Petroleum pipe tool repairing device
Technical Field
The invention relates to a petroleum pipe repairing device, in particular to a petroleum casing pipe chemical method repairing device.
Background
In the process of exploiting oil and gas fields, due to the fact that geological conditions are complex, such as inclined wells and horizontal wells, the condition that oil well casings are damaged often occurs. Damage to the well casing can cause the following hazards to oil field development: 1. the production string cannot be normally run into the well; 2. when the damaged part of the casing is positioned at the position of a water layer or a sand layer, a large amount of water or sand can be discharged from the oil well; 3. oil well production increasing measures cannot be carried out; 4. the well blowout outside the casing is easy to cause; 5. causing the well to fail.
For repairing broken casing, slotted casing or hole, the following methods are available: 1. extruding cement paste: when the oil layer pressure is not large and the fracture and the leakage are not serious, the repairing can be carried out by a cement paste squeezing method. The process method comprises the following steps: firstly, a drift diameter of a drift size which is 8-10 mm smaller than the inner diameter of a casing is used, then a suspended plugging device (the name of a tool is called a bridge plug) is arranged at a proper position of a broken opening, a shaft below the broken opening is temporarily sealed off, a certain amount of cement slurry is injected above the bridge plug to be solidified into a cement plug, after the cement plug is solidified, the cement plug in the casing is drilled, the quality of the broken opening of cement sealing is checked through pressure testing, after the sealing quality is confirmed to be qualified, the suspended plugging device (the bridge plug) is drilled, and sand is flushed to the bottom of a well. The casing repaired by the method can bear 40-80 MPa of pressure generally, and the well is protected by a packer under high-pressure construction later, so that the section is prevented from bearing high pressure. 2. A patch method: namely, a layer of thin-wall pipe is adhered to the inner wall of the damaged sleeve pipe so as to achieve the aim of repairing. The process principle is as follows: after a corrugated pipe (thin-wall pipe) is sleeved on a specially-made high-pressure resistant rubber cylinder and is put down to a damaged position of a casing in a well, the pressure is suppressed to expand the rubber cylinder and expand the corrugated pipe, so that the corrugated pipe is tightly attached to the inner wall of the damaged position of the casing, the casing and the corrugated pipe are bonded into a whole by using an adhesive, and after the adhesive is cured, a drilling tool is moved to take out the high-pressure resistant rubber cylinder. The patching process is simple and safe to operate. 3. Replacing the sleeve: when the fracture position is at the upper part of the oil well and the casing above the break opening can be taken out in a reverse buckling mode, the casing above the accident section can be lifted up completely by a reverse buckling method, a new casing is put in again, and the casing is well buckled up tightly. The method has the advantages that the consistency of the inner diameters of the casings is ensured, and downhole tools can pass through smoothly in later operation; the defects are that the screwing degree of the screw thread of the underground casing which is buckled up is not as tight as that of the underground well head, and the cost for replacing the casing is higher and the operation is difficult.
The patching repair method has the following problems: when sand prevention is needed, a sand prevention pipe column needs to be put in; when the stratum needs to be modified and acidified, an acidification pipe column needs to be put in; when the stratum needs to be fractured, the fracturing pipe column is put into the stratum; because the internal diameter of steel pipe is less than the internal diameter of sheathed tube, like this, the diameter and the specification of the instrument of going into all need diminish, cause the liquid volume of injection to diminish, influence the effect of sand control, acidizing and fracturing, in addition, the steel pipe forms a boss shape of intraductal wall of cover, and like this, the condition of blocking appears easily in the tubular column of going into.
The cement paste extruding method has the following problems: when acidizing operation is needed on site, since cement is alkaline, acid liquor reacts with the cement, and the repaired leak leaks can leak out again.
The invention discloses an invention patent with a Chinese patent application number of 2018100850589 and a patent name of 'a sleeve pipe repairing device', which adopts the technical scheme that: a packer is arranged at the bottom of the oil well casing pipe, and isolation protective sand is arranged above the packer; the invention discloses a method for repairing the damaged position of a sleeve by using an electric heating pipe, which is characterized in that an oil pipe anchor is arranged on the inner wall of an oil well sleeve on the upper part of isolation protective sand, the lower end of a central pipe is fixed with the inner wall of the oil well sleeve through the oil pipe anchor, a metal packer is arranged above the oil pipe anchor, the top of the central pipe is fixedly connected with a wellhead device, a fire-resistant protective sleeve is connected below a righting short section through a pressure balance one-way valve, aluminothermic reaction raw materials are arranged in an annular cavity of the fire-resistant protective sleeve and sleeved on the outer wall of the central pipe, and a reaction inducing pipe column is arranged in an inner cavity of the central pipe. But it has problems that: the initiation of the thermit reaction is to induce the tubular column through throwing into the reaction, induce the bottom of the tubular column to be equipped with the electric heating pipe in the reaction, connect to the electric heating pipe at the well head through the cable and heat the thermit reaction raw materials of the fire-resistant protective sheath inner chamber, its construction process is relatively troublesome.
Disclosure of Invention
The invention aims to solve the defects in the prior art, and provides a petroleum pipe repairing device, wherein a new ignition device is arranged to replace a reaction inducing pipe column, generated iron and aluminum oxide are coated on the damaged part of an oil well casing by an aluminothermic reaction method, and then the oil well casing is repaired by grinding, so that the problems of inner diameter reduction and secondary leakage in the prior art are solved.
The invention provides a chemical method repairing device for a petroleum casing, which has the technical scheme that: the device comprises a first blind plug (2), a first packer (3), isolation protective sand (4), a second blind plug (5), a second packer (6), a reaction auxiliary cylinder sleeve (7), a tin plug (8), a sparking fixing sleeve (12), an igniter (13), an ignition lock ring (14), a combustible ball seat (15), an aluminothermic reactant (16), a combustible seal sleeve (17), a pressure exchange cover (18), a reaction pipe column (19) and a central pipe (20), wherein the first packer (3) is arranged at the bottom of an oil well casing (1), the first blind plug (2) is arranged at the bottom of the first packer (3), the isolation protective sand (4) is arranged above the first packer (3), and an oil layer below the first packer is isolated and sealed; a second packer (6) is arranged on the inner wall of the oil well casing (1) between the lower part of a section to be repaired of the oil well casing (1) and the isolation protective sand (4), a central pipe (20) is supported and fixed through the second packer (6), a second blind plug (5) is arranged at the bottom of the central pipe (20), the outer wall of the central pipe (20) is fixedly connected with a reaction auxiliary cylinder sleeve (7), an aluminothermic reactant (16) is filled in the inner cavity of the reaction auxiliary cylinder sleeve (7), a plurality of inclined holes are formed in the outer wall of the reaction auxiliary cylinder sleeve (7), and the inclined holes are plugged through tin plugs (8); the ignition device is characterized in that a sparking fixing sleeve (12), an igniter (13), an ignition lock ring (14), a combustible ball seat (15), a combustible sealing sleeve (17) and a plug body (21) are sequentially arranged in the inner cavity of the central tube (20) from bottom to top, the sparking fixing sleeve (12) fixes the igniter (13), and the ignition lock ring (14) is arranged above the igniter (13); the bottom of the combustible ball seat (15) is in contact with the upper surface of an ignition lock ring (14), the top of the combustible ball seat (15) is installed on the inner wall of a combustible sealing sleeve (17), the outer wall of the combustible sealing sleeve (17) is in threaded connection with the inner wall of a central pipe (20), a steel ball (24) is thrown into the upper edge of the combustible ball seat (15) in the middle of the combustible sealing sleeve (17), a wire blocking body (21) is in threaded connection with the upper portion of the steel ball and the combustible sealing sleeve (17), and a one-way valve (22) and a reverse one-way valve (23) are installed on the wire blocking body (21) and are provided with temperature and pressure sensors; the igniter (13) is pressed down through the ignition lock ring (14) to realize ignition, the combustible ball seat (15) is ignited, the combustible sealing sleeve (17) is further combusted, meanwhile, the combustion of the combustible ball seat (15) realizes high-temperature heating on thermite reactant (16) in the reaction auxiliary cylinder sleeve (7), thermite reaction is initiated, so that tin plugs (8) are melted by iron and aluminum oxide in a generated molten state, the iron and the aluminum oxide in the molten state sequentially enter a cavity between the central pipe and the oil well casing pipe, the liquid level is continuously raised to fill a to-be-repaired section of the oil well casing pipe, and casing pipe repair is realized.
The top of the reaction auxiliary cylinder sleeve (7) is provided with an elastic extrusion device consisting of a spring pressing cap (9), a spring (10) and a steel ball (11), and the spring pressing cap (9) is pushed by the spring (10) to continuously apply pressure to the thermite reactant (16), so that the thermite reactant (16) is continuously pushed in the thermite reaction process, and sufficient reaction is facilitated.
The thermite reactant (16) is prepared by putting aluminum powder and ferric oxide into the inner cavity of the reaction auxiliary cylinder sleeve (7) according to the volume ratio of 2: 1.
Preferably, the igniter (13) adopts 3-6 groups of lighters, the lighters are sequentially arranged in a gap between the ignition fixing sleeve (12) and the central tube, and the lighter is pressed down through the ignition lock ring (14) to complete the ignition of the lighter.
Preferably, foretell combustible ball seat (15) include ball seat main part (15.1), go up connector (15.2), extension body (15.3), bleeder vent (15.4), guide way (15.5) and lower connector (15.6), the bottom of ball seat main part (15.1) is equipped with convex lower connector (15.6), is equipped with extension body (15.3) below the outside of lower connector (15.6), and is equipped with one or more bleeder vent (15.4) on lower connector (15.6), the top of ball seat main part (15.1) is equipped with connector (15.2), the top inboard of going up connector (15.2) be equipped with be used for with steel ball complex guide way (15.5).
Preferably, the combustible ball seat (15) and the combustible sealing sleeve (17) are made of magnesium.
Preferably, the diameter of the steel ball (24) is larger than the inner diameter of the central hole of the ball seat main body (15.1), and the diameter of the steel ball (24) is smaller than the inner diameter of the combustible sealing sleeve (17) and is also smaller than the inner diameter of the central hole of the sparking fixing sleeve (12); the inner wall of combustible seal cover (17) and center tube passes through threaded connection, ball seat main part (15.1) pass through sealing washer swing joint with combustible seal cover (17), like this, when suppressing to the center tube through check valve (22) on the plug body (21), promote steel ball (24) extrusion combustible ball seat (15) and move down to make igniters (13) combustible ball seat (15) the ignition of making the magnesium material, further with combustible seal cover (17) the ignition, because the magnesium burning produces a large amount of heat, it heats aluminothermic reactant (16) in vice cylinder liner (7) of reaction to reaction temperature.
Preferably, the second packer (6) is an all-metal packer.
The invention has the beneficial effects that: the method comprises the following steps of (1) separating oil at the lower part from a cavity at the damaged part of a casing by putting a first blind plug, a first packer and isolation protective sand into the casing of the oil well; then, a repairing pipe column is put into the position near the damaged position of the sleeve, a steel ball is put in, a wire plug body is installed, then the repairing pipe column is pressed from a well mouth, when the repairing pipe column is pressed to 0.8 MPa, the steel ball extrudes the ball seat main body to move downwards, an igniter is pressed downwards through an ignition lock ring to realize ignition, the combustible ball seat is ignited, the combustible sealing sleeve is further combusted, the pressing is stopped at the moment, the combustion of the combustible ball seat realizes high-temperature heating on an aluminothermic reactant in a reaction auxiliary cylinder sleeve, an aluminothermic reaction is initiated, so that the generated molten iron and aluminum oxide melt a tin plug, the molten iron and aluminum oxide enter a cavity between a central pipe and the oil well sleeve, and the liquid level is continuously raised to fill the section to be repaired of the oil well sleeve; and then taking out the screw plug body, putting in a grinding shoe to grind the left central tube and the reaction auxiliary cylinder sleeve, and finally completing the repair of the oil well casing, thereby avoiding the problem that the inner diameters of the repaired casings are different in the prior art, avoiding the problem that the cement can leak again in the prior art, reducing the working procedures and saving the construction cost by adopting different aluminothermic reaction ignition modes, so that the repaired part of the casing can be recovered to the same diameter requirement of the original casing, and the performance of the original casing can be achieved.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic structural view of a combustible ball seat;
FIG. 3 is a schematic structural view of a combustible seal cartridge;
in the upper diagram: the oil well casing pipe comprises an oil well casing pipe 1, a first blind plug 2, a first packer 3, isolation protective sand 4, a second blind plug 5, a second packer 6, a reaction auxiliary cylinder sleeve 7, a tin plug 8, a spring pressing cap 9, a spring 10, a steel ball 11, an ignition fixing sleeve 12, an igniter 13, an ignition locking ring 14, a combustible ball seat 15, an aluminothermic reactant 16, a combustible sealing sleeve 17, a pressure exchange cover 18, a reaction pipe column 19, a central pipe 20, a wire plug body 21, a check valve 22, a reverse check valve 23, a steel ball 24, a ball seat main body 15.1, an upper connecting body 15.2, an extension body 15.3, a vent hole 15.4, a guide groove 15.5 and a lower connecting body 15.6.
Detailed Description
The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.
Embodiment 1, referring to fig. 1, the present invention provides a chemical method petroleum casing pipe repairing apparatus, which has the following technical scheme: the device comprises a first blind plug 2, a first packer 3, isolation protective sand 4, a second blind plug 5, a second packer 6, a reaction auxiliary cylinder sleeve 7, a tin plug 8, a sparking fixing sleeve 12, an igniter 13, an ignition lock ring 14, a combustible ball seat 15, an aluminothermic reactant 16, a combustible seal sleeve 17, a pressure exchange cover 18, a reaction pipe column 19 and a central pipe 20, wherein the first packer 3 is installed at the bottom of an oil well casing 1, the first blind plug 2 is arranged at the bottom of the first packer 3, the isolation protective sand 4 is arranged above the first packer 3, and an oil layer below the first packer is isolated and sealed; a second packer 6 is arranged on the inner wall of the oil well casing 1 between the lower part of the section to be repaired of the oil well casing 1 and the isolation protective sand 4, a central pipe 20 is supported and fixed through the second packer 6, a second blind plug 5 is arranged at the bottom of the central pipe 20, the outer wall of the central pipe 20 is fixedly connected with a reaction auxiliary cylinder sleeve 7, an aluminothermic reactant 16 is arranged in the inner cavity of the reaction auxiliary cylinder sleeve 7, a plurality of inclined holes are formed in the outer wall of the reaction auxiliary cylinder sleeve 7, and the inclined holes are plugged through tin plugs 8; the ignition fixing sleeve 12, the igniter 13, the ignition lock ring 14, the combustible ball seat 15, the combustible sealing sleeve 17 and the wire blocking body 21 are sequentially arranged in the inner cavity of the central tube 20 from bottom to top, the igniter 13 is fixed by the ignition fixing sleeve 12, and the ignition lock ring 14 is arranged above the igniter 13; the bottom of the combustible ball seat 15 is in contact with the upper surface of the ignition lock ring 14, the top of the combustible ball seat 15 is installed on the inner wall of a combustible sealing sleeve 17, the outer wall of the combustible sealing sleeve 17 is in threaded connection with the inner wall of a central tube 20, a steel ball 24 is put into the upper edge of the combustible ball seat 15 in the middle of the combustible sealing sleeve 17, a wire plug body 21 is in threaded connection with the upper portions of the steel ball and the combustible sealing sleeve 17, and a one-way valve 22 and a reverse one-way valve 23 are installed on the wire plug body 21 and provided with temperature and pressure sensors; the igniter 13 is pressed downwards through the ignition lock ring 14 to achieve ignition, the combustible ball seat 15 is ignited, the combustible sealing sleeve 17 is further combusted, meanwhile, the combustion of the combustible ball seat 15 achieves high-temperature heating on thermite reactants 16 in the reaction auxiliary cylinder sleeve 7, thermite reaction is initiated, so that the generated iron and aluminum oxide in a molten state melt the tin plug 8, the iron and the aluminum oxide in the molten state sequentially enter a cavity between the central pipe and the oil well casing pipe, the liquid level continues to rise, the section to be repaired of the oil well casing pipe is filled, and casing pipe repair is achieved.
Wherein, the top of the vice cylinder liner 7 of reaction is equipped with spring pressure cap 9, spring 10, the elasticity extrusion device that steel ball 11 constitutes, press cap 9 to exert thrust through spring 10, thereby to 16 lasting applys pressure to the thermite reactant, what last in the thermite reaction process is promoted thermite reactant 16 like this, avoid aluminium powder and the iron oxide powder at top to seriously collapse in the reaction sequence, make the upper and lower pressure balance of the vice cylinder liner 7 of reaction, also avoid aluminium powder and iron oxide powder disposable quick reaction, reaction rate has been controlled.
In addition, the thermite reactant 16 adopts aluminum powder and ferric oxide which are put into the inner cavity of the reaction auxiliary cylinder sleeve 7 according to the volume ratio of 2:1, the first packer adopts a Y445 packer, and the second packer adopts a Y211 packer.
Preferably, the above-mentioned lighter 13 is a lighter of 3-6 groups, and may be an electronic lighter, and is arranged in the gap between the ignition fixing sleeve 12 and the central tube in turn, and the ignition of the lighter is completed by pressing down the lighter through the ignition lock ring 14.
Referring to the attached drawing 2, the combustible ball seat 15 of the invention comprises a ball seat main body 15.1, an upper connector 15.2, an extension body 15.3, air holes 15.4, a guide groove 15.5 and a lower connector 15.6, wherein the bottom of the ball seat main body 15.1 is provided with the convex lower connector 15.6, the extension body 15.3 is arranged below the outer side of the lower connector 15.6, one or more air holes 15.4 are arranged on the lower connector 15.6, the top of the ball seat main body 15.1 is provided with the upper connector 15.2, and the inner side of the top of the upper connector 15.2 is provided with the guide groove 15.5 matched with a steel ball.
In addition, the combustible seal sleeve 17 is of a circular structure, and the outer ring of the combustible seal sleeve is provided with threads for being in threaded connection with the inner cavity of the central tube 20; a circular groove is formed in the lower side of the inner cavity of the combustible sealing sleeve 17 and is used for being matched with the ball seat main body 15.1 and the upper connecting body 15.2 of the combustible ball seat 15, and sealing rings are respectively arranged at the connecting positions of the upper connecting body 15.2 and the ball seat main body 15.1 and the inner cavity of the combustible sealing sleeve 17, so that the acting force and the pressing of a steel ball are received above the upper connecting body 15.2, and the steel ball drives the combustible ball seat 15 to fall down in an accelerated manner; the above structure of the combustible ball seat 15 can keep it in a stable and non-falling state when no steel ball is thrown in.
And the combustible ball seat 15 and the combustible sealing sleeve 17 are made of magnesium, and the second packer 6 is an all-metal packer.
In addition, the diameter of the steel ball 24 is larger than the inner diameter of the central hole of the ball seat main body 15.1, and the diameter of the steel ball 24 is smaller than the inner diameter of the combustible sealing sleeve 17 and is also smaller than the inner diameter of the central hole of the sparking fixing sleeve 12; the combustible sealing sleeve 17 is in threaded connection with the inner wall of the central tube, the ball seat main body 15.1 is movably connected with the combustible sealing sleeve 17 through a sealing ring, and therefore when the one-way valve 22 on the screw plug body 21 is used for pressurizing the central tube, the steel ball 24 is pushed to extrude the combustible ball seat 15 to move downwards, the igniter 13 is used for igniting the combustible ball seat 15 made of magnesium materials, the combustible sealing sleeve 17 is further ignited, and the aluminothermic reactant 16 in the reaction auxiliary cylinder sleeve 7 is heated to the reaction temperature due to the fact that magnesium burns to generate a large amount of heat. After the aluminothermic reaction is finished, molten iron and aluminum oxide can be generated, the density of the molten iron is high, the molten iron flows out along the through hole of the reaction auxiliary cylinder sleeve 7, the tin plug 8 is melted at high temperature, the molten iron of the liquid smoothly flows out, the second packer 6 is arranged below the reaction auxiliary cylinder sleeve, the molten iron of the liquid can only flow upwards along the gap between the reaction auxiliary cylinder sleeve 7 and the sleeve, the whole cavity is small, the temperature is high, the aluminum powder and the ferric oxide of the reaction auxiliary cylinder sleeve 7 continue to react, the iron of the liquid continuously flows upwards until the damaged part of the sleeve is met, the damaged part is filled, the temperature outside the damaged part is low, the liquid begins to solidify until the damaged part is filled, the iron of the liquid continuously flows upwards along the gap between the sleeve and the reaction auxiliary cylinder sleeve 7 until the final aluminothermic reaction is finished, slowly cooling to form a firm repairing layer; at the moment, the steel ball also falls to the lower part of the inner cavity of the sparking fixing sleeve 12, the temperature sensor and the pressure sensor can upload temperature data and pressure data to a control chamber outside a wellhead, whether thermite reaction is finished or not can be judged according to the temperature and the pressure from the wellhead, then a wire is lifted to plug the body, and then the next grinding and scraping operation is carried out.
The invention provides a using method of a chemical method repairing device for a petroleum casing, which comprises the following steps:
1. firstly, finding a damaged part of an oil well casing 1 through a detector for logging, putting a first packer 3 into the lower part of the oil well casing for packing, installing a first blind plug 2 to isolate crude oil at the lower part of the casing, and putting isolation protective sand 4 into the upper part of the first packer 3 to form a protective layer;
2. the installed base pipe 20 is lowered into the well casing 1: a central tube 20 is supported and fixed through a second packer 6, a second blind plug 5 is arranged at the bottom of the central tube 20, the outer wall of the central tube 20 is fixedly connected with a reaction auxiliary cylinder sleeve 7, an aluminothermic reactant 16 is filled in the inner cavity of the reaction auxiliary cylinder sleeve 7, a plurality of inclined holes are formed in the outer wall of the reaction auxiliary cylinder sleeve 7, and the inclined holes are plugged through a tin plug 8; the ignition fixing sleeve 12, the igniter 13, the ignition lock ring 14, the combustible ball seat 15, the combustible sealing sleeve 17 and the wire blocking body 21 are sequentially arranged in the inner cavity of the central tube 20 from bottom to top, the igniter 13 is fixed by the ignition fixing sleeve 12, and the ignition lock ring 14 is arranged above the igniter 13; the bottom of the combustible ball seat 15 is in contact with the upper surface of the ignition lock ring 14, the top of the combustible ball seat 15 is installed on the inner wall of a combustible sealing sleeve 17, the outer wall of the combustible sealing sleeve 17 is in threaded connection with the inner wall of a central tube 20, a steel ball 24 is put into a wellhead, the upper edge of the combustible ball seat 15 in the middle of the combustible sealing sleeve 17 is sealed through the steel ball seat, then a plug body 21 is put into the wellhead, and a check valve 22 and a reverse check valve 23 are arranged on the plug body 21;
3. pressurizing to 0.8 MPa from the wellhead into the oil well casing 1, under the seat seal of the steel ball 24, because the combustible ball seat 15 is connected with the combustible sealing sleeve 17 through a sealing ring, the combustible ball seat 15 can move downwards in an accelerated manner under the pressure, the ignition lock ring 14 is further pushed to press the igniter 13 to realize ignition, the combustible ball seat 15 made of magnesium material is ignited, the combustible sealing sleeve 17 made of magnesium material is further combusted, the steel ball 24 falls to the upper part of the second blind plug, and the pressurizing from the wellhead is stopped at the moment; the combustion of the combustible ball seat 15 and the combustible sealing sleeve 17 realizes high-temperature heating of the thermite reactant 16 in the reaction auxiliary cylinder sleeve 7 and initiates thermite reaction, molten iron and aluminum oxide generated by the thermite reaction melt the tin plug 8, the molten iron and aluminum oxide enter a cavity between the central tube 20 and the oil well casing 1 along the cavity, and continuously rise and fill a section to be repaired of the oil well casing;
4. after the thermit reaction is finished, the screw-thread plug body 21 is lifted, the grinding shoe is put in from the wellhead to grind the oil well casing, the central pipe, the reaction auxiliary cylinder sleeve 7, the ignition fixing sleeve 12, the igniter 13, the ignition lock ring 14 and the steel ball 24 which are left in the oil well casing are ground through the grinding shoe, then the scraper is put in from the wellhead, the inner wall of the oil well casing is scraped smoothly through scraping, and the casing is repaired.
It should be noted that: when the igniters ignite the combustible ball seat 15 made of magnesium, in order to facilitate the combustion of the combustible ball seat 15, a circle of air holes 15.4 are arranged at the lower part of the combustible ball seat 15, so that the heating area is increased, the combustible ball seat 15 made of magnesium is ensured to be easier to combust, and simultaneously enough heat is emitted to initiate the reaction of ferric oxide and aluminum powder in the reaction auxiliary cylinder sleeve 7; and the oxygen in the initial stage of ignition can be supplemented due to the falling of the steel ball, and at the moment, the central hole of the combustible sealing sleeve 17 is communicated with the plug body, and the upper part of the combustible sealing sleeve is continuously pressed.
In addition, as the aluminothermic reaction is a severe oxidation-reduction reaction at high temperature, and finally liquid iron and aluminum oxide are generated, the reaction auxiliary cylinder sleeve is required to be made of a material resistant to higher temperature, such as refractory earth, so that the liquid iron and aluminum oxide can smoothly flow out through the inclined hole instead of directly melting the reaction auxiliary cylinder sleeve, the liquid iron and aluminum oxide quickly fill the cavity between the central tube 20 and the oil well casing 1 and enter the to-be-repaired position of the oil well casing 1, and then the filling of the repaired position is slowly completed by natural cooling.
Example 2, the difference of the invention from example 1 is: the combustible sealing sleeve 17 is made of aluminum, and the combustible ball seat 15 made of magnesium is burnt, so that the combustible sealing sleeve made of aluminum is easy to ignite, the aluminum continuously generates combustion reaction, a large amount of heat energy is released, thermite in the auxiliary cylinder sleeve 7 can be heated and initiated to initiate thermite reaction, and the combination reduces the manufacturing cost.
Example 3, the difference of the invention from example 1 is: under the condition of ensuring safety, an oxidant storage bag can be arranged on the combustible ball seat 15, and potassium chlorate can be particularly adopted. Magnesium is combustible in air and oxygen is the oxidant. However, when magnesium in the partially closed cavity in the central tube is combusted, potassium chlorate is an oxidant to ensure the continuous combustion of the magnesium and simultaneously emit enough heat to trigger thermite in the reaction auxiliary cylinder sleeve 7 to generate thermite reaction; of course, the initial ignition of the local space in the embodiment 1 and the embodiment 2 is not problematic, and the addition of potassium chlorate, which is an oxidant, is determined according to the needs of the field, because the steel ball falls to make the oxygen supplemented in the later period, and the steel ball is not extinguished due to oxygen deficiency, and the magnesium and the nitrogen can react and are also in an exothermic reaction.
The above description is only a few of the preferred embodiments of the present invention, and any person skilled in the art may modify the above-described embodiments or modify them into equivalent ones. Therefore, any simple modifications or equivalent substitutions made in accordance with the technical solution of the present invention are within the scope of the claims of the present invention.