Visualization experimental device for self-escape oil and gas in shale pressure-maintained closed full-diameter core water tank

Abstract

The present invention relates to the technical field of shale reservoir development, and in particular to a shale pressure-maintaining and airtight full-diameter core water tank self-escape oil and gas visualization experimental device, which comprises an upper cover, wherein upper and lower baffles are arranged in the upper cover and the lower tank at a certain interval, and the middle part of the baffle in contact with the core is set as a semicircular surface; two air holes are opened between the two baffles at the top of the upper cover, and the air holes are provided with bakelite boards with the same opening positions, and the bakelite boards are connected to a three-way valve and a ball valve; telescopic brackets are provided at both ends of the lower tank, and slots are provided around; inserts are provided around the upper cover, corresponding to the slots; a bottom bracket is provided below the lower tank, and a pulley is provided below the bottom bracket, and the upper cover and the lower tank are respectively equipped with a female buckle and a male buckle. The present invention provides a shale pressure-maintaining and airtight full-diameter core water tank self-escape oil and gas visualization experimental device, which is convenient to move, has high experimental interpretation accuracy, is widely applicable to cores of different sizes, is easy to operate, has a wide source of materials, and is low in cost.

Description

Technical Field

[0001] The invention relates to the technical field of shale oil reservoir development, and in particular to a shale pressure-maintaining closed full-diameter core water tank self-escaping oil and gas visualization experimental device. Background Art

[0002] The existing evaluation methods for sweet spots in shale reservoirs and the evaluation methods for oil and gas production capacity are mainly concentrated in two aspects. One is the indirect evaluation method, which is based on the logging results of completed wells and the results of three-dimensional seismic data processing, and is calculated and speculated through theoretical models and indirect analysis methods. The interpretation accuracy is in meters or tens of meters. The second is the experimental test method, which obtains general oil and gas products reflecting the whole well or layered exploitation of a certain layer through wellhead sampling. The test results are affected by the changes in temperature and pressure during the migration of oil and gas in the wellbore. In addition, some methods use bottom hole sampling methods, but experiments show that this method has a low success rate and requires a long preparation time, which affects the test efficiency. In addition, there is a method of obtaining pressure-maintained core samples through closed coring, which is applicable, but the subsequent monitoring and analysis generally use small-size samples to simulate gas production tests. Similar experimental test methods will affect the representativeness of shale samples with strong heterogeneity, and the crushed samples will destroy the original pore structure and ignore the effect of unconnected pores on gas production, which can easily make the test results too high. Therefore, in response to the above shortcomings, a shale pressure-maintained closed full-diameter core water tank self-escape oil and gas visualization experimental device is proposed. Summary of the invention

[0003] The purpose of the present invention is to provide a shale pressure-maintaining closed full-diameter core water tank self-escaping oil and gas visualization experimental device to overcome the defects of low measurement accuracy, inability to detect on-site, great influence during migration, long preparation time and insufficient representativeness of experimental objects in the prior art.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device, comprising an upper cover, a lower tank, a bottom support and a pulley; the upper cover and the lower tank are combined to form a self-escape experimental tank; the core to be measured is placed in the self-escape experimental tank, wherein a plurality of upper partitions are arranged at intervals along the axial direction of the core in the upper cover, and a lower partition is placed at intervals along the axial direction of the core in the lower tank; the upper partitions are arranged correspondingly to the lower partitions, and the self-escape experimental tank is divided into a plurality of self-escape experimental chambers after the upper cover is engaged with the lower tank; the upper cover at the top of each self-escape experimental chamber has two first holes eyes; a bakelite board is provided on the upper cover at the top of each self-escape experiment chamber, and the bakelite board is provided with second holes corresponding to the two first holes; the upper and lower partitions are processed into semicircular surfaces at the contact points with the core, and the rest of the positions are straight; the contact surfaces of the upper and lower partitions at both ends of the self-escape experiment tank are always horizontal; telescopic brackets are provided at both ends of the lower tank; an artificial full-size core is provided between the upper and lower partitions; the upper cover and the two sides of the lower tank adopt a slot-type design; a bottom bracket is provided under the lower tank, and a pulley is provided under the bottom bracket; the upper cover, lower tank, upper partition and lower partition all adopt a transparent structure.

[0005] Preferably, the holes of the bakelite board are respectively connected to a three-way valve and a ball valve; one connecting port of the three-way valve is connected to a gas nozzle and a gas sample bag, and the other connecting port is switchably connected to a nitrogen bottle and a water replenishment tank.

[0006] Preferably, a coating is provided on the outer side of one side of the lower groove, and a movable lamp holder equipped with an LED lamp is connected to the base on the other side.

[0007] Preferably, insert strips are provided on both sides of the upper cover, and slots are provided on both sides of the lower groove.

[0008] Preferably, after the upper cover and the lower trough are connected, the core is placed in the circular hole of the organic glass partition, the upper edge of the core is located below the root of the cutting, and the lower edge of the core is more than 2 cm away from the bottom of the lower trough.

[0009] Preferably, corner pads are added to the bottom corners on both sides of each lower partition, the straight part of the upper partition is provided with an H-shaped sealing strip, the straight part of the upper partition is inserted into a groove on one side of the H-shaped sealing strip, the upper and lower partitions are provided with soft sealing belts on the contact surface with the core, and sealing belts are installed at the root of the slot and the root of the insert.

[0010] Preferably, three clips are arranged on both sides of the Ziyi experimental trough body, and a clip is set on the outer side of each partition on both sides of the trough body, and the female clip and the male clip of the clip are respectively installed on the wooden board glued to the upper cover or the lower trough.

[0011] Preferably, the upper edge of the base is lower than the lower edge of the core, and base handles are provided around it.

[0012] Preferably, the pulley at the bottom end of the pulley vehicle is a lockable universal wheel.

[0013] The shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device provided by the present invention has the following beneficial effects:

[0014] The shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device provided by the present invention divides the interior of the container into a number of self-escape experimental chambers by upper and lower partitions, and divides the core to be tested into a plurality of small blocks of unit volume at fixed intervals for measurement respectively, and can accurately measure the unit volume of spontaneously escaping oil and gas and the corresponding oil and gas component information of shale with different lithology and depth in each section, and can accurately measure the degree of subdivision to the centimeter scale; through the combination of the bottom support and the pulley, the flexibility of the device on site is improved, and it can be transported over long distances; after the device is assembled, it is only necessary to collect the experimental gas through the top opening of the device during the experiment, and the operation is simple; the bakelite board glue sealing design is adopted in the frequent disassembly and assembly places to replace the main body wear, and timely replacement can avoid damage to the main body, and the maintenance cost is low; most of the main body of the device is made of transparent glass material, which is convenient for observing the experimental results, clarifying the experimental information, and improving the success rate of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a front view of the present invention;

[0016] Figure 2 It is a structural diagram of the upper cover of the present invention;

[0017] Figure 3 It is the structural diagram of the lower tank of the present invention;

[0018] Figure 4 It is the installation diagram of the telescopic bracket of the present invention.

[0019] Legend:

[0020] 1. Upper cover; 2. Lower trough; 3. Bottom support; 4. Pulley; 5. Three-way valve; 6. Ball valve; 7. Bakelite; 8. Female snap buckle; 9. Upper partition; 10. Insert; 11. Full-diameter core; 12. Male snap buckle; 13. Slot; 14. Telescopic bracket; 15. Lower partition; 16. Bottom support handle; 17. Lockable universal wheel. Implementation

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] like Figure 1-4 As shown, the present invention provides a shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device, comprising: an upper cover 1, a lower tank 2, a bottom support 3 and a pulley 4.

[0023] A plurality of upper baffles 9 are arranged at intervals in the upper cover 1, and a plurality of lower baffles 15 are arranged at intervals in the lower tank 2. The upper cover 1 is buckled on the lower tank 2 to form a self-escape test tank. The self-escape test tank can place the core to be tested to conduct an overall oil and gas self-escape test on the core of a certain length.

[0024] Among them, the upper partition 9 corresponds to the lower partition 15, and the self-escape test tank is divided into multiple self-escape test chambers. The core to be tested is placed between the upper partition 9 and the lower partition 15. The contact surface between the upper partition 9 and the lower partition 15 and the core is set to a semicircular contact surface, and the rest of the contact surface remains straight. The core to be tested is divided into multiple parts according to the unit volume through the self-escape test chamber, and each part is tested separately and simultaneously. The escaped oil and gas volume and oil and gas components of the core at different depths are analyzed. By adjusting the partition spacing, the subdivision degree can be accurately adjusted to the centimeter scale, improving the precision and accuracy of the experiment.

[0025] Among them, the upper partition 9 and the lower partition 15 located at both ends of the device remain straight, so that separate partitions are formed at both ends of the self-escape experimental tank, which are used to conduct oil and gas self-escape experiments on small-sized cores such as cores and core fragments less than ten centimeters or irregular shapes, so that the device can be used to experiment on objects of various sizes, thereby improving the applicability of the device.

[0026] In the present invention, the upper cover 1, the lower tank 2, the upper partition 9 and the lower partition 15 are all made of transparent organic glass, which is convenient for observing the oil and gas self-escape process during the experiment.

[0027] Preferably, a soft sealing pressure belt is provided at the contact core position of the upper partition 9 and the lower partition 15, so that the device can normally conduct experiments on cores with rough surfaces when coring on site. An H-shaped sealing strip is provided on the straight part of the upper partition 9, and a groove on one side of the H-shaped sealing strip engages with the straight part of the upper partition. When the upper cover 1 is buckled with the lower groove 2, the groove on the other end of the H-shaped sealing strip engages with the straight part of the lower partition, so that the sealing of the device is improved, and the liquid and gas in the self-escape experiment chamber are prevented from flowing out to the adjacent chamber due to insufficient sealing, which affects the experimental results.

[0028] In the present invention, as a preference, a core holder with multiple holes is provided between the partitions to carry the core, so that when the device conducts experiments on shale cores with cracks and high content of easily expandable clay minerals, the core will not be broken due to hydration and affect the accuracy of the experimental data, making the experiment more stable and reliable, and improving the success rate of the experiment.

[0029] Among them, a protective pad with a corner is respectively provided on both sides of each lower partition 9 until the bottom corner, which prevents the device from being damaged or cracked due to bumps during movement and transportation, improves the seismic resistance of the device, and improves the stability of the device.

[0030] Preferably, by batch processing the device of the present invention, oil and gas self-escape experiments are carried out on cores to achieve testing of the oil and gas production capacity and component information of the entire well section of the coring well. The obtained experimental results can be used as an experimental basis for evaluating the optimal development of sweet spots, or provide data correction for development numerical simulation research.

[0031] In the present invention, the upper cover 1 and the lower tank 2 adopt a slot design, the edge of the upper cover 1 is provided with an insert 10, and the edge of the lower tank 2 is provided with a slot 13, and the insert 10 corresponds to the slot 13. The insert design can play a role in installation and fixing while maintaining the overall sealing effect of the tank body, and at the same time improve the efficiency of disassembly and assembly of the device.

[0032] Among them, after the upper cover 1 and the lower tank 2 are connected, the upper edge of the core is lower than the root of the cutting to prevent water from overflowing after the core is immersed in water in the container; the lower edge of the core is more than 2 cm away from the bottom of the lower tank to prevent the overflowing gas from floating incompletely due to the core being too close to the bottom of the lower tank, resulting in insufficient space for the gas to move after overflowing. This improves the accuracy and precision of the experiment and makes the experimental data more authentic and reliable.

[0033] In the present invention, each upper cover 1 corresponds to a self-escape experiment chamber, and has two first openings at the top. A bakelite board 7 is provided on the upper cover 1 corresponding to each self-escape experiment chamber, and a second opening corresponding to the position of the first opening is provided on the bakelite board 7.

[0034] The bakelite board 7 is fixed to the upper cover 1 by gluing, and the component that should be connected to the first opening is connected to the second opening, so as to prevent the upper cover 1 from being broken or worn due to frequent disassembly and replacement of components at the first opening. The bakelite board 7 is used to replace the upper cover 1 to install other components. When the bakelite board 7 is damaged or disassembled and replaced for a certain number of times, only the bakelite board 7 needs to be replaced, which greatly reduces the equipment cost and workload in the daily maintenance of the device and saves the maintenance cost.

[0035] like Figure 1 As shown, the second openings on the bakelite board 7 are connected to the three-way valve 5 and the ball valve 6 respectively.

[0036] Among them, one connecting port of the three-way valve 5 is connected to a gas nozzle, which is used to connect the gas sample bag. The gas nozzle and the gas sample bag are connected and sealed. During the experiment, the gas sample bag is periodically replaced and the gas components and gas volume in the replaced gas sample bag are detected to achieve the measurement of the gas components and gas volume of the core. The other connecting port of the three-way valve 5 is switched and connected with the nitrogen bottle and the water replenishment tank, which are used to empty the air in the device with nitrogen before the experiment and to discharge the residual gas and residual oil in the device when the experiment is about to end. The ball valve 6 is used as a pressure relief hole when adding water or gas to the device, and the oil in the container can be connected and measured through the ball valve 6. The whole operation process is simple and easy to operate.

[0037] As a further preferred solution, when measuring the oil in the container, a measuring instrument can be inserted through the ball valve 6 to sample and measure the oil, thereby preventing the oil sample from remaining on the ball valve 6 when taking the oil sample, resulting in inaccurate experimental data and reducing experimental errors.

[0038] In the present invention, telescopic brackets 14 are provided at both ends of the lower trough 2 for fixing the core to be measured.

[0039] Among them, an artificial full-size core 10 is provided in the upper partition 9 and the lower partition 13, and its length can be 5cm, 10cm, 15cm, 20cm, 25cm, 30cm and other sizes. It is used to cooperate with the telescopic bracket 14 to firmly fix the core to be tested in the experimental position during the experiment to prevent the axial movement of the core to be tested and cause inaccurate experimental data.

[0040] like Figure 3 As shown, three buckles are arranged on both sides of the self-escape experiment tank body, and a buckle is set on the outer side of each partition on both sides of the tank body to seal and tighten the connection between the upper cover 1 and the lower tank 2 to prevent liquid or gas from flowing out during the experiment.

[0041] Among them, the female buckle 8 and the male buckle 12 are respectively installed on the wooden board glued to the upper cover 1 or the lower groove 2. When the female buckle 8 and the male buckle 12 are damaged or aged, the purpose can be achieved by replacing and disassembling them on the wooden board. When the wooden board is damaged, it is fixed by gluing, and the upper cover 1 or the lower groove 2 is not affected during the replacement of the wooden board, thereby avoiding damage to the device body due to frequent disassembly and replacement of parts, reducing the daily maintenance cost and workload of the equipment.

[0042] In this embodiment, the female buckle 8 is installed on the upper cover 1 , and the male buckle 12 is installed on the lower groove 2 .

[0043] like Figure 1As shown, a bottom support 3 is provided under the lower trough 2, and the two are designed as a split body. The bottom support 3 is used to support the device body to prevent the main body from being broken due to vibration during long-term use and transportation. The upper edge of the bottom support 3 is lower than the lower edge of the core, which is convenient for observing experimental changes and reaction processes during the experiment.

[0044] Among them, a base handle 16 is arranged around the base 3 to provide a force point for carrying the self-escape test tank, which is convenient for long-distance transportation.

[0045] like Figure 1 As shown, a pulley 4 is provided under the base 3 for moving the device, and the base 3 and the pulley 4 are designed to be separated, which is convenient for loading and unloading and moving the device. A lockable universal wheel 17 is provided under the pulley 4, so that the device can be fixed on an uneven ground, reducing the requirements of the device on the use site and improving the applicability of the device.

[0046] In this experiment, as a preference, a coating is provided on one side of the outer surface of both sides of the lower tank 2, and the coating is made of ordinary dark gray paint, and a movable lamp holder equipped with an LED lamp is connected to the corresponding base on the other side, so that the oil and gas escape phenomenon is more obvious during the experiment, which is convenient for observing and monitoring the progress of the experiment.

[0047] Therefore, through the shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device of the above structure, it is possible to carry out shale gas production characteristic analysis experiments at different depths of the core. Its working principle and operation mainly include the following steps:

[0048] Step 1: transport the device to the experimental site through the base 3 and the pulley 4, and fix the device in a suitable position through the lockable universal wheels 17 at the bottom;

[0049] Step 2: Fill the lower tank 2 with water, place the sealed full-diameter core on the semicircular contact surface of the lower partition 15, adjust the telescopic bracket 14 and select a suitable full-size core 11, clamp and fix the experimental test core, and place it in separate partitions at both ends of the lower tank when the experimental object is a small-size core such as less than ten centimeters;

[0050] Step 3: Close the upper cover 1, insert the insert strip 10 into the slot 13, and connect the male buckle 12 and the female buckle 8;

[0051] Step 4: Connect the nitrogen bottle to the three-way valve 5, open the ball valve, and open the nitrogen bottle to exhaust the air in the device;

[0052] Step 5: Connect the gas sample bag to the three-way valve 5. During the experiment, you only need to continuously replace the gas sample bag and measure the gas volume and components in the replaced gas sample bag;

[0053] Step 6: When the experiment is about to end, the nitrogen tank can be replaced with a water tank, and the ball valve 6 can be opened to add water to the device. The ball valve 6 is connected to an external liquid to measure the amount of oil discharged from the shale. As a further preferred solution, the ball valve can be extended into a metering tube to extract the discharged oil for volume measurement and component analysis;

[0054] Step 7: After the experiment, remove the upper cover 1, take out the experimental measurement core, empty the liquid in the device, wash it and store it.

[0055] In the present invention, the core is subdivided into several sections through the cooperation of the upper and lower partitions, and experimental measurements are carried out separately in the device, so that the degree of subdivision of the experiment is accurate to the centimeter scale; at the same time, the contact surfaces of the partitions at both ends are always horizontal, so that separate partitions are left at both ends of the device to analyze the small-sized core experiments, and the size applicability of the experimental target is wide; the bottom end is provided with a bottom support with a bottom support handle and a pulley with a lockable universal wheel, so that the device can be transported to the collection site for the first time to carry out the experiment, avoiding the influence of the experimental materials during the transportation process; the whole device is made of organic glass, which is convenient for observing the changes of the core during the experiment, and the bakelite board gluing method is adopted on the connecting devices such as buckles, which is simple to maintain and not easy to damage, saving the equipment cost.

[0056] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A shale pressure-maintaining, sealed, full-diameter core water tank self-escape oil and gas visualization experimental device, characterized in that , comprising an upper cover (1), a lower trough (2), a bottom support (3) and a pulley (4); the upper cover (1) and the lower trough (2) are combined to form a self-escape experimental trough; a core to be measured is placed in the self-escape experimental trough, wherein a plurality of upper baffles (9) are arranged at intervals along the axial direction of the core in the upper cover (1), and a plurality of lower baffles (15) are placed along the axial direction of the core in the lower trough (2); the upper baffles (9) and the lower baffles (15) are arranged correspondingly, and the self-escape experimental trough is divided into a plurality of self-escape experimental chambers after the upper cover (1) and the lower trough (2) are joined; two first holes are opened on the upper cover (1) corresponding to the top of each self-escape experimental chamber; a bakelite board (7) is provided on the upper cover (1) located at the top of each self-escape experimental chamber, and the bakelite board (7) ) is provided with second holes corresponding to the two first holes; the contact points of the upper baffle (9) and the lower baffle (15) with the rock core are processed into semicircular surfaces, and the rest of the positions are straight; the contact surfaces of the upper baffle (9) and the lower baffle (15) at both ends of the self-escape experimental tank are always horizontal; telescopic brackets (14) are provided at both ends of the lower tank (2); an artificial full-size rock core (11) is provided between the upper baffle (9) and the lower baffle (15); the upper cover (1) and the lower tank (2) are designed with slots on both sides; a bottom bracket (3) is provided below the lower tank (2), and a pulley (4) is provided below the bottom bracket (3); the upper cover (1), the lower tank (2), the upper baffle (9) and the lower baffle (15) are all transparent structures.

2. The shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device according to claim 1 is characterized in that: The second holes are respectively connected to the three-way valve (5) and the ball valve (6); one connecting port of the three-way valve (5) is connected to the gas nozzle and the gas sample bag, and the other connecting port is switchably connected to the nitrogen bottle and the water replenishment tank.

3. The shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device according to claim 1 is characterized in that: A coating is provided on the outer side of one side of the lower groove (2), and a movable lamp holder equipped with an LED lamp is connected to the bottom bracket (3) on the other side.

4. The shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device according to claim 1 is characterized in that: Insert strips (10) are provided on both sides of the upper cover (1), and slots (13) are provided on both sides of the lower groove (2).

5. The shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device according to claim 1 is characterized in that: After the upper cover (1) and the lower trough (2) are connected, the core is placed in the circular hole of the organic glass partition, the upper edge of the core is located below the root of the cutting, and the lower edge of the core is more than 2 cm away from the bottom of the lower trough (2).

6. The shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device according to claim 1 is characterized in that: A protective pad with a corner is added to the bottom corners of both sides of each lower baffle (15), an H-shaped sealing strip is provided on the straight portion of the upper baffle (9), and the straight portion of the upper baffle (9) is inserted into a groove on one side of the H-shaped sealing strip. A sealing pressure strip is provided on the contact surface between the upper baffle (9) and the lower baffle (15) and the core, and a sealing pressure strip is installed at the root of the slot (13) and the root of the insert (10).

7. The shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device according to claim 1 is characterized in that: Three buckles are arranged on each side of the self-escape experiment tank body, and one buckle is arranged on each side of the tank body corresponding to the outer side of each partition. The buckle female buckle (8) and the buckle male buckle (12) of the buckle are respectively installed on the wooden board glued to the upper cover (1) or the lower tank (2).

8. The shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device according to claim 1 is characterized in that: The upper edge of the base support (3) is located lower than the lower edge of the core, and base support handles (16) are provided around the base support.

9. The shale pressure-maintaining closed full-diameter core water tank self-escape oil and gas visualization experimental device according to claim 1 is characterized in that: The pulley at the bottom end of the pulley vehicle (4) adopts a lockable universal wheel (17).

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