excitation coil; and the signal acquisition and emission device comprises a leakage flux sensor, an amplification filtering circuit, an A / D (Analog to Digital) conversion circuit, a coder and an electromagnetic wave emitter and is used for acquiring and transmitting flaw signals. The marine drift diameter gauge type drill rod or oil pipe leakage flux detection device has the beneficial effects that the online detection of an oil pipe or a drill rod is realized, the flawed drill rod or the flawed oil pipe is timely rejected; the additional operation cost resulting from drilling troubles caused by descending a well is avoided; and the drill rod or the oil pipe does not need to be transported to the land for detection.

The invention provides a cuttings bed recognition system. The system comprises a cuttings bed recognition device, a signal transmission device, a signal decoding recognition device and a display device. The cuttings bed recognition device is arranged on a drill column and used for collecting cuttings bed information data, a coding rule is used for coding information data, and a coding result is obtained; the signal transmission device receives the coding result, and the coding result is transmitted to the signal decoding recognition device, the signal decoding recognition device is arranged onthe ground and can receive the coding result, according to the coding rule, the coding result is subjected to decoding recognition to obtain a decoding recognition result, and the display device receives the decoding recognition result and displays a cuttings bed simulated diagram according to the decoding recognition result. The cuttings bed recognition system can achieve real-time detection andreal-time processing on the cuttings bed, long-time rotation stop condition of the drill column can be avoided, and the drilling work efficiency is improved.

The invention provides a cuttings bed identification method and a position determination method. The identification method comprises the steps of: arranging a plurality of signal receiving points in awell, determining whether the position of each signal receiving point in the well corresponds to the cuttings bed or drilling liquid according to the time interval between a transmitted detection signal and a received return detection signal, and obtaining a detection result; setting a coding rule, coding the detection result by using the coding rule, and obtaining a coding result; transmitting the coding result to the ground and decoding the coding result, identifying the cuttings bed after decoding, and obtaining a decoding identification result; drawing a cuttings bed simulated diagram according to the diameter of a wellbore and the decoding identification result, and completing the cuttings bed identification. The position determination method comprises determining the position of thecuttings bed in the well according to the position of the signal receiving points. The invention can identify and monitor the condition of the underground cuttings bed in real time, and can optimizedrilling measures according to the obtained cuttings bed simulated diagram, so as to perform the continuous drilling work conveniently.

The invention provides an underground electromechanical combined under-pressure operation device and an application method. Through the effective cooperation of a main core system underground combinedoperation and ground control system, a blowout preventer, a blooie pipe, a pulley support, a pulley and the like, a complete operation system capable of completing underground restrictor sleeve milling and salvage can be constructed. Underground work condition parameter collection, ground parameter display and time control design can achieve visual controllable operation management can be realized, and reliability and safety of construction are effectively guaranteed. By means of elastic limit protection design, when tongs used in the salvage procedure cannot grab a target, the target can beautomatically dropped in a limit protection range, so that new underground accidents are avoided. A designed ground gas filtering and recycling tank has a certain time concept for safety, energy conservation and environmental protection management. The whole operation management process is high in controllability, the efficiency of handling actual underground accidents is good, and the device is suitable for being widely popularized in the field of natural gas well underground restrictor processing.

The invention discloses a pressure control device of a perforation fracturing test system. The perforation fracturing test system comprises a hydraulic pump (1) and a downhole test tool, wherein the hydraulic pump (1) and the downhole test tool are mutually communicated. The pressure control device comprises a needle valve (2). The needle valve (2) is arranged on a pipeline (3), wherein the pipeline (3) is arranged between the hydraulic pump (1) and the downhole test tool. The pressure control device can control pressure accurately so that stable annulus pressure between a downhole tubular column and a sleeve is guaranteed.

The invention provides a variable-diameter casing scraper. The variable-diameter casing scraper is characterized in that an upper joint and a lower joint are arranged at two ends of a mandrel, and a pressure transmission hole is formed in the mandrel. The end, close to the upper joint, of the mandrel is sleeved with a guide cylinder, the guide cylinder is sleeved with a plate spring, and the middle of the plate spring is sleeved with a scraping knife. One end of the plate spring is connected with the upper joint, and the other end of the plate spring is connected with a push cylinder. The push cylinder is connected with a piston, the piston and the mandrel are pre-fixed, and a hydraulic cylinder sleeve is arranged on the piston in a sleeving mode and located at the position close to the pressure transmission hole. The guide cylinder has a certain radian so as to guide the plate spring and the scraping knife to radially expand, and the plate spring is of an arch structure with the certain radian so as to drive the scraping knife to radially expand. According to the variable-diameter casing scraper, scraping of a combined casing of a technical casing and a tail pipe can be completed by adopting a scraping pipe column, and the purposes of shortening the scraping operation period, reducing the operation cost and improving the operation efficiency can be achieved on the premise of ensuring the safety of the scraping operation.

The invention discloses a metal mine downhole microseismic monitoring system which comprises at least one downhole network multi-channel collector arranged in a roadway of a downhole monitored section. Every downhole network multi-channel collector comprises a plurality of difference input channels for analog signal collection, every difference input channel is respectively connected with a microseismic signal collecting device, every microseismic signal collecting device is fixedly distributed on downhole roadway side walls in different directions, and output ends of the downhole network multi-channel collectors are connected with a ground data receiving processing platform sequentially through a transmission local area network and a concentrator local area network. The metal mine downhole microseismic monitoring system has the advantages of performing microseismic real-time on-line monitoring and analysis, preventing downhole accidents, optimizing blasting and ore falling effect in the recovery process and mastering vibration conditions of surrounding device systems and the like and is suitable for being widely applied to the technical field of microseismic monitoring.

The invention relates to a method for the sidetrack drilling of radial branch well bores through hydraulic jet and a device thereof. The device comprises a first oil pipe and a second oil pipe, wherein the external diameter of the first oil pipe is smaller than the internal diameter of a sleeve arranged inside an oil well; and the end part of the first oil pipe is connected with a deflector. The external diameter of the second oil pipe is smaller than the internal diameter of the first oil pipe; and the second oil pipe is connected with a sidetrack drilling tool carrying out the sidetrack drilling of the radial branch well bores. The external dimensions of the deflector are smaller than the internal diameter of the sleeve; the deflector has a through passage communicated with the top and the side wall; and the sidetrack drilling tool is deflected to the side wall from the top of the deflector via the through passage. The device overcomes well-known defects, can correctly and conveniently fix the deflector at a set stratum position and have a correct drilling position. The device is particularly suitable for the sidetrack drilling of a well with an ultra short radius, can operate conveniently on a ocean platform, thereby avoiding the downhole accidents caused by a downhole tool, effectively shortening the drilling cycle, saving the drilling cost, reducing the labor intensity ofworkers, improving the construction effects and having great market potential.

The invention discloses a novel hairbrush pipe scraping device. The novel hairbrush pipe scraping device comprises a mandrel and a lower connector connected with the lower end of the mandrel, wherein a hairbrush sleeve sleeves on an outer wall of the mandrel; three rows of hairbrushes are uniformly distributed on the outer wall of the hairbrush sleeve; an upper strengthening sleeve and a lower strengthening sleeve are arranged at two ends of the hairbrush sleeve respectively; the hairbrush sleeve is in clamping connection with a second clamping groove in the lower end of the upper strengthening sleeve and a third clamping groove in the upper end of the lower strengthening sleeve through first clamping grooves at two ends respectively; meanwhile, a fourth clamping groove is formed in the lower end of the lower strengthening sleeve; a fifth clamping groove, matched with the fourth clamping groove, is formed in the upper end of the lower connector; and an anti-clamping device is arranged between the fourth clamping groove and the fifth clamping groove. The novel hairbrush pipe scraping device provided by the invention is simple in structure, low in manufacturing cost and long in service life; and an anti-clamping problem of the hairbrush pipe scraping device is effectively solved and occurrence of downhole accidents is prevented.

The invention provides a well mouth operation visualization device, and solves the technical problem of bad underground accidents caused by falling of part of falling fishes into the well mouth againdue to possible cutting off of the falling fishes still in gas production trees during salvaging in the prior art. The device comprises a well mouth camera device; the well mouth camera device at least comprises a mounting base, a camera mechanism and a touch screen; the mounting base is provided with a hollow channel penetrating from one end to the other end; an upper joint and a lower joint arearranged at the two ends of the mounting base; and the camera mechanism is movably mounted in the mounting base. The device can directly help scene operators judge if tool strings pass through such well mouth devices as gas production trees under the condition of not influencing normal well mouth operation, so that the condition of cutting off of the falling fishes caused by wrong closing of wellmouth valves is totally prevented, and the underground accidents are prevented.

The invention belongs to the technical field of mechanical equipment, and particularly provides an electromagnet tripping mechanism capable of quickly hooking and a using method. The electromagnet tripping mechanism comprises a gland, an electromagnet, an overall fixing frame, a cover, a swing rod, an iron core assembly and a hanging plate assembly, wherein the electromagnet and the cover are sequentially connected to the middle of the overall fixing frame from left to right; the iron core assembly horizontally penetrates through the electromagnet from left to right, the right portion of the iron core assembly is connected into the cover, the left end of the iron core assembly and the left end of the electromagnet are connected through the gland, the right end of the iron core assembly is connected with the left portion of the swing rod in a matched mode, the right portion of the swing rod is movably connected with the overall fixing frame in the cover, and the lower portion of the swing rod is connected with the hanging plate assembly in a clamped mode. The problem that in a stall protection device of a trackless rubber-tyred vehicle, a steel wire rope large hook for hooking an intercepting device on the rubber-tyred vehicle cannot be hooked by a single person after falling off is solved, and the large hook can rapidly fall off when needing to fall off.

The invention relates to the technical field of oil recovery in oil fields, and discloses a soluble faucet, which includes a connecting pipe. One side of the cover is movably socketed with a faucet, and the front side of the faucet is welded with a connection block, and a hollow groove is opened on the front side of the connection block, and a limit block is movably socketed on the top side of the hollow groove, One end of the limiting block extends to the inner cavity of the hollow groove, the bottom of one side of the limiting block is fixedly installed with a clamping block located in the inner cavity of the hollow groove, and the bottom of the limiting block is fixedly connected with a spring. The soluble faucet facilitates better connection of the connecting pipe and the faucet through the mutual cooperation between the limit block, the clamping block and the spring, thereby solving the problem that the faucet is fixed with the connecting pipe by welding. The fixed method leads to the problem that it is difficult to replace the faucet when it is damaged, which improves the better connection effect.

The invention discloses an object falling prevention device of a shaft. The object falling prevention device is arranged in a sleeve pipe in the shaft and comprises a back off sub, a short pipe joint, at least one set of sealing rubber barrel and slips. The back off sub, the short pipe joint, the at least one set of sealing rubber barrel and the slips are sequentially connected from top to bottom, in work, a putting-down tool is connected with the back off sub and is used for putting the object falling prevention device of the shaft into a well, the at least one set of sealing rubber barrel and the slips are fixed with the sleeve pipe in an anchoring mode through hitting and pressing, and the back off sub and the short pipe joint are separated. According to the object falling prevention device of the shaft, the slips and the sealing rubber barrel are fixed with the sleeve pipe in the anchoring mode, the object falling prevention device and the sleeve pipe are firmly fixed together, the object falling prevention device can bear large impact force, oil pipes and various underground tools which fall from the upper portion are prevented from falling into an underground horizontal section, underground accidents are avoided, production operation cost is controlled, and the object falling prevention device is simple in structure and convenient to operate.

The invention relates to the technical field of screw drilling tools, in particular to a safety valve. The safety valve comprises a safety valve body, a float valve, a fixing nut, an integrated-type filter screen, a wave spring, a stop ring, an anti-falling nut, an anti-falling rod and a flow-guiding type anti-falling mat. A valve hole is formed in the safety valve body, a stair step is arranged on the valve hole, the integrated type filter screen is mounted and clamped on the stair step and fixed through the stop ring, the float valve is mounted at the lower end of the integrated type filterscreen and fixed through the nut, annular spaces are left between the periphery of the float valve and the valve hole, and the wave spring is arranged between the float valve and the integrated type filter screen. The anti-falling rod is arranged in the safety valve body, the anti-falling nut is arranged on the front portion of the anti-falling rod, and the flow-guiding type anti-falling mat is arranged between the anti-falling nut and the anti-falling rod. Through structurally integrated design of a bypass valve body and an anti-falling shell, the production safety coefficient is improved, the production cost is reduced, the length of the anti-falling shell is shortened, and raw materials are saved.

The invention discloses an underground cable docking device, which comprises a cover body, a commutating and voltage-stabilizing device, a metal cover, a coil, an upper metal post, an upper connection structure, a lower connection structure and a metal base. According to the underground cable docking device, the lower connection structure and the metal base can be connected with a motor of an underground submerged pump through a lower cable and directly put into a well, an upper cable is connected with the upper connection structure and then the upper connection structure and various components connected therewith are put into the well along with the center of a pipeline; the metal cover and the upper metal post generate electromagnetic suction force through electrifying the coil; and furthermore, due to the dead load of the upper cable, the upper connection structure and the components connected with the upper connection structure, the metal base and the bottom of the metal cover are close to each other and are docked and the lower connection structure and the upper connection structure are docked for electric conduction. The upper cable, the upper connection structure and the components connected with the upper connection structure can be put into the well along with the center of the pipeline, so that the cables are prevented from being extruded and damaged by the well wall, and meanwhile, the problem of downhole junks caused by friction with the well wall is solved.

The invention relates to a pump stopping wellhead pressure drop measuring transient well test method after acid fracturing. The method comprises the following steps that (1) pressure data in the whole acid fracturing process are recorded; (2) different fluid displacement data are recorded; (3) a well depth structure and the productive section well diameter are obtained; (4) frictional resistance is obtained; (5) well bottom pressure data in the whole acid fracturing process are simulated; (6) the effective reservoir thickness is gained; (7) the weighted porosity of the effective reservoir porosity is gained; (8) a rock compressibility coefficient is gained; (9) the formation pressure is converted, and the well bottom formation temperature is gained; (10) water saturation is obtained; (11) a water injection pressure drop transient well test analysis model is established; (12) all relevant parameter of the selected analytic model are obtained; and (13) all the parameters are obtained for reservoir evaluation. Through the method, the formation parameters are effectively obtained for reservoir evaluation. The test cost is reduced, the test construction risks are reduced, the individual well yield is not influenced, and the dynamic test data gaining rate is increased.

The invention relates to the technical field of oil field oil recovery, and discloses a soluble water nozzle. The soluble water nozzle comprises a connecting pipe; one side of the connecting pipe is fixedly connected with a fixed sleeve, and the outer surface of the fixed sleeve is movably sleeved with a sealing ring; one side of the fixed sleeve is movably sleeved with a water nozzle, and a connecting block is welded on one side of the front surface of the water nozzle; a hollow groove is formed in one side of the front surface of the connecting block, and one side of the top of the hollow groove is movably sleeved with a limiting block; one end of the limiting block extends into an inner cavity of the hollow groove; a clamping block positioned in the inner cavity of the hollow groove isfixedly mounted at the bottom of one side of the limiting block; and the bottom of the limiting block is fixedly connected with a spring. Through cooperation of the limiting block, the clamping blockand the spring, the soluble water nozzle is convenient for preferable connection of the connecting pipe and the water nozzle, so that the problem of more difficult replacement of the damaged water nozzle caused by a welding fixation mode in the fixing process of the water nozzle and the connecting pipe is solved, and the connecting effect is improved.