Thermal insulation material taking water-based rock debris as raw material as well as preparation method and application of thermal insulation material

Abstract

The invention discloses a thermal insulation material taking water-based rock debris as a raw material as well as a preparation method and application thereof. The thermal insulation material has the advantages of simplicity in preparation, easiness in implementation and good thermal insulation performance. The water-based rock debris, the cement and the hollow ceramsite proppant are used as raw materials and are compounded to obtain the thermal insulation material capable of being used for thermal insulation of oil field construction. The heat conductivity coefficient and strength of the heat insulation material can be adjusted by using different formulas, the purpose of adjusting the heat conductivity coefficient and strength is achieved by adopting hollow ceramsite proppants of different specifications, high strength and high heat insulation performance of the material can be considered, and the material has obvious application and popularization value.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of environmental protection and resource recycling, and in particular to a heat-insulating material using water-based rock cuttings as raw materials, and a preparation method and application thereof. Background Art

[0002] Water-based cuttings are a type of solid waste generated during oil exploration and development, with the main components being shale, bentonite, lubricants, chlorides, etc. If water-based cuttings are not treated or treated improperly, they can easily cause environmental pollution and endanger human health. In recent years, as my country continues to pay attention to environmental issues, it has required that solid wastes be reduced, environmentally friendly, and recycled. As an environmental pollutant and drilling waste, water-based cuttings pose a great challenge to environmental governance and resource utilization. The most common method for treating water-based cuttings in existing technologies is high-temperature calcination to make bricks, which inevitably has the defects of high energy consumption and being environmentally unfriendly. At present, only treating them through landfill, incineration, and brick making will cause problems such as secondary environmental pollution and low resource utilization.

[0003] If water-based rock cuttings are used as raw materials or ingredients to prepare valuable and useful engineering materials, it is expected to achieve resource recycling and reduce the harm of water-based rock cuttings to the environment to a certain extent. Therefore, it is urgent to develop pollution-free, low-energy, low-carbon, and environmentally friendly diversified processing methods to achieve green recycling of water-based rock cuttings. Summary of the invention

[0004] To this end, an embodiment of the present invention provides a thermal insulation material using water-based rock cuttings as raw materials, and a preparation method and application thereof. The thermal insulation material is prepared by compounding water-based rock cuttings, cement, and hollow expanded clay proppants as raw materials, which can be used for oilfield construction insulation to solve the technical problem of green recycling of solid waste water-based rock cuttings.

[0005] In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

[0006] According to a first aspect of an embodiment of the present invention, an embodiment of the present invention provides a thermal insulation material using water-based rock cuttings as raw materials, wherein the raw materials of the thermal insulation material include water-based rock cuttings, cement and hollow ceramsite proppants.

[0007] Furthermore, the water-based rock cuttings, cement and hollow expanded clay proppant are mixed in a mass ratio of 2:1:1 to 3.

[0008] Furthermore, the ratio of water-based rock cuttings to cement is fixed, and the ratio of hollow expanded clay proppant is changed in a single way, so as to adjust the thermal conductivity and strength of the thermal insulation material.

[0009] Furthermore, the water-based rock cuttings are water-based rock cuttings produced during oil and gas production. The rock cuttings are dried to obtain block substances, and the block substances are crushed to obtain powder substances.

[0010] Furthermore, the hollow ceramsite proppant is obtained by sintering water-based rock cuttings using a template method, which specifically includes the following steps:

[0011] The water-based rock cuttings are dried and crushed for later use;

[0012] The wheat straw is crushed and mixed with a polyvinyl alcohol aqueous solution, and then prepared into balls of a certain specification using a ball mill;

[0013] The water-based rock cuttings are coated on the surface of the prepared sphere by a rotation method to obtain a green body, the green body is sintered at a high temperature, and after natural cooling, a hollow ceramsite proppant of a certain specification is obtained.

[0014] Furthermore, the mass concentration of the polyvinyl alcohol aqueous solution is 4%, the mass ratio of wheat straw to the polyvinyl alcohol aqueous solution is 10:1, the diameter of the sphere is 40-60 μm, the green body sintering temperature is 1200° C., and the sintering time is 2 hours.

[0015] Furthermore, hollow ceramsite proppants of different specifications are used to adjust the thermal conductivity and strength of the thermal insulation material.

[0016] Furthermore, the hollow ceramsite proppant specifications include 20 / 40 mesh, 40 / 70 mesh and 70 / 140 mesh.

[0017] According to a third aspect of an embodiment of the present invention, an embodiment of the present invention provides a method for preparing a thermal insulation material as described in any one of the above items, the preparation method comprising:

[0018] The water-based rock cuttings, cement and hollow ceramsite proppant are mixed in a certain ratio, a certain amount of water is added, and the heat insulation material is obtained after mixing and drying.

[0019] According to a fourth aspect of an embodiment of the present invention, an embodiment of the present invention provides an application of a thermal insulation material as described in any one of the above items in oilfield construction insulation.

[0020] Compared with the prior art, the present invention provides a thermal insulation material using water-based rock cuttings as raw materials, and a preparation method and application thereof; the thermal insulation material using water-based rock cuttings as raw materials, the raw materials include water-based rock cuttings, cement and hollow ceramsite proppant. As environmental pollutants and drilling wastes, water-based rock cuttings pose great challenges to environmental governance and resource utilization. At present, only landfill, incineration and brick making methods will cause secondary environmental pollution and low resource utilization. If water-based rock cuttings are used as raw materials or ingredients to prepare valuable and useful engineering materials, it is expected to achieve resource recycling and reduce the harm of water-based rock cuttings to the environment to a certain extent. The prior art uses a high-temperature (greater than 1250°C) calcination brick making method to process water-based rock cuttings, resulting in excessively high sintering temperatures and high production costs. More importantly, high-temperature calcination brick making has problems such as excessively high calcination temperatures, high energy consumption, and environmental unfriendliness, which does not meet the requirements of low carbon and environmental protection. The present invention utilizes waste water-based rock cuttings to prepare hollow ceramsite proppants, and then compound the water-based rock cuttings, cement and the hollow ceramsite proppants to obtain a heat-insulating material that can be used for oilfield construction insulation. The material is pollution-free, low-carbon and environmentally friendly, thereby realizing the green recycling of solid waste-water-based rock cuttings.

[0021] Furthermore, the present invention can adjust the thermal conductivity and strength of the thermal insulation material by using different formulations.

[0022] Furthermore, the present invention achieves the purpose of adjusting the thermal conductivity and strength by adopting hollow ceramsite proppants of different specifications, and can take into account both the high strength and high thermal insulation performance of the material.

[0023] Furthermore, the present invention provides a method for preparing a thermal insulation material using water-based rock cuttings as raw materials, comprising mixing water-based rock cuttings, cement and hollow ceramsite proppants in a certain ratio, adding a certain amount of water, mixing and drying to obtain the thermal insulation material; in the present invention, the hollow ceramsite proppants can be commercially available mature hollow ceramsite; the entire preparation process does not involve a high-temperature sintering process, and the process energy consumption is relatively low. The thermal insulation material for oilfield construction insulation can be obtained by compounding at room temperature, thereby realizing the reuse of water-based rock cuttings and effectively solving the problem of excessively high water-based rock cuttings processing temperature. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below in conjunction with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0025] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0026] Example 1

[0027] In this embodiment, the water-based rock cuttings, cement, and hollow ceramsite proppant are mixed in a mass ratio of 2:1:1, and the hollow ceramsite proppant specification is 70 / 140 mesh. The specific preparation process of the thermal insulation material is as follows:

[0028] The water-based rock cuttings are dried and crushed to obtain a powdery substance (denoted as A), and 2 kg of A is weighed; 1 kg of cement is weighed (denoted as B); the wheat straw is crushed and mixed with a polyvinyl alcohol aqueous solution (PVA, mass concentration 4%), the mass ratio of the wheat straw to the PVA is 10:1, and a 50 μm sphere is prepared by a ball mill, A is coated on the surface of the 50 μm sphere by a rotation method to obtain a green body with a specification of 70 / 140 mesh, the green body is sintered at 1200°C for 2 hours, and naturally cooled to obtain a hollow ceramsite proppant (denoted as C) with a specification of 70 / 140 mesh; 1 kg of C is weighed, mixed with 2 kg of A and 1 kg of B, and 0.3 kg of water is added, and stirred evenly in a mixer, and a thermal insulation material is obtained after drying, and the obtained thermal insulation material can be used for oilfield construction insulation.

[0029] Example 2

[0030] In this embodiment, the water-based rock cuttings, cement, and hollow ceramsite proppant are mixed in a mass ratio of 2:1:2, and the hollow ceramsite proppant specification is 70 / 140 mesh. The specific preparation process of the thermal insulation material is as follows:

[0031] The water-based rock cuttings are dried and crushed to obtain a powdery substance (denoted as A), and 2 kg of A is weighed; 1 kg of cement is weighed (denoted as B); the wheat straw is crushed and mixed with a polyvinyl alcohol aqueous solution (PVA, mass concentration 4%), the mass ratio of the wheat straw to the PVA is 10:1, and a 50 μm sphere is prepared by a ball mill, A is coated on the surface of the 50 μm sphere by a rotation method to obtain a green body with a specification of 70 / 140 mesh, the green body is sintered at 1200° C. for 2 hours, and naturally cooled to obtain a hollow ceramsite proppant with a specification of 70 / 140 mesh (denoted as C); 2 kg of C is weighed, mixed with 2 kg of A and 1 kg of B, and 0.3 kg of water is added, and stirred evenly in a mixer, and a thermal insulation material is obtained after drying, and the obtained thermal insulation material can be used for oilfield construction insulation.

[0032] Example 3

[0033] In this embodiment, the water-based rock cuttings, cement, and hollow ceramsite proppant are mixed in a mass ratio of 2:1:3, and the hollow ceramsite proppant specification is 70 / 140 mesh. The specific preparation process of the thermal insulation material is as follows:

[0034] The water-based rock cuttings are dried and crushed to obtain a powdery substance (denoted as A), and 2 kg of A is weighed; 1 kg of cement is weighed (denoted as B); the wheat straw is crushed and mixed with a polyvinyl alcohol aqueous solution (PVA, mass concentration 4%), the mass ratio of the wheat straw to the PVA is 10:1, and a 50 μm sphere is prepared by a ball mill, A is coated on the surface of the 50 μm sphere by a rotation method to obtain a green body with a specification of 70 / 140 mesh, the green body is sintered at 1200° C. for 2 hours, and naturally cooled to obtain a hollow ceramsite proppant with a specification of 70 / 140 mesh (denoted as C); 3 kg of C is weighed, mixed with 2 kg of A and 1 kg of B, and 0.3 kg of water is added, and stirred evenly in a mixer, and a thermal insulation material is obtained after drying. The obtained thermal insulation material can be used for oilfield construction insulation.

[0035] Example 4

[0036] In this embodiment, the water-based rock cuttings, cement, and hollow ceramsite proppant are mixed in a mass ratio of 2:1:3, and the hollow ceramsite proppant specification is 40 / 70 mesh. The specific preparation process of the thermal insulation material is as follows:

[0037] The water-based rock cuttings are dried and crushed to obtain a powdery substance (denoted as A), and 2 kg of A is weighed; 1 kg of cement is weighed (denoted as B); the wheat straw is crushed and mixed with a polyvinyl alcohol aqueous solution (PVA, mass concentration 4%), the mass ratio of the wheat straw to the PVA is 10:1, and a 50 μm sphere is prepared by a ball mill, A is coated on the surface of the 50 μm sphere by a rotation method to obtain a green body with a specification of 40 / 70 mesh, the green body is sintered at 1200° C. for 2 hours, and naturally cooled to obtain a hollow ceramsite proppant with a specification of 40 / 70 mesh (denoted as C); 3 kg of C is weighed, mixed with 2 kg of A and 1 kg of B, and 0.3 kg of water is added, and stirred evenly in a mixer, and a thermal insulation material is obtained after drying, and the obtained thermal insulation material can be used for oilfield construction insulation.

[0038] Example 5

[0039] In this embodiment, the water-based rock cuttings, cement, and hollow ceramsite proppant are mixed in a mass ratio of 2:1:3, and the hollow ceramsite proppant specification is 20 / 40 mesh. The specific preparation process of the thermal insulation material is as follows:

[0040] The water-based rock cuttings are dried and crushed to obtain a powdery substance (denoted as A), and 2 kg of A is weighed; 1 kg of cement is weighed (denoted as B); the wheat straw is crushed and mixed with a polyvinyl alcohol aqueous solution (PVA, mass concentration 4%), the mass ratio of the wheat straw to the PVA is 10:1, and a 50 μm sphere is prepared by a ball mill, A is coated on the surface of the 50 μm sphere by a rotation method to obtain a green body with a specification of 20 / 40 mesh, the green body is sintered at 1200°C for 2 hours, and naturally cooled to obtain a hollow ceramsite proppant with a specification of 20 / 40 mesh (denoted as C); 3 kg of C is weighed, mixed with 2 kg of A and 1 kg of B, and 0.3 kg of water is added, and stirred evenly in a mixer, and a thermal insulation material is obtained after drying. The obtained thermal insulation material can be used for oilfield construction insulation.

[0041] Test Case

[0042] In Examples 1 to 3 of the present invention, a single variable is controlled: the specification of the hollow ceramsite proppant is kept unchanged at 70 / 140 mesh, and the mass ratios of water-based rock cuttings, cement, and hollow ceramsite proppant are changed to 2:1:1, 2:1:2, and 2:1:3, respectively. Table 1 below shows the thermal insulation performance and strength of the thermal insulation material samples prepared in Examples 1-3.

[0043] Table 1 Thermal insulation performance and strength results of samples of Examples 1 to 3

[0044] Example Thermal conductivity / (W(K·)m-1) Compressive strength / MPa 1 0.1903 21.8 2 0.1836 20.2 3 0.1782 18.6

[0045] It can be seen from the test results of Examples 1 to 3 that when the hollow ceramsite proppant specification is kept unchanged at 70 / 140 mesh, increasing the amount of hollow ceramsite proppant can reduce the thermal conductivity of the sample. This is because the hollow ceramsite proppant is not a heat-conducting material. Increasing its amount reduces the heat dissipation path, thereby reducing the thermal conductivity and improving the thermal insulation performance. At the same time, increasing the amount of hollow ceramsite proppant reduces the compressive strength of the sample. This is because the hollow structure of the hollow ceramsite proppant can reduce the compressive strength. Increasing the amount of the hollow ceramsite proppant reduces the compressive strength. The actual construction can select a suitable ratio according to needs.

[0046] In Examples 3 to 5 of the present invention, a single variable is controlled: the water-based rock cuttings, cement, and hollow ceramsite proppant are kept in a mass ratio of 2:1:3, and the specifications of the hollow ceramsite proppant are changed to 20 / 40 mesh, 40 / 70 mesh, and 70 / 140 mesh, respectively. Table 2 below shows the thermal insulation properties and strengths of the thermal insulation material samples prepared in Examples 3 to 5 of the present invention.

[0047] Table 2 Thermal insulation performance and strength results of samples of Examples 3 to 5

[0048] Example Thermal conductivity / (W(K·)m-1) Compressive strength / MPa 3 0.1782 18.6 4 0.1886 19.4 5 0.1973 20.1

[0049] It can be seen from the test results of Examples 3 to 5 that when the water-based rock cuttings, cement, and hollow ceramsite proppants are kept at a mass ratio of 2:1:3, reducing the mesh number of the hollow ceramsite proppants, that is, increasing the size of the hollow ceramsite proppants, can improve the thermal conductivity of the sample. This is because when the ratio is constant, increasing the size of the hollow ceramsite proppants reduces the contact surface of the non-conductive material and increases the thermal contact surface, resulting in an increase in the thermal conductivity, thereby reducing the thermal insulation performance. At the same time, increasing the size of the hollow ceramsite proppants increases the compressive strength of the sample. This is because when the size of the hollow structure is constant, increasing the size of the hollow ceramsite proppants can increase the strength of the hollow ceramsite proppants, and when the ratio is constant, the compressive strength is increased. In actual construction, hollow ceramsite proppants of appropriate specifications can be selected according to needs.

[0050] By comparing the test results of the above embodiments, it can be seen that the thermal insulation material for oilfield construction provided by the present invention can adjust the thermal conductivity and strength of the thermal insulation material by using different formulas. The purpose of adjusting the thermal conductivity and strength is achieved by using hollow ceramsite proppants of different specifications, and the high strength and high thermal insulation performance of the material can be taken into account. Users can choose appropriate formulas and specifications according to actual needs, such as site, equipment, process, cost, product performance, quality standards and other factors. The thermal insulation material for oilfield construction insulation provided by the present invention is pollution-free, low-carbon, and environmentally friendly, thereby realizing the green recycling of solid waste - water-based rock cuttings, which is conducive to promotion in the field of environmental protection and resource recycling technology and has broad application prospects.

[0051] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A thermal insulation material made of water-based rock cuttings, It is characterized in that The raw materials of the heat insulation material include water-based rock cuttings, cement and hollow ceramsite proppant.

2. A thermal insulation material using water-based rock cuttings as raw materials according to claim 1, It is characterized in that The mass ratio of water-based rock cuttings, cement and hollow expanded clay proppant is 2:1:1-3.

3. The thermal insulation material using water-based rock cuttings as raw materials according to claim 1, It is characterized in that The ratio of water-based rock cuttings to cement is fixed, and the ratio of hollow ceramsite proppant is changed in a single way, so as to adjust the thermal conductivity and strength of the thermal insulation material.

4. The thermal insulation material using water-based rock cuttings as raw materials according to claim 1, It is characterized in that The water-based rock cuttings are rock cuttings with water as the matrix produced in the process of oil and gas extraction. The rock cuttings are dried to obtain block materials, and the block materials are crushed to obtain powder materials.

5. The thermal insulation material using water-based rock cuttings as raw materials according to claim 1, It is characterized in that The hollow ceramsite proppant is obtained by sintering water-based rock cuttings using a template method, which specifically includes the following steps: The water-based rock cuttings are dried and crushed for later use; The wheat straw is crushed and mixed with a polyvinyl alcohol aqueous solution, and then prepared into balls using a ball mill; The water-based rock cuttings are coated on the surface of the prepared sphere by a rotation method to obtain a green body, the green body is sintered at a high temperature, and a hollow ceramsite proppant is obtained after natural cooling.

6. The heat insulating material using water-based rock cuttings as raw materials according to claim 5, It is characterized in that The mass concentration of the polyvinyl alcohol aqueous solution is 4%, the mass ratio of the straw to the polyvinyl alcohol aqueous solution is 10:1, the diameter of the sphere is 40-60 μm, the green body sintering temperature is 1200° C., and the sintering time is 2 hours.

7. The thermal insulation material using water-based rock cuttings as raw materials according to claim 1, It is characterized in that Hollow ceramsite proppants of different specifications are used to adjust the thermal conductivity and strength of the insulation material.

8. The heat-insulating material using water-based rock cuttings as raw materials according to claim 7, It is characterized in that The hollow ceramsite proppant specifications include 20 / 40 mesh, 40 / 70 mesh and 70 / 140 mesh.

9. A method for preparing the thermal insulation material according to any one of claims 1 to 8, It is characterized in that The preparation method comprises: The water-based rock cuttings, cement and hollow ceramsite proppant are mixed in a certain ratio, a certain amount of water is added, and the heat insulation material is obtained after mixing and drying.

10. Use of the thermal insulation material according to any one of claims 1 to 8 in oil field construction thermal insulation.