CN113881375A - Slip coating and preparation method thereof, slip and soluble bridge plug - Google Patents

Abstract

The invention provides a slip coating and a preparation method thereof, slips and a soluble bridge plug, wherein the preparation method of the slip coating comprises the following steps: degreasing the slips body, namely putting the slips body into an alkaline degreasing solution, soaking for 20-40 min at 60-80 ℃, and rotating the slips body during soaking; drying at 80-100 ℃; carrying out sand blasting treatment on the surface of the slip body; coating an epoxy resin adhesive on the surface of the slip body; forming a mixed layer of spherical silicon oxide particles and carbon alloy steel particles on the epoxy resin binder layer; forming a fluororesin paint layer on the surface of the mixed layer. The scheme greatly simplifies the coating preparation process, improves the adhesive force of the coating prepared on the slips through the pretreatment of the slips body, can effectively fix the bridge plug, has small damage to a shaft/sleeve in occlusion, and is favorable for implementation and popularization.

Description

Slip coating and preparation method thereof, slip and soluble bridge plug

Technical Field

The invention relates to the technical field of oil drilling, in particular to a slip coating, a preparation method thereof, slips and a soluble bridge plug.

Background

In fracturing operations for oil field drilling, bridge plugs are required to achieve zonal isolation. The bridge plug generally comprises slips, a sealing rubber cylinder, a body and the like, the slips act on the inner wall of a shaft/casing pipe to fix the bridge plug, and meanwhile, the sealing rubber cylinder is used for realizing packing. Generally, the slip body is mostly prepared by adopting soluble materials, and the surface of the slip body is coated. Currently, there are some problems with existing slips:

1. the slips are provided with the array of bulges on the action surface, so that when the bridge plug is used for packing, the slips can well act on the inner wall of the sleeve to realize the positioning of the bridge plug, but the mode causes great damage to the inner wall of the sleeve;

2. along with the popularization of the slip coating, the mode of arranging the protrusion is gradually replaced, and the scheme of combining the coating with the protrusion and the like is researched, but the conventional slip coating is realized by compounding various materials, so that the preparation process efficiency and the application popularization degree of the slip coating are limited, coating materials in part of the scheme are mixed materials and are not easy to obtain, and the coating materials can be obtained only by special processes and proportions, so that the preparation cost and the preparation difficulty are increased, and in addition, part of the coating can not even form effective acting force in the action of a shaft/casing to realize the fixation of the slip to the bridge plug;

3. at present, the research on the preparation of the slip coating is mostly limited to the coating material formula and process, but the morphological characteristics and the surface physical properties of the slip are neglected, and in many cases, the adhesion effect of the coating and the slip is influenced, so that the actual application value of the slip and the bridge plug is influenced.

Disclosure of Invention

Aiming at the defects of the related prior art, the invention provides the slip coating and the preparation method thereof, the slips and the soluble bridge plug, the preparation process of the coating is greatly simplified, the adhesion force of the coating prepared on the slips is improved through the pretreatment of the slips body, the prepared slips can effectively realize the fixation of the bridge plug, the damage to a shaft/sleeve in occlusion is small, and the implementation and popularization are facilitated.

In order to realize the purpose of the invention, the following scheme is adopted:

a slip coating comprising:

a binder layer coated on the surface of the slip body;

the spherical silicon oxide particles and the carbon alloy steel particles are laid on the binder layer, and the mixing ratio is 5: 5-8: 2;

a fluororesin paint layer sprayed on the surface of the spherical silica particle layer;

the adhesive layer is made of an epoxy resin adhesive, the thickness of the adhesive layer is 0.1-0.3 mm, the particle size of spherical silicon oxide particles in a spherical silicon oxide particle layer in the mixed layer is 0.43-0.85 mm, and the compressive strength of the spherical silicon oxide particle layer is greater than 69 MPa; the grain size of the carbon alloy steel particles is 0.43 mm-0.55 mm, and the hardness is HRC 58-62.

A preparation method of a slip coating comprises the following steps:

the slips body is subjected to oil removal treatment, the slips body is placed into alkaline degreasing liquid and soaked for 20-40 min at the temperature of 60-80 ℃, and the slips body is rotated during soaking. After soaking, wiping the slip body by using cotton cloth, cleaning the surface of the slip body, and removing oil;

drying at 80-100 ℃;

carrying out sand blasting treatment on the surface of the tile body, wherein the sand blasting particle size is 0.4-0.6 mm;

coating an epoxy resin binder on the surface of the slip body to form a binder layer with the thickness of 0.1 mm-0.3 mm, and baking at 40-60 ℃ for 20-45 min to enable the binder to be in a semi-solid state;

shot blasting is carried out on the surface of the slip body, the shot blasting particles are mixed particles of spherical silicon oxide particles and carbon alloy steel particles in a mixing ratio of 5: 5-8: 2, the mixed particles act on the binder layer and are bonded with the binder layer to form a mixed layer of spherical silicon oxide particles and carbon alloy steel particles, baking is carried out at 100-120 ℃ for 90-120 min to enable the spherical silicon oxide particles to be firmly bonded, and then cooling is carried out to normal temperature;

and (2) uniformly spraying fluororesin paint on the surface of the slip body, forming a fluororesin paint layer on the surface of the mixed layer of the spherical silica particles and the carbon alloy steel particles, and drying at normal temperature or baking at 40-60 ℃ for 20-45 min to solidify the fluororesin paint layer.

A slip, comprising: the slip coating is formed on the surface of the slip body and is prepared by the preparation method of the slip coating.

A soluble bridge plug comprises the slips.

The invention has the beneficial effects that:

1. the slip coating provided by the application is simple in structure, only the epoxy resin binder, the spherical silica particles, the carbon alloy steel particles and the fluororesin paint are adopted, and the materials are easy to obtain, so that the implementation difficulty of the slip coating is greatly reduced, and the preparation cost of the slip coating is reduced; the high hardness of the carbon alloy steel particles can be embedded into the inner wall of the sleeve to increase friction and prevent sliding, and the spherical silicon oxide particles are used as filling materials, so that the carbon alloy steel particles can be dispersed, the use amount of the carbon alloy steel particles is reduced, and the cost is saved;

2. compared with the prior art, the slip coating preparation method provided by the application only adopts the binder to adhere spherical silica particles and carbon alloy steel particles, and sprays fluororesin paint, and simultaneously, before the coating is prepared, the slip body is subjected to oil removal treatment and sand blasting treatment, so that the surface of the slip body is clean and is frosted, and the adhesive force of the slip coating is improved;

3. the utility model provides a preferred embodiment is through the centre gripping to the slips body when the centre gripping frock deoils, on the one hand can realize deoiling to the slips body in batches, be applicable to not unidimensional slips body simultaneously, and be applicable to the slips body for the slice or for the condition of tube-shape, and can make two adjacent slips bodies stagger, avoid bumping together, simultaneously in the deoiling, accessible slewing mechanism, swing mechanism, rotate and swing, improve the deoiling effect when soaking, with the grease on better clean slips body surface, the defect of prior art to the neglected cleanliness factor of slips body surface has been solved, improve the preparation effect of slips coating.

Drawings

FIG. 1 is an example of a slip coating when the slip body of an embodiment of the present application is cambered.

FIG. 2 shows an example of a slip coating where the slip body of an embodiment of the present application is a surface with straight faces.

FIG. 3 shows an example of a slip coating when the slip body of an embodiment of the present application is a curved surface.

FIG. 4 shows an example of a slip coating where the slip body of an embodiment of the present application is a serrated face.

Fig. 5 is a schematic structural view of a clamping tool used in oil removal according to an embodiment of the present application.

Fig. 6 is a schematic structural view of a clamping assembly of the clamping tool according to the embodiment of the present application.

Fig. 7 is a schematic structural view of a clamping bar and a top block of the clamping tool according to the embodiment of the application.

Fig. 8 is an enlarged view of a portion a of fig. 5.

Fig. 9 is a schematic structural view of a rotating mechanism of the clamping tool according to the embodiment of the application.

Fig. 10 is a schematic bottom view of the swing mechanism of the clamping fixture according to the embodiment of the present application.

Fig. 11 is a schematic top view of a swing mechanism of the clamping tool according to the embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings, but the described embodiments of the present invention are a part of the embodiments of the present invention, not all of the embodiments of the present invention.

One aspect of the embodiments of the present application provides a slip coating and a method for preparing the same, as shown in fig. 1 to 4, the slip coating of the present embodiment includes: theadhesive layer 2 is coated on the surface of theslip body 1; a mixedlayer 3 of spherical silicon oxide particles and carbon alloy steel particles laid on theadhesive layer 2; afluororesin paint layer 4 sprayed on the surface of the mixedlayer 3.

Theadhesive layer 2 is made of an epoxy resin adhesive, the thickness of the adhesive layer is 0.1 mm-0.3 mm, the particle size of spherical silicon oxide particles in the mixedlayer 3 is 0.43 mm-0.85 mm, the compressive strength is larger than 69MPa, the particle size of carbon alloy steel particles is 0.43 mm-0.55 mm, and the hardness is HRC 58-62. The mixing ratio of the spherical silicon oxide particles to the carbon alloy steel particles is 5: 5-8: 2.

The method for preparing the slip coating of the present example includes the steps of:

s100, degreasing theslip body 1, putting theslip body 1 into an alkaline degreasing solution, soaking for 20-40 min at 60-80 ℃, and rotating theslip body 1 during soaking; after soaking, utilize the cotton to cleanslips body 1,clean slips body 1 surface, accomplish the deoiling.

S200, drying at 80-100 ℃.

S300, carrying out sand blasting treatment on the surface of theslip body 1, wherein the sand blasting particle size is 0.4-0.6 mm.

S400, coating an epoxy resin binder on the surface of theslip body 1 to form abinder layer 2 with the thickness of 0.1 mm-0.3 mm, and baking at 40-60 ℃ for 20-45 min to enable the binder to be in a semi-solid state.

S500, shot blasting is carried out on the surface of theslip body 1, the shot blasting particles are mixed particles of spherical silicon oxide particles and carbon alloy steel particles in a mixing ratio of 5: 5-8: 2, the mixed particles act on thebinder layer 2 and are bonded with thebinder layer 2 to form a mixedlayer 3 of the spherical silicon oxide particles and the carbon alloy steel particles, baking is carried out at 100-120 ℃ for 90-120 min to enable the spherical silicon oxide particles to be firmly bonded, and then cooling is carried out to normal temperature.

S600, uniformly spraying fluororesin paint on the surface of theslip body 1, forming afluororesin paint layer 4 on the surface of the spherical silica particle and carbon alloy steelparticle mixing layer 3, and air-drying at normal temperature or baking at 40-60 ℃ for 20-45 min to solidify thefluororesin paint layer 4.

Because the slips body adopts soluble material preparation more, and after the preparation is accomplished, generally its surface all adheres to grease etc. these grease will cause the influence to the adhesion of slips coating, and prior art has all ignored this aspect, in the aspect of the material development of slips coating has been arrived to the focus of focus average, not only caused difficult preparation of slips coating, and the actual effect is unsatisfactory, and in the preparation method of this embodiment, at first introduce the deoiling process, make to get rid of the grease, then introduce the sandblast technology and carry out the sandblast to slips body surface, make the surface alligatoring form the dull polish form, through the introduction of these two kinds of processes, make the adhesive force of epoxy binder greatly improve.

In the preferred embodiment of the present example, the slip body can be clamped by the clamping tool shown in fig. 5 to 11 so as to be suitable for sheet-shaped slip bodies or cylindrical slip bodies of different sizes for facilitating oil removal and oil removal in batches.

Specifically, the centre gripping frock includes: the disc type clamping device comprises adisc 6, a plurality ofclamping assemblies 5 which are arrayed on thedisc 6 along the circumference, arotating mechanism 7 connected with thedisc 6, alifting mechanism 8 connected with therotating mechanism 7, and aswinging mechanism 9 connected with thelifting mechanism 8.

Specifically, as shown in fig. 6 to 7, the clampingassembly 5 includes a pair of supportingblocks 52 disposed at intervals and clampingbars 51 disposed at the clamping blocks 51, the pair of clampingbars 51 are disposed at intervals, a horizontally disposed slidinggroove 521 is formed in a concave manner on an inner side surface of the supportingblock 52, the slidinggroove 521 does not penetrate through an outer side surface of the supportingblock 52, a slidingplate 513 is disposed in a middle portion of the supportingblock 52, and the slidingplate 513 is slidably fitted in the slidinggroove 521. A plurality ofsprings 512 are connected between the clamping bars 51. The upper portion of the holdingbar 51 has asecond slope 511, and thesecond slope 511 is inclined downward from the top of the holdingbar 51 to the outside. The supportingshoe 52 is connected in thepassageway 53 bottom, and thepassageway 53 top is connected withcentre gripping roof 56, andcentre gripping strip 51 upper portion is located thepassageway 53, and 53 is equipped withvertical cylinder 57 in the passageway, andvertical cylinder 57 is fixed incentre gripping roof 56 bottom, andvertical cylinder 57 expansion end is connected with kickingblock 54, and kickingblock 54 bottom is sunken to be formed with and is acted on the groove, and the effect groove both sides wall is firstinclined plane 541, is used for acting on the secondinclined plane 511 of a pair ofcentre gripping strip 51 respectively.

Specifically, as shown in fig. 8, a plurality of sections of adjusting slidinggrooves 61 are arranged radially on thedisc 6 along a circumferential array, the number of the adjusting sliding grooves is matched with the number of theclamping assemblies 5, the clampingtop plate 56 is connected with a slidingblock 62, the slidingblock 62 is in sliding fit with theadjusting sliding grooves 61, the slidingblock 62 is located on two sides of theadjusting sliding grooves 61 and supported by the top surface of thedisc 6, arotating seat 63 and an adjustingmotor 65 are arranged on thedisc 6 and respectively located on two ends of theadjusting sliding grooves 61, an output shaft of the adjustingmotor 65 is connected with one end of ascrew rod 64, the other end of thescrew rod 64 is in rotating fit with therotating seat 63, and the slidingblock 62 penetrates through thescrew rod 64. Each set of adjustingmotor 65, rotatingseat 63,screw 64, adjusting slidinggroove 61 and slidingblock 62 corresponds to oneclamping component 5.

Specifically, as shown in fig. 5 and 9, therotating mechanism 7 includes anexternal spline 71 concentric with thedisc 6 and fixed to the top surface of thedisc 6, aninternal spline 75 is fitted in theexternal spline 71, theinternal spline 75 is connected to an output shaft of a vertically arrangedrotating motor 76, therotating motor 76 is fixed to the bottom surface of anupper disc 73, theupper disc 73 is connected to the movable end of thelifting mechanism 8, two sections of arc-shapedgrooves 731 are formed in theupper disc 73, a pair of arc-shapedlimit plates 72 are arranged on theexternal spline 71, the arc-shapedlimit plates 72 are respectively fitted to one section of arc-shapedgroove 731, the top of each arc-shapedlimit plate 72 is connected with alimit ring 74, and thelimit ring 74 is arranged on the top surface of theupper disc 73 and is in contact fit with theupper disc 73. Thelifting mechanism 8 comprises 3lifting cylinders 81, the liftingcylinders 81 operate synchronously, the top parts of the lifting cylinders are connected to acylinder fixing plate 82, and the movable ends of the lifting cylinders are connected to theupper disc 73.

Specifically, as shown in fig. 10 to 11, theswing mechanism 9 includes abase 91 and arotating sleeve 92 fixed on the base, and thebase 91 is fixedly connected with thecylinder fixing plate 82. Therotating sleeve 92 penetrates through the rotatingshaft 93, connectingplates 94 are arranged at two ends of therotating shaft 93, the connectingplates 94 are connected with anupper frame 95, a movinggap 950 is formed in the middle of theupper frame 95, matchinggrooves 951 are formed in two ends of theupper frame 95, a drivingplate 96 is arranged at the position of the movinggap 950, arack 961 is arranged on the bottom surface of the middle of the drivingplate 96, two ends of the drivingplate 9 are matched with the matchinggrooves 951, the rotatingsleeve 92 is provided with an arc top surface, and atooth part 921 is arranged on the arc top surface. Therack 961 is engaged with thetooth 921. A pair ofhorizontal oil cylinders 98 which are oppositely arranged at intervals are arranged on theupper frame 95, the movable ends of thehorizontal oil cylinders 98 are connected to thesame stress block 97, and thestress block 97 is fixed on the drivingplate 96.

Adopt deoiling centre gripping frock to go on when removing oil toslips body 1, including the step:

s110, clamping eachslip body 1 on oneclamping assembly 5 respectively, specifically, placing the upper part of eachslip body 1 between a pair of clampingstrips 51 arranged at intervals, at the moment, the clamping strips 51 are in sliding fit with the slidinggrooves 521 of the supportingblocks 52 through slidingplates 513 arranged in the middle, a plurality ofsprings 512 in a compressed state are arranged between the upper parts of the clamping strips 51, pushing the jackingblocks 54 downwards throughvertical air cylinders 57 arranged on the clampingtop plates 56, enabling the firstinclined surfaces 541 at the lower ends of the jackingblocks 54 to act on the secondinclined surfaces 511 at the upper ends of the clamping strips 51, and enabling the clamping strips 51 to move oppositely until the clamping strips 51 clamp the upper part of theslip body 1. Since the clampingtop plates 56 of the clampingcomponents 5 are respectively connected with slidingblocks 62, the slidingblocks 62 are matched in theadjusting sliding grooves 61 of thedisc 6; before clamping eachslip body 1, the position of theclamping assemblies 5 is adjusted according to the size of theslip body 1, so that the positions of twoadjacent clamping assemblies 5 are staggered, theslip bodies 1 after being clamped cannot touch each other, and specifically, ascrew rod 64 connected with an output shaft of the adjustingmotor 65 fixed on thedisc 6 rotates, so that a slidingblock 62 penetrating through thescrew rod 64 moves along the length direction of theadjusting sliding groove 61. The sheet-shapedslip body 1 can be clamped according to the above mode, the position of the clampingassembly 5 along theadjusting sliding groove 61 can be adjusted according to the diameter of the cylinder-shapedslip body 1 so as to adapt to the cylinder-shapedslip body 1, and part or all of theclamping assemblies 5 are selected to clamp the cylinder-shapedslip body 1, so that 1 piece of the cylinder-shapedslip body 1 is clamped at a time.

S120, descending therotating mechanism 7 and thedisc 6 connected with therotating mechanism 7 through thelifting mechanism 8, and descending theclamping assemblies 5 arranged on thedisc 6 in a circumferential array, so that theslip body 1 clamped by theclamping assemblies 5 is descended and submerged in a soaking pool filled with alkaline degreasing fluid, wherein the liquid temperature of the soaking pool is 60-80 ℃;

and S130, after soaking for 5min, rotating thedisc 6 once through therotating mechanism 7, wherein the rotating direction is opposite each time, and the rotating angle is smaller than 80 degrees each time. Specifically, thedisk 6 is rotated by therotating mechanism 7, theinternal spline 75 connected with the output shaft of therotating motor 76 of therotating mechanism 7 is driven to rotate, theinternal spline 75 drives theexternal spline 71 matched with the internal spline to rotate, so that thedisk 6 connected with theexternal spline 71 is driven to rotate, when theexternal spline 71 rotates, the pair ofarc limiting plates 72 arranged on theexternal spline 71 move in the arc-shapedgroove 731 of theupper disk 73, and the rotation angle is limited by the fact that thearc limiting plates 72 move to the other end from one end of the arc-shapedgroove 731 every time.

In soaking, every 5min, act on thelifting mechanism 8 through theswing mechanism 9, make thelifting mechanism 8, theslewing mechanism 7, thedisc 6 swings, thereby make theslips body 1 that thecentre gripping subassembly 5 centre gripping swung, specifically act on theatress piece 97 through locating a pair of horizontal hydro-cylinder 98 ofupper bracket 95, make theatress piece 97 drive thedrive plate 96 of being connected with it along theremoval clearance 950 in the middle part ofupper bracket 95 and thecooperation groove 951 removal atupper bracket 95 both ends, thereby the volume acts on thetooth portion 921 of the circular arc top surface of therotating sleeve 92 through therack 961 of thedrive plate 96 bottom surface, drive the rotatingsleeve 92 and support thebase 91 of rotatingsleeve 92 and rotate along the axis ofrotation 93 of wearing in therotating sleeve 92, thereby make theslewing mechanism 7 swing of being connected withbase 91.

S140, after rotating for 4-9 times, completing soaking, lifting therotating mechanism 7, thedisc 6 and the clampingassembly 5 through thelifting mechanism 8 to enable theslip body 1 to rise above the liquid level, and standing for dripping for a preset period of time;

s150, taking down theslip bodies 1, wiping theslip bodies 1 by using cotton cloth, and cleaning the surfaces of theslip bodies 1 to finish oil removal.

In another aspect of the embodiments of the present application, there is provided a slip, including: the slip coating comprises aslip body 1 and a slip coating layer formed on the surface of theslip body 1, wherein the slip coating layer is prepared by the preparation method of the slip coating layer in the previous embodiment.

In yet another aspect of an embodiment of the present application, there is provided a soluble bridge plug comprising the slips of the previous embodiments.

The foregoing is merely a preferred embodiment of this invention and is not intended to be exhaustive or to limit the invention to the precise form disclosed. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention.

Claims (6)

1. A slip coating, comprising:

the adhesive layer (2) is coated on the surface of the slip body (1);

a mixing layer (3) of spherical silicon oxide particles and carbon alloy steel particles laid on the binder layer (2) in a mixing ratio of 5: 5-8: 2;

a fluororesin paint layer (4) sprayed on the surface of the mixed layer (3).

2. The slip coating of claim 1, wherein the adhesive layer (2) is made of epoxy resin adhesive and has a thickness of 0.1mm to 0.3mm, the spherical silica particles in the mixed layer (3) have a particle size of 0.43mm to 0.85mm, a compressive strength of more than 69MPa, a particle size of carbon alloy steel particles of 0.43mm to 0.55mm, and a hardness of HRC 58 to 62.

3. A preparation method of a slip coating is characterized by comprising the following steps:

carrying out oil removal treatment on the slip body (1);

drying at 80-100 ℃;

carrying out sand blasting treatment on the surface of the tile body (1), wherein the sand blasting particle size is 0.4-0.6 mm;

coating an epoxy resin binder on the surface of the slip body (1) to form a binder layer (2) with the thickness of 0.1-0.3 mm, and baking at 40-60 ℃ for 20-45 min to make the binder in a semi-solid state;

shot blasting is carried out on the surface of the slip body (1), the shot blasting particles are mixed particles of spherical silicon oxide particles and carbon alloy steel particles in a mixing ratio of 5: 5-8: 2, the mixed particles act on the binder layer (2) and are bonded with the binder layer (2) to form a mixed layer (3) of spherical silicon oxide particles and carbon alloy steel particles, baking is carried out at 100-120 ℃ for 90-120 min to enable the spherical silicon oxide particles to be firmly bonded, and then cooling is carried out to normal temperature;

evenly spraying fluororesin paint on the surface of the slip body (1), forming a fluororesin paint layer (4) on the surface of the spherical silica particle and carbon alloy steel particle mixing layer (3), and air-drying at normal temperature or baking at 40-60 ℃ for 20-45 min to solidify the fluororesin paint layer (4).

4. The preparation method of the slip coating according to claim 3, wherein the step of degreasing the slip body (1) comprises the steps of putting the slip body (1) into an alkaline degreasing solution, soaking at 60-80 ℃ for 20-40 min, rotating the slip body (1) during soaking, wiping the slip body (1) by using cotton cloth after soaking, and cleaning the surface of the slip body (1) to finish degreasing.

5. A slip, comprising:

the slip coating is characterized by comprising a slip body (1) and a slip coating layer formed on the surface of the slip body (1), wherein the slip coating layer is prepared by the preparation method of the slip coating according to any one of claims 3-4.

6. A soluble bridge plug comprising the slip of claim 5.

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