Well logging device and well logging method

Abstract

The invention relates to a well logging device and a well logging method, and relates to the technical field of well logging equipment. The logging device comprises a pipe body assembly, a heat preservation assembly, a neutron source short circuit assembly, a detector assembly and a circuit assembly. A containing cavity is formed in the pipe body assembly; the heat preservation assembly is arranged in the containing cavity, and a heat preservation cavity is formed in the heat preservation assembly; the neutron source short section assembly is arranged in the accommodating cavity, and the neutron source short section assembly is used for emitting neutron rays to the stratum; the detector assembly is arranged in the heat preservation cavity, and the detector assembly is used for receiving the neutron rays reflected by the stratum and converting the neutron rays into electric signals; the circuit assembly is arranged in the heat preservation cavity, the circuit assembly is electrically connected with the detector assembly, and the circuit assembly can receive the electric signals and transmit the electric signals to a ground terminal. According to the technical scheme disclosed by the invention, the problem that an existing neutron logging instrument is difficult to normally and continuously work under a high-temperature condition can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of logging equipment, and particularly to a logging device and a logging method. Background Art

[0002] A compensated neutron logging tool is a logging instrument that measures the neutron intensity using two thermal neutron detectors. It is a radioactive logging instrument that determines the formation porosity by measuring the hydrogen content of the formation and then judges the lithology. It can measure the porosity of underground rock formations and is an essential instrument in porosity logging projects. However, the normal working time of existing compensated neutron logging tools is significantly reduced under the high-temperature well conditions of ultra-deep oil and gas wells, unable to meet single-trip logging, and thus unable to meet the logging requirements. Summary of the Invention

[0003] Embodiments of the present invention provide a logging device and a logging method to at least solve the problem that existing compensated neutron logging tools cannot meet the logging requirements under the high-temperature well conditions of ultra-deep oil and gas wells.

[0004] In a first aspect, embodiments of the present invention provide a logging device, including:

[0005] A pipe body assembly, with a receiving cavity provided therein;

[0006] A heat preservation assembly, disposed in the receiving cavity, and a heat preservation cavity is provided in the heat preservation assembly;

[0007] A neutron source short section assembly, disposed in the receiving cavity, and the neutron source short section assembly is used to emit neutron rays to the formation;

[0008] A detector assembly, disposed in the heat preservation cavity, and the detector assembly is used to receive the neutron rays reflected by the formation and convert them into electrical signals; and

[0009] A circuit assembly, disposed in the heat preservation cavity, the circuit assembly is electrically connected to the detector assembly, and the circuit assembly can receive the electrical signals and transmit them to a ground terminal.

[0010] In an embodiment, the heat preservation assembly includes:

[0011] A thermos flask, having opposite first and second ends, an opening is provided on the first end, the second end is closed, and the opening is in communication with the heat preservation cavity;

[0012] A first heat absorption member, disposed inside the thermos flask; and

[0013] A second heat absorption member, disposed inside the thermos flask, and the second heat absorption member has a preset distance from the first heat absorption member in the axial direction of the thermos flask;

[0014] A heat insulation sleeve is arranged on the first end, and the heat insulation sleeve seals the opening;

[0015] Wherein, at least part of the circuit component is arranged between the first heat absorbing member and the second heat absorbing member, and the detector component is arranged between the second heat absorbing member and the second end.

[0016] In one embodiment, a first wire hole is arranged on the first heat absorbing member, and the first wire hole penetrates the first heat absorbing member in the axial direction of the thermos flask: a second wire hole is arranged on the second heat absorbing member, and the second wire hole penetrates the second heat absorbing member in the axial direction of the thermos flask.

[0017] In one embodiment, the logging device includes a skeleton assembly arranged in the accommodating cavity, the skeleton assembly is located at one end of the heat preservation assembly away from the neutron source subassembly, and the skeleton assembly is used for electrically connecting with an external circuit;

[0018] Wherein, a first socket assembly is arranged on the first end, and the skeleton assembly is electrically connected with the first socket assembly.

[0019] In one embodiment, the circuit component includes a circuit assembly and two preamplifier circuit modules electrically connected to the circuit assembly. The circuit assembly is arranged between the first heat absorbing member and the second heat absorbing member, and the circuit assembly includes:

[0020] A digital-to-analog conversion module for converting the alternating current input by the external circuit into direct current and outputting a voltage;

[0021] A high-voltage power supply module is electrically connected to the digital-to-analog conversion module. The high-voltage power supply is used for converting the output voltage of the digital-to-analog conversion module into the working voltage of the detector component and supplying power to the detector component through the two preamplifier circuit modules.

[0022] A high-voltage filtering module for filtering the electrical signal output by the detector component;

[0023] An analog signal module for amplifying the electrical signal processed by the high-voltage filtering module;

[0024] A spectrum acquisition module for performing energy spectrum acquisition and amplitude analysis on the electrical signal processed by the analog signal module;

[0025] A digital processing module for transmitting the electrical signal processed by the spectrum acquisition module to a ground terminal;

[0026] A low-voltage power supply module, electrically connected to the digital-to-analog conversion module, and the low-voltage power supply is used to supply power to the high-voltage filtering module, the analog signal module, the spectrum acquisition module, and the digital processing module; and

[0027] A first conductive path, passing through the first routing hole, and the first conductive path is electrically connected to the first socket assembly to deliver electrical energy to the circuit assembly;

[0028] Wherein, the two preamplifier circuit modules are disposed between the second heat sink and the second end.

[0029] In one embodiment, the detector assembly includes:

[0030] A long-source-distance detector, one end of which abuts against the second heat sink and the other end abuts against the two preamplifier circuit modules, and the long-source-distance detector is configured to receive long-source neutrons in the neutron rays reflected by the formation and convert them into a first current signal; and

[0031] A short-source-distance detector, one end of which abuts against the two preamplifier circuit modules and the other end abuts against the second end, and the short-source-distance detector is configured to receive short-source neutrons in the neutron rays reflected by the formation and convert them into a second current signal;

[0032] Wherein, the two preamplifier circuit modules are electrically connected to the long-source-distance detector and the short-source-distance detector respectively.

[0033] In one embodiment, the neutron source short section assembly includes:

[0034] A neutron source chamber for placing a neutron source, and the neutron source is capable of emitting the neutron rays;

[0035] A neutron source short section main body, disposed at one end of the neutron source chamber, and the neutron source short section main body is configured to transmit the neutron rays to the formation; and

[0036] A pull ring, disposed at one end of the neutron source chamber away from the neutron source short section main body, and the pull ring is threadedly connected to the pipe body assembly;

[0037] Wherein, a second socket assembly is disposed on the second end, and a second conductive path is disposed on the pull ring, and the conductive path is electrically connected to the second socket assembly to deliver electrical energy to the neutron source short section assembly.

[0038] In one embodiment, a strengthening structure is disposed in the neutron source chamber.

[0039] In one embodiment, the pipe body assembly includes:

[0040] A pipe body;

[0041] A first protective cap, located at one end of the pipe body, and the first protective cap is detachably connected to the pipe body;

[0042] A second protective cap, located at the end of the pipe body away from the first protective cap, and the second protective cap is detachably connected to the pipe body;

[0043] Wherein, the pipe body, the first protective cap and the second protective cap together form the accommodation cavity.

[0044] In a second aspect, an embodiment of the present invention provides a logging method, which is applied to the logging device as described above, and includes:

[0045] Lower the logging device to a preset depth underground;

[0046] Emit neutron rays to the formation through the neutron source short section assembly;

[0047] Receive the neutron rays reflected by the formation through the detector assembly and convert the neutron rays into electrical signals;

[0048] Receive the electrical signals through the circuit assembly and transmit them to the ground terminal.

[0049] Compared with the prior art, the advantages of the embodiment of the present invention are that by arranging the detector assembly and the circuit assembly in the heat preservation cavity of the heat preservation assembly, it can effectively prevent the detector assembly and the circuit assembly from being affected by the high temperature of the formation, so that the detector assembly and the circuit assembly can continuously work at high temperature, thus solving the problem that the existing neutron logging tool is difficult to work normally and continuously under high temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The present invention will be described in more detail below based on embodiments and with reference to the drawings.

[0051] Figure 1 is a cross-sectional view of the logging device provided by the embodiment of the present invention;

[0052] Figure 2 is Figure 1 a connection diagram of the skeleton assembly, the heat preservation assembly and the neutron source short section assembly provided by the embodiment in;

[0053] Figure 3 is Figure 1 a cross-sectional view of the heat preservation assembly provided by the embodiment in;

[0054] Figure 4 is Figure 1 a cross-sectional view of the neutron source short section assembly provided by the embodiment in;

[0055] Figure 5 isFigure 1 Schematic diagram of the circuit structure of the circuit component and the detector component provided in the embodiment;

[0056] Figure 6 is Figure 1 Schematic diagram of the internal structure of the neutron source bin provided in the embodiment.

[0057] Reference numerals:

[0058] 10, pipe body assembly; 20, skeleton assembly; 30, heat insulation assembly; 31, heat insulation sleeve; 32, thermos flask; 40, circuit assembly; 41, long source distance detector; 42, preamplifier circuit module; 43, short source distance detector; 44, circuit assembly; 441, digital-to-analog conversion module; 442, high-voltage power supply module; 443, low-voltage power supply module; 444, high-voltage filter module; 445, analog signal module; 446, spectrum acquisition module; 447, digital processing module; 51, first heat absorption member; 52, second heat absorption member; 60, neutron source short section assembly; 61, pull ring; 62, neutron source bin; 63, main body part of neutron source short section; 64, seal; 70, first socket assembly; 80, second socket assembly; 90, first protective cap; 100, second protective cap. Detailed implementation manners

[0059] The present invention will be further described below with reference to the accompanying drawings.

[0060] The compensated neutron logging tool is a logging tool that measures the neutron intensity using two thermal neutron detectors. It is a radioactive logging tool that determines the formation porosity by measuring the hydrogen content of the formation and then judges the lithology. It can measure the porosity of underground rock formations and is an essential tool in the porosity logging project.

[0061] The neutron source short section of the compensated neutron logging tool is loaded with a 20-curie Am-Be neutron source, and the energy is about several million electron volts. It generates 7.4X10 11 fast neutrons per second. The fast neutrons shoot into the formation and undergo a series of nuclear reactions with the formation materials. These include: inelastic reflection of fast neutrons, activation of atomic nuclei by fast neutrons, elastic scattering and deceleration of fast neutrons. After a series of elastic and inelastic collisions, the energy of the fast neutrons weakens. When the neutron energy is in thermal equilibrium with the atoms of the formation, the neutrons no longer decelerate. Neutrons in this energy state are called thermal neutrons. The energy of standard neutrons is 0.025ev, and the speed is about 2.2×10 5cm / s. According to the collision theory, the energy loss in neutron collisions is related to the mass of the collided material and the incident angle. In an elastic collision with a material having a mass comparable to that of the neutron, the neutron loses the most energy. In the formation, hydrogen atoms have a mass very close to that of neutrons. Therefore, the deceleration ability of the formation for fast neutrons mainly depends on the hydrogen content of the formation. The formation with a high hydrogen content has a strong macroscopic deceleration ability and a small deceleration length. After several collisions, the fast neutrons will be decelerated, and the energy will decay from the average energy of the fast neutrons, 5.6 MeV, to thermal neutrons with an energy of 0.025 eV. Some of these thermal neutrons enter the detector, strike the He-3 nucleus, cause a nuclear reaction, produce H3 (tritium) ions, and these ions ionize a part of the other He-3, generating charged ions and electrons. Under the action of a high-voltage electric field, the electrons move towards the anode, generating a negative pulse, which is amplified and recorded by the electronic circuit. The amount of neutrons received by the detector directly reflects the amount of hydrogen atoms in the formation. Therefore, the downhole tool composed of the He-3 detector and its electronic circuit can measure the hydrogen content in the formation. Formation pores are fine spaces filled with fluid. Water and hydrocarbons contain hydrogen atoms, while there is very little or no hydrogen in oil-free formations and ore rocks. Thus, the response of the instrument basically reflects the fine spaces of the fluid-filled formation, that is, the porosity.

[0062] The compensated neutron logging tool has small measurement errors, high reliability, and good use and calibration performance. However, the existing compensated neutron logging tool has a maximum operating temperature of 175 °C and a pressure resistance of 140 MPa. When the well temperature exceeds 260 °C, its normal working time is greatly reduced, and it cannot meet the requirements of single-trip logging, thus making it difficult to meet the measurement needs of ultra-deep oil and gas wells with a well temperature exceeding 260 °C.

[0063] As Figure 1 shown, at least one embodiment of the present invention provides a logging device, including a pipe body assembly 10, a heat insulation assembly 30, a neutron source short section assembly 60, a detector assembly, and a circuit assembly 40; a receiving cavity is provided in the pipe body assembly 10; the heat insulation assembly 30 is arranged in the receiving cavity, and a heat insulation cavity is provided in the heat insulation assembly 30; the neutron source short section assembly 60 is arranged in the receiving cavity, and the neutron source short section assembly 60 is used to emit neutron rays to the formation; the detector assembly is arranged in the heat insulation cavity, and the detector assembly is used to receive the neutron rays reflected by the formation and convert them into electrical signals; the circuit assembly 40 is arranged in the heat insulation cavity, the circuit assembly 40 is electrically connected to the detector assembly, and the circuit assembly 40 can receive the electrical signals and transmit them to the ground terminal.

[0064] By arranging the detector assembly and the circuit assembly 40 in the heat insulation cavity of the heat insulation assembly 30, it is possible to effectively prevent the detector assembly and the circuit assembly 40 from being affected by the high temperature of the formation, enabling the detector assembly and the circuit assembly 40 to continuously work at high temperatures, thereby solving the problem that the existing neutron logging tool is difficult to work normally under high-temperature conditions.

[0065] AsFigures 1 - 3 As shown, in some embodiments, the heat insulation assembly 30 includes a thermos 32, a first heat absorber 51, a second heat absorber 52, and a heat insulation sleeve 31; the thermos 32 has opposite first and second ends, an opening is provided on the first end, the second end is closed, and the opening communicates with the heat insulation cavity; the first heat absorber 51 is disposed within the thermos 32; the second heat absorber 52 is disposed within the thermos 32, and the second heat absorber 52 has a preset spacing from the first heat absorber 51 in the axial direction of the thermos 32; the heat insulation sleeve 31 is disposed on the first end, and the heat insulation sleeve 31 seals the opening; wherein, at least a part of the circuit assembly 40 is disposed between the first heat absorber 51 and the second heat absorber 52, and the detector assembly is disposed between the second heat absorber 52 and the second end.

[0066] By providing the first heat absorber 51 and the second heat absorber 52 in the heat insulation cavity to absorb the heat in the heat insulation cavity, the temperature in the heat insulation cavity can be stably controlled, ensuring that the circuit assembly 40 and the detector assembly can operate normally and extending the normal operating time of the circuit assembly 40 and the detector assembly. For example, the present invention can operate for at least 70 hours in an environment of 175°C, at least 20 hours in an environment of 200°C, and at least 6 hours in an environment of 260°C. Compared with the existing compensated neutron logging tool, the normal operating duration of the present invention in a high-temperature environment is significantly increased.

[0067] It should be noted that the specific structure of the thermos 32 is prior art and will not be elaborated in this application. For example, the thermos 32 includes a double-layer glass bottle, and the space between the double layers is evacuated. The evacuated state can avoid heat convection, and glass is a poor conductor of heat, thereby reducing heat conduction to reduce the heat entering the heat insulation cavity.

[0068] It should also be noted that the first heat absorber 51 and the second heat absorber 52 are prior art and will not be elaborated in this application. For example, the first heat absorber 51 and the second heat absorber 52 include, but are not limited to, fiberglass heat absorbers, asbestos heat absorbers, and silicate heat absorbers.

[0069] It should further be noted that the first heat absorber 51 and the second heat absorber 52 extend along the axial direction of the pipe body assembly 10. The lengths of the first heat absorber 51 and the second heat absorber 52 in the axial direction of the pipe body assembly 10 are set as needed. This length is closely related to the heat absorption effect, but it cannot be too long, as it will increase the length of the logging tool and lead to failure to meet the simplified design requirements. Of course, it cannot be too short either, as it will result in poor heat absorption effect and shorten the continuous operating time of the logging tool in high-temperature well conditions.

[0070] Such as Figure 1 、 Figure 3As shown, in some embodiments, a first wire hole is provided on the first heat absorber 51, and the first wire hole penetrates the first heat absorber 51 in the axial direction of the thermos 32. A second wire hole is provided on the second heat absorber 52, and the second wire hole penetrates the second heat absorber 52 in the axial direction of the thermos 32.

[0071] As Figures 1 - 3 shown, in some embodiments, the logging device includes a skeleton assembly 20 disposed in the accommodation cavity. The skeleton assembly 20 is located at one end of the thermal insulation assembly 30 away from the neutron source short joint assembly 60, and the skeleton assembly 20 is used for electrical connection with an external circuit. Among them, a first socket assembly 70 is provided at the first end, and the skeleton assembly 20 is electrically connected to the first socket assembly 70.

[0072] By providing the electrical connection between the skeleton assembly 20 and the external circuit to supply power to the logging tool, and setting the first socket assembly 70 as the power shunt point of the skeleton assembly 20, the connection structure during power supply is simplified, and the problem of a large number of lines being required when the skeleton assembly 20 supplies power to the logging tool is avoided.

[0073] It should be noted that the heat insulation sleeve 31 is connected to the skeleton assembly 20, and the first socket assembly 70 is provided on the heat insulation sleeve 31.

[0074] It should also be noted that the skeleton assembly 20, the thermal insulation assembly 30, and the neutron source short joint assembly 60 are sequentially connected by screws, so as to strengthen the tight connection between the various parts and avoid displacement and gaps between the various parts.

[0075] As Figure 3 、 Figure 5 shown, in some embodiments, the circuit assembly 40 includes a circuit assembly 44 and two preamplifier circuit modules 42 electrically connected to the circuit assembly 44. The circuit assembly 44 is disposed between the first heat absorber 51 and the second heat absorber 52. The circuit assembly 44 includes a digital-to-analog conversion module 441, a high-voltage power supply module 442, a high-voltage filtering module 444, an analog signal module 445, a spectrum acquisition module 446, a digital processing module 447, a low-voltage power supply module 443, and a first conductive path;

[0076] The digital-to-analog conversion module 441 is used to convert the alternating current input from the external circuit into direct current and output a voltage.

[0077] The high-voltage power supply module 442 is electrically connected to the digital-to-analog conversion module 441. The high-voltage power supply is used to convert the output voltage of the digital-to-analog conversion module 441 into the working voltage of the detector assembly and supply power to the detector assembly through the two preamplifier circuit modules 42.

[0078] The high-voltage filtering module 444 is used to filter the electrical signals output by the detector assembly; the analog signal module 445 is used to amplify the electrical signals processed by the high-voltage filtering module 444; the spectrum acquisition module 446 is used to perform energy spectrum acquisition and amplitude analysis on the electrical signals processed by the analog signal module 445; the digital processing module 447 is used to transmit the electrical signals processed by the spectrum acquisition module 446 to the ground terminal; the low-voltage power supply module 443 is electrically connected to the digital-to-analog conversion module 441, and the low-voltage power supply is used to supply power to the high-voltage filtering module 444, the analog signal module 445, the spectrum acquisition module 446, and the digital processing module 447; a first conductive path is disposed through the first routing hole, and the first conductive path is electrically connected to the first socket assembly 70 to supply electrical energy to the circuit assembly 40; wherein, two preamplifier circuit modules 42 are disposed between the second heat sink 52 and the second end.

[0079] Power is transmitted through the high-voltage power supply module 442 and the low-voltage power supply module 443 respectively, and the power supply mode is more reasonable, effectively controlling power consumption and reducing the heat generated by the operation of the circuit assembly 44, further avoiding the increase in temperature in the insulation cavity. By setting the spectrum acquisition module 446, the accuracy of measurement data is improved. The neutron measurement data of the long-source-distance detector 41 and the short-source-distance detector 43 enter the spectrum acquisition module 446 for analysis, and the analysis results are compared with the temperature calibration structure. When the spectral peak value is too high, a low-point high-voltage control voltage is output to reduce the high-voltage values of the long-source-distance detector 41 and the short-source-distance detector 43. After reducing the high voltage, the measurement data of the long-source-distance detector 41 and the short-source-distance detector 43 are re-analyzed for spectrum, compared, and the high voltage is adjusted until the spectral peak coincides with the calibrated value; when the spectral peak value is too low, a high-point high-voltage control voltage is output to increase the high-voltage values of the long-source-distance detector 41 and the short-source-distance detector 43. After increasing the high voltage, the measurement data of the long-source-distance detector 41 and the short-source-distance detector 43 are re-analyzed for spectrum, compared, and the high voltage is adjusted until the spectral peak coincides with the calibrated value, thereby ensuring the accuracy of neutron measurement data.

[0080] It should be noted that both ends of the circuit assembly 44 are in contact with the first heat sink 51 and the second heat sink 52 respectively.

[0081] It should also be noted that the circuit assembly 44 further includes a circuit board, and the high-voltage power supply module 442, the high-voltage filtering module 444, the analog signal module 445, the spectrum acquisition module 446, the digital processing module 447, and the low-voltage power supply module 443 are all disposed on the circuit board. The specific structures and circuit compositions of each module are prior art and are set according to the corresponding functions, which will not be elaborated in this application;

[0082] For example, the spectrum acquisition module 446 includes a peak detection circuit and an analog-to-digital conversion circuit. The peak detection circuit is used to analyze the amplitude of the signal, and the analog-to-digital conversion circuit is used to convert the electrical signal into a digital signal. The digital processing module 447 includes a microprocessor and a digital-to-analog converter. The microprocessor is used to receive the digital signal and transmit the digital signal to the ground, facilitating the ground to output appropriate control instructions based on the received digital signal. The digital-to-analog converter is used to convert the digital signal into an analog signal. Specifically, after the microprocessor receives the digital signal control instruction sent from the ground, it converts the control instruction into an analog signal through the digital-to-analog converter. The converted analog signal is input into the long-spacing detector 41 and the short-spacing detector 43 to control the long-spacing detector 41 and the short-spacing detector 43.

[0083] It should also be noted that the first conductive path includes but is not limited to wires.

[0084] As Figure 3 , Figure 5 shown, in some embodiments, the detector assembly includes a long-spacing detector 41 and a short-spacing detector 43. One end of the long-spacing detector 41 abuts against the second heat-absorbing member 52 and the other end abuts against two preamplifier circuit modules 42. The long-spacing detector 41 is used to receive the long-source neutron rays in the neutron rays reflected by the formation and convert them into a first current signal. One end of the short-spacing detector 43 abuts against two preamplifier circuit modules 42 and the other end abuts against the second end. The short-spacing detector 43 is used to receive the short-source neutron rays in the neutron rays reflected by the formation and convert them into a second current signal. Among them, the two preamplifier circuit modules 42 are electrically connected to the long-spacing detector 41 and the short-spacing detector 43 respectively.

[0085] It should be noted that both the long-spacing detector 41 and the short-spacing detector 43 are He3 neutron detectors, which have the advantages of high detection efficiency and stability. Their specific structures are prior art and will not be elaborated in this application.

[0086] It should also be noted that the long-spacing detector 41 and the short-spacing detector 43 are respectively electrically connected to the circuit assembly 44. The circuit assembly 44 can control the operation of the long-spacing detector 41 and the short-spacing detector 43 to prevent excessive energy consumption of the long-spacing detector 41 and the short-spacing detector 43, which may affect the operation of the logging tool.

[0087] As Figure 4As shown, in some embodiments, the neutron source short section assembly 60 includes a neutron source chamber 62, a neutron source short section main body 63, and a pull ring 61. The neutron source chamber 62 is used to place a neutron source, which can emit neutron rays. The neutron source short section main body 63 is disposed at one end of the neutron source chamber 62 and is used to transmit neutron rays to the formation. The pull ring 61 is disposed at the end of the neutron source chamber 62 away from the neutron source short section main body 63, and the pull ring 61 is threadedly connected to the pipe body assembly 10. A second socket assembly 80 is provided at the second end, and a second conductive path is provided on the pull ring 61. The conductive path is electrically connected to the second socket assembly 80 to supply electrical energy to the neutron source short section assembly 60.

[0088] By providing the second socket assembly 80 as the power shunt point of the skeleton assembly 20, the connection structure during power supply is simplified, and the problem of the need to set a large number of lines when the skeleton assembly 20 supplies power to the logging tool is avoided. In addition, by receiving power through the second socket assembly 80, the power input can be made more stable, and the normal operation of the neutron source chamber 62 and the neutron source short section main body 63 can be prevented from being affected by power problems.

[0089] It should be noted that the second conductive path includes, but is not limited to, a wire.

[0090] In some embodiments, a strengthening structure is provided inside the neutron source chamber 62.

[0091] As Figure 6 shown, exemplarily, in some embodiments, the strengthening structure includes a thickened chamber wall and a seal 64. By thickening the chamber wall, the neutron source chamber 62 can withstand the high-pressure downhole working pressure, enabling the neutron source chamber 62 to emit neutron rays normally under high-pressure environments. For example, the high pressure is 206 MPa, and the neutron source chamber 62 of the present invention can emit neutron rays normally in an environment of 206 MPa. The seal 64 is disposed at the connection between the neutron source chamber 62 and the neutron source short section main body 63. The seal 64 includes a double O-ring, and this design makes the neutron source chamber 62 have better sealing performance under high pressure, improving the pressure resistance safety factor of the neutron source chamber 62.

[0092] As Figure 1 、 Figure 3 shown, in some embodiments, the pipe body assembly 10 includes a pipe body, a first cap 90, and a second cap 100. The first cap 90 is located at one end of the pipe body, and the first cap 90 is detachably connected to the pipe body. The second cap 100 is located at the end of the pipe body away from the first cap 90, and the second cap 100 is detachably connected to the pipe body. Among them, the pipe body, the first cap 90, and the second cap 100 together form a receiving cavity.

[0093] By providing a first protective cap 90 and a second protective cap 100 to seal the openings at both ends of the pipe body, damage to the interior during transportation and use can be avoided.

[0094] At least one embodiment of the present invention further provides a logging method, which is applied to the logging device described in any of the previous embodiments and includes:

[0095] Lower the logging device to a preset depth in the well.

[0096] Emit neutron rays to the formation through the neutron source subassembly.

[0097] Receive the neutron rays reflected by the formation through the detector assembly and convert the neutron rays into electrical signals.

[0098] Receive the electrical signals through the circuit assembly and transmit them to the ground terminal.

[0099] The logging method provided in this embodiment has all the technical effects brought by the technical solutions of the above embodiments.

[0100] Although the present invention has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A well logging device, characterized in that: include: A tube body assembly, wherein a receiving cavity is provided in the tube body assembly; A heat preservation component is arranged in the accommodating cavity, and a heat preservation cavity is arranged in the heat preservation component; A neutron source short section assembly is arranged in the accommodating chamber, and the neutron source short section assembly is used to emit neutron rays to the formation; A detector assembly is disposed in the heat preservation chamber, and is used to receive the neutron rays reflected by the formation and convert them into electrical signals; as well as A circuit component is arranged in the heat preservation chamber, the circuit component is electrically connected to the detector component, and the circuit component can receive the electrical signal and transmit it to the ground terminal.

2. The well logging device according to claim 1, characterized in that: The thermal insulation component comprises: The thermos bottle has a first end and a second end opposite to each other, the first end is provided with an opening, the second end is closed, and the opening is connected to the heat preservation cavity; A first heat absorbing member is disposed in the thermos bottle; and A second heat absorbing member is disposed in the thermos bottle, wherein a preset distance is formed between the second heat absorbing member and the first heat absorbing member in the axial direction of the thermos bottle; A heat-insulating sleeve, disposed on the first end, the heat-insulating sleeve sealing the opening; Wherein, the circuit component is at least partially disposed between the first heat absorbing member and the second heat absorbing member, and the detector component is disposed between the second heat absorbing member and the second end.

3. The well logging device according to claim 2, characterized in that: The first heat absorbing member is provided with a first wiring hole, and the first wiring hole passes through the first heat absorbing member in the axial direction of the thermos bottle; the second heat absorbing member is provided with a second wiring hole, and the second wiring hole passes through the second heat absorbing member in the axial direction of the thermos bottle.

4. The well logging device according to claim 3, characterized in that: The logging device comprises a skeleton assembly disposed in the accommodating cavity, the skeleton assembly being located on an end of the thermal insulation component away from the neutron source short section assembly, and the skeleton assembly being used for being electrically connected to an external circuit; Wherein, a first socket assembly is disposed on the first end, and the skeleton assembly is electrically connected to the first socket assembly.

5. The well logging device according to claim 4, characterized in that: The circuit assembly includes a circuit assembly and two preamplifier circuit modules electrically connected to the circuit assembly, the circuit assembly is arranged between the first heat sink and the second heat sink, and the circuit assembly includes: A digital-to-analog conversion module, used to convert the alternating current input from the external circuit into direct current and output voltage; A high-voltage power supply module, electrically connected to the digital-to-analog conversion module, the high-voltage power supply is used to convert the output voltage of the digital-to-analog conversion module into the working voltage of the detector assembly, and supply power to the detector assembly through the two preamplifier circuit modules; A high-voltage filter module, used for filtering the electrical signal output by the detector assembly; An analog signal module, used to amplify the electrical signal processed by the high-voltage filter module; A spectrum acquisition module, used for performing energy spectrum acquisition and amplitude analysis on the electrical signal processed by the analog signal module; A digital processing module, used for transmitting the electrical signal processed by the spectrum acquisition module to a ground terminal; a low-voltage power supply module, electrically connected to the digital-to-analog conversion module, the low-voltage power supply being used to supply power to the high-voltage filtering module, the analog signal module, the spectrum acquisition module and the digital processing module; and a first conductive path, passing through the first wiring hole, the first conductive path being electrically connected to the first socket assembly to transmit electrical energy to the circuit assembly; Wherein, the two preamplifier circuit modules are arranged between the second heat absorption component and the second end.

6. The well logging device according to claim 5, characterized in that: The detector assembly comprises: a long source distance detector, one end of which is abutted against the second heat absorbing member and the other end of which is abutted against the two preamplifier circuit modules, the long source distance detector being used to receive the long source neutron rays among the neutron rays reflected by the formation and convert them into a first current signal; and A short source distance detector, one end of which is abutted against the two preamplifier circuit modules and the other end of which is abutted against the second end, the short source distance detector being used to receive the short source neutron rays in the neutron rays reflected by the formation and convert them into a second current signal; The two preamplifier circuit modules are electrically connected to the long source distance detector and the short source distance detector respectively.

7. The well logging device according to any one of claims 2 to 6, characterized in that: The neutron source short section assembly comprises: A neutron source chamber, used for placing a neutron source, the neutron source being capable of emitting the neutron rays; a neutron source short section main body, disposed at one end of the neutron source chamber, the neutron source short section main body being used to transmit the neutron rays to the formation; and A pull ring is arranged at one end of the neutron source compartment away from the main body of the neutron source short section, and the pull ring is threadedly connected to the tube assembly; Wherein, a second socket assembly is arranged on the second end, a second conductive path is arranged on the pull ring, and the conductive path is electrically connected to the second socket assembly to transmit electrical energy to the neutron source short section assembly.

8. The well logging device according to claim 7, characterized in that: A reinforcement structure is arranged in the neutron source chamber.

9. The well logging device according to any one of claims 1 to 6, characterized in that: The pipe body assembly comprises: tube body; A first protective cap is located at one end of the tube body, and the first protective cap is detachably connected to the tube body; A second protective cap is located at an end of the tube body away from the first protective cap, and the second protective cap is detachably connected to the tube body; Wherein, the tube body, the first protective cap and the second protective cap together form the accommodating cavity.

10. A well logging method, applied to the well logging device according to any one of claims 1 to 9, characterized in that: include: Providing the logging device deep into the well to a preset depth; emitting neutron rays to the formation through the neutron source short section assembly; receiving the neutron rays reflected by the formation through the detector assembly and converting the neutron rays into electrical signals; The electrical signal is received by the circuit component and transmitted to the ground terminal.

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