Rock plunger heating structure, heating method and rock plunger in-situ comparison method

Abstract

The invention belongs to the field of rock heating in laboratories in the fields of petroleum, geology and mining industry, and particularly relates to a rock plunger heating structure, a heating method and a rock plunger in-situ comparison method. The rock plunger heating structure comprises a graphite tank, the inner surface of the graphite tank is matched with the outer surface of a rock plunger, and a through hole is formed in the bottom of the graphite tank. According to the heating structure, the rock plunger can be prevented from being broken, the rock plunger can be scanned after being heated, scanning of the rock plunger after heating can be achieved, and it is guaranteed that the rock plunger is subjected to in-situ comparison before and after heating.

Description

Technical Field

[0001] The present invention belongs to the field of rock heating in laboratories in the fields of petroleum, geology and mining, and particularly relates to a rock plunger heating structure, a heating method and a rock plunger in-situ comparison method. Background Art

[0002] Organic matter in formation rocks can produce hydrocarbons under certain temperature and pressure conditions, and the structure of the organic matter will also change accordingly. Therefore, heating simulation experiments have become an effective means to study hydrocarbon generation from source rocks. Currently, research on shale gas has become a hot topic. Heating simulation experiments can reflect changes in the structure of organic matter and the physical properties of shale reservoirs, and further study the gas storage mechanism of shale.

[0003] Specifically, images of a rock plunger before and after heating can be compared to determine the locations of oil, gas, and pores in the rock. However, during heating, cracks or even breakage can occur in the rock plunger, making it impossible to scan. Furthermore, if the rock plunger moves during heating, in-situ comparisons before and after heating are impossible.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a rock plunger heating structure, a heating method and an in-situ comparison method for rock plungers. The heating structure of the present invention can prevent the rock plunger from breaking, so that the rock plunger can be scanned after heating, and the rock plunger after heating can be scanned, ensuring in-situ comparison of the rock plunger before and after heating.

[0006] The present invention includes the following technical solutions:

[0007] A first aspect of the present invention provides a rock plunger heating structure, comprising a graphite tank, the inner surface of the graphite tank being adapted to the outer surface of the rock plunger, and a through hole being provided at the bottom of the graphite tank.

[0008] Furthermore, the through holes are provided in plurality, and the plurality of through holes are evenly arranged on the bottom of the graphite tank.

[0009] Furthermore, after the rock plunger is placed in the graphite tank, the top of the graphite tank is higher than the top of the rock plunger.

[0010] Furthermore, the wall thickness of the graphite tank is 1 mm.

[0011] A second aspect of the present invention provides a rock plunger heating method, comprising the rock plunger heating structure described above, the heating method comprising the following steps:

[0012] S10: placing heat-resistant glue at the bottom of the graphite tank;

[0013] S20: placing the rock plunger in the graphite tank, pressing and waiting for the rock plunger to be fixed in the graphite tank;

[0014] S30: Heating the rock plunger fixed in the graphite tank.

[0015] Furthermore, step S30 includes the following steps: placing the graphite can with the rock plunger fixed thereon in a high-temperature oven and heating it to the formation temperature of the rock plunger for 48 hours.

[0016] A third aspect of the present invention provides an in-situ comparison method for a rock plunger, comprising the rock plunger heating structure described above. The in-situ comparison method for a rock plunger comprises the following steps:

[0017] obtaining rock plugs from the formation;

[0018] placing a rock plunger in the graphite can;

[0019] Mark the scanned locations of the rock plungers;

[0020] Scanning the scanning position to obtain a first scan image;

[0021] heating the rock plunger placed in the graphite tank, and scanning the scanning position again after the heating is completed to obtain a second scanning image;

[0022] The pores and cracks of the rock plug are obtained by comparing the first scanning image and the second scanning image.

[0023] Furthermore, the heating temperature is the temperature of the formation where the rock plunger is located.

[0024] Furthermore, after setting the temperature-resistant glue at the bottom of the graphite tank, the rock plunger is placed.

[0025] Furthermore, scanning is performed using CT, electron microscopy or MRI.

[0026] By adopting the above technical solution, the present invention has the following advantages:

[0027] 1. The heating structure of the present invention can prevent the rock plunger from breaking, so that the rock plunger can be scanned after heating, and can realize the scanning of the rock plunger after heating, ensuring in-situ comparison of the rock plunger before and after heating.

[0028] 2. The present invention sets heat-resistant glue in the graphite tank before placing the rock plunger to prevent the rock plunger from rotating in the graphite tank during heating and movement. At the same time, it prevents cracks and microscopic movements generated during the heating process from affecting the position of the shale, ensuring that the rock plunger is scanned in the same position and direction before and after heating, thereby improving the accuracy of in-situ comparison.

[0029] 3. The conventional clamp of the present invention requires a very thick wall thickness for high temperature resistance, which greatly reduces the resolution of the image during scanning; the heating structure of the present invention innovatively adopts a graphite tank, which can not only ensure ultra-high temperature resistance but also achieve a wall thickness of less than 1mm, solving the contradiction between resolution and high temperature resistance.

[0030] 4. The graphite tank of the present invention is provided with a through hole at the bottom, which can ensure that the fluid discharged from the rock plunger during the heating process can be discharged, so that the plunger rock can effectively form an oil path gap after heating, which has the advantage of improving the accuracy of in-situ comparison.

[0031] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 This is a schematic structural diagram of a rock plunger heating structure according to an embodiment of the present invention;

[0034] Figure 2 This is a flow chart of a rock plunger heating method according to an embodiment of the present invention;

[0035] Figure 3 This is a flow chart of a rock plunger in-situ comparison method according to an embodiment of the present invention;

[0036] Figure 4 A comparison diagram of the first scanned image and the second scanned image in an embodiment of the present invention;

[0037] In the figure: 10-graphite tank, 11-through hole. DETAILED DESCRIPTION

[0038] The following description provides many different embodiments or examples for implementing different features of the present invention. The components and arrangements described in the following specific examples are only used to simplify the present invention and are only used as examples, not to limit the present invention.

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0040] This embodiment provides a rock plunger heating structure, such as Figure 1 As shown, it includes a graphite tank 10, the inner surface of which is adapted to the outer surface of the rock plunger, and a through hole 11 is provided at the bottom of the graphite tank 10. The term "adapted" should be understood as meaning that the rock plunger can be placed within the graphite tank 10, and the inner wall of the graphite tank 10 can fit the outer wall of the rock plunger, thereby constraining the rock plunger.

[0041] The heating structure of the present invention can restrain the rock plunger during heating, preventing cracking and enabling in-situ comparison of the heated rock plunger. This reduces costs and improves the accuracy of in-situ comparison. The graphite tank 10 is made of graphite, which is not only heat-resistant but also easy to move manually.

[0042] In some embodiments, a plurality of through holes 11 are provided, and the plurality of through holes 11 are evenly arranged at the bottom of the graphite tank 10. The through holes 11 can ensure that the oil, gas and water generated during the heating process are discharged; the even arrangement of the through holes 11 can improve the uniformity and efficiency of the discharge of the oil, gas and water.

[0043] In some embodiments, after the rock plunger is placed in the graphite tank 10, the top of the graphite tank 10 is higher than the top of the rock plunger. Figure 1 As shown in the figure, the top of the graphite tank 10 is its upper surface. After the rock plunger is placed in the graphite tank 10, the upper surface of the graphite tank 10 is higher than the upper surface of the rock plunger. This has a better restraining effect on the rock plunger and further prevents the rock plunger from cracking.

[0044] In some embodiments, the wall thickness of the graphite can 10 is 1 mm. Such a wall thickness can prevent the graphite can 10 from affecting the imaging of the rock plunger when scanning, thereby improving the resolution of the scanning imaging.

[0045] This embodiment also provides a rock plunger heating method, such as Figure 2 As shown, including the rock plunger heating structure described above, the heating method includes the following steps:

[0046] S10: placing heat-resistant glue at the bottom of the graphite tank 10;

[0047] S20: placing the rock plunger in the graphite tank 10, pressing and waiting until the rock plunger is fixed in the graphite tank 10; fixing the rock plunger in the graphite tank 10 with glue can prevent the rock plunger from moving relative to the graphite tank 10 during heating and moving, so that the scanning direction of the rock plunger before and after heating remains consistent, thereby improving the accuracy of in-situ comparison;

[0048] S30: Heating the rock plunger fixed in the graphite tank 10.

[0049] The heating method of the present invention can ensure that the rock plunger will not crack during the heating process, and the heating method of the present invention can ensure that images of the rock plunger before and after scanning heating in the same direction and position are obtained, thereby achieving accurate in-situ comparison and improving the accuracy of the in-situ comparison.

[0050] In some embodiments, step S30 includes the following steps: placing the graphite can 10 with the rock plunger fixed thereto in a high-temperature oven and heating it to the formation temperature of the rock plunger for 48 hours. This simulates the actual formation conditions and facilitates in-situ comparison. Furthermore, heating for 48 hours ensures that the oil, gas, and water in the rock plunger are completely expelled, improving the accuracy of the in-situ comparison.

[0051] This embodiment also provides a rock plunger in-situ comparison method, including the rock plunger heating structure described above, such as Figure 3 As shown, the rock plug in-situ comparison method includes the following steps:

[0052] obtaining rock plugs from the formation;

[0053] Placing a rock plunger in the graphite tank 10;

[0054] Mark the scanned locations of the rock plungers;

[0055] Scanning the scanning position to obtain a first scan image;

[0056] heating the rock plunger placed in the graphite tank 10, and scanning the scanning position again after the heating is completed to obtain a second scanning image;

[0057] The pores and cracks of the rock plug are obtained by comparing the first scanning image and the second scanning image.

[0058] After heating, the oil, gas and water in the rock plunger are completely discharged before scanning to obtain a second scan image, thereby improving the accuracy of the obtained second scan image.

[0059] The in-situ comparison method of the present invention can obtain accurate pores and can provide better guidance for oil and gas production.

[0060] In some embodiments, the heating temperature is the temperature of the formation in which the rock plug is located.

[0061] In some embodiments, the rock plunger is placed after heat-resistant glue is provided at the bottom of the graphite tank 10 .

[0062] In some embodiments, the scan is performed using CT, electron microscopy, or MRI.

[0063] According to the in-situ contrast method of the present invention, a first scan image and a second scan image are obtained, such as Figure 4 As shown, the left side is the first scan image obtained by CT scanning of the rock plunger before heating, and the right side is the second scan image obtained by CT scanning of the rock plunger after heating. The images obtained by the two scans were compared in situ using AVI ZO software. The images before and after heating show that the landmark images in the box in the figure can achieve consistency comparison. Specifically, the area of ​​the two can be calculated using AVI ZO software. In addition, according to the threshold value of pixel values ​​below 500 in the figure as pores and cracks, the pores and cracks increased significantly after heating, and the surface area ratio (that is, the ratio of pores to image area) increased from 1% to about 4%. These increased pores and cracks are most likely organic pores and cracks generated after the production of oil and gas by organic matter during the heating process.

[0064] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention. In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and shall not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0065] In the description of the present invention, it should be understood that all terms used to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and cannot be understood as a limitation on the present invention.

[0066] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rock plunger heating structure, characterized in that: It comprises a graphite tank (10), the inner surface of the graphite tank (10) is adapted to the outer surface of the rock plunger, and a through hole (11) is provided at the bottom of the graphite tank (10).

2. A rock plunger heating structure and rock plunger in-situ comparison method according to claim 1, characterized in that: A plurality of through holes (11) are provided, and the plurality of through holes (11) are evenly arranged on the bottom of the graphite tank (10).

3. A rock plunger heating structure according to claim 1, characterized in that: After the rock plunger is placed in the graphite tank (10), the top of the graphite tank (10) is higher than the top of the rock plunger.

4. A rock plunger heating structure according to claim 1, characterized in that: The wall thickness of the graphite tank (10) is 1 mm.

5. A rock plunger heating method, characterized in that: The rock plunger heating structure according to any one of claims 1 to 4, wherein the heating method comprises the following steps: S10: placing heat-resistant glue at the bottom of the graphite tank (10); S20: placing the rock plunger in the graphite tank (10), pressing and waiting for the rock plunger to be fixed in the graphite tank (10); S30: Heating the rock plunger fixed in the graphite tank (10).

6. A rock plunger heating method according to claim 5, characterized in that: Step S30 includes the following steps: placing the graphite tank (10) with the rock plunger fixed thereon in a high-temperature oven and heating it to the formation temperature of the rock plunger for 48 hours.

7. A rock plug in-situ comparison method, characterized in that: The rock plunger heating structure according to any one of claims 1 to 4 is included, and the rock plunger in-situ comparison method comprises the following steps: obtaining rock plugs from the formation; placing a rock plunger in the graphite tank (10); Mark the scanned locations of the rock plungers; Scanning the scanning position to obtain a first scan image; heating the rock plunger placed in the graphite tank (10), and scanning the scanning position again after the heating is completed to obtain a second scanning image; The pores and cracks of the rock plug are obtained by comparing the first scanning image and the second scanning image.

8. The rock plug in-situ comparison method according to claim 7, characterized in that: The heating temperature is the temperature of the formation where the rock plunger is located.

9. The rock plug in-situ comparison method according to claim 7, characterized in that: After setting the temperature-resistant glue at the bottom of the graphite tank (10), the rock plunger is placed.

10. The rock plug in-situ comparison method according to claim 7, characterized in that: Scanning is done using CT, electron microscopy, or MRI.

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