CN111577206B - Water injection well descaling device and method - Google Patents
Water injection well descaling device and method Download PDFInfo
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- CN111577206B CN111577206B CN202010310171.XA CN202010310171A CN111577206B CN 111577206 B CN111577206 B CN 111577206B CN 202010310171 A CN202010310171 A CN 202010310171A CN 111577206 B CN111577206 B CN 111577206B
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B37/00—Methods or apparatus for cleaning boreholes or wells
- E21B37/06—Methods or apparatus for cleaning boreholes or wells using chemical means for preventing, limiting or eliminating the deposition of paraffins or like substances
Abstract
The invention relates to a descaling device and method for a water injection well. The technical scheme is as follows: the annular cavity formed by the outer container tube and the inner container tube is filled with powdery acidic ammonium salt, the bottom of the annular cavity is provided with a lower retaining ring, the upper side of the lower retaining ring is connected with a liquid outlet piston through a closing spring, the annular cavity is internally provided with a plurality of pressure transmission capillary tubes, the top of the annular cavity is provided with a container gland, a liquid inlet channel is arranged in the container gland, the upper part of the liquid inlet channel is communicated with a liquid outlet opening tube of a central tube, the inner cavity of the liquid inlet channel is provided with an opening piston, and the upper part of the opening piston is connected with a reset spring. The beneficial effects are as follows: by adopting the powdery solid acidic ammonium salt, more substances can be filled under the same volume, and the opening and releasing structure of the container is replaced, so that the anti-scaling time is prolonged, the adverse influence on the well site environment caused by collision damage of the anti-scaling and scale-removing device is reduced, and the potential safety hazard is eliminated.
Description
Technical Field
The invention relates to a water injection well descaling device and a method, in particular to a water injection well acid salt antiscaling descaling device.
Background
In the process of oil field development, water is injected into an oil reservoir through a special water injection well, so that the pressure of an oil layer is maintained or recovered, the oil reservoir has stronger driving force, and the exploitation rate and the recovery rate of the oil reservoir are improved. However, the liquid injected into the stratum through the water injection well is oil field reinjection water generally, and contains higher calcium ions and magnesium ions, along with the injection of the oil field reinjection water, the temperature is increased to 100 ℃ due to the increase of the temperature and the pressure, calcium carbonate and magnesium carbonate are gradually formed and then deposited in the inner cavity of the water injection pipe column and the water nozzle of the eccentric water distributor, and along with the increasing of scaling conditions, the water nozzle is finally blocked and cannot normally complete water injection, so that only the well can be stopped for repairing, the operation cost is increased, and the effect of supplementing energy to the stratum is reduced.
At present, the technology for preventing scaling in oil fields can be divided into a physical method, a chemical method and a process method. The physical method for preventing scale adopts physical instruments such as ultrasonic waves, magnetization, high-frequency electric fields and the like to inhibit the formation of scale, and the commonly used magnetic method for preventing scale has short implementation effective period and small action range. Chemical method antiscaling is to add chemical antiscaling agent, and to prevent the formation of scale by means of the complexing solubilization, dispersion and crystal distortion of antiscaling agent, but the chemical method has very limited effect, and the performance of the agent may change with time, pH value and formation temperature. The traditional acidification measure has a certain problem, and the Chinese patent document No. 104879105B is named as water injection well continuous injection acidification equipment and comprises an acid liquid storage tank, a hydraulic double-diaphragm metering pump, a control system, an acid liquid pipeline system, an online monitoring system and a truck moving system, wherein the acid liquid storage tank is connected with the hydraulic double-diaphragm metering pump, an outlet of the hydraulic double-diaphragm metering pump is connected with the acid liquid pipeline system, the control system is connected with the hydraulic double-diaphragm metering pump, the online monitoring system is connected with the acid liquid pipeline system, and a common steel base of the acid liquid storage tank, the hydraulic double-diaphragm metering pump and the control system is connected with a truck moving system chassis. The invention realizes efficient, rapid and large-scale blockage removal of the water injection well through online construction, reduces the water injection pressure and improves the water injection quantity. But it has problems that: firstly, be full of hydrogen ion in the whole water injection pipe, easy oxidation, the corruption of water injection tubular column, secondly the water injection well acidization volume is more and more big, and repeated acidizing well increases year by year, nevertheless increases and annotates the effect and more worsen, and the acidizing validity period is more and more short. Thirdly, the stratum liquid is acidized, so that the acid content of the petroleum produced in the later period is higher, the influence on the oil refining device in the later period is caused, and the oil refining cost is increased.
The method comprises the steps of installing the scale prevention and removal device underground, forming an inner pipe of a storage device and an outer pipe of the storage device into an annular cavity, filling hydrochloric acid liquid into the annular cavity, releasing hydrochloric acid when a water nozzle of an eccentric water distributor is scaled, carrying out chemical reaction with scales, and removing the scales, so that scale prevention and removal are realized. It has the following disadvantages: the annular cavity body is filled with hydrochloric acid liquid which has strong acidity and is suitable for a water injection well needing to quickly eliminate dirt or other special requirements; however, the device is inevitably collided sometimes in the process of ground operation and construction, and then the leakage of the device is caused, because liquid hydrochloric acid is adopted, the leakage can corrode other tools and cause environmental pollution, or when the hydrogen chloride gas is filled, the pollution can be caused to the well site environment, and greater potential safety hazard is generated. In addition, the scale prevention and removal device has the advantages that under the same volume, the amount of substances filled in the liquid hydrochloric acid is small, and the situation that the amount of the substances is insufficient in water injection wells with special requirements possibly exists, so that the scale prevention and removal time is relatively short, and the requirement for long-time scale prevention and removal cannot be met; the third problem is that liquid hydrochloric acid injects hydrochloric acid liquid or hydrogen chloride gas into the annular cavity through the check valve of the injection end when injecting, and when releasing, the export design is on the upper portion, and is pushed out from down to up through spring and piston, and whole process needs complicated mechanical structure to accomplish, and its manufacturing cost is high, and the reliability can not guarantee very stably.
Disclosure of Invention
The invention aims to provide an acid salt anti-scaling and descaling device for a water injection well, aiming at the defects in the prior art, the anti-scaling and descaling device is arranged underground, the device is replaced by powdery solid acid ammonium salt, more substances can be filled under the same volume, and the opening and releasing structure of a container is replaced, so that the powdery solid acid ammonium salt can form weak acid when water nozzles of a water distributor scale, and then the weak acid reacts with the dirt, thereby eliminating the dirt, prolonging the anti-scaling time, reducing the adverse effect of the anti-scaling device on the well site environment caused by collision and damage, and eliminating the potential safety hazard.
The invention provides an acid salt antiscaling and descaling device for a water injection well, which adopts the technical scheme that: the device comprises a lower baffle ring, a closing spring, a liquid outlet piston, pressure transmission capillary tubes, a protective sleeve, a container outer tube, a container inner tube, a central tube, an opening piston, a reset spring, a container gland, an upper baffle ring, a liquid outlet opening tube and a liquid outlet tube, wherein an annular cavity is formed by the container outer tube and the container inner tube, the container inner tube is sleeved on the outer wall of the central tube, powdery acidic ammonium salt is filled in the annular cavity, the lower baffle ring is arranged at the bottom of the annular cavity, the liquid outlet piston is connected to the upper side of the lower baffle ring through the closing spring, the annular cavity is contacted with the liquid outlet tube on the outer wall through the liquid outlet piston, a plurality of pressure transmission capillary tubes are arranged on the upper surface of the liquid outlet piston, the container gland is arranged at the top of the annular cavity, a liquid inlet channel is arranged in the container gland, the upper part of the liquid inlet channel is communicated with the liquid outlet tube of the central tube, the inner cavity of the liquid inlet channel is provided with the opening piston, the upper part of the opening piston is connected with the reset spring, and the upper baffle ring is arranged on the upper part of the container gland; the outer side of the outer pipe of the container is sleeved with a protective sleeve.
Preferably, the liquid outlet pipe comprises an inner liquid outlet pipe and an outer liquid outlet pipe, and the inner liquid outlet pipe penetrates through the inner pipe and the central pipe of the container to enable the annular cavity to be communicated with the inner cavity of the central pipe; the liquid outlet pipe penetrates through the outer pipe of the container and the protective sleeve, so that the annular cavity is communicated with the cavity of the sleeve.
Preferably, the lower baffle ring is provided with a plurality of pressure balance holes, so that the lower pressure of the liquid outlet piston is equal to the pressure of the inner cavity of the sleeve, each pressure balance hole corresponds to one closing spring, and the upper part of each closing spring is connected to the liquid outlet piston.
Preferably, a limiting table is arranged on the pipe wall of the annular cavity at the upper side of the liquid outlet piston and used for limiting the liquid outlet piston at a certain position at the upper part of the liquid outlet pipe.
The liquid outlet piston is of a circular structure, and the upper inner diameter, the lower inner diameter, the upper outer diameter and the lower outer diameter of the liquid outlet piston are equal, so that the pore diameters of an upper cavity and a lower cavity of an annular cavity formed by a container outer pipe and a container inner pipe are the same; the outer wall of the liquid outlet piston is contacted with the outer pipe of the container and the inner pipe of the container through a sealing ring.
The other liquid outlet piston is of a circular structure, the section of the upper part of the liquid outlet piston is of a conical structure, so that the area of the upper side is different from that of the lower side, in addition, the aperture of a cavity at the lower part of an annular cavity formed by the outer container pipe and the inner container pipe is larger than that of the cavity at the upper part, the upper part of the liquid outlet piston is matched with the upper cavity of the annular cavity, the lower part of the liquid outlet piston is matched with the upper cavity of the annular cavity, and the upper part of the liquid outlet piston is contacted with the upper parts of the outer container pipe and the inner container pipe through a small sealing ring; the lower part of the liquid outlet piston is contacted with the lower parts of the outer pipe and the inner pipe of the container through a large sealing ring.
Preferably, a gap of 2-10mm is reserved between the upper end of the pressure transmission capillary tube and the bottom of the container gland, the lower end of the pressure transmission capillary tube is in contact with the upper surface of the liquid outlet piston, and the pressure transmission capillary tube is made of pvc materials or polytetrafluoroethylene materials.
Preferably, the liquid outlet piston is provided with a vertical liquid outlet hole which is communicated up and down, a polytetrafluoroethylene sealing ball and an inner spring are arranged in the vertical liquid outlet hole, and the inner spring is connected with a closing spring on the lower side through a spring base.
Preferably, the lower part of the central pipe is connected with a water distributor through a coupling, a lower packer is arranged in an annular space between a sleeve pipe at the lower part of the water distributor and the central pipe, the upper part of the central pipe is communicated with a water injection pipe column, and an upper packer is arranged in the annular space between the sleeve pipe and the central pipe.
Preferably, the acid salt is ammonium chloride, ammonium sulfate or ammonium nitrate solid powder.
The invention has the beneficial effects that: the invention installs the water injection well acid salt antiscaling and descaling device on the upper part of the water distributor of the underground central pipe, when the water nozzle of the water distributor scales, the pressure in the central pipe will increase, when the pressure increases to be larger than the pressure of the closing spring, the liquid will go through the liquid outlet opening pipe and make the opening piston go down, make the opening piston open the liquid inlet channel, the oil field reinjection water enters and takes place the hydrolysis reaction with the acid ammonium salt to form the weak acid, at the same time, the oil field reinjection water flows to the upper surface of the liquid outlet piston through the pressure transmission capillary, and push the liquid outlet piston to move downwards, compress the closing spring to move downwards, when the liquid outlet piston moves to the underside of the liquid outlet pipe as a whole, the acid ammonium salt that is generated by the reaction with the water continuously flows into the cavity between the sleeve and the central pipe through the liquid outlet pipe, and reacts with the scale formed in the water distributor and the sleeve, in addition, the descaling also flows into the inner cavity of the central pipe through the liquid outlet pipe, thus reacts to the water inlet of the water distributor, until the scale inside and outside of the water nozzle and inner cavity of the central pipe of the water distributor is removed, thus realizing the water nozzle and preventing and scaling of the water distributor; in addition, compared with the prior art, as the powdery solid acidic ammonium salt is adopted, the amount of substances in the same container is more, the anti-scaling time is longer, the frequent shut-in operation caused by the scaling problem is avoided, and the operation cost is greatly reduced; moreover, because the powdery solid acidic ammonium salt is adopted, the problems of liquid leakage and damage of the acid salt anti-scaling and descaling device of the water injection well are avoided during well site construction, the environment pollution and the corrosion effect on other metal devices in the well site are avoided, and the potential safety hazard is eliminated; the third advantage is simple structure, need not design complicated structure and accomplish and pour into and release, only need pack into annular cavity with solid powder when the installation, when the field usage, oil field reinjection water is with its hydrolysis production acid, slowly releases from the drain pipe of lower part, and its reliability is high, and stable performance obtains large tracts of land popularization easily.
Drawings
FIG. 1 is a schematic structural view in examples 1 to 3 of the present invention;
FIG. 2 is a schematic representation of the operation of examples 1-3 of the present invention to release a solid powder;
FIG. 3 is a schematic structural view of embodiment 4 of the present invention;
FIG. 4 is a schematic view of the construction of the container closure;
FIG. 5 is a schematic view of the opening piston;
in the upper diagram: the device comprises a sleeve 1, a water distributor 2, a coupling 3, a water injection pipe column 4, a lower baffle ring 5, a closing spring 6, a liquid outlet piston 7, a pressure transmission capillary tube 8, a protective sleeve 9, a container outer pipe 10, a container inner pipe 11, a central pipe 12, an opening piston 13, a return spring 14, a container gland 15, an upper baffle ring 16, a liquid outlet opening pipe 17, a liquid outlet pipe 18, an upper packer 19, a lower packer 20, a pressure balance hole 21 and a limiting table 22;
an upper end head 13.1, a lower end head 13.2, a middle body 13.3 and a sealing groove 13.4; the upper cover body 15.1, the lower main body 15.2, the second liquid inlet channel 15.3, the third liquid inlet channel 15.4, the first liquid inlet channel 15.5, the sealing groove 15.6, the perforation 1.1 and the water nozzle 2.1.
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.
In the embodiment 1, the invention provides an acid salt scale prevention and removal device for a water injection well, which refers to the attached drawings 1-2, and the technical scheme is as follows: the container comprises a lower baffle ring 5, a closing spring 6, a liquid outlet piston 7, pressure transmission capillary tubes 8, a protective sleeve 9, a container outer tube 10, a container inner tube 11, a central tube 12, an opening piston 13, a reset spring 14, a container gland 15, an upper baffle ring 16, a liquid outlet opening tube 17 and a liquid outlet tube 18, wherein the container outer tube 10 and the container inner tube 11 form an annular cavity, the container inner tube 11 is sleeved on the outer wall of the central tube 12, powdery ammonium chloride solid is filled in the annular cavity, the bottom of the annular cavity is provided with the lower baffle ring 5, the upper side of the lower baffle ring 5 is connected with the liquid outlet piston 7 through the closing spring 6, the annular cavity is contacted with the liquid outlet tube 18 on the outer wall through the liquid outlet piston 7, the upper surface of the liquid outlet piston 7 is provided with a plurality of pressure transmission capillary tubes 8, the top of the annular cavity is provided with the container gland 15, a liquid inlet channel is arranged in the container gland 15, the upper part of the liquid inlet channel is communicated with the liquid outlet opening tube 17 of the central tube 12, the inner cavity of the liquid inlet channel is provided with the opening piston 13, the upper part of the opening piston 13 is connected with the reset spring 14, and the upper baffle ring 16 is arranged on the upper part of the container gland 15; the outer side of the outer pipe 10 of the container is sleeved with a protective sleeve 9.
Referring to fig. 1 and 2, the liquid outlet pipe 18 of the present invention comprises an inner liquid outlet pipe and an outer liquid outlet pipe, wherein the inner liquid outlet pipe passes through the inner pipe 11 and the central pipe 12 of the container to communicate the annular cavity with the inner cavity of the central pipe 12, and the outer liquid outlet pipe passes through the outer pipe 10 of the container and the protective sleeve 9 to communicate the annular cavity with the cavity of the sleeve 1. Interior drain pipe is after going out liquid piston 7 and moving down, can be with the interior liquid of center tube through the supplementary flow direction sleeve pipe cavity of play liquid pipe, simultaneously with the supplementary sleeve pipe cavity of taking to of the acid ammonium salt of dissolving, when inside and outside pressure balance, the acid ammonium salt of dissolving also can be through interior drain pipe reverse inflow center tube inner chamber, the reaction of descaling is carried out to the inboard of water injection well choke, at this moment, pressure balance can lead to going up of liquid piston 7, close inlet channel, if the dirt of water injection well choke department can not be eliminated to the amount of the acid ammonium salt of this release, can be again inside and outside pressure disequilibrium, the opening process of play liquid piston 7 is repeated once more, release acid ammonium salt once more, the dirt of up to the water injection well choke is eliminated.
Referring to the attached drawings 1 and 2, a plurality of pressure balance holes 21 are arranged on the lower baffle ring 5, so that the lower pressure of the liquid outlet piston 7 is equal to the pressure of the inner cavity of the sleeve 1, each pressure balance hole corresponds to one closing spring 6, the upper part of each closing spring is connected to the liquid outlet piston 7, the liquid outlet piston 7 is of a circular structure, the upper inner diameter, the lower inner diameter, the upper outer diameter and the lower outer diameter of the liquid outlet piston are equal, and the pore diameters of the upper cavity and the lower cavity of an annular cavity formed by the outer container pipe 10 and the inner container pipe 11 are the same; the outer wall of the liquid outlet piston 7 is contacted with the outer container pipe 10 and the inner container pipe 11 through sealing rings.
It should be noted that: the pipe wall of the annular cavity at the upper side of the liquid outlet piston 7 is provided with a limiting table 22 for limiting the liquid outlet piston 7 at a certain position at the upper part of the liquid outlet pipe 18. The limiting table has the function of enabling the opening pressure of the invention to be a constant value, and compared with the opening pressure of the last patent application of the inventor mentioned in the comparison document, the opening pressure of the last patent application of the inventor is dynamic, so that the judgment and the control of ground operators are facilitated.
The upper portion of the liquid inlet channel of the embodiment is provided with a necking part, a cylindrical structure can be adopted, the inner diameter of the liquid inlet channel is smaller than that of the middle part, the opening piston 13 is matched with the necking part, when liquid is fed, the opening piston 13 moves downwards to enter the middle part with the larger inner diameter, and therefore the liquid inlet amount is enlarged.
In addition, the upper end of the pressure transmission capillary tube 8 and the bottom of the container gland 15 provided by the invention are provided with a 2-10mm gap, the lower end of the pressure transmission capillary tube is contacted with the upper surface of the liquid outlet piston 7, the pressure transmission capillary tube 8 is made of pvc material or polytetrafluoroethylene material, a certain gap is left between the pressure transmission capillary tube and the opening piston to avoid blocking the pressure transmission capillary tube, the gap is left to enable liquid to enter the pressure transmission capillary tube more easily, then the liquid transmits pressure downwards, and further the closing spring can be compressed to enable the closing spring to be opened smoothly, and the description is as follows: pass and press capillary 8's main effect to be used for opening play liquid piston 7, in addition, has laid a plurality of apertures on passing and press capillary 8, and the oil field reinjection hydroenergy of being convenient for oozes the outside through the aperture, takes place the reaction with the powdered acid ammonium salt of solid to the acid that generates flows down along the outer pipe wall of passing and pressing capillary, flows out until passing through drain pipe 18, and then takes place chemical reaction to the incrustation scale, thereby eliminates the incrustation scale.
In addition, the lower part of the central tube 12 of the invention is connected with the water distributor 2 through the coupling 3, the water nozzle 2.1 is arranged on the water distributor 2, when water is normally injected, the oilfield reinjection water enters the cavity of the casing through the water nozzle 2.1 and then is pressed into the stratum through the perforation 1.1 of the casing. A lower packer 20 is arranged in an annular space between a sleeve and a central pipe at the lower part of the water distributor 2, the upper part of the central pipe 12 is communicated with the water injection string 4, and an upper packer 19 is arranged in the annular space between the sleeve and the central pipe.
Preferably, the acidic ammonium salt is ammonium chloride.
Referring to fig. 4, the container cap 15 of the present invention includes an upper cap body 15.1, a lower main body 15.2, a second liquid inlet channel 15.3, a third liquid inlet channel 15.4, a first liquid inlet channel 15.5, and a seal groove 15.6, wherein the upper cap body 15.1 is disposed on the top of the lower main body 15.2, a plurality of first liquid inlet channels 15.5 are transversely disposed in the upper cap body 15.1, such that one end of the first liquid inlet channel 15.5 is communicated with the inner cavity, the other end is communicated with the second liquid inlet channel 15.3, the lower portion of the second liquid inlet channel 15.3 is communicated with the third liquid inlet channel 15.4, and an inner diameter of the second liquid inlet channel 15.3 is greater than an inner diameter of the third liquid inlet channel 15.4.
When in use, the opening piston 13 is arranged in the second liquid inlet channel 15.3 and the third liquid inlet channel 15.4, and the return spring 14 is arranged at the lower side of the second liquid inlet channel 15.3.
Referring to fig. 5, the structure of the opening piston 13 includes an upper end 13.1, a lower end 13.2 and a middle body 13.3, the diameter of the upper end 13.1 is larger than that of the lower end 13.2, and the outer diameter of the middle body 13.3 is smaller than that of the lower end 13.2; the upper end head 13.1 is provided with a sealing groove 13.4, when the pressure in the central tube is greater than the pressure of the sealing spring, the water injection of the central tube extrudes the upper end head 13.1 through the liquid outlet opening tube, and pushes the upper end head 13.1 to move downwards, and then drives the lower end head 13.2 to move downwards until the lower end head is inserted into the annular cavity filled with solid powder, and because the outer diameter of the intermediate body 13.3 is small, the water can smoothly flow out, and is collected into the pressure transmission capillary tube, and then the liquid outlet piston is opened, so that more water enters the annular cavity filled with the solid powder, and the water reacts with acidic ammonium salt to produce weak acid.
The use method of the water injection well acid salt scale prevention and removal device provided by the invention comprises the following steps:
1. assembling an acid salt anti-scaling and descaling device of a water injection well, connecting the upper end of the acid salt anti-scaling and descaling device of the water injection well with a water injection pipe column 4, connecting the lower end of the acid salt anti-scaling and descaling device of the water injection well with a water distributor 2, and separating an annular space between the water injection pipe column 4 and a sleeve 1 by an upper packer and a lower packer to separate a water injection layer from other layers;
2. when injecting oilfield reinjection water from a wellhead through the water injection pipe column 4, injecting the oilfield reinjection water into a well through the water injection pipe column 4, spraying the oilfield reinjection water into an annular space between the central pipe 12 and the casing 1 from an inner cavity of the water injection pipe column through a water nozzle 2.1 of the water distributor 2, and entering a stratum through a perforation hole 1.1 outside the casing 1, so that water injection of the stratum is realized, the pressure of the stratum is improved, and at the moment, the acid salt anti-scaling and descaling device of the water injection well is in a waiting working state;
3. in the reinjection process of oilfield reinjection water, the wellhead water injection pressure is 5-15 MPa, because the oilfield reinjection water is low in temperature and high in calcium ion and magnesium ion content, when the oilfield reinjection water passes through a water nozzle 2.1 of a water distributor 2, because the diameter of a through hole of the water nozzle is small and generally ranges from 3 mm to 5 mm, scaling is easy, the pressure difference between the liquid pressure of an inner cavity of a water injection pipe column and an outer cavity is increased after scaling, a water injection passage is blocked, the pressure of the inner cavity of the water injection pipe column is increased, when the pressure difference is larger than the pressure of a closing spring 6, liquid passes through a liquid outlet opening pipe 17 and an opening piston 13 to move downwards, the opening piston 13 opens a liquid inlet channel, the oilfield reinjection water enters and undergoes a hydrolysis reaction with powdery solid taking ammonium chloride as an example to form weak acid, meanwhile, the oilfield reinjection water flows onto the upper surface of a liquid outlet piston 7 through a pressure transfer capillary 8 and pushes the liquid outlet piston 7 to move downwards, the closing spring 6 is compressed to move downwards, when the liquid outlet piston 7 integrally moves to the lower side of the liquid outlet pipe 18, a scale source generated by the acid ammonium salt and water reaction flows into the inner cavity of the liquid outlet pipe 18, and the central pipe, and a reaction product is formed in the central pipe, so that the central pipe and the central pipe so that the water distributor 2 is removed.
4. When the inner and outer scales of the water distributor 2 are removed, the pressure difference between the liquid pressure of the inner cavity of the water injection pipe column and the outer cavity is reduced, the closing spring returns to drive the liquid outlet piston 7 to move upwards, so that the liquid outlet pipe is closed, the liquid outlet opening pipe 17 at the top is also closed, at the moment, the liquid outlet opening pipe is closed in the annular cavity between the outer pipe 10 of the container and the inner pipe 11 of the container, and the steps 1-3 are repeated when the next water distributor is subjected to scaling.
Wherein, the descaling process in step 3 needs to be further described:
in the process that the liquid outlet piston 7 moves downwards to the lower side of the liquid outlet pipe 18, part of oilfield reinjection water passing through the liquid outlet opening pipe 17 from the central pipe firstly meets solid powder at the top of the annular cavity, at the moment, chemical reaction begins to occur, generated H ions flow downwards along the outer wall of the pressure transfer capillary, in addition, the other part of oilfield reinjection water directly flows to the upper surface of the liquid outlet piston 7 along the pressure transfer capillary, as the pressure of the liquid in the central pipe is high, the liquid outlet piston 7 is pushed to move downwards until the liquid outlet pipe 18 is completely exposed, at the moment, the oilfield reinjection water in the central pipe directly enters the annular cavity through the liquid outlet pipe 18, the powdery solid is dissolved and simultaneously flushed into the cavity between the sleeve and the protection pipe, and then the generated H ions continuously flow into the oil field reinjection water until the pressure inside and outside the central pipe is balanced again, and the water nozzle 2.1 of the water distributor at the lower part and the dirt in the sleeve are reacted; when the internal and external pressures reach balance, the generated H ions flow into the inner cavity of the central tube along the liquid outlet tube to carry out chemical reaction for removing scale on a water nozzle of the water distributor and scale on the central tube, and at the moment, the liquid outlet piston 7 also moves upwards under the action of the closing spring 6 to close the liquid outlet tube. When the pressure of the inner cavity of the central tube is larger than the pressure of the sleeve again, the steps are repeated again, the liquid outlet piston 7 moves downwards, the hydrolyzed acid is released again to perform chemical reaction with the dirt, until the dirt at the water nozzle of the water distributor is completely removed, the oilfield reinjection water in the central tube enters the sleeve through the water distributor and then is injected into the formation energy through the perforation 1.1 on the sleeve, and normal energy supplement is realized.
In embodiment 2, the invention provides a device for preventing and removing scale from acidic salt in a water injection well, wherein powdery ammonium sulfate solid is filled in an annular cavity formed by an outer tube 10 of a container and an inner tube 11 of the container, and the ammonium sulfate has weak acidity after meeting water, can also react with scales, and further achieves the purposes of removing and preventing scale, the using method of the device is the same as that of embodiment 1, and the dosage is adjusted according to the scaling condition of the water injection well.
In embodiment 3, the invention provides a device for preventing and removing scale from acidic salt in a water injection well, wherein powdery ammonium nitrate solid is filled in an annular cavity formed by an outer tube 10 of a container and an inner tube 11 of the container, and ammonium nitrate has weak acidity after meeting water and can react with the scale, so that the purposes of removing and preventing scale are achieved. The application method is the same as that of the embodiment 1, and the dosage is adjusted according to the scaling condition of the water injection well.
Further, there are differences from examples 1 to 3 in that: the shapes of the liquid inlet channels arranged in the container gland 15 are different, the upper part of the liquid inlet channel of the embodiment is provided with a necking part, a square structure can be adopted, the inner diameter of the necking part is smaller than that of the middle part, the opening piston 13 is matched with the necking part, and the opening piston 13 moves downwards when liquid is fed, so that the rotation of the opening piston is avoided, and the opening piston is limited to move up and down.
The advantages of the structure are: firstly, a limit platform is not needed to be arranged above the liquid outlet pipe, the limit action enables the opening pressure of the liquid outlet piston to be a constant value, the opening pressure is constant compared with the opening pressure of the last patent application of the inventor mentioned in a comparison document, the opening pressure of the comparison document is dynamic, and secondly, the local section of the upper part is of a conical structure, so that the area of the upper side and the area of the lower side are accumulated in a difference area, and thus, the liquid outlet piston is more easily pushed to open.
In addition, the liquid outlet piston 7 of the invention is provided with a vertical liquid outlet hole which is communicated up and down, a polytetrafluoroethylene sealing ball and an inner spring are arranged in the vertical liquid outlet hole, and the inner spring is connected with a closing spring 6 at the lower side through a spring base. When the pressure difference is too large, a check valve formed by the polytetrafluoroethylene sealing ball and the inner spring can be opened, the liquid outlet amount is increased, and the scaling condition of the lower baffle part is reduced.
The use method of the water injection well acid salt scale prevention and removal device provided by the invention comprises the following steps:
1. assembling an acid salt anti-scaling and descaling device of a water injection well, connecting the upper end of the acid salt anti-scaling and descaling device of the water injection well with a water injection pipe column 4, connecting the lower end of the acid salt anti-scaling and descaling device of the water injection well with a water distributor 2, and separating an annular space between the water injection pipe column 4 and a sleeve 1 by an upper packer and a lower packer to separate a water injection layer from other layers;
2. when injecting oilfield reinjection water from a wellhead through the water injection pipe column 4, injecting the oilfield reinjection water into a well through the water injection pipe column 4, spraying the oilfield reinjection water into an annular space between the central pipe 12 and the casing 1 from an inner cavity of the water injection pipe column through a water nozzle of the water distributor 2, and entering a stratum through a perforation outside the casing 1 to realize water injection of the stratum and improve the pressure of the stratum, wherein at the moment, the acid salt anti-scaling and descaling device of the water injection well is in a waiting working state;
3. in the reinjection process of oilfield reinjection water, the wellhead water injection pressure is 5-15 MPa, because the oilfield reinjection water is low in temperature and high in calcium ion and magnesium ion content, when the oilfield reinjection water passes through a water nozzle of the water distributor 2, because the diameter of a through hole of the water nozzle is small and is generally 3-5 mm, scaling is easy, the pressure difference between the liquid pressure of an inner cavity of a water injection pipe column and an outer cavity is increased after scaling, a water injection passage is blocked, the pressure of the inner cavity of the water injection pipe column is increased, when the pressure difference is larger than the pressure of the closing spring 6, liquid passes through the liquid outlet opening pipe 17 and the opening piston 13 descends, the opening piston 13 opens a liquid inlet passage, the oilfield reinjection water enters and is hydrolyzed with acidic ammonium salt to form weak acid, meanwhile, the oilfield reinjection water flows to the upper surface of the liquid outlet piston 7 through the pressure transfer capillary 8, because of the upper surface and the lower surface of the liquid outlet piston 7 are different, the liquid outlet piston is more easily pushed to descend, the closing spring 6 is compressed to move downwards, when the liquid outlet piston 7 integrally moves to the lower side of the liquid outlet pipe 18, a source generated by the acidic ammonium salt which reacts with the inner cavity of the liquid outlet pipe 18, and the central pipe, and the water distributor, and the central pipe can continuously remove water inlet pipe, and the scale.
4. When the scales inside and outside the water distributor 2 are removed, the pressure difference between the liquid pressure of the inner cavity of the water injection pipe column and the outer cavity is reduced, the closing spring returns to drive the liquid outlet piston 7 to move upwards, so that the liquid outlet pipe is closed, the liquid outlet opening pipe 17 at the top is also closed, at the moment, the liquid outlet opening pipe is closed in the annular cavity between the outer pipe 10 of the container and the inner pipe 11 of the container, and the steps 1-3 are repeated when the next water distributor is subjected to scaling.
The invention has the advantages that: the powdery solid acidic ammonium salt is adopted, the amount of substances in the same container is more, the anti-scaling time is longer, the frequent shut-in operation caused by the scaling problem is avoided, and the operation cost is greatly reduced; moreover, because the powdery solid acidic ammonium salt is adopted, the problems of liquid leakage and damage of the acid salt anti-scaling and descaling device of the water injection well are avoided during well site construction, the environment pollution and the corrosion effect on other metal devices in the well site are avoided, and the potential safety hazard is eliminated; in addition, because the powdery solid acidic ammonium salt is adopted, the method and the structure for releasing the acidic ammonium salt are greatly different from those for releasing liquid hydrochloric acid or hydrogen chloride gas, the problems existing on site are solved, the device is suitable for water injection wells requiring long descaling and antiscaling time, and users can select different descaling and antiscaling devices according to different well conditions.
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.
Claims (4)
1. The utility model provides a water injection well scale removal device which characterized by: comprises a lower baffle ring (5), a closing spring (6), a liquid outlet piston (7), a pressure transmission capillary tube (8), a protective sleeve (9), a container outer tube (10), a container inner tube (11), a central tube (12), an opening piston (13), a reset spring (14), a container gland (15), an upper baffle ring (16), a liquid outlet opening tube (17) and a liquid outlet tube (18), an annular cavity formed by the container outer tube (10) and the container inner tube (11), wherein the container inner tube (11) is sleeved on the outer wall of the central tube (12), powdery acidic ammonium salt is filled in the annular cavity, a lower baffle ring (5) is arranged at the bottom of the annular cavity, the upper side of the lower baffle ring (5) is connected with a liquid outlet piston (7) through a closing spring (6), the annular cavity is contacted with a liquid outlet pipe (18) on the outer wall through a liquid outlet piston (7), a plurality of pressure transmission capillary tubes (8) are arranged on the upper surface of the liquid outlet piston (7), a container gland (15) is arranged at the top of the annular cavity, a liquid inlet channel is arranged in the container gland (15), the upper part of the liquid inlet channel is communicated with a liquid outlet opening pipe (17) at the upper part of the central pipe (12), an opening piston (13) is arranged in the inner cavity of the liquid inlet channel, and a return spring (14) is connected to the upper part of the opening piston (13), an upper baffle ring (16) is arranged at the upper part of the container gland (15); the outer side of the outer pipe (10) of the container is sleeved with a protective sleeve (9);
the liquid outlet piston (7) is of a circular structure, the section of the upper part of the liquid outlet piston is of a conical structure, so that the area of the upper side is different from that of the lower side, in addition, the aperture of a cavity at the lower part of an annular cavity formed by the outer container pipe (10) and the inner container pipe (11) is larger than that of the cavity at the upper part, the upper part of the liquid outlet piston (7) is matched with the upper cavity of the annular cavity, the lower part of the liquid outlet piston (7) is matched with the lower cavity of the annular cavity, and the upper part of the liquid outlet piston (7) is contacted with the upper parts of the outer container pipe (10) and the inner container pipe (11) through a small sealing ring; the lower part of the liquid outlet piston (7) is contacted with the lower parts of the outer pipe (10) and the inner pipe (11) of the container through a large sealing ring.
2. The water injection well descaling device according to claim 1, wherein: the liquid outlet piston (7) is provided with a vertical liquid outlet hole which is communicated up and down, a polytetrafluoroethylene sealing ball and an inner spring are arranged in the vertical liquid outlet hole, and the inner spring is connected with a closing spring (6) on the lower side through a spring base.
3. The water injection well descaling device of claim 1, wherein: the liquid outlet pipe (18) comprises an inner liquid outlet pipe and an outer liquid outlet pipe, and the inner liquid outlet pipe penetrates through the inner pipe (11) and the central pipe (12) of the container to enable the annular cavity to be communicated with the inner cavity of the central pipe (12); the liquid outlet pipe penetrates through the outer container pipe (10) and the protective sleeve (9) to enable the annular cavity to be communicated with the cavity of the sleeve (1).
4. The water injection well descaling device of claim 1, wherein: the lower retaining ring (5) is provided with a plurality of pressure balance holes, so that the lower pressure of the liquid outlet piston (7) is equal to the pressure of the inner cavity of the sleeve (1); and each pressure balance hole corresponds to one closing spring (6), and the upper part of each closing spring is connected to the liquid outlet piston (7).
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| CN202010310171.XA CN111577206B (en) | 2018-04-24 | 2018-04-24 | Water injection well descaling device and method |
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| CN202010310171.XA CN111577206B (en) | 2018-04-24 | 2018-04-24 | Water injection well descaling device and method |
| CN201810372584.3A CN108716384B (en) | 2018-04-24 | 2018-04-24 | Acid salt scale prevention and removal device for water injection well |
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| CN201810372584.3A Division CN108716384B (en) | 2018-04-24 | 2018-04-24 | Acid salt scale prevention and removal device for water injection well |
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| CN109538163B (en) * | 2019-01-29 | 2023-05-16 | 吉林大学 | Ultrasonic vibration combined well washer and well washing method |
| US11598154B2 (en) * | 2019-07-01 | 2023-03-07 | Baker Hughes Oilfield Operations Llc | System and method for conditioning a downhole tool |
| CN112943193A (en) * | 2021-03-19 | 2021-06-11 | 大庆油田有限责任公司 | Preparation and injection integrated acidizing plug removal process |
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| US5135050A (en) * | 1991-04-23 | 1992-08-04 | Den Norske Stats Oljeselskap A.S. | Device for collecting particulate matter and debris in horizontal or high-deviation oil or gas wells |
| CN201184170Y (en) * | 2008-04-17 | 2009-01-21 | 翟福顺 | Slow corrode scale inhibition tube |
| CN104818962A (en) * | 2015-04-17 | 2015-08-05 | 西南石油大学 | Removing method for gas recovery well shaft aquo-complex blockage |
| CN106522886A (en) * | 2016-12-28 | 2017-03-22 | 河南东晟环保科技股份有限公司 | Integrated wellhead continuous dosing device |
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| CN111577206A (en) | 2020-08-25 |
| CN108716384A (en) | 2018-10-30 |
| CN108716384B (en) | 2020-09-29 |
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