High temperature resistant coated sand and method of processing and using same

Abstract

This invention relates to the field of oil and gas well sand control technology, and discloses a high-temperature resistant coated sand. The coated sand has a core-shell structure, with the core being skeleton particles and the outer shell being a glass powder coating. This invention also provides a processing method and application method for the high-temperature resistant coated sand. The high-temperature resistant coated sand of this invention uses inorganic glass powder as the coating material, significantly improving its temperature resistance from the current maximum of 350℃ to 400℃, which can meet the sand control requirements of supercritical steam injection heavy oil thermal recovery wells. Under long-term high temperatures in the formation, its performance remains stable, without aging, and its bonding strength remains excellent for a long time, greatly extending the sand control effectiveness. During surface storage, it will not clump or deteriorate due to heat or moisture, allowing for a longer storage time.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well sand control technology, and in particular to a high-temperature resistant coated sand and its processing and application methods. Background Technology

[0002] Currently, heavy oil thermal recovery wells commonly experience sand production during extraction due to the loose cementation of the reservoir and the high-temperature steam injection development method. Resin-coated sand artificial wellbore sand control technology utilizes a sand-carrying fluid to fill coated sand into the near-wellbore formation. Under the stimulation of a curing agent or temperature, the resin-coated sand bonds together to form an artificial wellbore sand barrier with a certain strength and permeability. Resin-coated sand is a sand control material in which a cementable resin coating is uniformly applied to the surface of the skeleton particles; its performance directly affects the sand control effect and its effective period.

[0003] According to different temperatures, resin-coated sand can generally be divided into low-temperature resin-coated sand (20-40℃), normal-temperature resin-coated sand (40-120℃), and high-temperature resin-coated sand (120-350℃). Currently, the downhole temperature of conventional heavy oil thermal recovery wells can generally reach 200-350℃, while the downhole temperature of supercritical steam injection heavy oil thermal recovery wells can reach 350℃-400℃, requiring the use of resin-coated sand with higher temperature resistance to construct artificial well walls for sand control. However, the main problems with existing high-temperature coated sand and artificial well walls are: (1) the temperature resistance of high-temperature resin-coated sand is insufficient, with a maximum temperature resistance of only 350℃, which cannot meet the sand control requirements of supercritical steam injection heavy oil thermal recovery wells; (2) the organic coating material on the outer layer of the coated sand is prone to aging under long-term high-temperature action, resulting in a decrease in its bonding strength and a shorter sand control period.

[0004] Therefore, there is a need for improvements to high-temperature resistant coated sand in the existing technology. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a high-temperature resistant coated sand and its processing and application method. The coated sand uses inorganic glass powder as the coating material to solve the technical problem of poor tolerance of coated sand under supercritical steam huff and puff conditions in the prior art.

[0006] Based on the above objectives, embodiments of the present invention provide high-temperature resistant coated sand, which has a core-shell structure, with the core being skeletal particles and the outer shell being a glass powder coating.

[0007] In some embodiments, the skeleton particles include any one of quartz sand, ceramsite, coke, mullite, corundum, slag, and glass microspheres.

[0008] In some embodiments, the particle size of the skeleton particles is 0.15~1.2 mm.

[0009] In some embodiments, the thickness of the glass powder coating is 10~50μm.

[0010] In another aspect, the present invention provides a method for processing high-temperature resistant coated sand, for processing the above-mentioned high-temperature resistant coated sand, comprising: S1 preheats the skeleton particles to a preset temperature range; S2 is stirred while preheated skeleton particles and glass powder are added sequentially. The mixture is stirred thoroughly to make the glass powder uniformly coated on the surface of the skeleton particles. S3 cools the mixture to room temperature, then crushes and screens it to obtain high-temperature resistant coated sand.

[0011] In some implementations, in S1, the preset temperature range is 600~1000°C.

[0012] In some embodiments, the stirring time in S2 is 3 to 20 minutes.

[0013] In some implementations, in S2, a sand mixer is used for mixing.

[0014] In some embodiments, in S2, the amount of glass powder used is 3 to 15% of the amount of skeleton particles by mass percentage.

[0015] Another aspect of the present invention relates to a method for applying high-temperature resistant coated sand, used to coat the aforementioned high-temperature resistant coated sand to construct an artificial well wall, comprising: S1 will fill the coated sand into the wellbore prevention sand location near the wellbore formation; S2 connects the working tube of the catalytic heater to the lower end of the injection string, lowers it into the wellbore so that the working tube of the catalytic heater reaches the sand prevention position, and pressurizes the catalytic heater into the working tube of the catalytic heater. S3 injects a high-temperature gas flow into the injection column to activate the catalytic heater and release heat. The coated sand absorbs heat and then gels. S4 adjusts the temperature of the high-temperature gas flow to allow the coated sand to solidify and form an artificial well wall.

[0016] In some implementations, in S1, coated sand is filled into the near-wellbore formation using fracturing and a proppant-carrying fluid.

[0017] In some embodiments, the catalytic heater housing has an inlet hole at the top and an outlet hole at the bottom, and the housing is filled with catalyst particles. The diameters of the inlet hole and the outlet hole are smaller than the diameter of the catalyst particles.

[0018] In some embodiments, the diameter of the catalyst particles is 3-5 mm, and the diameter of the inlet and outlet holes is 1-2 mm.

[0019] In some embodiments, the catalyst particles are molecular sieve particles that adsorb cobalt-based catalysts.

[0020] In some embodiments, in S3, injecting a high-temperature gas flow into the injection column to exothermize the catalytic heater includes: A mixture of steam, hot water, and non-condensable gas is injected into the gas injection string to activate the catalytic heater and release heat, raising the well temperature to over 400°C.

[0021] In some embodiments, the minimum temperature of the steam is not less than 200°C, and the maximum dryness of the steam is not greater than 80%. In some embodiments, the non-condensable gas includes one or any mixture of methane, formaldehyde, methanol, and ethanol.

[0022] In some embodiments, in S4, adjusting the temperature of the high-temperature gas flow to cause the coated sand to solidify and form an artificial well wall includes: Stop injecting hot water and non-condensable gas mixture, and continue to inject steam to reduce the temperature of the high-temperature gas flow to below 400°C, so that the coating sand solidifies to form an artificial well wall.

[0023] In some embodiments, the steam temperature is 150~350°C and the steam dryness is 50%~80%.

[0024] The present invention has at least the following beneficial technical effects: (1) The high temperature resistant coated sand uses inorganic glass powder as the coating material, which greatly improves the temperature resistance, from the current maximum of 350℃ to 400℃, which can meet the sand control requirements of supercritical steam injection heavy oil thermal recovery wells. (2) The high-temperature resistant coated sand uses inorganic glass powder as the coating material. Under long-term high temperature in the formation, the performance is stable and will not age. The bonding strength is maintained in a good state for a long time, which greatly extends the sand prevention period. (3) The high-temperature resistant coated sand uses inorganic glass powder as the coating material. During ground storage, it will not clump or deteriorate due to heat or moisture, and can be stored for a longer time. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of an embodiment of the artificial wellbore construction and gas injection construction string provided by the present invention; Figure 2 A schematic diagram of an embodiment of the working cylinder of the catalytic heater provided by the present invention; Figure 3 This is a schematic diagram of an embodiment of the catalytic heater provided by the present invention.

[0027] Explanation of reference numerals in the attached figures: 1. Catalytic heater; 2. Catalytic heater working cylinder; 3. Gas injection string; 4. High-temperature resistant coated sand; 5. Oil layer; 6. Casing; 11. Catalyst particles; 12. Catalytic heater shell; 121. Liquid inlet; 122. Liquid outlet; 123. Step. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, terms such as “length,” “width,” “upper,” “lower,” “left,” “right,” “front,” “rear,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” indicate orientations or positions based on the orientations or positions shown in the accompanying drawings and are for ease of description only, and should not be construed as limiting the technical solution.

[0030] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0031] In the description and claims of this invention and the foregoing drawings, when an element is referred to as "fixed to," "mounted to," "disposed on," or "connected to" another element, it can be located directly or indirectly on that other element. For example, when an element is referred to as "connected to" another element, it can be directly or indirectly connected to that other element.

[0032] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] To address the problems in the prior art, the first aspect of the present invention provides a high-temperature resistant coated sand, which has a core-shell structure, with the core being skeletal particles and the outer shell being a glass powder coating.

[0034] Furthermore, the skeletal particles include any one of the following: quartz sand, ceramsite, coke, mullite, corundum, slag, and glass microspheres.

[0035] Furthermore, the particle size of the skeleton particles is 0.15~1.2mm.

[0036] Furthermore, the thickness of the glass powder coating is 10~50μm.

[0037] Compared with existing high-temperature resistant coated sand, the present invention has the following advantages: (1) The high temperature resistant coated sand uses inorganic glass powder as the coating material, which greatly improves the temperature resistance, from the current maximum of 350℃ to 400℃, which can meet the sand control requirements of supercritical steam injection heavy oil thermal recovery wells. (2) The high-temperature resistant coated sand uses inorganic glass powder as the coating material. Under long-term high temperature in the formation, the performance is stable and will not age. The bonding strength is maintained in a good state for a long time, which greatly extends the sand prevention period. (3) The high-temperature resistant coated sand uses inorganic glass powder as the coating material. During ground storage, it will not clump or deteriorate due to heat or moisture, and can be stored for a longer time.

[0038] In another aspect, the present invention provides a method for processing high-temperature resistant coated sand, for processing the above-mentioned high-temperature resistant coated sand, comprising the following steps: S1 preheats the skeleton particles to a preset temperature range; S2 is stirred while preheated skeleton particles and glass powder are added sequentially. The mixture is stirred thoroughly to make the glass powder uniformly coated on the surface of the skeleton particles. S3 cools the mixture to room temperature, then crushes and screens it to obtain high-temperature resistant coated sand.

[0039] Furthermore, in S1, the preset temperature range is 600~1000℃.

[0040] Furthermore, in S2, a sand mixer is used for mixing, and the mixing time is 3 to 20 minutes.

[0041] Further, in S2, the amount of glass powder used is 3-15% of the amount of skeleton particles by mass percentage. In some preferred embodiments, glass powder is added while stirring, and the amount of glass powder is 10% of the mass fraction of skeleton particles. When the glass powder comes into contact with the high-temperature skeleton particles, it melts and adheres to the surface of the skeleton particles. After stirring for 3-20 minutes to allow the glass powder to be fully heated and melted, it is uniformly coated on the surface of the skeleton particles to form a high-temperature resistant coated sand.

[0042] The present invention will be further explained and described below with reference to specific embodiments.

[0043] Example 1 High-temperature coated sand made from glass powder is prepared using coated sand production equipment. 300 kg of ceramsite with a particle size of 0.425~0.812 mm is heated to 700°C using gas combustion. The heated ceramsite is poured into a sand mixer and stirred at 30 rpm. While stirring, 20 kg of glass powder is added. Stirring continues for 10 minutes to melt the glass powder and coat the surface of the skeletal particles. After cooling the skeletal particles to room temperature, they are crushed and sieved again to obtain the high-temperature coated sand. In some embodiments, the melting point of the glass powder is 400°C, and the fineness is 1000~5000 mesh. Using this embodiment, the glass powder is fully melted and uniformly coated on the surface of the ceramsite, resulting in high-temperature coated sand with good particle dispersibility and a low scrap rate (<5%).

[0044] Example 2 The high-temperature coated sand is prepared using glass powder and manufactured using coated sand production equipment. 300 kg of ceramsite with a particle size of 0.425~0.812 mm is heated to 600°C using gas combustion. The heated ceramsite is poured into a sand mixer and stirred at 30 rpm. While stirring, 20 kg of glass powder is added. Stirring continues for 10 minutes to melt the glass powder and coat the surface of the framework particles. After cooling the framework particles to room temperature, they are crushed and sieved again to obtain the high-temperature coated sand. In some embodiments, the melting point of the glass powder is 400°C, and the fineness is 1000~5000 mesh. In this embodiment, some glass powder fails to fully melt on the surface of the ceramsite, resulting in uneven coating and a large amount of residual glass powder. The prepared high-temperature coated sand particles do not meet the usage requirements.

[0045] Example 3 The high-temperature coated sand is prepared using glass powder and manufactured using coated sand production equipment. 300 kg of ceramsite with a particle size of 0.425~0.812 mm is heated to 800°C using gas combustion. The heated ceramsite is poured into a sand mixer and stirred at 30 rpm. While stirring, 20 kg of glass powder is added. Stirring continues for 10 minutes to melt the glass powder and coat the surface of the skeletal particles. After cooling the skeletal particles to room temperature, they are crushed and sieved again to obtain the high-temperature coated sand. In some embodiments, the melting point of the glass powder is 400°C, and the fineness is 1000~5000 mesh. In this embodiment, the glass powder completely melts on the surface of the ceramsite; however, because the surface temperature of the ceramsite is too high, the glass powder does not easily adhere to the surface, resulting in uneven coating. Furthermore, insufficient cooling during processing can lead to agglomeration and poor dispersibility of the prepared high-temperature coated sand particles, resulting in a high scrap rate (>20%).

[0046] The high-temperature resistant coated sand made from glass powder prepared in Example 1 was evaluated for its performance according to the following experimental methods: a. Take 20g of high-temperature resistant glass powder coating sand and put it into a Φ25×50mm glass tube. Press both ends with metal mesh and fix it with a clamp to keep the coating sand in a compacted state. Place it in a high-temperature oven, set the temperature to 450℃, and cure it at high temperature for 2 hours. Then break the glass tube to obtain the solidified rock core.

[0047] b. Take 20g of existing high-temperature resistant resin coating sand and put it into a Φ25×50mm glass tube. Press both ends with metal mesh and fix it with a clamp to keep the coating sand in a compacted state. Place it in a high-temperature oven, set the temperature to 300℃, and cure it at high temperature for 2 hours. Then break the glass tube to obtain the cured rock core.

[0048] c. Place the glass powder high-temperature resistant coating sand and the resin high-temperature resistant coating sand into a high-temperature oven, set the temperature to 400℃, and age at high temperature for 24 hours. Take them out and test their compressive strength.

[0049] d. Test the permeability of aged cores according to the method in SY / T 5276-2000 "Test Method for Flexural Strength, Compressive Strength and Permeability of Chemical Sand Control Artificial Cores".

[0050] e. Test the compressive strength of aged cores according to the method in SY / T 5276-2000 "Test Method for Flexural Strength, Compressive Strength and Permeability of Chemical Sand Control Artificial Cores".

[0051] The experimental test results are shown in the table below. The results show that the permeability of glass powder high-temperature coated sand and resin high-temperature coated sand are similar. After aging at 400℃, glass powder high-temperature coated sand can maintain a high compressive strength, which meets the requirements for sand control in oil wells, while the compressive strength of resin high-temperature coated sand is only 0.4MPa, which cannot meet the requirements for sand control in oil wells.

[0052]

[0053] In another aspect, the present invention provides a method for applying high-temperature resistant coated sand, used to coat high-temperature resistant coated sand to construct artificial well walls, such as... Figure 1 A schematic diagram of the artificial wellbore construction and steam injection pipeline includes: a gas injection pipeline 3 connected from top to bottom, and a catalytic heater working cylinder 2. An outer casing 6 is provided, and the catalytic heater 1 is located inside the catalytic heater working cylinder 2. Figure 1 As shown, sand 4 needs to be coated on the oil layer 5 near the ground layer for artificial well wall sand control. Figures 2-3 This is a schematic diagram of the structure and installation of the catalytic heater. The catalytic heater 1 includes catalyst particles 11 and a catalytic heater shell 12, wherein the catalyst particles 11 are filled inside the shell 12. The shell 12 has a cylindrical structure, with a liquid inlet 121 at the top and a liquid outlet 122 at the bottom. The outer wall of the shell has steps 123. The working cylinder 2 of the catalytic heater has steps inside, which engage with the steps of the shell 123 of the catalytic heater 1 to fix the catalytic heater 1.

[0054] A method for applying high-temperature resistant coated sand specifically includes the following steps: S1 will fill the coated sand into the wellbore prevention sand location near the wellbore formation; S2 connects the working tube of the catalytic heater to the lower end of the injection string, lowers it into the wellbore so that the working tube of the catalytic heater reaches the sand prevention position, and pressurizes the catalytic heater into the working tube of the catalytic heater. S3 injects a high-temperature gas flow into the injection column to activate the catalytic heater and release heat. The coated sand absorbs heat and then gels. S4 adjusts the temperature of the high-temperature gas flow to allow the coated sand to solidify and form an artificial well wall.

[0055] Furthermore, in S1, coated sand is injected into the near-wellbore formation using fracturing and proppant-carrying fluid. The specific method includes: first, installing and commissioning the wellhead and surface equipment; preparing the coated sand; and assessing the formation. Pre-flush fluid is injected to open fractures, followed by pumping in proppant-carrying fluid, which carries the coated sand into the fractures at precisely controlled speed and pressure. The coated sand is deposited in the fractures as the proppant-carrying fluid is lost. After injection, pressure is released and flowback is performed, the flowback fluid is treated and recovered, and the filling effect of the coated sand in the near-wellbore formation is assessed through well logging to achieve the goal of increasing production.

[0056] Furthermore, the catalytic heater has an inlet hole at the top and an outlet hole at the bottom of the shell, and the shell is filled with catalyst particles. The diameter of the inlet hole and the outlet hole is smaller than the diameter of the catalyst particles.

[0057] Furthermore, the diameter of the catalyst particles is 3-5 mm, and the diameter of the inlet and outlet holes is 1-2 mm.

[0058] Furthermore, the catalyst particles are molecular sieve particles that adsorb cobalt-based catalysts.

[0059] Furthermore, in S3, the injection of a high-temperature gas flow into the injection column to exothermize the catalytic heater includes: A mixture of steam, hot water, and non-condensable gas is injected into the gas injection string to activate the catalytic heater and release heat, raising the well temperature to over 400°C.

[0060] Furthermore, the minimum temperature of the steam shall not be less than 200℃, and the maximum dryness of the steam shall not exceed 80%. Furthermore, non-condensable gases include one or any mixture of methane, formaldehyde, methanol, and ethanol.

[0061] Furthermore, in S4, adjusting the temperature of the high-temperature gas flow to cause the coated sand to solidify and form an artificial well wall includes: Stop injecting hot water and non-condensable gas mixture, and continue to inject steam to reduce the temperature of the high-temperature gas flow to below 400°C, so that the coating sand solidifies to form an artificial well wall.

[0062] Furthermore, the steam temperature is 150~350℃, and the steam dryness is 50%~80%.

[0063] The application method of the present invention will be further explained below with reference to specific embodiments.

[0064] Example 4 Following the conventional method of artificial well wall sand control construction, a 2.5m... 3 A sand-carrying fluid with a displacement of / min, a sand ratio of 10%-30%, and a sand-carrying capacity of 50-80mPa.s is used to fill high-temperature coated sand into the near-wellbore formation, with a sand-filling scale of 1.0-2.5m3 / m.

[0065] The catalytic heater working cylinder is connected to the lower end of the steam injection string and lowered into the well. The steam injection string uses an 89mm or 73mm insulated pipe. Specifically, the catalytic heater is lowered from the wellhead, falling into the working cylinder and settling on the steps. Multiple catalytic heaters can be lowered depending on heating requirements. The catalytic heater consists of catalyst particles and a shell. The catalyst particles fill the interior of the shell, which is a cylindrical structure with an outer diameter of 60mm and a length of 0.5m. An inlet is located at the top of the shell, and an outlet is located at the bottom. The outer wall of the shell has steps with a height of 4mm. The inlet and outlet have a diameter of 3mm, smaller than the diameter of the catalyst particles. The catalyst particles are molecular sieve particles that have adsorbed cobalt-based catalysts, obtained by thoroughly soaking the molecular sieve particles in cobalt-based catalyst. The catalytic heater working cylinder is a short connection to the tubing, with an outer diameter of 73mm and an inner diameter of 62mm. An internal step with a height of 4mm is also present.

[0066] Steam at 250℃ and 50% dryness is injected from one end of the injection wellhead, while a heating fluid is injected from the other end. The injection flow rate ratio of steam to heating fluid is 5:1. The heating fluid is a mixture of non-condensable gases containing carbon, hydrogen, and oxygen, derived from the byproducts of heavy oil refining, allowing for waste recycling. Under the action of a catalyst and high temperature, the non-condensable gases undergo a dehydration reaction to produce hydrocarbons, releasing heat. The catalyst lowers the reaction temperature of the non-condensable gases in the high-temperature gas stream, enabling them to undergo an exothermic reaction at steam temperature to produce hydrocarbons. The injected high-temperature gas stream must contain non-condensable gases, and its temperature must be above 150℃.

[0067] When steam and heating fluid pass through the catalytic heater, an exothermic reaction occurs under the continuous supply of heating fluid and steam, rapidly raising the bottom hole temperature to over 400°C, which is above the melting point of the high-temperature coated sand glass powder coating, causing the high-temperature coated sand to cement.

[0068] Stop injecting hot water and heating fluid, and inject steam according to normal steam injection parameters. At this time, the temperature at the bottom of the well drops to below 400℃, which is lower than the melting point of the high-temperature coated sand glass powder coating. The glass powder solidifies and hardens, causing the high-temperature coated sand to bond together and form an artificial well wall with a certain strength.

[0069] After steam injection is completed, the pump is lowered for production. At this time, the artificial well wall can prevent formation sand from being discharged.

[0070] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0071] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0072] The embodiment numbers disclosed in the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0073] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A high-temperature resistant coated sand, characterized in that, The high-temperature resistant coated sand has a core-shell structure, with the core being skeletal particles and the outer shell being a glass powder coating.

2. The high-temperature resistant coated sand according to claim 1, characterized in that, The skeleton particles include any one of the following: quartz sand, ceramsite, coke, mullite, corundum, slag, and glass microspheres.

3. The high-temperature resistant coated sand according to claim 1, characterized in that, The particle size of the skeleton particles is 0.15~1.2mm.

4. The high-temperature resistant coated sand according to claim 1, characterized in that, The thickness of the glass powder coating is 10~50μm, and the fineness of the glass powder is 300~5000 mesh.

5. A method for processing high-temperature resistant coated sand, characterized in that, For processing high-temperature resistant coated sand as described in any one of claims 1 to 4, comprising: S1 preheats the skeleton particles to a preset temperature range; S2 Under stirring, the preheated skeleton particles and glass powder are mixed so that the glass powder is uniformly coated on the surface of the skeleton particles to obtain a mixture; S3 cools the mixture to room temperature, then crushes and sieves it to obtain high-temperature resistant coated sand.

6. The high-temperature resistant coated sand processing method according to claim 5, characterized in that, In S1, the preset temperature range is 600~1000℃.

7. The high-temperature resistant coated sand processing method according to claim 5, characterized in that, In S2, the stirring time is 3~20 minutes.

8. The high-temperature resistant coated sand processing method according to claim 5, characterized in that, In S2, a sand mixer is used for mixing.

9. The high-temperature resistant coated sand processing method according to claim 5, characterized in that, In S2, the amount of glass powder used is 3 to 15% of the amount of skeleton particles by mass percentage.

10. A method for applying high-temperature resistant coated sand, characterized in that, For coating with high-temperature resistant coating sand as described in any one of claims 1 to 4 to establish an artificial well wall, comprising: S10 fills the high-temperature resistant coated sand into the wellbore prevention sand position near the wellbore formation; S20 connects the working tube of the catalytic heater to the lower end of the gas injection string, lowers it into the wellbore so that the working tube of the catalytic heater reaches the sand prevention position, and pressurizes the catalytic heater into the working tube of the catalytic heater; S30 injects a high-temperature gas flow into the gas injection column to activate the catalytic heater to release heat, and the high-temperature resistant coated sand undergoes cementation after absorbing heat. S40 adjusts the temperature of the high-temperature airflow to cause the coated sand to solidify and form an artificial well wall.

11. The application method of the high-temperature resistant coated sand according to claim 10, characterized in that, In S10, based on the fracturing method, coated sand is filled into the wellbore near the formation using a sand-carrying fluid to prevent sand from entering the wellbore.

12. The application method of the high-temperature resistant coated sand according to claim 10, characterized in that, The catalytic heater has an inlet hole at the top and an outlet hole at the bottom. The shell is filled with catalyst particles, and the diameters of the inlet hole and the outlet hole are smaller than the diameter of the catalyst particles.

13. The application method of the high-temperature resistant coated sand according to claim 12, characterized in that, The diameter of the catalyst particles is 3-5 mm, and the diameter of the liquid inlet and the liquid outlet is 1-2 mm.

14. The application method of the high-temperature resistant coated sand according to claim 12, characterized in that, The catalyst particles are molecular sieve particles that adsorb cobalt-based catalysts.

15. The application method of the high-temperature resistant coated sand according to claim 10, characterized in that, In S30, injecting a high-temperature gas flow into the injection column to exothermize the catalytic heater includes: A mixture of steam, hot water, and non-condensable gas is injected into the gas injection string to activate the catalytic heater and release heat, raising the well temperature to over 400°C.

16. The application method of the high-temperature resistant coated sand according to claim 15, characterized in that, The minimum temperature of the steam is not less than 200°C, and the maximum dryness of the steam is not greater than 80%.

17. The application method of the high-temperature resistant coated sand according to claim 15, characterized in that, The non-condensable gas includes one or any mixture of methane, formaldehyde, methanol, and ethanol.

18. The application method of the high-temperature resistant coated sand according to claim 15, characterized in that, In S40, adjusting the temperature of the high-temperature gas flow to cause the coated sand to solidify and form an artificial well wall includes: Stop injecting hot water and non-condensable gas mixture, and continue to inject steam to reduce the temperature of the high-temperature gas flow to below 400°C, so that the coated sand solidifies to form an artificial well wall.

19. The application method of the high-temperature resistant coated sand according to claim 18, characterized in that, The temperature of the steam is 150~350℃ and the dryness of the steam is 50%~80%.

Images