Handheld laser spectrometer and detection method for rapid detection of oil content in on-site cores

Abstract

The invention belongs to the technical field of energy exploration, and particularly relates to a handheld laser spectrometer and a detection method for rapid detection of oil content in on-site cores, comprising a core, a core box, a controller, a handheld detector and an optical cable. The optical cable comprises two optical fibers, namely an input optical fiber and a return optical fiber. Laser reflectors are respectively arranged on the core boxes at both ends of the core. The controller comprises a laser generator, a spectrum analyzer and a distance analyzer. The laser generated by the laser generator is transmitted to the handheld detector through the input optical fiber of the optical cable. The handheld detector comprises a spectroscope A, a spectrum detection port and a distance detection port. The laser is divided into two beams through the spectroscope A, one of which is irradiated to the core from the spectrum detection port to induce the core to generate fluorescence, which is captured by the spectrum detection port. The other beam is emitted from the distance detection port to the laser reflector, and returns to the distance detection port after reflection. The fluorescence and the reflected light of the laser reflector are returned to the inside of the controller through the return optical fiber of the optical cable.

Description

Technical Field

[0001] The invention belongs to the technical field of energy exploration, and in particular relates to a handheld laser spectrometer and a detection method for rapid detection of oil content in on-site cores. Background Art

[0002] In the process of developing oil shale, shale oil and oil-bearing sandstone resources, it is necessary to detect the main component parameters of oil shale samples in real time, such as oil content, TOC and oil-to-weight ratio, in order to evaluate the grade of the reservoir and determine the effective mining rock position. However, the laboratory sample measurement method is still used at present, which is cumbersome, inefficient and cannot meet the needs of rapid and large-scale on-site detection.

[0003] In the past, fluorescence microscopy technology could only take fluorescence photos of prepared thin sections, and the photos provided could not reflect the true oil-bearing properties of the samples. In addition, the grinding process destroyed the contact relationship between the rock skeleton and the oil. The experimental analysis cycle was long, so this technology was not suitable for on-site analysis.

[0004] The fluorescence display of oil-bearing mudstone on the mercury lamp fluorescence logging instrument is extremely weak, so the mercury lamp fluorescence logging instrument cannot detect the oil content of mudstone samples well. Summary of the invention

[0005] In order to solve the problems in the background technology and realize accurate on-site detection of mudstone samples, the present invention provides a handheld laser spectrometer and a detection method for rapid on-site core oil content detection, which are fast and accurate.

[0006] The technical solution provided by the present invention is: a handheld laser spectrometer and a detection method for rapid detection of oil content in a field core, comprising a rapid detection handheld laser spectrometer, the rapid detection handheld laser spectrometer comprising a core and a core box, the core being placed in the core box, and further comprising a controller, a handheld detector and an optical cable, the optical cable comprising two optical fibers, namely an input optical fiber and a return optical fiber, and laser reflection plates perpendicular to the core axis are respectively arranged on the core boxes at both ends of the core;

[0007] The controller includes an internal device and an external device. The internal device includes a laser generator, a spectrum analyzer, a distance analyzer, a beam splitter B, a beam splitter C and a prism. The laser generated by the laser generator is transmitted to a handheld detector through an input optical fiber of an optical cable. The handheld detector includes a beam splitter A, a spectrum detection port and a distance detection port. The laser is divided into two beams through the beam splitter A, one of which is irradiated to the core from the spectrum detection port to induce the core to generate fluorescence, and the fluorescence is captured by the spectrum detection port; the other beam is emitted from the distance detection port to the laser reflection plates at both ends of the core box, and returns to the distance detection port after reflection; the fluorescence and the reflected light of the laser reflection plate are returned to the inside of the controller through the return optical fiber of the optical cable, wherein the fluorescence is finally detected by the spectrum analyzer through the refraction of the beam splitter B, the transmission of the beam splitter C and the scattering of the prism, and the reflected light of the laser reflection plate is finally detected by the distance analyzer through the refraction of the beam splitter B and the refraction of the beam splitter C;

[0008] The external device includes an operation button, a memory and a display; the spectrum analyzer and the distance analyzer are communicatively connected with the memory, so that the detected spectrum signal and distance signal are input into the memory.

[0009] The method for detecting the oil content of core using a rapid detection handheld laser spectrometer includes the following steps:

[0010] a. The controller is connected to an external PC, which is equipped with fluorescence spectrum analysis software. The fluorescence spectrum analysis software establishes the relationship equation between oil content and spectrum;

[0011] b. Turn on the power of the controller so that it can supply power to the power receiving device;

[0012] c. Aim the handheld detector at a certain depth point of the core, and manually input parameters through the operation buttons on the controller panel. The parameters include the core box bottom depth D and the basic information of a single well. The control switch of the handheld detector is triggered to emit a laser beam. The distance S between the detection port and the laser reflector is analyzed by the distance analyzer. S and D are simply added and subtracted by the control operation program to obtain the accurate core depth of the depth point. At the same time, the spectrum analyzer obtains the spectrum signal, and the spectrum signal is analyzed by the software to obtain the oil content parameters of the core at the depth point;

[0013] d. The external PC draws a comprehensive logging diagram of the oil content of the single-well cuttings spectrum and displays it on the monitor.

[0014] A further technical solution is that the internal device of the controller also includes a power supply, and the power supply continuously and stably supplies power to the power receiving device.

[0015] A further technical solution is that a control switch for controlling laser emission is provided on the handheld detector.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention uses laser-induced fluorescence. Because the laser irradiation intensity is strong, the number of molecules excited to the excited state is large, so the fluorescence intensity generated is strong, and the sensitivity during measurement is high. It has been verified that the sensitivity of measuring the properties of substances by laser-induced fluorescence is 2-10 times higher than that measured by fluorescence induced by general light sources. Therefore, the present invention significantly improves the accuracy of oil content detection in cores.

[0018] 2. Since the present invention is provided with a distance analyzer and a laser reflector, the core depth of a single well only needs to be manually input once. When the laser beam is subsequently emitted, the core depth data will be automatically generated, thereby improving the automation degree of the test device and reducing the workload and error probability of manual input. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 It is a schematic diagram of the structure of the internal device of the controller in the present invention.

[0021] Figure 3 It is a schematic diagram of the internal structure of the handheld detector in the present invention.

[0022] In the figure: 1—controller; 2—operation button; 3—display; 4—optical fiber interface; 5—optical cable; 6—laser reflector; 7—core; 8—core box; 9—handheld detector; 10—beam splitter A; 11—distance detection port; 12—spectrum detection port; 13—power supply; 14—laser generator; 15—beam splitter B; 16—beam splitter C; 17—distance analyzer; 18—spectrum analyzer; 19—prism. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0024] The present invention includes a core 7 and a core box 8, wherein the core 7 is placed in the core box 8. The present invention also includes a controller 1, a handheld detector 9 and an optical cable 5, wherein the optical cable 5 includes two optical fibers, namely an input optical fiber and a return optical fiber. The core boxes 8 at both ends of the core 7 are respectively provided with laser reflection plates 6 perpendicular to the axis of the core 7.

[0025] The controller 1 includes an internal device and an external device. The internal device includes a laser generator 14, a spectrum analyzer 18, a distance analyzer 17, a spectroscope B15, a spectroscope C16 and a prism 19. The controller 1 is provided with an optical fiber interface 4 on the outside. The input optical fiber of the optical cable 5 is connected to the optical fiber interface 4 to conduct laser. The laser generated by the laser generator 14 is transmitted to the handheld detector 9 through the input optical fiber of the optical cable 5. The handheld detector 9 includes a spectroscope A10, a spectrum detection port 12 and a distance detection port 11. The laser is divided into two beams by the spectroscope A10, one of which is from the spectrum The detection port 12 irradiates the core 7, inducing the core 7 to generate fluorescence, and the fluorescence is captured by the spectrum detection port 12; another beam is emitted from the distance detection port 11 to the laser reflection plates 6 at both ends of the core box 8, and returns to the distance detection port 11 after reflection; the fluorescence and the reflected light of the laser reflection plate 6 are returned to the inside of the controller 1 through the return optical fiber of the optical cable 5, wherein the fluorescence is refracted by the spectroscope B15, transmitted by the spectroscope C16 and scattered by the prism 19 and finally detected by the spectrum analyzer 18, and the reflected light of the laser reflection plate 6 is refracted by the spectroscope B15 and the spectroscope C16 and finally detected by the distance analyzer 17.

[0026] The external device includes an operation button 2, a memory and a display 3; the spectrum analyzer 18 and the distance analyzer 17 are connected to the memory in communication, so that the detected spectrum signal and distance signal are input into the memory. When there is no external PC involved, the present invention can store a large number of spectrum signals and distance signal groups. The connection and use between the above electrical components are well-known technologies in the industry, which are not within the scope of protection claimed by the present invention and will not be described in detail here.

[0027] In order to make the present invention better adaptable to the use in the case where there is no power supply 13 at the well site, the internal device of the controller 1 also includes a power supply 13, and the power supply 13 is used to continuously and stably supply power to the power receiving device.

[0028] The handheld detector 9 is provided with a control switch for controlling the laser emission, and the light beam is emitted when the control switch is triggered.

[0029] A method for detecting the oil content of a core 7 using a rapid detection handheld laser spectrometer comprises the following steps:

[0030] a. The controller 1 is connected to an external PC in communication. The external PC is installed with fluorescence spectrum analysis software. The fluorescence spectrum analysis software establishes the relationship equation between oil content and spectrum. Software analysis of fluorescence spectrum to measure material characteristics is a prior art and will not be described in detail here.

[0031] b. Turn on the power supply 13 of the controller 1 to power the power receiving device;

[0032] c. The handheld detector 9 is aimed at a certain depth point of the core 7, and the parameters are manually input through the operation button 2 on the panel of the controller 1. The parameters include the bottom depth D of the core box 8 and the basic information of the single well. The control switch of the handheld detector 9 is triggered to emit a laser beam. The distance S between the detection port 11 and the laser reflection plate 6 is analyzed by the distance analyzer 17. S and D are simply added and subtracted by the operation program to obtain the accurate depth of the core 7 at this point. At the same time, the spectrum analyzer 18 obtains the spectrum signal, and the spectrum signal is analyzed by the software to obtain the oil content parameters of the core 7 at this depth. The oil content parameters include oil content, TOC content, S1 and S2 content;

[0033] d. The external PC draws a comprehensive logging diagram of the oil content of the single-well cuttings spectrum and displays it on the display 3.

[0034] From the principle of fluorescence, we know that the molecular fluorescence spectrum has nothing to do with the wavelength of the excitation light source, but is only related to the energy level structure of the fluorescent substance itself. Therefore, the fluorescent substance can be qualitatively analyzed and identified based on the fluorescence spectrum.

[0035] The present invention uses laser-induced fluorescence. Because the laser irradiation intensity is strong, the number of molecules excited to the excited state is large, so the fluorescence intensity generated is strong, and the sensitivity during measurement is high. It has been verified that the sensitivity of measuring the properties of substances by laser-induced fluorescence is 2-10 times higher than that by fluorescence induced by general light sources. Therefore, the present invention significantly improves the accuracy of oil content detection of core 7.

[0036] Each time the handheld detector in the present invention emits a laser beam, a fluorescence signal and a distance signal data are obtained, wherein the fluorescence signal is obtained in the radial direction of the core 7, and the distance signal is obtained in the axial direction of the core 7, and the two are spatially one-to-one corresponding, that is, while the distance analyzer 17 analyzes the distance of the measuring point, the spectrum analyzer 18 analyzes the fluorescence result of the measuring point. Since the present invention is provided with the distance analyzer 17 and the laser reflection plate 6, the depth of the core 7 only needs to be manually input once for a single well, and the depth data of the core 7 will be automatically generated when the laser beam is subsequently emitted, thereby improving the automation degree of the test device and reducing the workload and error probability of manual input.

Claims

1. A method for rapid detection of oil content in a rock core on site using a handheld laser spectrometer, comprising a rapid detection handheld laser spectrometer, the rapid detection handheld laser spectrometer comprising a rock core (7) and a rock core box (8), the rock core (7) being placed in the rock core box (8), characterized in that: It also includes a controller (1), a handheld detector (9) and an optical cable (5), wherein the optical cable (5) includes two optical fibers, namely an input optical fiber and a return optical fiber, and the core boxes (8) at both ends of the core (7) are respectively provided with laser reflection plates (6) perpendicular to the axis of the core (7); The controller (1) includes an internal device and an external device. The internal device includes a laser generator (14), a spectrum analyzer (18), a distance analyzer (17), a spectroscope B (15), a spectroscope C (16) and a prism (19). The laser generated by the laser generator (14) is transmitted to a handheld detector (9) through an input optical fiber of an optical cable (5). The handheld detector (9) includes a spectroscope A (10), a spectrum detection port (12) and a distance detection port (11). The laser is divided into two beams by the spectroscope A (10), one of which is irradiated from the spectrum detection port (12) to the core (7), thereby inducing the core (7) to generate The fluorescence is captured by the spectrum detection port (12); another beam is emitted from the distance detection port (11) to the laser reflection plates (6) at both ends of the core box (8), and returns to the distance detection port (11) after reflection; the fluorescence and the reflected light of the laser reflection plate (6) are returned to the inside of the controller (1) through the return optical fiber of the optical cable (5), wherein the fluorescence is refracted by the beam splitter B (15), transmitted by the beam splitter C (16) and scattered by the prism (19) and finally detected by the spectrum analyzer (18), and the reflected light of the laser reflection plate (6) is refracted by the beam splitter B (15) and refraction by the beam splitter C (16) and finally detected by the distance analyzer (17); The external device comprises an operation button (2), a memory and a display (3); the spectrum analyzer (18) and the distance analyzer (17) are communicatively connected to the memory, so that the detected spectrum signal and distance signal are input into the memory; The method for detecting the oil content of core using a rapid detection handheld laser spectrometer includes the following steps: a. The controller (1) is connected to an external PC for communication. The external PC is installed with fluorescence spectrum analysis software. The fluorescence spectrum analysis software establishes a relationship equation between oil content and spectrum. b. Turn on the power supply (13) of the controller (1) so that it supplies power to the power receiving device; c. The handheld detector (9) is aimed at a certain depth point of the core (7), and parameters are manually input through the operation buttons (2) on the panel of the controller (1), wherein the parameters include the bottom depth D of the core box (8) and basic information of a single well, and the control switch of the handheld detector (9) is triggered to emit a laser beam. The distance S between the distance detection port (11) and the laser reflection plate (6) is analyzed by the distance analyzer (17). S and D are simply added and subtracted by a calculation program to obtain the accurate depth of the core (7) at the depth point. At the same time, the spectrum analyzer (18) obtains the spectrum signal, and the spectrum signal is analyzed by software to obtain the oil content parameters of the core (7) at the depth point; d. The external PC draws a comprehensive logging diagram of the oil content of the single-well cuttings spectrum and displays it on the display (3).

2. The detection method of a handheld laser spectrometer for rapid detection of oil content in on-site cores according to claim 1 is characterized in that: The internal device of the controller (1) further includes a power supply (13), and the power supply (13) continuously and stably supplies power to the power receiving device.

3. The detection method of a handheld laser spectrometer for rapid detection of oil content in on-site cores according to claim 1 is characterized in that: The handheld detector (9) is provided with a control switch for controlling laser emission.

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