阅读说明：本技术 卡瓦涂层及其制备方法、卡瓦、可溶桥塞 (Slip coating and preparation method thereof, slip and soluble bridge plug ) 是由 苏东 郭明杨 卿显君 叶德彬 于 2021-10-08 设计创作，主要内容包括：本发明提供一种卡瓦涂层及其制备方法、卡瓦、可溶桥塞,卡瓦涂层的制备方法,包括：对卡瓦本体进行除油处理,将卡瓦本体放入碱性脱脂液中,在60℃～80℃条件下浸泡20min～40min,浸泡中对卡瓦本体进行转动；进行80℃～100℃烘干；对卡瓦本体表面进行喷砂处理；在卡瓦本体表面涂覆环氧树脂粘结剂；在环氧树脂粘结剂层上形成球形氧化硅颗粒和碳素合金钢颗粒混合层；在混合层表面形成氟树脂油漆层。本方案极大简化涂层制备工艺,并通过对卡瓦本体的预处理,提高涂层制备于卡瓦上后的附着力,制备的卡瓦可有效实现对桥塞的固定,并且咬合中对井筒/套筒的损伤小,利于实施推广。(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.)

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.

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: the adhesive layer 2 is coated on the surface of the slip body 1; a mixed layer 3 of spherical silicon oxide particles and carbon alloy steel particles laid on the adhesive layer 2; a fluororesin paint layer 4 sprayed on the surface of the mixed layer 3.

The adhesive 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 mixed layer 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 the slip body 1, putting the slip body 1 into an alkaline degreasing solution, soaking for 20-40 min at 60-80 ℃, and rotating the slip body 1 during soaking; after soaking, utilize the cotton to clean slips 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 the slip body 1, wherein the sand blasting particle size is 0.4-0.6 mm.

S400, 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 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 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 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 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.

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 a disc 6, a plurality of clamping assemblies 5 which are arrayed on the disc 6 along the circumference, a rotating mechanism 7 connected with the disc 6, a lifting mechanism 8 connected with the rotating mechanism 7, and a swinging mechanism 9 connected with the lifting mechanism 8.

Specifically, as shown in fig. 6 to 7, the clamping assembly 5 includes a pair of supporting blocks 52 disposed at intervals and clamping bars 51 disposed at the clamping blocks 51, the pair of clamping bars 51 are disposed at intervals, a horizontally disposed sliding groove 521 is formed in a concave manner on an inner side surface of the supporting block 52, the sliding groove 521 does not penetrate through an outer side surface of the supporting block 52, a sliding plate 513 is disposed in a middle portion of the supporting block 52, and the sliding plate 513 is slidably fitted in the sliding groove 521. A plurality of springs 512 are connected between the clamping bars 51. The upper portion of the holding bar 51 has a second slope 511, and the second slope 511 is inclined downward from the top of the holding bar 51 to the outside. The supporting shoe 52 is connected in the passageway 53 bottom, and the passageway 53 top is connected with centre gripping roof 56, and centre gripping strip 51 upper portion is located the passageway 53, and 53 is equipped with vertical cylinder 57 in the passageway, and vertical cylinder 57 is fixed in centre gripping roof 56 bottom, and vertical cylinder 57 expansion end is connected with kicking block 54, and kicking block 54 bottom is sunken to be formed with and is acted on the groove, and the effect groove both sides wall is first inclined plane 541, is used for acting on the second inclined plane 511 of a pair of centre gripping strip 51 respectively.

Specifically, as shown in fig. 8, a plurality of sections of adjusting sliding grooves 61 are arranged radially on the disc 6 along a circumferential array, the number of the adjusting sliding grooves is matched with the number of the clamping assemblies 5, the clamping top plate 56 is connected with a sliding block 62, the sliding block 62 is in sliding fit with the adjusting sliding grooves 61, the sliding block 62 is located on two sides of the adjusting sliding grooves 61 and supported by the top surface of the disc 6, a rotating seat 63 and an adjusting motor 65 are arranged on the disc 6 and respectively located on two ends of the adjusting sliding grooves 61, an output shaft of the adjusting motor 65 is connected with one end of a screw rod 64, the other end of the screw rod 64 is in rotating fit with the rotating seat 63, and the sliding block 62 penetrates through the screw rod 64. Each set of adjusting motor 65, rotating seat 63, screw 64, adjusting sliding groove 61 and sliding block 62 corresponds to one clamping component 5.

Specifically, as shown in fig. 5 and 9, the rotating mechanism 7 includes an external spline 71 concentric with the disc 6 and fixed to the top surface of the disc 6, an internal spline 75 is fitted in the external spline 71, the internal spline 75 is connected to an output shaft of a vertically arranged rotating motor 76, the rotating motor 76 is fixed to the bottom surface of an upper disc 73, the upper disc 73 is connected to the movable end of the lifting mechanism 8, two sections of arc-shaped grooves 731 are formed in the upper disc 73, a pair of arc-shaped limit plates 72 are arranged on the external spline 71, the arc-shaped limit plates 72 are respectively fitted to one section of arc-shaped groove 731, the top of each arc-shaped limit plate 72 is connected with a limit ring 74, and the limit ring 74 is arranged on the top surface of the upper disc 73 and is in contact fit with the upper disc 73. The lifting mechanism 8 comprises 3 lifting cylinders 81, the lifting cylinders 81 operate synchronously, the top parts of the lifting cylinders are connected to a cylinder fixing plate 82, and the movable ends of the lifting cylinders are connected to the upper disc 73.

Specifically, as shown in fig. 10 to 11, the swing mechanism 9 includes a base 91 and a rotating sleeve 92 fixed on the base, and the base 91 is fixedly connected with the cylinder fixing plate 82. The rotating sleeve 92 penetrates through the rotating shaft 93, connecting plates 94 are arranged at two ends of the rotating shaft 93, the connecting plates 94 are connected with an upper frame 95, a moving gap 950 is formed in the middle of the upper frame 95, matching grooves 951 are formed in two ends of the upper frame 95, a driving plate 96 is arranged at the position of the moving gap 950, a rack 961 is arranged on the bottom surface of the middle of the driving plate 96, two ends of the driving plate 9 are matched with the matching grooves 951, the rotating sleeve 92 is provided with an arc top surface, and a tooth part 921 is arranged on the arc top surface. The rack 961 is engaged with the tooth 921. A pair of horizontal oil cylinders 98 which are oppositely arranged at intervals are arranged on the upper frame 95, the movable ends of the horizontal oil cylinders 98 are connected to the same stress block 97, and the stress block 97 is fixed on the driving plate 96.

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

s110, clamping each slip body 1 on one clamping assembly 5 respectively, specifically, placing the upper part of each slip body 1 between a pair of clamping strips 51 arranged at intervals, at the moment, the clamping strips 51 are in sliding fit with the sliding grooves 521 of the supporting blocks 52 through sliding plates 513 arranged in the middle, a plurality of springs 512 in a compressed state are arranged between the upper parts of the clamping strips 51, pushing the jacking blocks 54 downwards through vertical air cylinders 57 arranged on the clamping top plates 56, enabling the first inclined surfaces 541 at the lower ends of the jacking blocks 54 to act on the second inclined 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 the slip body 1. Since the clamping top plates 56 of the clamping components 5 are respectively connected with sliding blocks 62, the sliding blocks 62 are matched in the adjusting sliding grooves 61 of the disc 6; before clamping each slip body 1, the position of the clamping assemblies 5 is adjusted according to the size of the slip body 1, so that the positions of two adjacent clamping assemblies 5 are staggered, the slip bodies 1 after being clamped cannot touch each other, and specifically, a screw rod 64 connected with an output shaft of the adjusting motor 65 fixed on the disc 6 rotates, so that a sliding block 62 penetrating through the screw rod 64 moves along the length direction of the adjusting sliding groove 61. The sheet-shaped slip body 1 can be clamped according to the above mode, the position of the clamping assembly 5 along the adjusting sliding groove 61 can be adjusted according to the diameter of the cylinder-shaped slip body 1 so as to adapt to the cylinder-shaped slip body 1, and part or all of the clamping assemblies 5 are selected to clamp the cylinder-shaped slip body 1, so that 1 piece of the cylinder-shaped slip body 1 is clamped at a time.

S120, descending the rotating mechanism 7 and the disc 6 connected with the rotating mechanism 7 through the lifting mechanism 8, and descending the clamping assemblies 5 arranged on the disc 6 in a circumferential array, so that the slip body 1 clamped by the clamping 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 the disc 6 once through the rotating mechanism 7, wherein the rotating direction is opposite each time, and the rotating angle is smaller than 80 degrees each time. Specifically, the disk 6 is rotated by the rotating mechanism 7, the internal spline 75 connected with the output shaft of the rotating motor 76 of the rotating mechanism 7 is driven to rotate, the internal spline 75 drives the external spline 71 matched with the internal spline to rotate, so that the disk 6 connected with the external spline 71 is driven to rotate, when the external spline 71 rotates, the pair of arc limiting plates 72 arranged on the external spline 71 move in the arc-shaped groove 731 of the upper disk 73, and the rotation angle is limited by the fact that the arc limiting plates 72 move to the other end from one end of the arc-shaped groove 731 every time.

In soaking, every 5min, act on the lifting mechanism 8 through the swing mechanism 9, make the lifting mechanism 8, the slewing mechanism 7, the disc 6 swings, thereby make the slips body 1 that the centre gripping subassembly 5 centre gripping swung, specifically act on the atress piece 97 through locating a pair of horizontal hydro-cylinder 98 of upper bracket 95, make the atress piece 97 drive the drive plate 96 of being connected with it along the removal clearance 950 in the middle part of upper bracket 95 and the cooperation groove 951 removal at upper bracket 95 both ends, thereby the volume acts on the tooth portion 921 of the circular arc top surface of the rotating sleeve 92 through the rack 961 of the drive plate 96 bottom surface, drive the rotating sleeve 92 and support the base 91 of rotating sleeve 92 and rotate along the axis of rotation 93 of wearing in the rotating sleeve 92, thereby make the slewing mechanism 7 swing of being connected with base 91.

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

s150, taking down the slip bodies 1, wiping the slip bodies 1 by using cotton cloth, and cleaning the surfaces of the slip 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 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 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.