A method for preparing a toughening agent for oilfield cementing

Abstract

The application discloses a preparation method of a toughening agent for oilfield cementing. The method comprises the following steps: S1, weighing 30-60 parts of drilling solid waste and 10-30 parts of waste rubber particles, melting and uniformly mixing the drilling solid waste and the waste rubber particles by heating and stirring at 150-260 DEG C for 35-50 min; S2, adding 5-10 parts of mineral fibers, and heating and stirring at 150-260 DEG C for 15-20 min; S3, naturally cooling to room temperature, grinding and crushing to pass through an 80-mesh sieve, and then immersing the surface of the sieved powder particles in 1-4 parts of a polybutadiene latex aqueous solution with a mass fraction of 63-73%, and mixing and stirring for 1.6-2.3 h; and S4, drying the mixed and stirred mixture at 30-40 DEG C, and then crushing the dried mixture to obtain the toughening agent for oilfield cementing. The application has the beneficial effects of improving the cementing quality, strengthening the cementation degree with the formation rock, reducing the rigid stress effect of the formation, and protecting and reducing the pressure bearing capacity of the oil well casing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of petroleum chemical industry, in particular to a preparation method of a toughening agent for oilfield cementing. BACKGROUND

[0002] In the process of cementing system, glass balls, barite, cement and other materials need to be added to ensure the firmness of the oil well casing, so as to ensure the normal oil production of the oil well. However, the added cement, barite and the like are often steel media connecting the casing and the formation rock. When the formation pressure, formation cracks and the like change, the cementing material does not have good cementing toughness, which greatly increases the casing damage probability. However, the existing method is to add expensive latex material. However, this method can only avoid the corrosion of some formation water on the cement curing and the casing, and cannot improve the toughness of the cement curing.

[0003] Therefore, the toughening agent for oilfield cementing, which is prepared by melting and mixing drilling solid waste, waste rubber particles and mineral fibers and then adding a latex agent, can improve the cementing quality, strengthen the cementing degree with the formation rock, reduce the steel stress effect of the formation, and protect and reduce the pressure bearing capacity of the oil well casing after being added to the cementing mud system. SUMMARY

[0004] The present application aims to provide a preparation method of a toughening agent for oilfield cementing, which can improve the cementing quality, strengthen the cementing degree with the formation rock, reduce the steel stress effect of the formation, and protect and reduce the pressure bearing capacity of the oil well casing.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical scheme, including the following steps:

[0006] S1, 30-60 parts of drilling solid waste and 10-30 parts of waste rubber particles are weighed, and the weighed drilling solid waste and waste rubber particles are added to a reactor, heated and stirred at 150-260 DEG C for 35-50 min, and the drilling solid waste and waste rubber particles are melted and uniformly mixed;

[0007] S2, 5-10 parts of mineral fibers are further added to the reactor, heated and stirred at 150-260 DEG C for 15-20 min, and a drilling solid waste mixture is obtained;

[0008] S3, the drilling solid waste mixture is naturally cooled to room temperature, ground and crushed through an 80 mesh sieve, and then 1-4 parts of a polybutadiene latex aqueous solution with a mass fraction of 63-73% is infiltrated on the surface of the sieved powder particles, and mixed and stirred for 1.6-2.3 h;

[0009] S4, the mixture after mixing and stirring is dried at 30-40 DEG C and then crushed, and a toughening agent for oilfield cementing is obtained.

[0010] Preferably, the waste rubber particles are one or more of polyurethane, waste tires, rubber.

[0011] Preferably, the waste rubber particles are waste tire particles.

[0012] Preferably, the mineral fibers are one or more of ferrite, aluminum silicate fiber, carbon fiber.

[0013] Preferably, the mineral fibers are aluminum silicate fibers.

[0014] Preferably, the mass fraction of the polybutadiene latex aqueous solution is 68%.

[0015] Preferably, the mass ratio of the drilling solid waste and the waste rubber particles is 6:1.

[0016] Preferably, in step S3, the mass ratio of the added amount of the polybutadiene latex aqueous solution to the drilling solid waste mixture is 15:1.

[0017] The beneficial effects of the present application: the prepared toughening agent for oilfield cementing can improve the cementing quality, strengthen the cementation degree with the formation rock, reduce the steel stress effect of the formation, and protect and reduce the pressure bearing capacity of the oil well casing. DETAILED DESCRIPTION

[0018] The invention will be further described in detail below, so that those skilled in the art can implement it according to the description.

[0019] It should be understood that the terms such as "have", "contain" and "include" used herein do not exclude the presence or addition of one or other elements or combinations thereof.

[0020] Example 1

[0021] S1, weigh 60 parts of drilling solid waste and 10 parts of polyurethane particles, add the weighed drilling solid waste and polyurethane particles into a reactor, heat and stir at 200°C for 40 min, melt and mix the drilling solid waste and polyurethane particles;

[0022] S2, add 8 parts of aluminum silicate fiber to the reactor, heat and stir at 190°C for 18 min to obtain a drilling solid waste mixture;

[0023] S3, cool the drilling solid waste mixture to room temperature naturally, grind and pass through an 80-mesh sieve, then immerse the surface of the sieved powder particles in 1 part of polybutadiene latex aqueous solution with a mass fraction of 68%, and mix and stir for 2 h;

[0024] S4, after drying the mixed and stirred mixture at 35°C, it is ground to obtain a toughening agent for oilfield cementing.

[0025] Example 2

[0026] S1, 40 parts of drilling solid waste and 20 parts of waste tire particles were weighed, and the weighed drilling solid waste and waste tire particles were added to a reactor, heated and stirred at 150°C for 50 min, and the drilling solid waste and waste tire particles were melted and uniformly mixed;

[0027] S2, 8 parts of iron aluminate fibers were further added to the reactor, heated and stirred at 150°C for 20 min, and a drilling solid waste mixture was obtained;

[0028] S3, the drilling solid waste mixture was naturally cooled to room temperature, ground and sieved through an 80-mesh sieve, and then 4 parts of a polybutadiene latex aqueous solution with a mass fraction of 63% was infiltrated on the surface of the sieved powder particles, and mixed and stirred for 1.6 h;

[0029] S4, the mixed and stirred mixture was dried at 40°C and then ground, and a toughening agent for oil well cementing was obtained.

[0030] Example 3

[0031] S1, 30 parts of drilling solid waste and 30 parts of rubber particles were weighed, and the weighed drilling solid waste and rubber particles were added to a reactor, heated and stirred at 260°C for 35 min, and the drilling solid waste and rubber particles were melted and uniformly mixed;

[0032] S2, 10 parts of carbon fibers were further added to the reactor, heated and stirred at 260°C for 15 min, and a drilling solid waste mixture was obtained;

[0033] S3, the drilling solid waste mixture was naturally cooled to room temperature, ground and sieved through an 80-mesh sieve, and then 3 parts of a polybutadiene latex aqueous solution with a mass fraction of 73% was infiltrated on the surface of the sieved powder particles, and mixed and stirred for 2.3 h;

[0034] S4, the mixed and stirred mixture was dried at 30°C and then ground, and a toughening agent for oil well cementing was obtained.

[0035] Example 4

[0036] S1, 35 parts of drilling solid waste, 5 parts of polyurethane particles and 10 parts of waste tire particles were weighed, and the weighed drilling solid waste, polyurethane particles and waste tire particles were added to a reactor, heated and stirred at 180°C for 45 min, and the drilling solid waste, polyurethane particles and waste tire particles were melted and uniformly mixed;

[0037] S2, 3 parts of iron aluminate fibers and 3 parts of aluminum silicate fibers were further added to the reactor, heated and stirred at 220°C for 18 min, and a drilling solid waste mixture was obtained;

[0038] S3, the drilling solid waste mixture is naturally cooled to room temperature, ground and crushed to pass through an 80-mesh sieve, then the surface of the sieved powder particles is infiltrated with 2 parts of a 64% by mass polybutadiene latex aqueous solution, and mixed and stirred for 1.7 hours;

[0039] S4, the mixed and stirred mixture is dried at 38°C and then crushed to obtain the toughening agent for oil well cementing.

[0040] Example 5

[0041] S1, 55 parts of drilling solid waste, 10 parts of polyurethane particles, 10 parts of waste tires, and 10 parts of rubber particles are weighed, and the weighed drilling solid waste, polyurethane particles, waste tires, and rubber particles are added to a reactor, heated and stirred at 215°C for 42 minutes, and the drilling solid waste, polyurethane particles, waste tires, and rubber particles are melted and mixed evenly;

[0042] S2, 3 parts of aluminum silicate fibers and 3 parts of carbon fibers are added to the reactor, heated and stirred at 190°C for 19 minutes to obtain a drilling solid waste mixture;

[0043] S3, the drilling solid waste mixture is naturally cooled to room temperature, ground and crushed to pass through an 80-mesh sieve, then the surface of the sieved powder particles is infiltrated with 3 parts of a 72% by mass polybutadiene latex aqueous solution, and mixed and stirred for 2.2 hours;

[0044] S4, the mixed and stirred mixture is dried at 39°C and then crushed to obtain the toughening agent for oil well cementing.

[0045] Example 6

[0046] S1, 35 parts of drilling solid waste, 10 parts of waste tires, and 10 parts of rubber particles are weighed, and the weighed drilling solid waste, waste tires, and rubber particles are added to a reactor, heated and stirred at 215°C for 42 minutes, and the drilling solid waste, waste tires, and rubber particles are melted and mixed evenly;

[0047] S2, 8 parts of carbon fibers are added to the reactor, heated and stirred at 195°C for 19 minutes to obtain a drilling solid waste mixture;

[0048] S3, the drilling solid waste mixture is naturally cooled to room temperature, ground and crushed to pass through an 80-mesh sieve, then the surface of the sieved powder particles is infiltrated with 4 parts of a 71% by mass polybutadiene latex aqueous solution, and mixed and stirred for 1.85 hours;

[0049] S4, the mixed and stirred mixture is dried at 38°C and then crushed to obtain the toughening agent for oil well cementing.

[0050] Comparative Example 1

[0051] S1, 80 parts of drilling solid waste and 5 parts of waste tire particles were weighed, and the weighed drilling solid waste and waste tire particles were added to a reactor, heated at 280°C and stirred for 20 min, and the drilling solid waste and waste tire particles were melted and uniformly mixed;

[0052] S2, 3 parts of aluminum silicate fiber were further added to the reactor, heated at 120°C and stirred for 25 min, to obtain a drilling solid waste mixture;

[0053] S3, the drilling solid waste mixture was naturally cooled to room temperature, ground and sieved through an 80-mesh sieve, and then 6 parts of a polybutadiene latex aqueous solution with a mass fraction of 54% were infiltrated on the surface of the sieved powder particles, and mixed and stirred for 2.5 h;

[0054] S4, the mixed and stirred mixture was dried at 45°C and then ground to obtain a toughening agent.

[0055] Comparative Example 2

[0056] S1, 25 parts of drilling solid waste and 40 parts of rubber particles were weighed, and the weighed drilling solid waste and rubber particles were added to a reactor, heated at 130°C and stirred for 60 min, and the drilling solid waste and rubber particles were melted and uniformly mixed;

[0057] S2, 12 parts of carbon fiber were further added to the reactor, heated at 280°C and stirred for 10 min, to obtain a drilling solid waste mixture;

[0058] S3, the drilling solid waste mixture was naturally cooled to room temperature, ground and sieved through an 80-mesh sieve, and then 0.5 parts of a polybutadiene latex aqueous solution with a mass fraction of 55% were infiltrated on the surface of the sieved powder particles, and mixed and stirred for 1.5 h;

[0059] S4, the mixed and stirred mixture was dried at 28°C and then ground to obtain a toughening agent for oil well cementing.

[0060] Data analysis

[0061] The toughening agents for well cementing prepared in Examples 1-6 and Comparative Examples 1-2 were mixed with 32.0 g of a fluid loss agent, 8.0 g of a dispersing agent, 3.0 g of an antifoaming agent, 800.0 g of G-grade cement, 310.0 g of distilled water, 28.0 g of a channeling prevention enhancer, 4.0 g of an expanding agent, 12.0 g of a retarder, and 16.0-40.0 g of the toughening agent (2%-5% of the mass of the cement) according to the API standard to obtain a cement slurry. The properties of the obtained cement slurry were tested, and Table 1 was obtained.

[0062] Table 1

[0063]

[0064] As shown in Table 1, the cementing toughening agent prepared according to the present application is obviously superior to Comparative Example 1 and Comparative Example 2 in terms of rheological property, API fluid loss, thickening time, compressive strength, Young's modulus and toughness improvement rate.

[0065] While embodiments of the application have been disclosed in connection with the above description and the drawings, it should be understood that there is no intent to limit the application to the specific form set forth, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the application as defined by the appended claims.

Claims

1. A method for preparing a toughening agent for oilfield cementing, characterized by, The method comprises the following steps: S1, taking 30-60 parts of drilling solid waste and 10-30 parts of waste rubber particles, adding the taken drilling solid waste and waste rubber particles into a reactor, heating and stirring at 150-260 DEG C for 35-50 min, melting and mixing the drilling solid waste and waste rubber particles; S2, adding 5-10 parts of mineral fibers into the reactor, heating and stirring at 150-260 DEG C for 15-20 min, and obtaining a drilling solid waste mixture; S3, cooling the drilling solid waste mixture to room temperature, grinding and crushing through an 80 mesh sieve, then immersing the surface of the sieved powder particles in 1-4 parts of a polybutadiene latex aqueous solution with a mass fraction of 63-73%, and mixing and stirring for 1.6-2.3 h; S4, drying the mixed and stirred mixture at 30-40 DEG C, and then crushing, to obtain a toughening agent for oil well cementing.

2. The method for preparing a toughener for oilfield cementing according to claim 1, characterized in that: The waste rubber particles are one or more of polyurethane, waste tires and rubber.

3. The method of preparing a toughener for oilfield cementing as claimed in claim 1, characterized in that: The mineral fibers are one or more of ferric aluminate, aluminum silicate fiber and carbon fiber.

4. The method of preparing a toughener for oilfield cementing as claimed in claim 1, characterized by: The mass fraction of the polybutadiene latex aqueous solution is 68%.

5. The method of preparing a toughener for oilfield cementing as claimed in claim 1, characterized by: The mass ratio of the drilling solid waste to the waste rubber particles is 6:

1.

6. The method of preparing a toughener for oilfield cementing as claimed in claim 1, characterized by: In step S3, the mass ratio of the added amount of the polybutadiene latex aqueous solution to the drilling solid waste mixture is 15:1.

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