CN119198687A - A device and method for measuring organic carbon characteristics of oil and gas reservoir rocks - Google Patents
A device and method for measuring organic carbon characteristics of oil and gas reservoir rocks Download PDFInfo
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Abstract
The invention belongs to the technical field of laser diagnosis and discloses a device and a method for measuring the characteristics of organic carbon of rock of an oil and gas reservoir, wherein the device comprises a LIBS spectrum system and an ultraviolet Raman laser system, the LIBS spectrum system comprises a nanosecond laser, the nanosecond laser is connected with a microscope through a light guide arm, a reflecting surface of a reflecting mirror is connected with the light guide arm, a convex lens is arranged below the reflecting mirror, a detachable spectroscope is arranged above the reflecting mirror, and a CCD (charge coupled device) camera is arranged in the horizontal reflecting direction of the spectroscope. The LIBS spectrum system has simple light path adjustment, and a microscope carrying CCD camera can observe the surface morphology of a sample at any time. According to the method, the LIBS spectrum system and the Raman spectrum equipment are used for measuring the spectrum data of each shale, so that a prediction model of the total organic carbon of the shale is constructed, and the rapid measurement of the total organic carbon of the rock can be realized.
Description
Technical Field
The invention belongs to the technical field of laser diagnosis, and particularly relates to a device and a method for measuring organic carbon characteristics of oil and gas reservoir rocks.
Background
Oil and gas shale can be stored in oil and gas, so that the oil and gas shale has abundant resource reserves and has important significance in the field of energy. Meanwhile, TOC (total organic carbon ) is one of the most important parameters for evaluating shale oil and gas potential, and rapid and accurate determination of shale total organic carbon content is of great significance for evaluating shale oil and gas resource potential and guiding geological dessert optimization. Laser induced breakdown spectroscopy (Laser induced breakdown spectroscopy), abbreviated as LIBS. The technology focuses laser pulse on a sample to generate laser plasma and spectrum emission, and simultaneously utilizes a spectrometer to collect characteristic spectral lines of the plasma emission so as to perform qualitative or quantitative analysis on the sample element types and the content thereof. LIBS has the advantages of simultaneous multi-element analysis, high detection speed, small sample damage and the like, and is widely applied to the fields of metallurgical analysis, mineral identification and the like. Raman spectroscopy is a fast, non-destructive analysis technique. The monochromatic light is incident into the medium and has two different scattering processes, and the Raman spectrum technology analyzes the structure of the substance by the scattered light with the frequency changed, so that the method has the advantages of nondestructive detection, simple pretreatment, small required sample size and the like.
Although the laser spectrum technology represented by LIBS and laser Raman spectrum has great application potential in the detection of the organic components of oil and gas shale, the single laser spectrum detection technology still faces the following technical problems. The LIBS technology is a more mature quantitative analysis method for elements, but because the carbon-containing components in shale are complex, part of carbon elements exist in carbonate in the form of inorganic carbon, and therefore, the LIBS technology is used for lack of a certain amount of theoretical explanation on the organic carbon content of the shale. For raman spectroscopy, the C-C and c=c bonds in the organic carbon component of shale can be characterized by the D and G peaks in the raman spectroscopy, and such characteristic peaks are absent in the carbonate, so that the TOC component in shale can be effectively identified by raman technique. However, since the laser Raman scattering spectrum signal intensity is seriously affected by the optical structure, the fluorescence signal of the shale complex mineral component seriously interferes with the detection of the organic carbon signal, so that the quantitative analysis precision is low.
The system comprises a platform, a laser fiber, a collimating lens, a first reflecting mirror, a near-infrared light source, a beam splitter, a light path converter, a second reflecting mirror and a data processor. The first reflecting mirror and the second reflecting mirror respectively reflect laser and a near infrared light source to a sample on the platform, and the microscope guides the fed back signals to the optical path converter. The patent application enables the combination of a micro raman spectrometer and a near infrared luminescence spectrometer, but does not enable the rapid measurement of the total organic carbon content of rock or rock soil.
Disclosure of Invention
In order to overcome the problems in the prior art, the invention aims to provide a device and a method for measuring the characteristics of organic carbon of oil and gas reservoir rock, wherein the device comprises a LIBS spectrum system and an ultraviolet Raman laser system, and the shale is evaluated and analyzed by utilizing a spectrum technology, and the measurement of the total organic carbon of a sample is realized by combining a laser-induced breakdown spectrum and a Raman spectrum.
In order to achieve the above purpose, the invention adopts the following technical scheme:
The device for measuring the organic carbon characteristics of the oil and gas reservoir rock comprises a LIBS spectrum system and an ultraviolet Raman laser system, wherein the LIBS spectrum system comprises a nanosecond laser, the nanosecond laser is connected with a microscope through a light guide arm, the microscope comprises a reflecting mirror, a reflecting surface of the reflecting mirror is connected with the light guide arm, a convex lens is arranged below the reflecting mirror, a detachable spectroscope is arranged above the reflecting mirror, an eyepiece is arranged above the spectroscope, a CCD camera is arranged in the horizontal reflecting direction of the spectroscope, a LIBS probe is arranged beside a focus of the convex lens, one end of the LIBS probe faces to a focus of the convex lens, the other end of the LIBS probe is connected with a multichannel spectrometer, and a three-dimensional moving platform is arranged below the convex lens.
Optionally, the multichannel spectrometer is in communication connection with a time sequence controller, the time sequence controller is in communication connection with a computer, the time sequence controller is in communication connection with the nanosecond laser, and the three-dimensional mobile platform is in communication connection with the computer.
Optionally, the eyepiece, the reflection point of the spectroscope, the reflection point of the reflector and the focal point of the convex lens are arranged in the same straight line direction.
Optionally, a collimating lens probe is disposed on a side of the LIBS probe close to the focal point of the convex lens, and a focusing lens probe is disposed on a side of the LIBS probe far from the focal point of the convex lens.
Optionally, the LIBS probe is connected to the multichannel spectrometer by a split multi-ray.
The application method of the device for measuring the rock organic carbon characteristics of the oil and gas reservoir comprises the following steps:
S1, acquiring LIBS spectrum of a sample through a LIBS spectrum system, and acquiring Raman spectrum of the sample through an ultraviolet Raman laser system;
s2, fusing LIBS spectrum and Raman spectrum data by adopting a dimension reduction algorithm to obtain spectrum fusion data;
and S3, taking the spectrum fusion data as an input variable, and establishing a quantitative analysis model of the total organic carbon content to predict the TOC content of the rock.
Optionally, prior to step S1, the detection spectral response efficiency of the multichannel spectrometer is calibrated.
Optionally, before step S2, the LIBS spectrum and raman spectrum data of the sample are normalized respectively.
Optionally, in step S2, PLS latent variables of LIBS spectrum data and raman spectrum data are extracted respectively, and the two kinds of latent variable data are spliced, so that the contribution rate of the latent variables is ensured to be higher than 95%.
Optionally, in step S2, a principal component analysis method is used to fuse the LIBS spectrum with the raman spectrum data.
Compared with the prior art, the invention has the following beneficial effects:
The LIBS spectrum system has the advantages that the laser outputs laser through the light guide arm, the light path is simple to adjust, the microscope is provided with the CCD camera, the surface morphology of a sample can be observed at any time, the lens distance of the sample can be controlled by combining with the displacement platform, the LIBS probe is used for focusing towards the convex lens, the lateral light receiving can be realized, the loss of ultraviolet wave bands in the objective lens and the dichroic mirror during axial light receiving can be avoided, the light path structure of the microscopic LIBS spectrum system is stable, the spectrum fluctuation caused by factors such as vibration is avoided, and the influence of fluorescence can be avoided by using the ultraviolet Raman laser system. The three-dimensional displacement platform can be used for controlling movement of the sample, and automatic scanning can be realized by combining a control system.
According to the invention, the LIBS spectrum system and the Raman spectrum equipment are used for measuring the spectrum data of each shale, and the corresponding data preprocessing is carried out on the spectrum data. And respectively extracting PLS latent variables, then carrying out data fusion, and constructing a prediction model of the total organic carbon of the shale by combining a PLSR algorithm to realize the measurement of the total organic carbon of the shale.
The invention combines the Raman spectrum technology and the laser-induced breakdown spectrum technology, performs data fusion on the basis of the traditional spectrum measurement technology, combines a machine learning algorithm, solves the difficulty in measuring the total organic carbon content of shale, and provides a method for evaluating the properties and the compositions of oil and gas rocks.
The method disclosed by the invention combines two laser spectrums to establish a quantitative analysis model of the total organic carbon content of shale, integrates the advantages of the two technologies, overcomes the defects of the two laser spectrum technologies to a certain extent, can realize rapid measurement of the total organic carbon content of rock or rock soil, and is lower in detection time cost and capable of realizing in-situ detection without complex pickling pretreatment and continuous heating process in detection compared with the conventional detection method.
Drawings
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, proportional sizes, and the like of the respective components in the drawings are merely illustrative for aiding in understanding the present invention, and are not particularly limited. In the drawings:
FIG. 1 is a method for measuring the total organic carbon content of oil and gas shale based on the fusion of a laser induced breakdown spectroscopy technology and a laser Raman spectroscopy technology;
FIG. 2 is a block diagram of an apparatus employing the LIBS spectroscopic system of the present invention;
FIG. 3 is a graph of a typical LIBS spectrum collected using the present invention experiment;
FIG. 4 is a typical Raman spectrum collected by the experiment of the present invention;
FIG. 5 is a graph showing the results of quantitative analysis of shale TOC obtained by the application of the present invention;
The device comprises a nanosecond laser, a light guide arm, a microscope, a CCD camera, a spectroscope, an eyepiece, a reflector, a convex lens, a three-dimensional moving platform, a stage, a LIBS probe, a collimating lens probe, a focusing lens probe, a multichannel spectrometer, a time sequence controller, a computer and a computer, wherein the light guide arm, the CCD camera, the microscope, the eyepiece, the spectroscope, the eyepiece, the reflector, the convex lens, the three-dimensional moving platform, the objective table, the LIBS probe, the collimating lens probe, the focusing lens probe, the multichannel spectrometer, the time sequence controller and the computer, and the time sequence controller.
Detailed Description
In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, shall fall within the scope of the invention.
It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
The present invention will be described in detail with reference to the accompanying drawings.
As shown in fig. 1, the device for measuring the organic carbon characteristics of the oil and gas reservoir rock comprises a LIBS spectrum system and an ultraviolet Raman laser system, wherein the LIBS spectrum system comprises a nanosecond laser 1, the nanosecond laser 1 is connected with a microscope 3 through a light guide arm 2, the microscope 3 comprises a reflecting mirror 31, a reflecting surface of the reflecting mirror 31 is connected with the light guide arm 2, a convex lens 32 is arranged below the reflecting mirror 31, a detachable spectroscope 302 is arranged above the reflecting mirror 31, a LIBS probe 4 is arranged beside a focal point of the convex lens 32, one end of the LIBS probe 4 faces to a focal point of the convex lens 32, the other end of the LIBS probe is connected with a multichannel spectrometer 5, a three-dimensional moving platform 33 is arranged below the convex lens 32, and the three-dimensional moving platform 33 is in communication connection with a computer 7.
The beam splitter 303 forms an angle of 45 degrees with the horizontal direction. When the beam splitter 302 is installed in the microscope 3, half of the light propagates upward in the original direction, and the other half is reflected horizontally. A CCD camera 301 is provided in the horizontal reflected light direction of the spectroscope 302, and an eyepiece 303 is provided in the vertical radiated light direction of the spectroscope 302.
When the spectroscope 302 is not installed, all light propagates into the eyepiece 303 in the original vertical direction, at which point the sample surface topography can be clearly observed in the eyepiece 303. When the beam splitter 302 is installed, half of the light level is reflected into the CCD camera 301, at which point the sample surface topography can be observed by the CCD camera 301.
The application method of the device for measuring the rock organic carbon characteristics of the oil and gas reservoir comprises the following steps:
S1, acquiring LIBS spectrum of a sample through a LIBS spectrum system, and acquiring Raman spectrum of the sample through an ultraviolet Raman laser system;
s2, fusing LIBS spectrum and Raman spectrum data by adopting a dimension reduction algorithm to obtain spectrum fusion data;
And S3, taking the spectrum fusion data as an input variable, and establishing a total organic carbon content quantitative analysis model to predict the TOC content of the shale.
The method disclosed by the invention combines two laser spectrums to establish a quantitative analysis model of the total organic carbon content of shale, integrates the advantages of the two technologies, can realize rapid measurement of the total organic carbon content of shale, and is low in detection time cost and capable of realizing in-situ detection without complex pickling pretreatment and continuous heating process in detection compared with a conventional detection method.
Example 1
The invention discloses a use method of a device for measuring organic carbon characteristics of oil and gas reservoir rock, which specifically comprises the following steps:
and step one, a LIBS experiment system is completely built.
The device for measuring the organic carbon characteristics of the oil and gas reservoir rock comprises a LIBS spectrum system and an ultraviolet Raman laser system, wherein the LIBS spectrum system comprises a nanosecond laser 1, and the nanosecond laser 1 is connected with a microscope 3 through a light guide arm 2.
Specifically, the ultraviolet Raman laser system adopts a Zhuo Lihan-light RTS-mini confocal Raman microscopic system. The laser is a 325nm ultraviolet continuous laser, and the nominal power is 200mW. The magnification treatment was performed with a short working distance lens (40 times), and the spot diameter of the laser light was about 5 μm. The RTS-mini confocal Raman microscope system can control a spectrometer, acquire spectrum data and analyze spectrum.
The main factor determining whether the raman system can be applied in this patent is the wavelength of the laser. In raman spectroscopy, when a sample is irradiated with excitation light, fluorescence may be generated in addition to raman scattered light, and raman detection at a suitable excitation wavelength is effective to avoid the influence of fluorescence. The raman spectrum under the ultraviolet laser is least influenced by fluorescence, but the raman spectrum under the excitation of the wavelength of 532nm, 633nm and 785nm is very seriously influenced by fluorescence, which can cause the raman spectrum to be covered, but due to the limited equipment, the accurate laser wavelength application range is difficult to determine.
The microscope 3 includes a reflecting mirror 31, a reflecting surface of the reflecting mirror 31 is connected to the light guiding arm 2, and the reflecting mirror 31 is provided with a convex lens 32 in a reflecting direction of the light emitted by the light guiding arm 2.
Specifically, the light guiding arm 2 is horizontally disposed, an included angle of 45 ° is formed between the reflecting mirror 31 and the horizontal plane, and the convex lens 32 is disposed right below the reflecting mirror 31.
A detachable spectroscope 302 is installed right above the reflecting mirror 31, an eyepiece 303 is arranged right above the spectroscope 302, a CCD camera 301 is arranged in the horizontal reflecting direction of the spectroscope 302, and the CCD camera 301 faces the spectroscope 302.
The LIBS probe 4 is arranged beside the focal point of the convex lens 32, one end of the LIBS probe 4 faces the focal point of the convex lens 32, and the other end of the LIBS probe is connected with the multichannel spectrometer 5.
The multichannel spectrometer 5 is in communication connection with a time sequence controller 6, the time sequence controller 6 is in communication connection with a computer 7, and the time sequence controller 6 is in communication connection with the nanosecond laser 1. The LIBS probe 4 is connected with the multichannel spectrometer 5 through one-to-many rays.
The nanosecond laser 1 is connected with the light guide arm 2, the other end of the light guide arm 2 is connected with the microscope 3, laser is focused on the surface of a sample through the reflecting mirror 31 and the convex lens 32, and meanwhile, characteristic spectral lines emitted by plasma are transmitted back to the spectrometer by the self-made LIBS probe for analysis, and the collimating lens and the focusing lens probe are integrated in the probe.
Optionally, an objective table 34 is disposed on the focal point of the convex lens 32, and a three-dimensional moving platform 33 is disposed below the objective table, and the three-dimensional moving platform 33 is communicatively connected to the computer 7. The three-dimensional displacement stage 33 is capable of controlling the movement of the sample.
For LIBS quantitative analysis, the distance (the mirror distance) from the focusing lens to the surface of the sample is different due to the different thickness of the sample when the sample is replaced, so that the light spot size is different. And the quantitative result is seriously affected by the different sizes of the light spots. When the sample is replaced, focusing of the sample can be achieved by controlling the motion of the Z axis and combining with a CCD camera 301 (Charge-coupled Device) mounted in a microscope, so that the consistency of the sample distance of the lens is ensured, the fluctuation of a spectrum is reduced, and the quantitative effect is improved.
In the experiment, multiple target shooting is needed on the surface of a sample, the X axis and the Y axis can be moved to realize point changing, and the CCD camera (301) is matched to avoid laser shooting into an ablation pit.
The LIBS probe 4 is provided with a collimator lens probe 41 on a side close to the focal point of the convex lens 32, and a focusing lens probe 42 on a side far from the focal point of the convex lens 32.
The LIBS probe 4 needs to be collimated and focused, and the laser beam may be affected by various factors including air disturbance and micro defects of optical elements in the propagation process, so that the quality of the beam is reduced, and the problems of increased divergence angle and light spot deformation occur. The laser beam is collimated by the collimating lens probe 41, so that the laser beam can maintain higher parallelism and smaller divergence angle during transmission, and the quality of the laser beam can be improved.
After passing through the collimating lens probe 41, the laser ensures the collimation, and then passes through the focusing lens probe 42 to achieve the purpose of focusing, and the high-power pulse laser is focused on the surface of the sample to induce plasma.
The method comprises the steps of respectively targeting M shale samples, receiving characteristic spectral lines emitted by transient plasmas by using a spectrometer, uniformly targeting the same sample on the surface of the sample for N times, pre-treating the surface of the sample to be detected by pre-etching 5 times for each targeting, and accumulating the influence of the target 20 on the reduction of spectrum uncertainty after pre-ablation.
And step two, correcting the response efficiency of the LIBS spectrum system. And connecting the optical fiber to a standard light source for calibrating the response efficiency of the whole spectrum system, repeatedly measuring for 5 times, taking an average to establish a response function of the standard light source, namely, detecting the ratio of the spectrum to the standard spectrum provided by a manufacturer with respect to the wavelength, and dividing spectrum data obtained by subsequent experiments to realize the correction of the response efficiency of the spectrum system.
And thirdly, preprocessing LIBS spectrum data. And processing the recorded spectrum data, and intercepting the spectrum data of 30 pixel points left and right of the characteristic spectral lines of carbon atoms with the distances of 193.09nm and 247.86 nm. A total of 124 data points were obtained and the average spectral intensity was calculated. And then carrying out mean normalization processing on the data so as to improve the calculation efficiency and the model precision.
And step four, acquiring Raman spectra of the shale sample by using an ultraviolet Raman laser system. The incident laser uses a 325nm ultraviolet laser to attenuate the effects of fluorescence. The integration time is set to 2s, and M shale samples are respectively targeted, and the same sample is uniformly targeted on the surface of the sample for N times, so that the measured spectrum is more representative.
And fifthly, preprocessing Raman spectrum data. For each spectrum, the baseline correction is carried out on the spectrum to smooth the fluorescent background, cosmic rays are eliminated, and finally D-peaks and G peaks (1350 cm < -1 >, 1580cm < -1 >) of the carbon atom crystal are extracted as characteristic spectral lines. Similarly, spectral data of about 30 pixels each from the vicinity of the characteristic spectral lines (1350 cm-1, 1580 cm-1) are taken. A total of 124 data points were obtained and the average spectral intensity was calculated. And then carrying out mean value normalization processing on the data.
And step six, reducing the dimension of the spectrum data and fusing the data. And respectively extracting PLS (PARTIAL LEAST square least square) latent variables of LIBS spectrum and Raman spectrum data, ensuring that the contribution rate of the latent variables is higher than 95% by controlling the number of the selected latent variables, respectively obtaining a latent variables and b latent variables, and splicing the obtained latent variable data to obtain spectrum fusion data so as to realize data dimension reduction and improve prediction precision. The selection of the number of latent variables is comprehensively selected by the evaluation index of the quantitative analysis model established in the step seven.
Optionally, the LIBS spectra are fused with raman spectral data using a principal component analysis method. And respectively extracting principal components of PCA of LIBS spectrum and Raman spectrum data, ensuring that the accumulated contribution rate of the principal components is higher than 95% by controlling the number of the selected principal components, respectively obtaining a latent principal components and b principal components, and splicing the obtained principal component data to obtain spectrum fusion data so as to realize data dimension reduction and improve prediction precision.
And step seven, establishing a shale total organic carbon content quantitative analysis model. And taking the obtained spectrum fusion data as an input variable, and carrying out predictive analysis on the TOC content of the shale by using a PLSR regression algorithm.
And respectively constructing quantitative analysis models by selecting different latent variable numbers, evaluating the models by using a leave-one-out method cross verification, calculating cross verification root mean square errors of different models, and selecting the model with the smallest cross verification root mean square error to avoid overfitting of the models and improve generalization capability of the quantitative analysis models. The quantitative analysis model can be established by using a Support Vector Machine (SVM) and a Random Forest (RF) algorithm according to different conditions.
The integration time of the Raman experiment is determined according to the target material, the obvious spectral characteristics are identified, and meanwhile, the total organic carbon is an important parameter for evaluating the oil and gas potential of the shale, so that the method has important significance for rapidly and accurately measuring the total organic carbon content of the shale.
Example 2
As shown in FIG. 2, the laser used in the LIBS experiment of the embodiment is an Nd-YAG laser with a pulse width of 8ns, the wavelength of 1064nm, the laser energy of 16mJ/pulse and the repetition frequency of 5Hz, the nanosecond laser is connected with a light guide arm, the other end of the light guide arm is connected with a microscope system, laser is focused on the surface of a sample through a reflector and a lens, and simultaneously, characteristic spectral lines emitted by plasma are transmitted back to a spectrometer by a self-made LIBS probe for analysis, and a collimating lens and a focusing lens probe are integrated in the probe. 5 shots are shot per shot, and 20 shots are shot after the shot. The exposure time of the spectrometer was 2ms and the detection delay was 800ns.
The LIBS spectrum system changes the laser path through a reflector, and then focuses nanosecond pulse laser on the surface of a sample through a lens to generate plasma. The emission line of the plasma is laterally received by a self-made LIBS probe and is transmitted back to a spectrometer for analysis through a one-to-many optical fibers.
The raman experiment of this example used an RTS-mini confocal raman microscopy system manufactured by Zhuo Lihan optical company. The excitation source was provided by a gas laser emitting 325nm radiation, amplified with a short working distance lens (40×), the spot diameter of the laser was about 5 μm, and the objective lens was at an optical power of about 2mW. The matched software is used for controlling the spectrometer, acquiring spectrum data and analyzing the spectrum.
The target used in the embodiment is an oil gas shale sample which is collected in 7 sections of a certain basin extension group length, 15 samples are collected, classified and crushed, the powdery samples are ground and then pass through a 200-mesh sieve so as to reduce the non-uniformity, and a part of fine powder is pressed for 3 minutes under the pressure of 30MPa to prepare a sheet sample. And three samples were selected as the validation sample set.
The resulting LIBS spectra and raman spectra are shown in fig. 3 and 4 for each sample. And then, respectively carrying out spectrum pretreatment, then intercepting corresponding characteristic spectral line data, carrying out mean value normalization treatment, respectively extracting 5 PLS latent variables of LIBS spectrum data and Raman spectrum data, and then carrying out data splicing. And taking the obtained spectrum fusion data as an input variable, and carrying out predictive analysis on the TOC content of the shale by using a PLSR regression algorithm.
2 Latent variables are selected to construct a quantitative analysis model, and TOC calibration results and prediction results are shown in FIG. 5. The determination coefficient, the calibration root mean square error and the prediction root mean square error of the model and the values of the cross verification root mean square error are 0.9966, 0.1480, 0.1420 and 0.3776 respectively, which indicate that the method can be used for extracting enough spectrum information and providing acceptable prediction results, and has good robustness and stability.
The device elements in the above embodiments are conventional device elements unless otherwise specified, and the structural arrangement, operation or control modes in the embodiments are conventional arrangement, operation or control modes in the art unless otherwise specified.
Finally, it is noted that the above-mentioned embodiments are merely for illustrating the technical solution of the present invention, and that other modifications and equivalents thereof by those skilled in the art should be included in the scope of the claims of the present invention without departing from the spirit and scope of the technical solution of the present invention.
Claims (10)
1. The device for measuring the organic carbon characteristics of the oil and gas reservoir rock is characterized by comprising a LIBS spectrum system and an ultraviolet Raman laser system, wherein the LIBS spectrum system comprises a nanosecond laser (1), the nanosecond laser (1) is connected with a microscope (3) through a light guide arm (2), the microscope (3) comprises a reflecting mirror (31), a reflecting surface of the reflecting mirror (31) is connected with the light guide arm (2), a convex lens (32) is arranged below the reflecting mirror (31), a detachable spectroscope (302) is arranged above the reflecting mirror (31), an eyepiece (303) is arranged above the spectroscope (302), a camera (301) is arranged in the horizontal reflecting direction of the spectroscope (302), a LIBS probe (4) is arranged beside a focal point of the convex lens (32), one end of the LIBS probe (4) faces a focal point of the convex lens (32), the other end of the LIBS probe is connected with a multichannel spectrometer (5), and a three-dimensional platform (33) is arranged below the convex lens (32).
2. An apparatus for measuring organic carbon characteristics of hydrocarbon reservoir rock according to claim 1, wherein the multi-channel spectrometer (5) is communicatively connected to a timing controller (6), the timing controller (6) is communicatively connected to a computer (7), and the timing controller (6) is communicatively connected to the nanosecond laser (1), and the three-dimensional mobile platform (33) is communicatively connected to the computer (7).
3. The device for measuring organic carbon characteristics of oil and gas reservoir rock according to claim 1, wherein the ocular (303), the reflecting point of the beam splitter (302), the reflecting point of the reflecting mirror (31) and the focal point of the convex lens (32) are arranged in the same straight line direction.
4. Device for measuring organic carbon characteristics of hydrocarbon reservoir rock according to claim 1, characterized in that the LIBS probe (4) is provided with a collimator lens probe (41) on the side close to the focal point of the convex lens (32) and a focusing lens probe (42) on the side remote from the focal point of the convex lens (32).
5. An apparatus for measuring organic carbon characteristics of hydrocarbon reservoir rock as claimed in claim 1, wherein said LIBS probe (4) is connected to said multi-channel spectrometer (5) by means of a split multi-light.
6. A method of using the apparatus for measuring organic carbon characteristics of hydrocarbon reservoir rock as claimed in any one of claims 1 to 5, comprising the steps of:
S1, acquiring LIBS spectrum of a sample through a LIBS spectrum system, and acquiring Raman spectrum of the sample through an ultraviolet Raman laser system;
s2, fusing LIBS spectrum and Raman spectrum data by adopting a dimension reduction algorithm to obtain spectrum fusion data;
and S3, taking the spectrum fusion data as an input variable, and establishing a quantitative analysis model of the total organic carbon content to predict the TOC content of the rock.
7. The method of using a device for measuring organic carbon characteristics of hydrocarbon reservoir rock as claimed in claim 6, wherein prior to step S1, the detection spectral response efficiency of the multi-channel spectrometer (5) is calibrated.
8. The method of claim 6, wherein before step S2, the LIBS spectrum and raman spectrum data of the sample are normalized, respectively.
9. The method according to claim 6, wherein in step S2, PLS latent variables of LIBS spectrum and raman spectrum data are extracted, and the two kinds of latent variable data are spliced to ensure that the contribution rate of the latent variables is higher than 95%.
10. The method of using a device for measuring organic carbon characteristics of hydrocarbon reservoir rock as defined in claim 6, wherein in step S2, a principal component analysis method is used to fuse LIBS spectrum data with raman spectrum data.
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