Oil gas fidelity core under-pressure nuclear magnetic test system

Abstract

The invention discloses an oil and gas fidelity core under-pressure nuclear magnetism testing system which comprises a transfer assembly, the transfer assembly is communicated with a nuclear magnetism testing assembly, the nuclear magnetism testing assembly is communicated with a high-pressure constant-temperature oil circulation assembly, and the high-pressure constant-temperature oil circulation assembly has a pressure monitoring function; the transfer assembly comprises a transfer pull rod, and the tail end of the transfer pull rod is installed in a hydraulic pull rod cabin communicated with a hydraulic oil control system. The nuclear magnetism testing assembly comprises a sample channel which penetrates through the testing cabin, a nuclear magnetism detecting device is arranged in the testing cabin, and the two ends of the sample channel are communicated with the upstream sealing section and the downstream sealing section respectively. The core can be transferred from a coring tool to a special pressure maintaining cabin under the condition of complete pressure maintaining, drilling fluid left on the surface of an inner cylinder of the core is cleaned in the transferring process, real-time nuclear magnetic resonance scanning testing is carried out, and the pore structure characteristics of the core in the pressure maintaining state are obtained; the oil and gas occurrence state and other key parameters in oil and gas geology comprehensive evaluation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coring test, in particular to an oil and gas fidelity core pressure nuclear magnetic test system. BACKGROUND

[0002] The oil and gas resource exploitation faces the technical problems of sample parameter distortion and inaccurate reservoir law, which affects the efficient and safe exploitation of deep resources. The pressure-maintained coring can maintain the original state of the core, and has great advantages in oil and gas composition understanding, saturation determination accuracy, rock mechanics test and the like compared with the conventional coring. However, the conventional core test method for the pressure-maintained coring does not have any pressure-maintained treatment on the core, so that the original pressure environment of the pressure-maintained core is lost after being taken out, and the real physical property parameters cannot be measured.

[0003] In order to prevent the influence of pressure environment change on the physical property of the core, it is necessary to perform necessary treatment on the core taken by the pressure-maintained coring under the condition of maintaining the pressure throughout the whole process and test the physical property parameters under the current pressure environment. The nuclear magnetic method is the best method for pressure non-contact test at present, but the pressure-maintained barrel used in the pressure-maintained coring is made of metal material, and the nuclear magnetic cannot penetrate the metal to scan the pressure-maintained core inside. In addition, the core in the pressure-maintained coring device is soaked in the drilling fluid, and the nuclear magnetic signal of the drilling fluid itself will seriously affect the nuclear magnetic scanning result. Therefore, it is necessary to transfer the core inner barrel and the core inside from the pressure-maintained coring device to the special nuclear magnetic scanning cabin under the condition of completely maintaining the pressure, and clean the residual drilling fluid on the surface of the core inner barrel, so that the nuclear magnetic resonance can obtain the accurate result of the real physical property of the pressure-maintained core. SUMMARY

[0004] The present application aims to provide an oil and gas fidelity core pressure nuclear magnetic test system, which can transfer the core from the coring tool to the special pressure-maintained cabin under the condition of completely maintaining the pressure, clean the residual drilling fluid on the surface of the core inner barrel during the transfer process, perform real-time nuclear magnetic resonance scanning test, and obtain the key parameters in the comprehensive evaluation of oil and gas geology, such as the pore structure characteristics of the core under the pressure-maintained state and the oil and gas occurrence state.

[0005] In order to achieve the above-mentioned purpose, the present application is implemented by adopting the following technical scheme: The present application discloses an oil and gas fidelity core pressure nuclear magnetic test system, which comprises a transfer assembly, the transfer assembly is connected with a nuclear magnetic test assembly, the nuclear magnetic test assembly is connected with a high-pressure constant-temperature oil circulation assembly, and the high-pressure constant-temperature oil circulation assembly has a pressure monitoring function; the transfer assembly comprises a transfer pull rod, the tail end of the transfer pull rod is installed in a hydraulic pull rod cabin, and the hydraulic pull rod cabin is connected with a hydraulic oil control system; the nuclear magnetic test assembly comprises a sample channel, the sample channel penetrates through a test cabin, a nuclear magnetic detection device is arranged in the test cabin, and the two ends of the sample channel are connected with an upstream sealing section and a downstream sealing section respectively.

[0006] Preferably, the upstream sealing section is provided with an upstream ball valve, and the downstream sealing section is provided with a downstream ball valve.

[0007] Preferably, a cleaning section is arranged between the upstream sealing section and the nuclear magnetic test assembly, and a plurality of cleaning rings are arranged in the cleaning section in the axial direction, and a plurality of elastic cleaning blades are arranged in the cleaning rings in the circumferential direction.

[0008] Preferably, the head end of the transfer rod is provided with a bayonet, and the bayonet is adapted to the core barrel.

[0009] Preferably, the sample channel is made of non-metal material.

[0010] Preferably, a pressure maintaining transfer cabin is arranged between the downstream sealing section and the transfer assembly.

[0011] Preferably, the high-pressure constant-temperature oil circulating assembly comprises an oil storage tank, the oil storage tank is connected with a heating circulating device, the heating circulating device is connected with an oil inlet control device and an oil return control device respectively, the oil inlet control device is connected with the tail end of the pressure maintaining transfer cabin and the inlet end of the downstream ball valve, and the oil return control device is connected with the outlet end of the upstream ball valve and the outlet end of the downstream ball valve respectively.

[0012] Preferably, the upstream ball valve and the downstream ball valve are both high-pressure ball valves.

[0013] The beneficial effects of the present application are that, when the present application is connected with the pressure maintaining coring tool raised to the ground surface, the core inner barrel in the pressure maintaining cabin is transferred from the coring tool to the storage cabin of the present equipment under the condition of maintaining pressure, and the drilling fluid remaining on the surface of the core inner barrel is cleaned during the transfer process, real-time nuclear magnetic resonance scanning test is carried out, and key parameters in oil and gas geological comprehensive evaluation such as pore structure characteristics of the core under the condition of maintaining pressure and oil and gas occurrence state are obtained. The core is maintained in the original position pressure in the pressure maintaining cabin for a long time, and can be used for subsequent fidelity environment test. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a schematic view of the present application; Figure 2 is a schematic view of the cleaning ring.

[0015] In the figure: 1 is a transfer rod, 2 is a hydraulic rod cabin, 3 is a hydraulic oil control system, 4 is a test cabin, 5 is a sample channel, 6 is a nuclear magnetic detection device, 7 is an upstream ball valve, 8 is a downstream ball valve, 9 is a bayonet, 10 is a cleaning section, 11 is a cleaning ring, 12 is a cleaning blade, 13 is a pressure maintaining transfer cabin, 14 is an oil storage tank, 15 is a heating circulating device, 16 is an oil inlet control device, and 17 is an oil return control device. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application will be further described in detail below with reference to the drawings.

[0017] AsFigure 1 、 Figure 2 As shown in the drawings, the application comprises a transfer assembly, the transfer assembly is connected with a nuclear magnetic test assembly, the nuclear magnetic test assembly is connected with a high-pressure constant-temperature oil circulation assembly, the high-pressure constant-temperature oil circulation assembly has a pressure monitoring function; the transfer assembly comprises a transfer pull rod 1, the tail end of the transfer pull rod 1 is installed in a hydraulic pull rod cabin 2, and the hydraulic pull rod cabin is connected with a hydraulic oil control system 3; the nuclear magnetic test assembly comprises a sample channel 5, the sample channel 5 penetrates through a test cabin 4, the test cabin 4 is provided with a nuclear magnetic detection device 6, and the two ends of the sample channel 5 are respectively connected with an upstream sealing section and a downstream sealing section.

[0018] In order to realize the sealing function of the upstream sealing section and the downstream sealing section, the upstream sealing section is provided with an upstream ball valve 7, and the downstream sealing section is provided with a downstream ball valve 8, and the upstream ball valve 7 and the downstream ball valve 8 are both high-pressure ball valves.

[0019] In order to remove the drilling fluid on the surface of the core, a cleaning section 10 is arranged between the upstream sealing section and the nuclear magnetic test assembly, a plurality of cleaning rings 11 are arranged in the cleaning section 10 along the axial direction, and a plurality of elastic cleaning blades 12 are arranged in the cleaning ring 11 along the circumferential direction.

[0020] In order to facilitate direct connection with the core barrel and move the core barrel, the head end of the transfer pull rod 1 is provided with a bayonet 9, the bayonet 9 is matched with the core barrel, the bayonet 9 can be connected with a pressure-maintaining core barrel unlocking device, and the core sample in the transfer core barrel can be transferred.

[0021] In order to realize real-time nuclear magnetic resonance scanning test, the sample channel 5 is made of non-metal material, and the nuclear magnetic detection device 6 is an NMR radio frequency coil which is arranged outside the periphery of the sample channel 5.

[0022] In order to facilitate the realization of other test items, the downstream sealing section and the transfer assembly are provided with a pressure-maintaining transfer cabin 13.

[0023] In order to realize the heat preservation and pressure maintaining experimental environment, the high-pressure constant-temperature oil circulation assembly comprises an oil storage tank 14, the oil storage tank 14 is connected with a heating circulation device 15, the heating circulation device 15 is provided with a pressure pump and an electric heating device, the heating circulation device 15 is respectively connected with an oil inlet control device 16 and an oil return control device 17, the oil inlet control device 16 is connected with the tail end of the pressure-maintaining transfer cabin 13 and the inlet end of the downstream ball valve 8, and the oil return control device is respectively connected with the outlet end of the upstream ball valve 7 and the outlet end of the downstream ball valve 8.

[0024] In actual use, the transfer pull rod 1 is stretched out from the hydraulic pull rod cabin 2, and sequentially passes through the pressure-maintaining transfer cabin 13, the downstream ball valve 8, the sample channel 5, the cleaning section 10, and the upstream ball valve 7 which remains in a closed state, and the upstream ball valve 7 is connected with the pressure-maintaining coring device; The heating circulation device 15 is driven to heat and pressurize each cabin body connected therewith, so as to ensure that the pressure in each cabin body is consistent with that in the pressure-maintaining coring device; Open the upstream ball valve 7, push the transfer rod 1 to the pressure-holding coring device, and use the bayonet 9 to unlock the pressure-holding coring device and the core cylinder; Drive the transfer lever 1 to drag the core cylinder into the chamber of this invention; The core tube first enters the cleaning section 10, which is equipped with multiple cleaning rings 11. The elastic cleaning scrapers 12 on the cleaning rings 11 are made of organic rubber. When the core tube passes through, it pushes open the elastic cleaning scrapers 12 to make them bend and scrape the surface of the core tube to clean the drilling fluid remaining on the surface. After cleaning, the core tube is placed into sample channel 5, and a pressure scan is performed in sample channel 5 to obtain the two-dimensional nuclear magnetic resonance spectrum of the core under pressure. After scanning, the core tube enters the pressure-holding transfer chamber 13. Once the entire core tube has entered, the downstream ball valve 8 is closed, allowing the core tube to be stored under pressure in the pressure-holding transfer chamber 13 for future testing.

[0025] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A system for oil and gas fidelity core pressure NMR testing, the system comprising: The transfer assembly is connected with the nuclear magnetic test assembly, the nuclear magnetic test assembly is connected with the high-pressure constant-temperature oil circulation assembly, and the high-pressure constant-temperature oil circulation assembly has a pressure monitoring function. The transfer assembly includes a transfer pull rod (1) installed at the tail end in a hydraulic pull rod cabin (2), and the hydraulic pull rod cabin is connected with a hydraulic oil control system (3). The nuclear magnetic test assembly includes a sample channel (5) penetrating through a test cabin (4), and the test cabin (4) is provided with a nuclear magnetic detection device (6); the sample channel (5) is connected with an upstream sealing section and a downstream sealing section at two ends, respectively.

2. The test system of claim 1, wherein: The upstream sealing section is provided with an upstream ball valve (7), and the downstream sealing section is provided with a downstream ball valve (8).

3. The test system of claim 1, wherein: A cleaning section (10) is arranged between the upstream sealing section and the nuclear magnetic test assembly, a plurality of cleaning rings (11) are arranged in the cleaning section (10) along the axial direction, and a plurality of elastic cleaning blades (12) are arranged in the cleaning ring (11) along the circumferential direction.

4. The test system of claim 1, wherein: The transfer pull rod (1) is provided with a bayonet (9) at the head end, and the bayonet (9) is matched with a core barrel.

5. The test system of claim 1, wherein: The sample channel (5) is made of a non-metal material.

6. The test system of claim 2, wherein: A pressure maintaining transfer cabin (13) is arranged between the downstream sealing section and the transfer assembly.

7. The test system of claim 6, wherein: The high-pressure constant-temperature oil circulation assembly includes an oil storage tank (14) connected with a heating circulation device (15), and the heating circulation device (15) is connected with an oil inlet control device (16) and an oil return control device (17), respectively; the oil inlet control device (16) is connected with the tail end of the pressure maintaining transfer cabin (13) and the inlet end of the downstream ball valve (8), and the oil return control device is connected with the outlet end of the upstream ball valve (7) and the outlet end of the downstream ball valve (8), respectively.

8. The test system of claim 2, wherein: The upstream ball valve (7) and the downstream ball valve (8) are high-pressure ball valves.

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