CN114311451A - Glue injection method for downhole instrument - Google Patents

Abstract

The invention provides a glue injection method for an underground instrument, which comprises the following steps: putting the underground instrument into a first mold, and injecting a first glue solution to form a first glue body for coating the underground instrument; taking out the first colloid from the first mold, and carrying out a first performance test on the first colloid; putting the first colloid into a second mold, and injecting a second glue solution to form a second colloid coating the first colloid; and taking out the second colloid from the second mold, and carrying out a second performance test on the second colloid.

Description

Glue injection method for downhole instrument

Technical Field

The invention relates to the field of petroleum drilling engineering, in particular to a method for injecting glue to an underground instrument.

Background

Downhole instruments such as measurement while drilling instruments and logging while drilling instruments have been widely used in drilling projects. However, the downhole operation is affected by the drilling environment, especially high temperature and pressure, strong shock and vibration, and thus higher requirements are put on the measurement while drilling instrument and the logging while drilling instrument.

At present, all the electronic components (e.g., circuit boards, chips, sensors, battery cells, etc.) used in these instruments need to be able to withstand higher temperatures and pressures. To ensure that the various chips operate stably and reliably at high temperatures, the chips are usually sealed in a relatively thermally insulating space. However, such insulation space tends to result in a reduction in resistance to shock and pressure. In addition, since all selected electronic components have not yet found a high-temperature high-voltage substitute, it is an expedient to reserve a plurality of non-high-temperature high-voltage regions in the circuit design. However, these non-high temperature and high pressure zones take up too much tool space, which has a significant impact on the downhole space, which is very limited in nature. In addition, the flexibility and the stress strength of the whole circuit board are seriously reduced due to the adoption of a higher soldering process and the intensive use of large-scale chips.

Therefore, a method for protecting a circuit board by injecting glue at high temperature and high pressure is proposed in the prior art. Such methods are relatively simple, simply by applying the glue directly to the circuit board. The method does not take the influence of the thickness, density, hardness and uniformity of the colloid after glue injection molding into consideration. If the gel is too thick, the circuit board does not dissipate heat well. If the colloid has pores, the colloid is easy to deform or even collapse under the action of external force. If the hardness of the colloid is low, the colloid can not resist the extrusion impact of external force, so that the purpose of high-temperature and high-pressure glue injection protection can not be achieved.

A method for injection protection using an injection mold is subsequently proposed, wherein the downhole instrument is placed in the mold and then injected with the glue solution. However, the downhole tool obtained in this way has large performance fluctuation and cannot be stably used in a downhole high-temperature and high-pressure environment.

Disclosure of Invention

The invention aims to provide a glue injection method for a downhole instrument.

The glue injection method for the downhole instrument comprises the following steps: putting the underground instrument into a first mold, and injecting a first glue solution to form a first glue body coating the underground instrument; taking the first colloid out of the first mold, and carrying out a first performance test on the first colloid; putting the first colloid into a second mold, and injecting a second glue solution to form a second colloid coating the first colloid; and taking out the second colloid from the second mold, and carrying out a second performance test on the second colloid.

According to an embodiment of the present invention, the first glue solution is a high temperature and high pressure resistant glue solution for absorbing vibration and impact and dispersing stress distribution on the downhole instrument, and the second glue solution is an impact vibration resistant glue solution for resisting deformation of the downhole instrument caused by an external force.

According to one embodiment of the invention, pre-treating the downhole tool prior to placing the downhole tool in the first mold comprises at least one of: cleaning the outer surface, removing dust and impurities, spraying waterproof liquid, dustproof liquid or anti-corrosion liquid, and coating a PCB nano waterproof film.

According to one embodiment of the present invention, the first performance test and the second performance test each include a temperature test and a pressure test.

According to one embodiment of the invention, the signal amplitude variation of the downhole tool is recorded during the temperature test and the pressure test.

According to one embodiment of the invention, the test result of the downhole instrument is judged to be qualified when: the underground instrument is a sensor, and the signal amplitude variation is lower than 0.1%; the underground instrument is a circuit board, and the signal amplitude variation is lower than 0.2%; the downhole instrument is other components, and the variation of the signal amplitude is less than 1%.

According to one embodiment of the invention, a temperature test is performed first, and then a pressure test is performed, and the interface of the first colloid or the second colloid is subjected to pressure-resistant protection between the temperature test and the pressure test.

According to one embodiment of the invention, the first mould comprises two half-mould parts used in pairs, which together enclose a closed cavity for injecting glue. Wherein, the both sides of inner chamber all are provided with a plurality of ear groove. At least one of the half-mould parts further comprises a protrusion arranged at a corner of the cavity, such that the first gel formed has a notch.

According to one embodiment of the invention, the second mold comprises an upper mold half and a lower mold half, which can be fixedly connected together, together defining an inner cavity for a second shot of glue, in which the first glue mass can be accommodated.

According to one embodiment of the invention, at least one inner surface of the upper die half body and the lower die half body is provided with a plurality of uniformly arranged grooves, so that at least one surface of the formed second colloid is provided with protrusions. At least one of the upper die half body and the lower die half body is provided with an insertion hole for a fixing piece to penetrate through so as to fix the first glue placed in the fixing piece.

Drawings

The invention will be described in detail below with reference to the attached drawing figures, in which:

FIG. 1 schematically illustrates an overall structure of a glue injection apparatus for a downhole tool according to the present invention;

fig. 2A and 2B schematically show the structure of a first mold for forming a first gel according to an embodiment of the present invention;

fig. 3 schematically shows a first glue obtained by a first glue injection using the first mold shown in fig. 2A and 2B;

FIGS. 4 and 5 schematically illustrate an upper mold half and a lower mold half, respectively, of a second mold used in an injection molding apparatus for a downhole tool according to an embodiment of the present invention;

fig. 6 and 7 schematically show a second glue obtained by a second glue injection using the second mold shown in fig. 4 and 5, respectively;

figures 8 and 9 show curves of temperature and pressure tests, respectively, performed on a first colloid;

FIGS. 10 and 11 show plots of temperature and pressure tests, respectively, performed on the second colloid;

FIGS. 12 and 13 show data comparison curves for a first temperature test and a second temperature test, respectively, for different downhole tools; and

fig. 14 and 15 show data comparison curves for a first pressure test and a second pressure test, respectively, for different downhole tools.

The figures are not drawn to scale and certain details in the figures are intentionally exaggerated to show desired details.

Detailed Description

The invention will be further explained with reference to the drawings.

Fig. 1 schematically shows the overall structure of a glue injection apparatus 100 for a downhole tool according to the present invention. As shown in FIG. 1, the glue injection device 100 comprises a glue solution storage tank 1-1 mounted on a support table 1-2, and a mold 1-8 mounted on a support frame 1-9. The glue solution tank 1-1 is a container for containing a glue solution to be injected, wherein a stirrer (not shown) may be provided to stir the glue solution contained therein.

The colloid from the colloid storage tank 1-1 is provided to the colloid injection port 1-6 of the mould 1-8 through the draft tube 1-3. For this, a glue injector 1-5 is provided at the end of the draft tube 1-3, which is disposed to be aligned with the glue injection port 1-6, so that the glue solution can be accurately injected into the mold 1-8. According to a preferred embodiment of the present invention, the alignment of the dispenser 1-5 with the dispensing opening 1-6 can be easily achieved by adjusting the angle and height of the support frame 1-9. In addition, a plurality of exhaust ports 1-7 can be arranged on the molds 1-8 to allow the gas in the molds 1-8 to be exhausted in the glue injection process.

In order to adjust the glue injection speed, a flow limiting valve 1-4 can be arranged on the flow guiding pipe 1-3. In addition, if the glue solution is thick, a booster (not shown) can be arranged on the guide pipe 1-3.

The above components of the glue solution storage tank 1-1, the flow guide pipe 1-3, the flow limiting valve 1-4, the glue injector 1-5 and the like are well known to those skilled in the relevant art, and thus detailed descriptions thereof will be omitted herein.

The applicant of the application finds that the performances of high temperature and high pressure resistance, high vibration resistance and strong impact resistance of the underground instrument can be greatly improved by a method of injecting glue twice. Specifically, the first injection of a relatively hard glue solution (i.e., the first glue solution) has the function of resisting high temperature and high pressure. And then, relatively soft glue solution (namely, second glue solution) is injected for the second time, so that the shock resistance and the shock absorption are realized. Meanwhile, the circuit board and the corresponding power supply units such as the sensors or the batteries are combined together in a glue injection mode, so that the installation and allocation are easy, and more instrument spaces can be saved. Through twice glue injection, the obtained underground instrument can stably work in severe drilling measurement environments such as high temperature, high pressure, high vibration, strong impact and the like.

According to the invention, the first glue solution can be selected from a high-temperature and high-pressure resistant glue solution for preventing the chip pins, the contacts and the like from being damaged by high temperature and high pressure. The second glue solution can be selected to be a glue solution resisting shock and vibration and used for balancing instant extrusion and impact of external shock and vibration on the battery (or the battery pack), the circuit board, the sensor and other small mechanical structure parts and the like.

In view of this, the molds 1-8 of the glue injection apparatus 100 for a downhole tool according to the present invention include a first mold for first injecting glue and a second mold for second injecting glue. In the actual use process, a first mold is firstly installed on the support frames 1-9, and the first glue injection is carried out. And then, mounting the second mold on the support frames 1-9, and performing secondary glue injection. The glue solution storage tank 1-1 can comprise two separated inner cavities for respectively containing first glue solution for first glue injection and second glue solution for second glue injection. Alternatively, the glue tank 1-1 has only one inner chamber, in which the first glue is first placed. And during secondary glue injection, emptying the first glue solution in the glue solution storage tank 1-1, and then containing the second glue solution.

The detailed structure of the first mold in the glue injection apparatus 100 for a downhole tool according to the present invention will be described in detail. It should be noted that the downhole tool includes various components, such as a circuit board, a chip, a power supply device, a sensor, and the like. The term "downhole tool" may also be understood herein as any one or more of these components.

Fig. 2A and 2B schematically show the structure of a first mold according to one embodiment of the present invention. This first mould has upper and lower mould halves 4-1 cooperating in pairs, of which fig. 2A is a plan view of the mould halves and fig. 2B is a perspective view of the upper mould half.

As shown, the mold half 4-1 has an open, elongated cavity 4-2 in which a first glue is injected. When the upper and lower half-mould parts 4-1 are brought together, a closed cavity is formed. A plurality of ear grooves 4-3 are arranged on two opposite side edges of the inner cavity 4-2. The ear grooves 4-3 can enhance the contact area between a first colloid formed by first glue injection and a second colloid formed by second glue injection, and enhance the fusion degree of the whole colloid after the glue injection for two times. In the embodiment shown in fig. 2A and 2B, 4 ear slots 4-3 are provided, which are arranged on the long sides of the inner cavity 4-2, two on each side. If the upper and lower half-mould parts 4-1 are perfectly symmetrical, the ear slots of the upper half-mould part and the ear slots of the lower half-mould part are also arranged perfectly symmetrical. However, if the upper and lower half-mould parts 4-1 are not symmetrical, i.e. the cavities 4-2 of the upper and lower half-mould parts 4-1 are different, for example different in depth, the ear grooves of the upper half-mould part are not completely symmetrical to the ear grooves of the lower half-mould part.

According to a preferred embodiment of the invention, the ear slots 4-3 are provided in a U-shape. For a lumen 4-2 having an overall length of 200mm, two pairs of ear slots may be provided, each ear slot having a length of 8 mm. In an embodiment not shown, the ear slots may also be provided with an inverted shape, i.e. with a smaller dimension on the side close to the cavity 4-2 and a larger dimension on the side remote from the cavity 4-2. Through this kind of mode, can further strengthen the associativity between twice injecting glue.

According to another preferred embodiment of the invention, the half-mould 4-1 further comprises protrusions 4-4 arranged at the four corners of the cavity 4-2. Like this, after the first injecting glue is accomplished, four breachs just can be formed in the four corners of the first colloid that forms, conveniently takes out first colloid from first mould. In addition, the protruding part can also enhance the contact area between the first colloid formed by the first glue injection and the second colloid formed by the second glue injection, and enhance the fusion degree of the whole colloid after the two glue injections.

The first mold shown in fig. 2A and 2B may be made of wood, or other materials, such as metal, alloy, rubber, polyester, or plastic, which have good insulation, acid corrosion resistance, and corrosion resistance. This first mold is particularly suitable for a relatively square small-sized long circuit board having no special requirement.

According to the invention, the upper half module and the lower half module can respectively inject glue to the circuit board in a grading way, and the half modules can also be provided with glue injection holes, are provided with holding sealing and fixing devices and simultaneously inject glue to two sides of the circuit board.

The first mold shown in fig. 2A and 2B employs upper and lower mold halves 4-1 which are used in cooperation in pairs, so that the first mold has a detachable structure. During glue injection, the upper half-module 4-1 and the lower half-module 4-1 are assembled and fixed together. After the glue injection is finished, the formed glue can be easily taken out by disassembling the upper half mould part 4-1 and the lower half mould part 4-1. Through the mode, the colloid can be protected to the greatest extent, and the circuit board and the chip are prevented from being damaged by external force when the colloid is taken out of the first die.

A first gel 5-1 formed using a first mold is schematically shown in fig. 3. The first colloid 5-1 comprises a circuit board 5-2, and a plurality of chips or electronic components 5-4 are arranged on the circuit board 5-2. Through the first glue injection, the chips or the electronic components 5-4 and the circuit board 5-2 are wrapped in the first glue solution together to form an integral first glue body 5-1. Since the first mould has the ear slots 4-3, the first gel 5-1 has the flanks 5-10. In fig. 3, two columns of six wings 5-10 are shown, however it will be appreciated that the number and location of the wings may vary. Through making first colloid have the flank, can strengthen the degree of fusion between first colloid and the second colloid after the injecting glue of second time.

It is easily understood that the first colloid formed has a similar structure in the case of containing a plurality of circuit boards, or the chips on the circuit boards are connected to the sensors or the power supply units through the connection lines.

According to the present invention, after a first gel is formed by performing a first gel injection using the gel injection apparatus 100 according to the present invention including a first mold, a first performance test is performed on the first gel. And if the result of the first performance test is qualified, performing secondary glue injection on the first colloid. Details of the first performance test will be described below.

And secondary glue injection is performed by using a second mold. Therefore, the first mold is first removed from the compound injection apparatus 100 and then the second mold is attached. By adjusting the supporting frames 1 to 9, the glue injector 1 to 5 of the glue injection device 100 is aligned with the glue injection port of the second mold. And then, secondary glue injection can be performed.

It will be readily appreciated that in an embodiment according to the present invention, not shown, the glue injection device 100 comprises two support frames 1-9 on which a first mould and a second mould are mounted, respectively. This saves time for mold replacement.

A second mould according to the invention is described below in connection with figures 4 and 5. The second mould according to the invention comprises an upper mould half 7-1 and a lower mould half 8-1, which are shown in figures 4 and 5 respectively.

As shown in fig. 4, the upper mold half 7-1 has a hollow rectangular body including a top plate, four upper side plates, and upper extending edges extending outward from the end portions of two of the upper side plates, respectively, in parallel with the top plate. An inner cavity 7-2 is defined in the upper half-mould body 7-1, in which a second glue is injected. It will be readily appreciated that although only one cavity 7-2 is shown in FIG. 7, the upper mold half 7-1 may include multiple cavities, either attached to each other or independent of each other. The upper mold half 7-1 further includes a glue injection hole 7-4 penetrating through the top plate of the upper mold half 7-1 to communicate with the cavity 7-2. One or more glue injection holes may be provided, depending on the nature of the glue solution injected. In addition, an openable/closable port 7-7 is provided on one of the upper side plates having an upper extending edge, whereby a first gel may be put into the cavity 7-2 or a second gel formed using a second mold may be taken out therefrom.

On the inner surface of the top plate of the upper mold half 7-1, i.e. the surface defining the cavity 7-2, there are provided a number of recesses 7-3, which are evenly arranged on the inner surface of the top plate. By providing the groove 7-3, it is possible to provide an absorption effect against an external pressure or impact shock for resisting deformation caused by an external force. In the embodiment shown in fig. 4, the groove 7-3 may be configured in a dome shape.

In one specific embodiment, lumen 7-2 has a length of 237mm, a width of 28mm, and a depth of 7.5 mm. In this case, the upper half-mould part 7-1 can have 36 dome-shaped recesses 7-3 arranged in a 2X 18 symmetrical manner, wherein the distance between two dome-shaped recesses 7-3 is 13mm, and each dome has a diameter of 10mm and a height of 1 mm.

A plurality of connecting holes 7-5 are also arranged on two upper extending edges of the upper die half body 7-1 and are used for connecting the upper die half body 7-1 with the lower die half body 8-1. Furthermore, to facilitate the connection, the two upper extending edges are provided at different height levels, i.e. the two upper extending edges are not coplanar.

As shown in fig. 8, the lower mold half 8-1 also has a hollow lid shape including a bottom plate, four lower side plates, and lower extending edges extending outward from the end portions of two of the lower side plates, respectively, in parallel with the bottom plate. An inner cavity 8-2 is defined in the lower mold half body 8-1 and is used for injecting a second glue solution. It will be readily appreciated that although only one cavity 8-2 is shown in FIG. 8, the lower mold half 8-1 may include multiple cavities, either contiguous or independent of each other. The lower die half body 8-1 also comprises a glue injection hole 8-4 which penetrates through the bottom plate of the lower die half body 8-1 and is communicated with the inner cavity 7-2. One or more glue injection holes may be provided, depending on the nature of the glue solution injected.

Grooves 8-3 are provided in the inner surface of the bottom plate of the lower mold half 8-1 (i.e., the surface defining the cavity 8-2) and are uniformly arranged on the inner surface of the bottom plate. By providing the groove 8-3, it is possible to provide an absorption effect against an external pressure or impact shock for resisting deformation caused by an external force. The groove 8-3 may be configured in a dome shape.

In one specific embodiment, lumen 8-2 has a length of 237mm, a width of 28mm, and a depth of 7.5 mm. In this case, the upper half-mould part 7-1 can have 36 dome-shaped recesses 7-3 arranged in a 2X 18 symmetrical manner, wherein the distance between two dome-shaped recesses 7-3 is 13mm, and each dome has a diameter of 10mm and a height of 1 mm.

The two lower extending edges of lower mold half 8-1 are likewise disposed out of plane. A plurality of connecting holes 8-5 are also arranged on two lower extending edges of the lower half die body 8-1 and are used for connecting the upper half die body 7-1 with the lower half die body 8-1. After the attachment holes 8-5 of the lower mold half 8-1 are aligned with the corresponding attachment holes 7-5 of the upper mold half 7-1, the upper mold half 7-1 and the lower mold half 8-1 can be fixedly attached together easily and securely by bolts.

In addition, insertion holes 8-6 are formed in both side plates of the lower mold half 8-1, which are not provided with lower extending edges. The fixing member can be inserted into the insertion hole 8-6 to fix the first paste, which is loaded into the cavity 8-2 of the lower mold half 8-1, from both sides, and prevent it from being displaced during the secondary paste injection.

In some cases, the upper mold half 7-1 and the lower mold half 8-1 may be used alone. In an alternative embodiment, the second mold further comprises a press plate 8-8 for compacting and flattening the formed second glue mass.

When secondary glue injection is carried out, the connecting hole 7-5 of the upper half body 7-1 and the connecting hole 8-5 of the lower half body 8-1 are aligned with each other and are screwed by bolts. And then, slowly filling the selected second glue solution along the glue injection hole 7-4 and/or the glue injection hole 8-4 for secondary glue injection. The upper half mould body 7-1 and the lower half mould body 8-1 can also be independently used for secondary glue injection.

Fig. 6 shows a schematic plan view of the second gel 9-1 formed after the second gel injection. As shown in fig. 6, the first glue 9-2 formed by the first glue injection includes a circuit board 9-3 encapsulated therein, a chip 9-6 mounted on the circuit board 9-3, and a wing 9-5 formed on the first glue 9-2. Fig. 7 shows a schematic front view of the second gel 10-1 formed after the second gel injection. As shown in fig. 7, the first glue 10-2 formed by the first glue injection includes a circuit board 10-3 encapsulated therein and a chip 10-6 mounted on the circuit board 10-3. A plurality of protrusions 10-5 formed by the grooves 7-3 and 8-3 of the second mold are formed on the top and bottom surfaces of the second gel 10-1.

Thus, in the formed second colloid, the previously formed first colloid is tightly packed therein. The contact area between the first colloid and the second colloid is increased through the side wings 9-5 on the first colloid, so that the fusion degree of the whole colloid after twice glue injection is improved. In addition, the protrusions 10-5 formed on the outer surface of the second gel can effectively absorb external pressure or impact shock to resist deformation caused by external force.

The method of injecting glue into a downhole tool will be described below.

First, the glue injection apparatus 100 is installed as shown in fig. 1. Wherein, a first glue solution is contained in the glue solution storage tank 1-1, and a first mould is arranged on the support frame 1-9.

According to the invention, the first glue solution can be selected from organic silicon and polyurethane, the temperature resistance range of the first glue solution is-40-200 ℃, and the pressure resistance range of the first glue solution is 70-150 MPa. The first glue solution has good heat conductivity, heat resistance, hydrophobicity and electrical insulation, can quickly disperse heat generated by electrical elements, avoids liquid infiltration and ensures electrical insulation among the elements. Meanwhile, the first glue solution has strong tensile strength and tearing strength, large relative elongation and low thermal expansion coefficient, and is used for absorbing vibration and impact and dispersing stress distribution on components. According to the requirements of specific application, proper additives can be added into the first glue solution.

Then, the downhole instruments (batteries or battery packs, circuit boards, sensors, mechanical structural components and the like) needing glue injection are subjected to pretreatment operation. The pretreatment operation comprises cleaning the outer surface of the component, removing dust and impurities, and spraying corresponding waterproof, dustproof and anticorrosive liquid. In addition, for the circuit board, a PCB nanometer waterproof film can be uniformly coated on the circuit board, and the thickness of the coating is preferably less than 10 micrometers. The nano waterproof film can provide the functions of water resistance and strong acid salt corrosion resistance. The nano waterproof film should not affect the conductivity of the connector on the circuit board and be resistant to temperatures above 100 ℃.

And then, injecting glue for the first time. And injecting the first glue solution into the first mould. The rate of injection of the first cement may be suitably selected according to different downhole tools. After the first mold was filled, the first mold was placed in a high-temperature drying oven and allowed to stand at 20 ℃ for 12 hours.

And then, taking out the first colloid from the first mould, and carrying out a first performance test on the first colloid.

And if the result of the first performance test is qualified, performing second glue injection. And a second glue solution is contained in the glue solution storage tank 1-1, a second mold is arranged on the support frame 1-9, and the first glue solution is placed in the second mold.

According to the invention, the second glue solution can be selected from an organic silicon, polyurethane or epoxy system, the temperature resistance range of the second glue solution is-100-350 ℃, and the pressure resistance range of the second glue solution is 100-250 MPa. The second glue solution has low viscosity, naturally discharges bubbles and can resist deformation caused by external stress.

And then, injecting glue for the second time. After the second mold was filled, the second mold was placed in a high temperature drying oven and allowed to stand at 20 ℃ for 12 hours.

And then, taking out the second colloid from the second mold, and carrying out a second performance test on the second colloid.

And if the result of the second performance test is qualified, the quality of the second colloid containing the downhole instrument is qualified, and the second colloid can be used for downhole operation. The whole method is finished.

The first performance test is described below in conjunction with fig. 8 and 9.

The first colloid taken out of the first mold is placed in a high-temperature drying oven, and a temperature resistance test is performed according to a temperature test curve shown in fig. 8.

A low temperature test was first performed. Keeping the high-temperature drying oven filled with the first colloid at normal temperature, and standing for 1 hour. Slowly cooling to-10 deg.C after 20 min, and standing for 20 min. And continuously reducing the temperature to-20 ℃ after 20 minutes. In the cooling process, the signal variation of each part in the first colloid is monitored in real time through the external interface, and the maximum variation is recorded. And (3) keeping the high-temperature drying oven at the constant temperature of-20 ℃ for 1 hour, monitoring the signal variation of each component in the first colloid in real time, and recording the maximum variation. Then slowly raising the temperature, raising the temperature to-10 ℃ after 20 minutes, and standing for 20 minutes. And (4) continuing heating, wherein the temperature is increased to 0 ℃ after 20 minutes, monitoring the signal variation of each component in the first colloid in real time in the heating process, and recording the maximum variation.

After the low-temperature test is finished, the high-temperature drying oven is kept at 0-20 ℃ and kept stand for 1 hour.

The high temperature test was then started. Slowly raising the temperature, raising the temperature to 100 ℃ after 30 minutes, and standing for 15 minutes. The temperature is continuously increased to 120 ℃ after 30 minutes, and the mixture is kept stand for 15 minutes. The temperature was increased further to 140 ℃ after 30 minutes. And monitoring the signal variation of each component in the first colloid in real time in the temperature rise process, and recording the maximum variation. And then keeping the temperature at 140 ℃, standing for 1 hour, monitoring the signal variation of the parts in the first colloid in real time, and recording the maximum variation. Slowly cooling to 120 ℃ after 30 minutes, and standing for 15 minutes. And continuously reducing the temperature to 100 ℃ after 30 minutes, and standing for 15 minutes. And continuously reducing the temperature, and reducing the temperature to 0 ℃ after 30 minutes. And monitoring the signal variation of each component in the first colloid in real time in the cooling process, and recording the maximum variation. Thereby, the temperature test is ended.

During the whole temperature test period, if the tested part is a sensor, the signal amplitude variation is lower than 0.1%; if the tested part is a circuit board, the signal amplitude variation should be lower than 0.2%; the remaining components (i.e., other downhole instruments besides sensors and circuit boards, as is well known to those skilled in the art) should have signal amplitude variations of less than 1%. And if the signal amplitude variation during the temperature test meets the requirement, the temperature test is qualified. Otherwise, the temperature test is unqualified, and the first colloid is treated as waste.

After the temperature test is finished, the interface of the first colloid is subjected to pressure-resistant protection, and then the first colloid is placed in a high-pressure water tank capable of adjusting temperature.

First, the temperature of the high-pressure water tank was set to 20 ℃, and a pressure test was performed according to the high-pressure test curve shown in fig. 9.

First, the high-pressure water tank was kept at normal pressure and left to stand for 20 minutes. The pressure was slowly increased to 70MPa after 5 minutes, and the mixture was allowed to stand for 5 minutes. Continuously increasing the pressure to 100MPa after 5 minutes, and standing for 5 minutes. The pressure is continuously increased to 150MPa after 5 minutes. And monitoring the signal variation of each component in the first colloid in real time in the boosting process, and recording the maximum variation. Keeping the high pressure of 150MPa for 20 minutes, monitoring the signal variation of the components in the first colloid in real time, and recording the maximum variation. Slowly reducing the pressure, reaching 100MPa after 5 minutes, and standing for 5 minutes. Continuously reducing the pressure, reaching 70MPa after 5 minutes, and standing for 5 minutes. The pressure is continuously reduced, and the normal pressure is reached after 5 minutes. And monitoring the signal variation of each component in the first colloid in real time in the pressure reduction process, and recording the maximum variation.

And adjusting the temperature of the high-pressure water tank to 100 ℃, repeating the pressure test, monitoring the signal variation of each component in the first colloid in real time in the test process, and recording the maximum variation.

And adjusting the temperature of the high-pressure water tank to 140 ℃, repeating the pressure test, monitoring the signal variation of each component in the first colloid in real time in the test process, and recording the maximum variation.

After standing for 20 minutes, the first colloid was taken out.

During the whole pressure test period, if the tested part is a sensor, the signal amplitude variation is lower than 0.1%; if the tested part is a circuit board, the signal amplitude variation should be lower than 0.2%; the signal amplitude variation of the remaining components should be less than 1%. And if the signal amplitude variation during the pressure test meets the requirement, the pressure test is qualified. Otherwise, the pressure test is not qualified, and the first colloid is treated as waste.

After the second gel was formed, it was subjected to a second performance test. The second performance test is described below in conjunction with fig. 10 and 11.

The second colloid taken out of the second mold is placed in a high-temperature drying oven, and a temperature resistance test is performed according to a temperature test curve shown in fig. 10.

A low temperature test was first performed. Keeping the high-temperature drying oven filled with the first colloid at normal temperature, and standing for 1 hour. Slowly cooling to-20 deg.C after 20 min, and standing for 20 min. The temperature is continuously reduced, and the temperature is reduced to-40 ℃ after 20 minutes. In the cooling process, the signal variation of each part in the second colloid is monitored in real time through the external interface, and the maximum variation is recorded. And (3) keeping the high-temperature drying oven at the constant temperature of-40 ℃ for 1 hour, monitoring the signal variation of each component in the second colloid in real time, and recording the maximum variation. Then slowly raising the temperature, raising the temperature to-20 ℃ after 20 minutes, and standing for 20 minutes. And (4) continuing heating, wherein the temperature is increased to 0 ℃ after 20 minutes, monitoring the signal variation of each component in the second colloid in real time in the heating process, and recording the maximum variation.

After the low-temperature test is finished, the high-temperature drying oven is kept at 0-20 ℃ and kept stand for 1 hour.

The high temperature test was then started. Slowly raising the temperature, raising the temperature to 100 ℃ after 30 minutes, and standing for 15 minutes. The temperature is continuously increased to 150 ℃ after 30 minutes, and the mixture is kept stand for 15 minutes. The temperature was increased further to 200 ℃ after 30 minutes. And monitoring the signal variation of each component in the second colloid in real time in the temperature rise process, and recording the maximum variation. And then keeping the temperature at 200 ℃, standing for 1 hour, monitoring the signal variation of each component in the second colloid in real time, and recording the maximum variation. Slowly cooling to 150 deg.C after 30 min, and standing for 15 min. And continuously reducing the temperature to 100 ℃ after 30 minutes, and standing for 15 minutes. And continuously reducing the temperature, and reducing the temperature to 0 ℃ after 30 minutes. And monitoring the signal variation of each component in the second colloid in real time in the cooling process, and recording the maximum variation. Thereby, the temperature test is ended.

During the whole temperature test period, if the tested part is a sensor, the signal amplitude variation is lower than 0.1%; if the tested part is a circuit board, the signal amplitude variation should be lower than 0.2%; the signal amplitude variation of the remaining components should be less than 1%. And if the signal amplitude variation during the temperature test meets the requirement, the temperature test is qualified. Otherwise, the temperature test is unqualified, and the second colloid is treated as waste.

After the temperature test is finished, the interface of the second colloid is subjected to pressure-resistant protection, and then the second colloid is placed in a high-pressure water tank capable of adjusting temperature. The high pressure tank was set to a temperature of 20 c and pressure test was performed according to the high pressure test curve shown in fig. 11.

First, the high-pressure water tank was kept at normal pressure and left to stand for 20 minutes. The pressure was slowly increased to 100MPa after 5 minutes, and the mixture was allowed to stand for 5 minutes. Continuously increasing the pressure to 150MPa after 5 minutes, and standing for 5 minutes. The pressure is increased continuously and reaches 200MPa after 5 minutes. And monitoring the signal variation of each component in the second colloid in real time in the boosting process, and recording the maximum variation. Keeping the high pressure of 200MPa for 20 minutes, monitoring the signal variation of each part in the second colloid in real time, and recording the maximum variation. Slowly reducing the pressure, reaching 150MPa after 5 minutes, and standing for 5 minutes. Continuously reducing the pressure, reaching 100MPa after 5 minutes, and standing for 5 minutes. The pressure is continuously reduced, and the normal pressure is reached after 5 minutes. And monitoring the signal variation of each component in the second colloid in real time in the pressure reduction process, and recording the maximum variation.

And adjusting the temperature of the high-pressure water tank to 150 ℃, repeating the pressure test, monitoring the signal variation of each component in the first colloid in real time in the test process, and recording the maximum variation.

And adjusting the temperature to 200 ℃, repeating the pressure test, monitoring the signal variation of each part in the first colloid in real time in the test process, and recording the maximum variation.

After standing for 20 minutes, the second colloid was taken out.

During the whole pressure test period, if the tested part is a sensor, the signal amplitude variation is lower than 0.1%; if the tested part is a circuit board, the signal amplitude variation should be lower than 0.2%; the signal amplitude variation of the remaining components should be less than 1%. And if the signal amplitude variation during the pressure test meets the requirement, the pressure test is qualified. Otherwise, the pressure test is not qualified, and the second colloid is treated as waste.

And when the result of the second performance test is qualified, the obtained second colloid is regarded as a qualified product and can be used for underground work.

According to the temperature and pressure testing process, temperature and pressure testing experiments are carried out on three underground instruments including the sensor, the circuit board and the battery under the conditions of no glue injection, primary glue injection and secondary glue injection, and the variation of signals is recorded. The results are shown in fig. 12 to 15.

Fig. 12 shows the results of testing performed according to the first temperature test for three downhole instruments, sensor, circuit board and battery, without glue injection and with glue injection for the first time. As can be seen from fig. 12, in the temperature test range of-20 ℃ to 140 ℃, the temperature changes of the sensor, the circuit board and the battery without glue injection are all in the threshold range, which are 0.1%, 0.2% and 1%, respectively. However, as the temperature rises, the battery and the circuit board are both characterized by large fluctuation amplitude of the variation amount, and the variation of the sensor is not obvious. The temperature changes of the sensor, the circuit board and the battery after the first glue injection are all within a threshold range.

Fig. 13 shows the results of testing according to the second temperature test for three downhole instruments, sensor, circuit board and battery, without glue injection and with a second glue injection. As can be seen in fig. 13, the sensor, circuit board and battery tests without glue injection all exceeded the threshold value to varying degrees throughout the-40 c-200 c temperature test. In particular, after exceeding 160 ℃, the change in signal is very dramatic. In contrast, for the sensor, the circuit board and the battery after the second glue injection, the variation amounts are all within the threshold range, and the variation is gentle.

Fig. 14 shows the results of testing performed according to the first pressure test for three downhole instruments, sensor, circuit board and battery, without glue injection and with glue injection for the first time. It can be seen from fig. 14 that the variation of the non-adhesive sensor and the battery both significantly exceeded the threshold range over the entire pressure test range (70 MPa-150 MPa). To avoid an overpressure explosion of the battery, and to ensure that the sensor is not permanently damaged by high temperature and pressure, the test has to be terminated. The circuit board without glue is tested under high voltage, but the threshold value range is also seriously exceeded. Compared with the prior art, the sensor, the circuit board and the battery which are subjected to the first glue injection have the advantages that the respective variable quantities of the sensor, the circuit board and the battery are gradually changed in the whole test range, the threshold value is not exceeded, and the high-temperature and high-pressure resistant effect is achieved.

Fig. 15 shows the results of tests performed according to the second pressure test (temperature 150 c) for three downhole instruments, sensor, circuit board and battery, without glue injection and with a second glue injection. As can be seen from fig. 15, the variation of both the non-adhesive sensor and the battery significantly exceeded the threshold range over the entire pressure test range (70MPa to 200 MPa). To avoid an overpressure explosion of the battery, and to ensure that the sensor is not permanently damaged by high temperature and pressure, the test has to be terminated. For circuit boards without glue, the test was terminated early, since the test data exceeded the threshold value severely. After the circuit board is taken out, the circuit board is found to be seriously bent and deformed, the chip is burst, and the pins fall off through inspection. Compared with the prior art, the sensor, the circuit board and the battery which are subjected to the second glue injection have the advantages that the respective variation of the sensor, the circuit board and the battery in the whole test range is smooth, the threshold value is not exceeded, and the high-temperature and high-pressure resistant effect is achieved.

From the results of the above experiments, it can be seen that by adopting the glue injection method of the present invention, various downhole instruments such as sensors, circuit boards, batteries, etc. can be tested to be qualified under high temperature and high pressure. On the contrary, the corresponding component without glue injection cannot pass the test of high temperature and high pressure.

By adopting the glue injection method, various electronic and mechanical elements can be protected to the maximum extent, vibration and impact can be prevented, and high temperature, collision and corrosion can be prevented. The glue injection method can ensure the glue injection quality, simplify the glue injection process, reduce the glue injection cost and the glue injection damage, and is suitable for high-temperature glue injection protection products of various underground instruments.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (10)

1. A method of injecting glue for a downhole tool, comprising:

putting the underground instrument into a first mold, and injecting a first glue solution to form a first glue body coating the underground instrument;

taking the first colloid out of the first mold, and carrying out a first performance test on the first colloid;

putting the first colloid into a second mold, and injecting a second glue solution to form a second colloid coating the first colloid;

and taking out the second colloid from the second mold, and carrying out a second performance test on the second colloid.

2. The method according to claim 1, wherein the first glue solution is a high-temperature and high-pressure resistant glue solution for absorbing vibration and impact and dispersing stress distribution on the downhole instrument, and the second glue solution is an impact vibration resistant glue solution for resisting deformation of the downhole instrument caused by external force.

3. A method of injecting glue for a downhole tool according to claim 1 or 2, wherein the downhole tool is pre-conditioned prior to being placed in the first mould, comprising at least one of: cleaning the outer surface, removing dust and impurities, spraying waterproof liquid, dustproof liquid or anti-corrosion liquid, and coating a PCB nano waterproof film.

4. A method of injecting glue for a downhole instrument according to claim 1 or 2, wherein the first and second performance tests each comprise a temperature test and a pressure test.

5. A method for injecting glue into a downhole tool according to claim 4, wherein the variation of signal amplitude of the downhole tool is recorded during the temperature test and the pressure test.

6. A method for injecting glue into a downhole tool according to claim 5, wherein the test result of the downhole tool is determined to be qualified when:

the underground instrument is a sensor, and the signal amplitude variation is lower than 0.1%;

the underground instrument is a circuit board, and the signal amplitude variation is lower than 0.2%;

the downhole instrument is other components, and the variation of the signal amplitude is less than 1%.

7. A method according to claim 4, wherein the temperature test is performed first, then the pressure test is performed, and the interface of the first gel or the second gel is protected against pressure between the temperature test and the pressure test.

8. A method according to claim 1 or 2, wherein the first mould comprises two half-mould parts for use in pairs, which half-mould parts together enclose a closed cavity for injecting glue, wherein a number of ear slots are provided on both sides of the cavity, and

at least one of the half-mould parts further comprises a protrusion arranged at a corner of the cavity, such that the first gel formed has a notch.

9. A compound injection device for a downhole tool according to claim 1 or 2, wherein the second mold comprises an upper mold half and a lower mold half, the upper mold half and the lower mold half being fixedly connectable together to define an inner cavity for a second compound injection, the first compound being receivable in the inner cavity.

10. The apparatus according to claim 9, wherein the upper and lower mold halves have a plurality of grooves formed on at least one inner surface thereof, such that the second gel body is formed to have protrusions on at least one surface thereof, and

at least one of the upper die half body and the lower die half body is provided with an insertion hole for a fixing piece to penetrate through so as to fix the first glue placed in the fixing piece.

Images