Composite temporary plugging ball with strong erosion resistance

Abstract

The invention discloses a composite temporary plugging ball with strong erosion resistance. The composite temporary plugging ball comprises a ball core and a metal fiber coating layer coating the ball core. Compared with a common temporary plugging ball, the temporary plugging ball has higher erosion-resistant strength and plugging capacity, the inner-layer ball core is protected through rock chippings or proppant particles embedded in gaps of the outer-layer metal fiber coating layer, a subsequent proppant only polishes the particles embedded in the gaps of the metal fiber coating layer, and the particles are not prone to falling off along with aggravation of abrasion. Original particles are abraded and generate new gaps, new rock debris or proppant particles can be embedded into the new gaps, continuous protection of the temporary plugging ball is achieved, the influence of erosion of the temporary plugging ball on the temporary plugging effect is avoided, and meanwhile, the proppant can be gradually gathered at the gaps and self-accumulated to improve the plugging effect. The flow limiting effect and the exploitation efficiency can be effectively improved, all clusters of cracks can be evenly and effectively expanded, abrasion of a propping agent to the temporary plugging ball when the temporary plugging ball sets an irregular-shaped shot hole can be reduced, and the oil and gas exploitation efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field exploitation, and in particular to a highly erosion-resistant composite temporary plugging ball. Background Art

[0002] In the field of oil and gas field exploitation in my country, unconventional oil and gas reservoirs have gradually become the main development direction. However, unconventional oil and gas reservoirs have low porosity and low permeability, making them difficult to exploit. During the staged fracturing process, the perforation diversion is different, resulting in uneven expansion of some cracks, which will affect the efficiency of oil and gas extraction.

[0003] Fracturing ball-dropping temporary plugging and diversion technology is an oil and gas production technology widely used in unconventional oil and gas reservoirs such as shale gas and tight oil. The ball-dropping temporary plugging and diversion technology is to drop a temporary plugging ball into the well, which is then carried by the fluid to the hole and sealed, so that the fluid is redistributed to the hole of the original low permeability fracture to achieve uniform expansion and transformation of the fracture.

[0004] However, the fracturing fluid will be throttled at the blasthole, and the proppant will flow at high speed, causing serious erosion at the blasthole, increasing the blasthole aperture to form irregular holes. Due to the irregularity of the holes, the common temporary plugging balls cannot completely block the holes after being set. The proppant will pass through at high speed and continue to grind the temporary plugging balls, causing material loss in the temporary plugging balls, making it difficult to redistribute the fluid to the holes of low permeability fractures, and the undeveloped fractures are difficult to continue to expand, making it difficult to increase production. Summary of the invention

[0005] In view of the above problems, the present invention aims to provide a highly erosion-resistant composite temporary plugging ball.

[0006] The technical solution of the present invention is as follows:

[0007] A highly erosion-resistant composite temporary plugging ball comprises a ball core and a metal fiber coating layer coating the ball core.

[0008] Preferably, the core is made of degradable material or non-degradable material.

[0009] Preferably, the core is a rigid core or an elastic core.

[0010] Preferably, the core is a hollow structure or a solid structure.

[0011] Preferably, the metal fiber coating layer is provided in multiple layers.

[0012] Preferably, the metal fiber coating layer is formed by interweaving metal fibers.

[0013] The beneficial effects of the present invention are:

[0014] 1. The temporary plugging ball structure of the present invention has high interchangeability, and the shape, material and structure of the ball core can be adjusted arbitrarily according to actual conditions.

[0015] 2. The temporary plugging ball of the present invention is composed of an outer metal fiber coating and an inner ball core. Rock debris or proppant particles will be embedded in the gaps of the outer metal fiber coating layer, so that the temporary plugging ball has higher wear resistance.

[0016] 3. The temporary plugging ball of the present invention has a continuously updated wear-resistant protective layer. After rock cuttings or proppant particles are embedded in the gaps of the metal fiber coating layer of the temporary plugging ball, the subsequent proppant will only grind the particles originally embedded in the gaps of the metal fiber coating layer. As the wear intensifies, the original particles are worn away and new gaps are generated. New rock cuttings or proppant particles will be embedded in the gaps of the metal fiber coating layer of the temporary plugging ball to form a new wear-resistant layer.

[0017] 4. Due to the restrictive effect of the metal fiber coating layer, the proppant will gradually gather in the gaps and self-accumulate to improve the sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 This is a schematic diagram of the structure of the highly erosion-resistant composite temporary plugging ball of the present invention;

[0020] Figure 2 It is a schematic diagram of the structure of the strong erosion-resistant composite temporary plugging ball and the common temporary plugging ball for sealing the hole;

[0021] Figure 3 This is a schematic diagram of the state of erosion of ordinary temporary plugging balls;

[0022] Figure 4 It is a schematic diagram of the state in which the highly erosion-resistant composite temporary plugging ball of the present invention undergoes erosion and generates a proppant self-accumulation protective layer;

[0023] Figure 5 It is a schematic diagram of the structure when the ball core is spherical and its shape is consistent with the shape of the outer metal fiber coating layer;

[0024] Figure 6 It is a schematic diagram of the structure when the ball core is non-spherical and its shape is consistent with the shape of the outer metal fiber coating layer;

[0025] Figure 7 It is a schematic diagram of the state of the strong erosion-resistant composite temporary plugging ball cuttings and proppant particles embedded in the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, in the absence of conflict, the embodiments in this application and the technical features in the embodiments can be combined with each other. It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as those generally understood by those of ordinary skill in the art to which this application belongs. The words "including" or "comprising" and the like used in the disclosure of the present invention mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0027] like Figure 1 As shown, the present invention provides a highly erosion-resistant composite temporary plugging ball, comprising a ball core and a metal fiber coating layer coating the ball core.

[0028] In the present invention, the core can be any suitable material, structure and shape, and the outer metal fiber coating enables the present invention to meet the wear resistance required by the temporary plugging ball. The temporary plugging ball of the present invention has the property of continuously renewing the wear-resistant layer. Specifically, the temporary plugging ball protects the temporary plugging ball core through the rock cuttings or proppant particles embedded in the gaps of the outer metal fiber coating. The subsequent proppant will only grind the particles embedded in the gaps of the metal fiber coating. As the wear intensifies, the original particles are worn and new gaps are generated. New rock cuttings or proppant particles will be embedded in the gaps of the outer metal fiber coating of the temporary plugging ball to achieve the above-mentioned function of continuously renewing the wear-resistant layer, thereby improving the wear resistance of the temporary plugging ball, thereby avoiding the impact of temporary plugging due to erosion of the temporary plugging ball. At the same time, due to the limiting effect of the metal fiber coating, the proppant will gradually gather at the gaps and self-accumulate to improve the plugging effect.

[0029] In a specific embodiment, the core is made of a degradable material or a non-degradable material. Optionally, the degradable material includes polylactic acid (PLA), polyglycolic acid (PGA), polyvinyl alcohol (PVA), etc. The non-degradable material includes olefin thermoplastic elastomers TPO and TPV, insoluble metal materials, glass, rubber, etc.

[0030] In a specific embodiment, the core is a rigid core or an elastic core.

[0031] In a specific embodiment, the core is a hollow structure or a solid structure.

[0032] In a specific embodiment, the metal fiber coating layer is provided with multiple layers. It should be noted that the number of layers of the metal fiber coating layer can be any number, which can be determined according to the wear resistance requirements on site.

[0033] In a specific embodiment, the metal fiber coating layer is formed by interweaving metal fibers.

[0034] The state when the strong erosion-resistant composite temporary plugging ball of the present invention and the ordinary temporary plugging ball are used for setting is as follows: Figure 2 and Figure 3 As shown in the figure, since the microstructure of the hole is not theoretically circular, ordinary temporary plugging balls will still have gaps after being sealed. The proppant will grind the temporary plugging balls through the gaps. Ordinary temporary plugging balls will wear quickly, causing the gaps to gradually expand and the plugging ability to decrease rapidly.

[0035] The present invention uses a temporary plugging ball with a spherical core to plug the hole, achieving a temporary plugging effect with strong erosion resistance. Figure 4 As shown, the highly erosion-resistant composite temporary plugging ball of the present invention has a continuously updated wear-resistant protective layer. After the rock cuttings or proppant particles are embedded in the gaps of the metal fiber coating layer of the outer layer of the temporary plugging ball, the subsequent proppant will only grind the particles originally embedded in the gaps of the metal fiber coating layer. As the wear intensifies, the original particles are worn and new gaps are generated. New rock cuttings or proppant particles will be embedded in the gaps of the metal fiber coating layer of the outer layer of the temporary plugging ball to form a new wear-resistant layer. At the same time, due to the limiting effect of the metal fiber coating layer, the proppant will gradually gather at the gaps and self-accumulate to improve the plugging effect. Therefore, the highly erosion-resistant temporary plugging ball of the present invention avoids the influence of temporary plugging ball erosion on the temporary plugging effect, effectively improves the flow limiting effect, mining efficiency, and allows each cluster of cracks to expand evenly and effectively.

[0036] In a specific embodiment, the highly erosion-resistant composite temporary plugging ball structure of the present invention is as follows Figure 5 As shown, it is composed of an outer metal fiber layer covering a spherical core, and the shape of the inner core of the temporary plugging ball is consistent with the outer metal fiber covering layer.

[0037] In a specific embodiment, the highly erosion-resistant composite temporary plugging ball structure of the present invention is as follows Figure 6 As shown, it is composed of an outer metal fiber layer covering a special-shaped non-spherical core, and the shape of the inner core of the temporary blocking ball is consistent with the outer metal fiber covering layer.

[0038] In a specific embodiment, the state of the rock cuttings or proppant particles embedded in the gaps of the outer metal fiber coating layer of the highly erosion-resistant composite temporary plugging ball of the present invention is as follows: Figure 7 shown.

[0039] The above description is only a representative embodiment of the present invention and does not limit the present invention in any form. Any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, uses the above-disclosed technical contents to make some changes or modifications to the embodiments are equivalent embodiments of the present invention. However, any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A strong erosion-resistant composite temporary plugging ball, characterized in that: The invention comprises a ball core and a metal fiber covering layer covering the ball core.

2. The strong erosion-resistant composite temporary plugging ball according to claim 1 is characterized in that: The ball core is made of degradable material or non-degradable material.

3. The strong erosion-resistant composite temporary plugging ball according to claim 1 is characterized in that: The ball core is a rigid ball core or an elastic ball core.

4. The strong erosion-resistant composite temporary plugging ball according to claim 1 is characterized in that: The spherical core is a hollow structure or a solid structure.

5. The strong erosion-resistant composite temporary plugging ball according to claim 1 is characterized in that: The metal fiber coating layer is provided in multiple layers.

6. The strong erosion-resistant composite temporary plugging ball according to any one of claims 1 to 5, characterized in that: The metal fiber coating layer is formed by interweaving metal fibers.

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