CN111749667A - A kind of metal soluble ball with adjustable acid resistance time and self-dissolving and preparation method thereof - Google Patents

Abstract

The invention relates to an acid-resistant time-adjustable self-dissolving metal soluble ball and a manufacturing method thereof, belonging to the technical field of oil and gas field development, and the invention provides an acid-resistant time-adjustable self-dissolving metal soluble ball, which comprises the following components: the working layer is a soluble ball made of metal; the acid-resistant slow-melting layer is a polylactic acid layer or an epoxy resin layer, and the polylactic acid layer or the epoxy resin layer is subjected to post-curing treatment; the acid-resistant slow-melting layer is uniformly attached to the surface of the outer layer of the working layer. The invention has the advantages that the soluble ball can meet the requirement of the oil field underground acid fracturing environment, can normally work within a certain period of time, and after the certain period of time is exceeded, the coating is gradually dissolved to expose the metal material part of the soluble ball and quickly reacts with acid until the soluble ball is completely dissolved, so that the technical problem that the metal soluble ball cannot be effectively sealed in the acid environment is solved.

Description

A kind of metal soluble ball with adjustable acid resistance time and self-dissolving and preparation method thereof

technical field

The invention belongs to the technical field of oil and gas field development, is suitable for acid drilling, and particularly relates to a metal soluble ball with adjustable acid resistance time and self-dissolving and a preparation method thereof.

Background technique

Soluble ball is one of the important plugging tools for downhole layered and staged fracturing in oilfields. It relies on the cooperation of the sliding sleeve ball seat and the soluble ball to realize the opening of the sliding sleeve and the sealing of the soluble ball to realize the layered and staged fracturing. Thereby, the fracturing efficiency and the reconstruction effect are improved.

At present, the materials of soluble spheres are mainly magnesium alloys and aluminum alloys, as shown in Figure 1.

In the process of implementing the embodiments of the present invention, the inventor found that at least the following defects exist in the background technology:

Soluble balls can meet certain normal working time requirements in water environment, but magnesium alloys and aluminum alloys can quickly react with acid in acidic environment, which greatly shortens the working time of soluble balls, so it cannot meet the requirements of fracturing in acid environment Construction requirements.

SUMMARY OF THE INVENTION

The invention provides a metal soluble ball with adjustable acid resistance time and self-dissolving and a preparation method thereof, aiming at solving the above problems and solving the problem that the soluble ball can meet a certain normal working time requirement in a water environment, but the magnesium alloy in an acidic environment And aluminum alloy can quickly react with acid, which greatly shortens the working time of soluble ball, so it cannot meet the requirements of fracturing construction in acid environment.

For achieving the above object, the technical scheme adopted in the present invention is as follows:

A self-dissolving metal soluble ball with adjustable acid resistance time, comprising:

a working layer, the working layer is a metal soluble ball;

an acid-resistant slow-melting layer, the acid-resistant slow-melting layer is a polylactic acid layer or an epoxy resin layer, and the polylactic acid layer or the epoxy resin layer is post-cured;

The acid-resistant and slow-melting layer is uniformly attached to the outer surface of the working layer.

The acid-resistant and slow-melting layer has several layers.

The thickness of the acid-resistant and slow-melting layer outside the working layer is 0.05-0.10 mm.

The working layer is aluminum alloy or magnesium alloy.

A method for making metal soluble balls with adjustable acid resistance time and self-dissolving, comprising:

Step 1, making metal soluble balls;

Step 2, attaching a polylactic acid layer or an epoxy resin layer to the surface layer of the metal soluble ball;

Step 3, performing post-curing treatment on the polylactic acid layer or epoxy resin layer attached to the surface layer of the metal soluble ball.

Between the step 1 and the step 2, it also includes:

Step 1.1, drill a small threaded hole on the soluble ball, screw it into the small hole and hang it up, clean the surface of the ball with ether and dry it.

The step 2 is specifically:

The polylactic acid layer or epoxy resin layer is sprayed by electrostatic spraying and oven vulcanization.

Specifically in step 2:

A 0.05-0.10mm polylactic acid layer or epoxy resin layer is attached to the surface layer of the metal soluble ball.

After the step 3, it also includes:

Step 4, if it is necessary to attach multiple layers of polylactic acid or epoxy resin on the metal soluble ball, repeat steps 2 to 3 several times.

The material of the metal soluble ball is magnesium alloy or aluminum alloy metal.

The beneficial effect of the present invention is that the present invention enables the soluble ball to meet the requirements of the acid fracturing environment in the oil field, and can work normally within a certain period of time. The acid reacts until it is completely dissolved, thereby solving the technical problem that metal soluble spheres cannot be effectively sealed in an acid environment.

Description of drawings

1 is a schematic diagram of a metal soluble sphere in the prior art;

2 is a schematic diagram of a single-layer structure of a metal soluble ball with adjustable acid resistance time and self-dissolving metal according to the present invention;

3 is a schematic diagram of a multilayer structure of a soluble ball with adjustable acid resistance time and self-dissolving according to the present invention;

FIG. 4 shows the relationship between the thickness of the epoxy resin layer and the breakage time of a soluble ball with adjustable acid resistance time and self-dissolving spheres according to the present invention.

The figures are marked as: 1. Working layer; 2. Acid-resistant slow-melting layer; 3. Second acid-resistant slow-melting layer; 4. Third acid-resistant slow-melting layer.

Detailed ways

Hereinafter, the solution of the self-dissolving metal soluble ball with adjustable acid resistance time provided by the embodiment of the present invention will be described in detail through several specific embodiments.

Example 1

Please refer to FIG. 2 and FIG. 3 , which show a schematic structural diagram of a metal soluble ball with adjustable acid resistance time and self-dissolving metal according to the present invention. The self-dissolving metal soluble ball with adjustable acid resistance time includes:

a working layer, the working layer is a metal soluble ball;

The acid-resistant slow-melting layer 2, the acid-resistant slow-melting layer 2 is a polylactic acid layer or an epoxy resin layer, and the polylactic acid layer or the epoxy resin layer is post-cured;

The acid-resistant and slow-melting layer 2 is uniformly attached to the outer surface of the working layer.

In the above embodiment, the working layer 1 is an ordinary metal soluble sphere that dissolves at a desired position during the fracturing process. After the ordinary metal soluble sphere dissolves, a channel is formed, which can maintain the integrity of the wellbore. Metal soluble spheres dissolve rapidly in acid and cannot be effectively sealed.

In the metal soluble ball of this embodiment, a post-cured acid-resistant slow-melting layer 2, that is, a polylactic acid layer or an epoxy resin layer, is sprayed on the outside of an ordinary metal-soluble ball. The post-cured acid-resistant slow-melting layer 2 is The dissolution is slow under acidic conditions, and the working layer 1 can be temporarily isolated from the external acidic environment. During the temporary isolation time, the metal soluble spheres are moved to the target area. After the temporary isolation time limit, the metal soluble spheres are separated from the outside world. Reacts rapidly until complete dissolution, working on the target area.

Further, as shown in Figure 3, the metal soluble ball can be multi-layered, and the second acid-resistant slow-melting layer 3 and the third acid-resistant slow-melting layer 4 are shown in the figure. The multi-layer acid-resistant slow-melting layer can effectively improve the acid resistance time. The stability and working time of self-dissolving metal soluble balls can be adjusted.

Example 2

Further, please refer to FIG. 3 , another embodiment of a metal soluble ball with adjustable acid resistance time and self-dissolving metal according to the present invention, the acid resistance slow-melting layer 2 has several layers.

In the above embodiment, when the working layer 1 needs to be isolated for a longer time, several more layers of acid-resistant and slow-melting layer 2 can be sprayed, so as to extend the isolation time.

Example 3

Further, please refer to FIG. 3 and FIG. 4 , another embodiment of a metal soluble ball with adjustable acid resistance time and self-dissolving metal according to the present invention, the acid resistance slow melting layer 2 outside the working layer 1 has a thickness of 0.05-0.10 mm.

In the above-mentioned embodiment, when the thickness of the acid-resistant slow-melting layer 2 is 0.05-0.10 mm, the time for isolation in the downhole is about two hours.

When the thickness is fixed, the number of sprayed layers can be increased, and the stability of the sprayed layer can be greatly enhanced due to the increase of the number of layers, avoiding the early work of the working layer 1 due to local leakage, and the stability of the working ball is greatly increased.

Example 4

Further, in another embodiment of the soluble sphere of a metal with adjustable acid resistance time and self-dissolving metal of the present invention, the working layer 1 is an aluminum alloy or a magnesium alloy.

In the above embodiment, the working layer 1 is an ordinary metal soluble ball, and its material is aluminum alloy or magnesium alloy.

Example 5

The present invention relates to a method for making soluble metal spheres with adjustable acid resistance time and self-dissolving metal, and the method for making the self-dissolving metal soluble spheres with adjustable acid resistance time includes:

Step 1, making metal soluble balls;

Step 2, attaching a polylactic acid layer or an epoxy resin layer to the surface layer of the metal soluble ball;

Step 3, performing post-curing treatment on the polylactic acid layer or epoxy resin layer attached to the surface layer of the metal soluble ball.

In the above embodiment, metal soluble balls are first produced, and then polylactic acid or epoxy resin is attached to the outer surface of the metal soluble balls. Soluble spheres tuned to self-dissolving metals are more stable at work.

Example 6

Further, in another embodiment of the present invention, another embodiment of the method for making soluble metal spheres with adjustable acid resistance time and self-dissolving metal further includes between the steps 1 and 2:

Step 1.1, drill a small threaded hole on the soluble ball, screw it into the small hole and hang it up, clean the surface of the ball with ether and dry it.

In the above embodiment, suspending the soluble ball and cleaning the surface of the ball with ether can prepare for the subsequent spraying of epoxy resin and enhance the stability of the epoxy resin layer.

Example 7

Further, in another embodiment of the present invention, another embodiment of a method for producing a self-dissolving metal soluble ball with adjustable acid resistance time, the step 2 is specifically:

The polylactic acid layer or epoxy resin layer is sprayed by electrostatic spraying and oven vulcanization.

In the above embodiment, the polylactic acid layer or epoxy resin layer can be uniformly sprayed on the metal soluble ball by electrostatic spraying, and the polylactic acid layer or epoxy resin layer is more stable after oven vulcanization.

Example 8

Further, another embodiment of a method for producing a metal soluble ball with adjustable acid resistance time of the present invention is specifically as follows in step 2:

A 0.05-0.10mm polylactic acid layer or epoxy resin layer is attached to the surface layer of the metal soluble ball.

In the above embodiment, 0.05-0.10mm epoxy resin is attached to the surface of the metal soluble ball, and its action time is about two hours.

Example 9

Further, in another embodiment of the present invention, another embodiment of a method for manufacturing a metal soluble ball with an adjustable acid resistance time and self-dissolving metal, after the step 3, the method further includes:

Step 4, if it is necessary to attach multiple layers of polylactic acid or epoxy resin on the metal soluble ball, repeat steps 2 to 3 several times.

In the above embodiment, in order to ensure the stability of the self-dissolving metal soluble ball with adjustable acid resistance time and prolong its working time, polylactic acid or epoxy resin can be sprayed on its surface by multiple spraying.

Example 10

Further, another embodiment of the present invention is another embodiment of a method for manufacturing soluble metal spheres with adjustable acid resistance time and self-dissolving metal, wherein the material of the metal soluble spheres is magnesium alloy or aluminum alloy metal.

In the above embodiment, the material of the metal soluble ball is selected from magnesium alloy or aluminum alloy, and its material is selected from the same magnesium alloy or aluminum alloy as the prior art. Because the acid resistance time can be adjusted, the metal soluble balls that dissolve independently are directly sprayed with an epoxy resin layer on the outside, so the material of the metal soluble balls does not need to be changed. This product is simple to produce and practical.

The technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of technical solutions does not exist, and It is not within the scope of protection claimed by the present invention.

Claims (10)

1. An acid-resistant time-adjustable self-dissolving metal-dissolvable sphere, comprising:

the working layer is a soluble ball made of metal;

the acid-resistant slow-melting layer is a polylactic acid layer or an epoxy resin layer, and the polylactic acid layer or the epoxy resin layer is subjected to post-curing treatment;

the acid-resistant slow-melting layer is uniformly attached to the surface of the outer layer of the working layer.

2. The acid-resistant time tunable autonomous dissolving metal soluble sphere of claim 1 wherein said acid-resistant buffer layer has a plurality of layers.

3. The acid-resistant time-tunable self-dissolving metal soluble sphere of claim 1 or 2, wherein the thickness of the acid-resistant slow-melting layer outside the working layer is 0.05 to 0.10 mm.

4. The acid-resistant time-tunable self-dissolving metal soluble sphere of claim 1 or 2, wherein said working layer is an aluminum alloy or a magnesium alloy.

5. A method for manufacturing an acid-resistant time-adjustable self-dissolving metal soluble ball is characterized by comprising the following steps:

step 1, manufacturing a metal soluble ball;

step 2, attaching a polylactic acid layer or an epoxy resin layer on the surface layer of the metal soluble ball;

and 3, performing post-curing treatment on the polylactic acid layer or the epoxy resin layer attached to the surface layer of the metal soluble ball.

6. The method for making acid-resistant time-tunable self-dissolving metal soluble spheres of claim 5, further comprising between step 1 and step 2:

step 1.1, drilling small threaded holes on the soluble ball, screwing the small threaded holes into the small threaded holes by screws, hanging the small threaded holes, cleaning the surface of the soluble ball by ether, and drying the soluble ball in the air.

7. The method for manufacturing the acid-resistant time-adjustable self-dissolving metal soluble sphere according to claim 5, wherein the step 2 is specifically:

and the polylactic acid layer or the epoxy resin layer is sprayed in a manner of electrostatic spraying and oven vulcanization.

8. The method for manufacturing the acid-resistant time-adjustable self-dissolving metal soluble sphere according to claim 5, wherein the step 2 comprises:

and a polylactic acid layer or an epoxy resin layer with the thickness of 0.05-0.10mm is attached to the surface layer of the metal soluble ball.

9. The method of claim 5, wherein said step 3 is followed by the steps of:

and 4, if a plurality of polylactic acid layers or epoxy resin layers need to be attached to the metal soluble ball, repeating the steps 2 to 3 for a plurality of times.

10. The method of claim 5, wherein the acid-resistant time-adjustable self-dissolving metal soluble sphere is made of magnesium alloy or aluminum alloy.

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