Device for calculating gas content of rock core

Abstract

The utility model relates to the technical field of oil and gas field exploration logging engineering equipment, in particular to a device for calculating the gas content of a rock core. The device for calculating the gas content of the rock core comprises a main body and a cover body which are buckled with each other, the main body is of a groove-shaped structure, a water outlet is formed in the side wall of the bottom of the main body, and a bracket for placing a rock core is arranged in the main body; the cover body is provided with a water injection port and a gas collection port which are communicated with each other, and the gas collection port is externally connected with gas collection equipment; the side wall of the main body is a visual window, and a graduated scale is arranged on the visual window. The utility model provides a device for calculating the gas content of a rock core, which can realize the controllability and integrity rate of observation of the rock core out of a cylinder, reduce data deviation, is low in equipment cost, meets the design coring requirement while meeting the field coring requirement, can replace the detection of part of special items, and saves the production cost.

Description

Technical Field

[0001] This utility model relates to the technical field of oil and gas field exploration logging engineering equipment, specifically to a device for calculating the gas content of rock cores. Background Technology

[0002] In geological exploration, core drilling is an important task for geologists. Core sampling is used to analyze the collected rock cores to determine the condition of underground mineral layers (including oil-bearing layers) or geological structures, accumulating first-hand geological data for further development. Geological rock cores provide direct characteristic data on the characteristics, thickness, and grade (content of useful components or minerals in the ore), as well as the development effects of underground mineral layers. After the rock cores are extracted from the well to the surface, on-site personnel must process, describe, and conduct comprehensive rock chemical analysis of the cores after they are removed from the inner cylinder. After the cores are removed from the inner cylinder, on-site logging personnel need to conduct immersion tests in time to confirm the gas vents in the cores and collect the natural gas that has escaped from the cores. Therefore, core processing and timely description after the geological rock cores are removed from the cylinder are important operations.

[0003] Current core immersion test methods:

[0004] After the core is removed from the casing, it should be placed in an iron basin or bucket to observe the gas vent and the presence of air bubbles. A beaker filled with water should be placed upside down above the gas vent to collect the natural gas contained in the core using the water displacement method.

[0005] Because the container used in this method is made of opaque material, it is easy to miss some of the vent holes. Moreover, a core may have multiple vent holes, and when collecting natural gas contained in the core, only a beaker can be aimed at a small number of vent holes, resulting in a small amount of natural gas collected. Therefore, it is necessary to improve the core immersion test device.

[0006] Meanwhile, with the continuous development of science and technology and the increasing refinement of core analysis parameters, new challenges have been posed to logging technology. Traditional core preparation methods are obviously not suitable for the current demand for efficient and rapid core production. In order to meet the needs of drilling technology development and exploration and development, it is necessary to continuously innovate and introduce new logging and coring technologies. Summary of the Invention

[0007] This invention aims to avoid the limitations of traditional core immersion experiments in fully observing core data and collecting natural gas contained in the core, and proposes a device that can calculate the gas content of the core with minimal error.

[0008] The technical solution of this utility model is as follows:

[0009] A device for calculating the gas content of rock cores includes a main body and a cover that are interlocked; the main body is a trough-shaped structure, with a water outlet on the bottom side wall of the main body, and a bracket for placing the rock core inside the main body; the cover has a through water inlet and a gas collection outlet, and a gas collection device is connected to the outside of the gas collection outlet; the side wall of the main body is a viewing window, and a scale is provided on the viewing window.

[0010] A slide rail is fixedly provided at the bottom of the main body, and brackets are slidably connected on the slide rail, with the number of brackets being ≥2.

[0011] The gas collection device is an airbag.

[0012] Switches are provided on the water inlet, water outlet, and air collection port.

[0013] Both the main body and the cover are fitted with sealing rings.

[0014] It also includes a support device located at the bottom of the main body; the support device is a support base, which is located at the top corner of the bottom of the main body.

[0015] Both the main body and the cover have rectangular cross-sections.

[0016] The support base is located at the four apex corners of the bottom of the main body.

[0017] The technical advantages of this utility model are as follows:

[0018] (1) Compared with the traditional immersion test, the side wall of the main body of this utility model is a viewing window, which can clearly observe the gas escaping of the core; on the other hand, it can collect all the natural gas overflowing from the core, which will not cause waste and the test results are accurate.

[0019] (2) The slide rail of this utility model is provided with several brackets, and the position of the brackets can be adjusted to adapt to rock cores of various lengths;

[0020] (3) The volume and gas content of the core obtained by this invention are beneficial to the calculation of reservoir reserves and lay the foundation for exploring the natural gas reserves in the target area.

[0021] (4) This utility model provides a device for calculating the gas content of rock cores, which can realize the controllability and integrity of rock core observation after core exit, reduce data deviation, and has low equipment cost. It can meet the requirements of on-site core sampling while meeting the design requirements for core sampling. It can replace the detection of some special projects and save production costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model.

[0023] Reference numerals in the attached drawings: 1. Main body; 2. Cover; 3. Water outlet; 4. Bracket; 5. Water inlet; 6. Air collection port; 7. Air collection device; 8. Slide rail; 9. First switch; 10. Second switch; 11. Third switch; 12. Support base. Detailed Implementation

[0024] Example 1

[0025] A device for calculating the gas content of rock cores includes a main body 1 and a cover 2 that are interlocked. The main body 1 is a trough-shaped structure, with a water outlet 3 on the bottom side wall of the main body 1, and a bracket 4 for placing the rock core inside the main body 1. The cover 2 has a through water inlet 5 and a gas collection port 6, and a gas collection device 7 is connected to the outside of the gas collection port 6. The side wall of the main body 1 is a viewing window, and a scale is provided on the viewing window.

[0026] The specific implementation process of this embodiment is as follows.

[0027] (a) Core soaking: Place the core on the bracket 4; close the water outlet 3, inject pure water into the main body 1, and observe the gas escaping point and bubble shape of the core.

[0028] (II) Calculating the core volume:

[0029] 1. Close outlet 3, inject pure water into main body 1, and read the volume of injected pure water through the viewing window; place the core on bracket 4, and read the total volume through the viewing window; the difference between the total volume and the volume of injected pure water is the core volume;

[0030] 2. Place the core on the bracket 4 and close the outlet 3; inject pure water into the main body 1, read the total volume through the viewing window, then open the outlet 3 to drain all the pure water in the main body 1, and record the volume of the drained pure water. The difference between the total volume and the volume of the drained pure water is the core volume.

[0031] (iii) Collecting natural gas contained in the core:

[0032] Place the core on the bracket 4, close the water outlet 3, and fasten the main body 1 and the cover 2 to seal it; inject pure water into the main body 1 through the water inlet 5 until pure water overflows from the gas collection port 6, purge the air from the gas collection device 7 and connect it to the gas collection port 6; close the water inlet 5, and when no more bubbles overflow from the core through the viewing window, remove the gas collection device 7 and measure the volume of gas collected in the gas collection device 7.

[0033] Example 2

[0034] Based on Example 1, it also includes:

[0035] A slide rail 8 is fixedly installed at the bottom of the main body 1, and a bracket 4 is slidably connected to the slide rail 8. The number of brackets 4 is ≥2. The position of the brackets 4 can be adjusted to accommodate rock cores of various lengths.

[0036] Example 3

[0037] Based on Embodiment 2, the following are also included: the air collection device is an air bag; the water inlet 5 is provided with a first switch 9, the air collection port 6 is provided with a second switch 10, and the water outlet 3 is provided with a third switch 11; the fastening points of the main body 1 and the cover 2 are all provided with sealing rings.

[0038] Example 4

[0039] Based on Embodiment 3, the system further includes: a support device located at the bottom of the main body 1; the support device is a support base 12, which is located at the apex corner of the bottom of the main body 1. Both the main body 1 and the cover 2 have rectangular cross-sections. The support base 12 is located at the four apex corners of the bottom of the main body 1.

[0040] The specific implementation process of this embodiment is as follows.

[0041] (a) Core soaking: Place the core on the bracket 4; close the outlet 3 through the third switch 11, inject pure water into the main body 1, and observe the gas escaping point and bubble shape of the core through the viewing window.

[0042] (II) Calculation of core volume: 1. Close the outlet 3 through the third switch 11, open the first switch 9 and inject pure water into the main body 1 through the water inlet 5, and read the volume of injected pure water through the viewing window; place the core on the bracket 4 and read the total volume through the viewing window; the difference between the total volume and the volume of injected pure water is the core volume;

[0043] 2. Place the core on the bracket 4 and close the outlet 3 through the third switch 11; open the first switch 9 and inject pure water into the main body 1 through the water inlet 5. Read the total volume through the viewing window, then open the third switch 11 to open the outlet 3, drain all the pure water in the main body 1, and record the volume of the drained pure water. The difference between the total volume and the volume of the drained pure water is the core volume.

[0044] (iii) Collecting natural gas contained in the core:

[0045] Place the core on the bracket 4, close the water outlet 3 through the third switch 11, and fasten the main body 1 and the cover 2 to seal. Open the gas collection port 6 through the second switch 10, and open the first switch 9 to inject pure water into the main body 1 through the water inlet 5 until pure water overflows from the gas collection port 6. Expel the gas in the airbag and connect it to the gas collection port 6. Close the water inlet 5 through the first switch 9. When no more bubbles overflow from the core, remove the airbag and invert the outlet of the airbag underwater. After the airbag is completely expelled, read the volume of liquid in the measuring cylinder. This volume of liquid is the volume of gas collected by the airbag. Alternatively, special reagents can be added to the core to release all the natural gas contained in the core (such as the reaction of carbonate rocks with acid). The volume of natural gas contained in the core can be obtained, and then divided by the core volume to obtain the natural gas content per unit volume of the core.

Claims

1. A device for calculating the gas content of rock cores, comprising a main body (1) and a cover (2) that interlock with each other; characterized in that: The main body (1) is a trough-shaped structure. A water outlet (3) is provided on the bottom side wall of the main body (1). A bracket (4) for placing rock cores is provided inside the main body (1). A through water inlet (5) and an air collection port (6) are provided on the cover (2). An air collection device (7) is connected to the outside of the air collection port (6). The side wall of the main body (1) is a viewing window. A scale is provided on the viewing window.

2. The apparatus for calculating the gas content of rock cores according to claim 1, characterized in that: The main body (1) has a slide rail (8) fixedly installed at the bottom, and a bracket (4) is slidably connected on the slide rail (8), with the number of brackets (4) being ≥2.

3. The apparatus for calculating the gas content of rock cores according to claim 1, characterized in that: The gas collection device is an airbag.

4. The apparatus for calculating the gas content of rock cores according to claim 1, characterized in that: Switches are provided on the water inlet (5), water outlet (3), and air collection port (6).

5. The apparatus for calculating the gas content of rock cores according to claim 1, characterized in that: Both the main body (1) and the cover (2) are provided with sealing rings at the fastening points.

6. The apparatus for calculating the gas content of rock cores according to claim 1, characterized in that: It also includes a support device located at the bottom of the main body (1); the support device is a support base (12), which is located at the top corner of the bottom of the main body (1).

7. The apparatus for calculating the gas content of rock cores according to claim 6, characterized in that: Both the main body (1) and the cover (2) have rectangular cross sections.

8. The apparatus for calculating the gas content of rock cores according to claim 7, characterized in that: The support base (12) is located at the four apex corners of the bottom of the main body (1).

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