Method for determining material source information of sandstone

Abstract

The invention relates to a method for determining material source information of sandstone. The sandstone source information determination method comprises the following steps: acquiring sandstone, and separating first zircon particles from the sandstone; grinding and polishing the first zircon particles to obtain second zircon particles; performing imaging processing on the second zircon particles to determine internal fissure development characteristics and magma rhythm annulus development characteristics of the second zircon particles; third zircon particles are screened out from the second zircon particles based on the internal fracture development characteristics and magma rhythm annulus development characteristics of the second zircon particles; performing laser ablation treatment on the third zircon particles, and determining age information of the third zircon particles; and determining the material source information of the sandstone according to the age information of the third zircon particles.

Description

Technical Field

[0001] The present invention relates to the technical field of rock stratum detection, and particularly to a method for determining provenance information of sandstone. Background Art

[0002] In related technologies, the commonly used methods for provenance research mainly include the analysis of the characteristics of heavy and light minerals in clastic rocks and the chemical analysis of rock elements, etc. However, the above methods all have problems such as low discrimination accuracy and strong multiple solutions due to the inability to understand the characteristics of the source rock area.

[0003] Therefore, when analyzing the provenance of basin sandstone, how to improve the accuracy of tracing provenance by traditional methods is an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the present invention provides a method for determining provenance information of sandstone.

[0005] Specifically, the present invention is implemented by the following technical solutions:

[0006] According to the first aspect of the present invention, there is provided a method for determining provenance information of sandstone.

[0007] In view of this, according to the first aspect of the present invention, there is provided a method for determining provenance information of sandstone, including: obtaining sandstone, and separating first zircon grains from the sandstone; grinding and polishing the first zircon grains to obtain second zircon grains; performing imaging processing on the second zircon grains to determine the internal crack development characteristics and magmatic rhythmic zoning development characteristics of the second zircon grains; screening out third zircon grains from the second zircon grains based on the internal crack development characteristics and magmatic rhythmic zoning development characteristics of the second zircon grains; performing laser ablation treatment on the third zircon grains to determine the age information of the third zircon grains; and determining the provenance information of the sandstone according to the age information of the third zircon grains.

[0008] The method for determining the provenance information of sandstone provided by the present invention first obtains sandstone at the target layer of the target well, and then crushes and selects the sandstone to screen out the first zircon grains from the debris of the sandstone, that is, the zircon grains separated from the sandstone debris. Then, the first zircon grains are polished to obtain the second zircon grains. The first zircon grains after polishing are the second zircon grains. Through the polishing process, it is beneficial to expose the interior of the zircon grains for observing the development characteristics. Further, the second zircon grains are photographed to obtain the development characteristics of internal fissures in the zircon in the photo, and at the same time, the development characteristics of magmatic rhythmic zonation are also obtained in the photo to facilitate observing the development of its magmatic rhythmic zonation. Then, by selecting the second zircon grains with undeveloped internal fissure development characteristics and relatively developed magmatic rhythmic zonation, after the above screening process, the selected second zircon grains are used as the third zircon grains, and the third zircon grains are subjected to laser ablation treatment. Specifically, the laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) technology is used for zircon U-Pb (uranium-lead) geochronological analysis. By measuring the uranium and lead (U-Pb) isotope composition in the third zircon grains, the dating work is completed, which is also called U-Pb dating, a method for determining the age of zircon by using the radioactive decay relationship between uranium and lead in zircon crystals. Through this method, the age information of the third zircon grains is determined, and based on the age information of the third zircon grains, the provenance information of the sandstone is determined, effectively overcoming the uncertainty of provenance analysis using traditional heavy minerals and rock element chemistry and other means, and improving the accuracy of provenance analysis.

[0009] It can be understood that the parent rock, that is, the rock, is an aggregate of one or several rocks, which is the rock that supplies clastic materials during the deposition process of sandstone. As a common heavy mineral in sandstone, zircon has stable properties, and the age information it records is less likely to be reset and changed during the transportation and deposition process, and can retain and reflect the age characteristics of the parent rock area. On the basis of fully understanding the age characteristics of the parent rock in the provenance area around the basin, the characteristics and changes of the source-sink system of sandstone reservoirs in different horizons can be inverted, the transportation and deposition process of clastic materials can be understood, so as to predict the distribution of sand bodies and sedimentary facies characteristics, achieve fine research and evaluation of sand bodies, and provide solid basic data support for oil and gas exploration and development. At the same time, the method of obtaining the zircon age information in sandstone debris by LA-ICP-MS technology for zircon U-Pb dating is both efficient and very convenient. Therefore, while overcoming the problem of low accuracy of provenance tracing by traditional methods and improving the accuracy of provenance analysis, the efficiency and convenience of provenance analysis are also improved.

[0010] In addition, based on the method proposed in the present invention, provenance analysis of sandstone can be carried out under the framework of the fifth-order depositional sequence, meeting the requirements of fine exploration of current oilfields. At the same time, combined with paleogeomorphic characterization, the source-sink characteristics of sandstone in the target layer can be comprehensively analyzed, the sedimentation process can be understood, the spatial distribution characteristics of sandstone bodies can be predicted, the exploration risk can be reduced, and the drilling success rate can be improved.

[0011] In addition, the method for determining the provenance information of sandstone in the above technical solution provided by the present invention may further have the following additional technical features:

[0012] In the above technical solution, further, the step of determining the age information of the third zircon particle by performing laser ablation treatment on the third zircon particle specifically includes: performing laser ablation treatment on the third zircon particle by a laser ablation inductively coupled plasma mass spectrometer to determine the age information of the third zircon particle.

[0013] In this technical solution, laser ablation inductively coupled plasma mass spectrometry is used for zircon U-Pb geochronology analysis to obtain the age information of the third zircon particle. Based on the development and maturity of laser ablation inductively coupled plasma mass spectrometry technology, it is becoming more and more efficient and convenient to obtain zircon age information in sandstone through LA-ICP-MS U-Pb dating. Therefore, the efficiency and convenience of analyzing zircon age information are improved.

[0014] In the above technical solution, further, the step of determining the provenance information of sandstone according to the age information of the third zircon particle specifically includes: obtaining the age information of the sandstone's parent rock; comparing the age information of the sandstone's parent rock with the age information of the third zircon, and determining the provenance information of the sandstone according to the comparison result.

[0015] In this technical solution, the age information of the sandstone's parent rock is obtained by understanding the age characteristics of the parent rock in the potential provenance areas of the basin. Based on the obtained age information of the sandstone's parent rock and zircon U-Pb dating by LA-ICP-MS technology to obtain zircon age information in sandstone for comparison, and using the iconic characteristic age peaks to determine the provenance information of the sandstone, and then determine the potential provenance areas of the sandstone in the target layer.

[0016] In the above technical solution, further, the step of obtaining the age information of the sandstone's parent rock specifically includes: determining the spatial distribution characteristics of the potential provenance areas around and inside the basin and the age information of the sandstone's parent rock according to geological data.

[0017] In this technical solution, when obtaining the age information of the sandstone's parent rock, the spatial distribution characteristics and the age information of the parent rock of the potential provenance areas around and inside the basin can be determined by collecting relevant geological data and relevant research results. By understanding the age information of the sandstone's parent rock, strong evidence is provided for determining the provenance information of the sandstone.

[0018] In the above technical solution, further, the step of performing imaging processing on the second zircon particle to obtain the internal crack development characteristics of the second zircon particle and the development characteristics of the magmatic rhythmic zonation of the second zircon particle specifically includes: performing transmitted light imaging and reflected light imaging processing on the second zircon particle to determine the surface morphological characteristics and internal crack development characteristics of the second zircon particle.

[0019] In this technical solution, transmitted light and reflected light photography are performed on the second zircon particle to obtain the surface morphological characteristics and internal crack development characteristics of the second zircon particle. Through the above imaging processing, it is convenient to observe the internal crack development characteristics of the second zircon particle, and thus a foundation is laid for selecting zircon particles without developed internal cracks, improving the accuracy of provenance analysis.

[0020] In the above technical solution, further, the step of performing imaging processing on the second zircon particle to obtain the internal crack development characteristics of the second zircon particle and the development characteristics of the magmatic rhythmic zonation of the second zircon particle specifically includes: performing cathodoluminescence imaging processing on the second zircon particle to determine the development characteristics of the magmatic rhythmic zonation of the second zircon particle.

[0021] In this technical solution, transmitted light and reflected light photography are performed on the second zircon particle to obtain the surface morphological characteristics and internal crack development characteristics of the second zircon particle. Through imaging inspection, it is convenient to observe the development characteristics of the magmatic rhythmic zonation of the second zircon particle, and thus understand the development of the magmatic rhythmic zonation, thereby improving the accuracy of provenance analysis.

[0022] Specifically, cathodoluminescence imaging inspection is performed by a scanning electron microscope with a cathode probe to observe the growth zonation characteristics of zircon particles to inspect the homogeneous composition and its magmatic growth pattern;

[0023] In the above technical solution, further, the step of performing cathodoluminescence imaging processing on the second zircon particle further includes: determining the dotting position based on the image information of the third zircon particle generated by performing cathodoluminescence imaging processing on the second zircon particle, and performing laser ablation processing on the third zircon particle based on the dotting position.

[0024] In this technical solution, when performing cathodoluminescence imaging processing on the second zircon particle, the dotting position to be marked when performing laser ablation dating processing on the third zircon particle is determined based on the image information of the third zircon particle generated, improving the determination of the dotting position, which is beneficial to improving the accuracy of laser ablation dating processing.

[0025] In the above technical solution, further, the steps of obtaining sandstone and separating the first zircon particles from the sandstone specifically include: crushing the sandstone to obtain sandstone debris; performing magnetic separation, flotation, and microscopic observation on the sandstone debris to screen out the first zircon particles from the sandstone debris.

[0026] In this technical solution, the sandstone is crushed to obtain sandstone debris. By crushing, the overall structure of the sandstone can be broken, facilitating the exclusion of other substances. Further, magnetic separation, flotation, and manual microscopic observation are performed on the obtained sandstone debris to screen out the first zircon particles therein. The first zircon particles obtained through the above screening method have high screening efficiency and high accuracy, and can avoid waste caused by unselected zircon particles.

[0027] In the above technical solution, further, before performing the steps of grinding and polishing the first zircon particles to obtain the second zircon particles, it further includes: adhering the first zircon particles to an epoxy resin plastic target, and grinding and polishing the first zircon particles on the epoxy resin plastic target.

[0028] In this technical solution, the first zircon particles are first adhered to the epoxy resin plastic target to fix the first zircon particles and prevent loss due to grinding and polishing operations. Specifically, the epoxy resin plastic target is selected to have a circular shape and a transparent color, which can better observe the first zircon particles, facilitate the operations of grinding and polishing the first zircon particles, and improve safety.

[0029] In the above technical solution, further, the steps of obtaining sandstone specifically include: obtaining the depth of the target well, and determining the target layer position according to the depth of the target well; obtaining the sandstone from the target layer position.

[0030] In this technical solution, the sandstone is selected from the target layer position of the target well. Specifically, the depth of the target layer is first determined to determine the target layer position, and the sandstone at the target layer position is selected. Preferably, core or cuttings can be taken. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention.

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or related technologies. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0033] Figure 1Schematic diagram of the method for determining provenance information of sandstone provided by an embodiment of the present invention;

[0034] Figure 2 Schematic diagram of the method for determining provenance information of sandstone provided by an embodiment of the present invention;

[0035] Figure 3 Cathodoluminescence photograph of zircon, dotting position and zircon age comparison chart of the lower third submember of the Dongsan Formation in the study area;

[0036] Figure 4 Schematic diagram of the method for determining provenance information of sandstone provided by an embodiment of the present invention;

[0037] Figure 5 Schematic diagram of the method for determining provenance information of sandstone provided by an embodiment of the present invention;

[0038] Figure 6 Measured detrital zircon frequency distribution histogram and Yanshan provenance age frequency distribution histogram of the target layer of the lower third submember of the Dongsan Formation in the study area. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] Figure 1 Schematically shows one of the flow diagrams of the method for determining provenance information of sandstone according to an embodiment of the present invention. Among them, the method includes:

[0041] Step S102: Obtain sandstone and separate the first zircon particles from the sandstone;

[0042] Step S104: Grind and polish the first zircon particles to obtain the second zircon particles;

[0043] Step S106: Perform imaging processing on the second zircon particles to determine the internal crack development characteristics and magmatic rhythmic zonation development characteristics of the second zircon particles;

[0044] Step S108: Based on the internal crack development characteristics and magmatic rhythmic zonation development characteristics of the second zircon particles, screen out the third zircon particles from the second zircon particles;

[0045] Step S110: Perform laser ablation treatment on the third zircon particles to determine the age information of the third zircon particles;

[0046] Step S112: Determine the provenance information of the sandstone based on the age information of the third zircon grains.

[0047] In this embodiment, first, sandstone is obtained at the target layer of the target well, and then the sandstone is crushed and sorted to screen out the first zircon grains from the debris of the sandstone, that is, the zircon grains separated from the sandstone debris. Then, the first zircon grains are polished to obtain the second zircon grains. The first zircon grains after polishing are the second zircon grains. Through the polishing process, it is beneficial to expose the interior of the zircon grains for observing the development characteristics. Further, the second zircon grains are photographed to obtain the development characteristics of the internal fissures in the zircon on the photo, and at the same time, the development characteristics of the magmatic rhythmic zonation are also obtained on the photo to facilitate observing the development of its magmatic rhythmic zonation. Then, by selecting the second zircon grains with underdeveloped internal fissure development characteristics and relatively developed magmatic rhythmic zonation, after the above screening process, the selected second zircon grains are used as the third zircon grains, and the third zircon grains are subjected to laser ablation treatment. Specifically, the zircon U-Pb geochronology analysis is carried out by using the laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) technology. By measuring the U-Pb isotope composition in the third zircon grains, the dating work is completed, thereby determining the age information of the third zircon grains. Based on the age information of the third zircon grains, the provenance information of the sandstone is determined, effectively overcoming the uncertainty of provenance analysis using traditional heavy minerals and rock element chemistry and other means, and improving the accuracy of provenance analysis.

[0048] It can be understood that the parent rock, that is, the rock, is an aggregate of one or several rocks and is the rock that supplies clastic materials during the deposition process of the sandstone. As a common heavy mineral in the sandstone, zircon has stable properties, and the age information it records is less likely to be reset and changed during the transportation and deposition process, and can retain and reflect the age characteristics of the area where the parent rock is located. On the basis of fully understanding the age characteristics of the parent rock in the provenance areas around the basin, the characteristics and changes of the source-sink system of the sandstone reservoirs in different horizons can be inverted, the transportation and deposition process of the clastic materials can be understood, so as to predict the distribution of sand bodies and sedimentary facies characteristics, achieve fine research and evaluation of sand bodies, and provide solid basic data support for oil and gas exploration and development. At the same time, by using the laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) technology to obtain the zircon age information in the sandstone debris by the zircon U-Pb dating method, it is both efficient and very convenient. Therefore, while overcoming the problem of low accuracy of provenance tracing by traditional methods and improving the accuracy of provenance analysis, the efficiency and convenience of provenance analysis are also improved.

[0049] In addition, based on the method proposed in the present invention, provenance analysis of sandstone can be carried out under the framework of the fifth-order depositional sequence, meeting the requirements of fine exploration of current oilfields. At the same time, combined with paleogeomorphic characterization, the source-sink characteristics of sandstone in the target layer can be comprehensively analyzed, the sedimentation process can be understood, the spatial distribution characteristics of sandstone bodies can be predicted, the exploration risk can be reduced, and the drilling success rate can be improved.

[0050] In some embodiments, optionally, the step of determining the age information of the third zircon particle by performing laser ablation treatment on the third zircon particle specifically includes: performing laser ablation treatment on the third zircon particle by a laser ablation inductively coupled plasma mass spectrometer to determine the age information of the third zircon particle.

[0051] In this embodiment, laser ablation inductively coupled plasma mass spectrometry is used for zircon U-Pb geochronology analysis to obtain the age information of the third zircon particle. Based on the development and maturity of laser ablation inductively coupled plasma mass spectrometry technology, it is becoming more efficient and convenient to obtain zircon age information in sandstone through LA-ICP-MS technology. Therefore, the efficiency and convenience of analyzing zircon age information are improved.

[0052] Among them, the diameter of the laser beam spot used by the laser ablation inductively coupled plasma mass spectrometer is 24 μm, and the number of zircon particles analyzed for each sandstone is between 120 and 150 to ensure that as much age information as possible is highlighted.

[0053] Figure 2 Schematically shows the second flow diagram of the method for determining the provenance information of sandstone according to an embodiment of the present invention. Among them, the steps of determining the provenance information of sandstone according to the age information of the third zircon particle include:

[0054] Step S202, obtaining the parent rock age information of the sandstone;

[0055] Step S204, comparing the parent rock age information of the sandstone with the third zircon age information, and determining the provenance information of the sandstone according to the comparison result.

[0056] In this embodiment, the parent rock age information of the sandstone is obtained by understanding the parent rock age characteristics of the potential provenance areas of the basin. Based on the obtained parent rock age information of the sandstone and the zircon age information in the sandstone obtained by using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) technology for zircon U-Pb geochronology analysis, the provenance information of the sandstone is determined by using the iconic characteristic age peak, and then the potential provenance areas of the sandstone in the target layer are determined.

[0057] In some embodiments, optionally, the step of obtaining the provenance age information of sandstone specifically includes: determining the spatial distribution characteristics of potential provenance areas on the periphery and inside of the basin and the provenance age information of sandstone according to geological data.

[0058] In this embodiment, when obtaining the provenance age information of sandstone, the spatial distribution characteristics of potential provenance areas on the periphery and inside of the basin and the provenance age information can be determined by collecting relevant geological data and relevant research results. Understanding the provenance age information of sandstone provides strong evidence for determining the provenance information of sandstone.

[0059] Furthermore, the provenance age information of sandstone includes the zircon age of the provenance area. The zircon age information of the provenance area in the obtained provenance age information of sandstone and the third zircon age information are used to respectively make age frequency distribution histograms by using an isotope dating program, such as ISOPLOT software. By comparing the characteristic age peaks of the provenance area zircon age frequency distribution histogram and the third zircon age frequency distribution histogram, the provenance information of sandstone is determined according to the matching of the comparison results, so as to determine the potential provenance area of the target layer sandstone.

[0060] In some embodiments, optionally, the step of performing imaging processing on the second zircon grains to determine the internal crack development characteristics and the magmatic rhythmic zonation development characteristics of the second zircon grains specifically includes;

[0061] Performing transmitted light imaging and reflected light imaging processing on the second zircon grains to determine the surface morphological characteristics and the internal crack development characteristics of the second zircon grains.

[0062] In this embodiment, transmitted light and reflected light photography are performed on the second zircon grains to obtain the surface morphological characteristics and the internal crack development characteristics of the second zircon grains. Through the above imaging processing, it is convenient to observe the internal crack development characteristics of the second zircon grains, and thus a foundation is laid for selecting zircon grains with undeveloped internal cracks, improving the accuracy of provenance analysis.

[0063] Performing transmitted light and reflected light photography on the second zircon grains to obtain the surface morphological characteristics and the internal crack development characteristics of the second zircon grains. Through imaging inspection, it is convenient to observe the magmatic rhythmic zonation development characteristics of the second zircon grains, and thus understand the development of the magmatic rhythmic zonation, thereby improving the accuracy of provenance analysis.

[0064] Specifically, cathodoluminescence imaging inspection is performed by a scanning electron microscope with a cathode probe to observe the growth zonation characteristics of zircon grains to examine the homogeneous composition and its magmatic growth pattern.

[0065] In some embodiments, optionally, the step of performing cathodoluminescence imaging on the second zircon particles further includes: determining a dotting position based on the image information of the third zircon particles generated by performing cathodoluminescence imaging on the second zircon particles, and performing laser ablation on the third zircon particles based on the dotting position.

[0066] In this embodiment, when performing cathodoluminescence imaging on the second zircon particles, the dotting position to be marked during the laser ablation treatment of the third zircon particles is determined based on the image information of the third zircon particles generated, which improves the determination of the dotting position and is beneficial to improving the accuracy of the laser ablation treatment.

[0067] Figure 3 The cathodoluminescence photographs, dotting positions, and age comparison diagrams of each zircon in the lower sub-member of the Dongsan Formation in the study area are shown. It can be seen that the dotting positions corresponding to each zircon in the cathodoluminescence pictures of zircon are different based on different age information.

[0068] Specifically, Figure 3 The ages of the zircons in the first row of the shown cathodoluminescence photographs of zircon are 125 Ma, 155 Ma, 287 Ma, 213 Ma, and 2520 Ma respectively. In the corresponding cathodoluminescence photographs, the dotting positions corresponding to the ages of each zircon are circled. Similarly, in Figure 3 The ages of the zircons in the second row of the shown cathodoluminescence photographs of zircon are 130 Ma, 140 Ma, 156 Ma, 2135 Ma, and 1917 Ma respectively. In the corresponding cathodoluminescence photographs, the dotting positions corresponding to the ages of each zircon are circled.

[0069] Figure 4 Schematically shows the third flow diagram of the method for determining the provenance information of sandstone according to an embodiment of the present invention. Among them, the steps of obtaining sandstone and separating the first zircon particles from the sandstone specifically include:

[0070] Step S402: Crush the sandstone to obtain sandstone debris;

[0071] Step S404: Perform magnetic separation, flotation, and microscopic observation on the sandstone debris to screen out the first zircon particles from the sandstone debris.

[0072] In this embodiment, the sandstone is crushed to obtain sandstone debris. By crushing, the overall structure of the sandstone can be broken, which is convenient for excluding other substances. Further, magnetic separation, flotation, and microscopic manual observation are performed on the obtained sandstone debris to screen out the first zircon particles among them. The first zircon particles obtained through the above screening method have high screening efficiency and high accuracy, and can avoid waste caused by unselected zircon particles.

[0073] In some embodiments, optionally, before performing the steps of grinding and polishing the first zircon particles to obtain the second zircon particles, the method further includes: adhering the first zircon particles to an epoxy resin plastic target, and grinding and polishing the first zircon particles on the epoxy resin plastic target.

[0074] In this embodiment, first, the first zircon particles are adhered to the epoxy resin plastic target to fix the first zircon particles and prevent loss due to the operations of grinding and polishing. Preferably, the epoxy resin plastic target is generally circular and transparent, which can better observe the first zircon particles, facilitate the operations of grinding and polishing the first zircon particles, and improve safety.

[0075] Figure 5 FIG. 4 schematically shows a flow chart of a method for determining the provenance information of sandstone according to an embodiment of the present invention. Among them, the step of obtaining the sandstone specifically includes:

[0076] Step S502: Obtain the depth of the target well, and determine the position of the target layer according to the depth of the target well;

[0077] Step S504: Obtain the sandstone from the position of the target layer.

[0078] In this embodiment, the sandstone is selected from the position of the target layer of the target well. Specifically, first, the depth of the target layer is determined to determine the position of the target layer, and the sandstone at the position of the target layer is selected. Preferably, core or cuttings can be taken. Preferably, the weight of the sandstone is generally between 150 grams and 200 grams to ensure that a sufficient amount of zircon particles can be picked out.

[0079] Figure 6 FIG. shows a comparison chart of the measured detrital zircon age spectrum of the target layer in the lower part of the third member of the Dongying Formation in the study area and the Yanshan provenance age spectrum according to an embodiment of the present invention. Among them, the method for determining the provenance information of the sandstone specifically includes the following steps:

[0080] The first step is to understand the bedrock age characteristics of the potential provenance areas of the basin: The main external provenances in the beach area in the middle of the Qikou Sag include the Yanshan fold belt and the Cangxian Uplift. The bedrock zircon ages of the Yanshan fold belt are statistically analyzed. As Figure 6 shown, the age peaks mainly show three age peaks of 100 Ma to 480 Ma (megaannus, a geological time unit), 1650 Ma to 1850 Ma, and 2360 Ma to 2600 Ma.

[0081] Since there is a lack of zircon age data for the Cangxian Uplift, its zircon age can be determined to be roughly distributed between 250 Ma and 350 Ma, and 900 Ma and 1000 Ma according to the stratigraphic development characteristics.

[0082] Step 2: Take core samples from the target layer, and conduct detrital zircon sorting, target making, and cathodoluminescence photography: To determine the provenance area of the lower third member of the Dongying Formation in the beach area in the middle of the Qikou Sag, take the core of the lower third member of the Dongying Formation from the target well as sandstone, sort out the zircons in it, and paste them on a circular epoxy resin target;

[0083] Step 3: Use laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) technology to conduct zircon U-Pb dating: Mark the positions that need to be sampled on the cathodoluminescence photograph of the zircon, and complete the dating work in the laboratory;

[0084] Step 4: Make a histogram of zircon age frequency distribution: Use ISOPLOT software to make a histogram of zircon age frequency distribution with the zircon age data obtained from the test, and obtain the main age peak distribution characteristics of the lower third member of the Dongying Formation;

[0085] Step 5: Compare the characteristics of the histogram of age frequency distribution: Based on the histogram of age frequency distribution, the main age peak distribution characteristics of the lower third member of the Dongying Formation are mainly concentrated in 100Ma - 480Ma, 1650Ma - 1850Ma, and 2360Ma - 2600Ma. Compare them with the age peaks of the Yanshan fold belt, which are 100Ma - 480Ma, 1650Ma - 1850Ma, and 2360Ma - 2600Ma respectively, and the age peaks of the Cangxian Uplift, which are 250Ma - 350Ma and 900Ma - 1000Ma. It can be found that the age peaks presented by the detrital zircons in the lower third member of the Dongying Formation match well with the age peaks of the Yanshan fold belt, almost completely matching. Thus, it can be determined that the provenance area of the lower third member of the Dongying Formation in the beach area in the middle of the Qikou Sag is the Yanshan fold belt.

[0086] It can be seen that the present invention effectively overcomes the uncertainty in provenance analysis by using traditional methods such as heavy minerals and rock element chemistry, and improves the accuracy of provenance analysis. Based on the method proposed by the present invention, provenance analysis of sandstone can be carried out under the framework of the fifth-order sedimentary sequence, meeting the requirements of fine exploration of current oilfields. At the same time, combined with paleogeomorphic characterization, the source-sink characteristics of the sandstone in the target layer can be comprehensively analyzed, the sedimentation process can be understood, the spatial distribution characteristics of sandstone bodies can be predicted, the exploration risk can be reduced, and the drilling success rate can be improved.

[0087] Although this specification contains many specific implementation details, these should not be construed as limiting the scope of any invention or the scope of what is claimed, but rather as mainly describing the features of specific embodiments of a particular invention. Certain features that are described in multiple embodiments in this specification may also be implemented in combination in a single embodiment. On the other hand, the various features described in a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. Additionally, although features may act in certain combinations as described above and even be initially claimed as such, one or more features from a claimed combination may in some cases be removed from that combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination.

[0088] Similarly, although operations are depicted in the drawings in a particular order, this should not be construed as requiring that those operations be performed in the particular order shown or sequentially, or that all illustrated operations be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Additionally, the separation of the various system modules and components in the above embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0089] Accordingly, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the acts recited in the claims may be performed in a different order and still achieve the desired result. Additionally, the processes depicted in the drawings are not necessarily in the particular order or sequential order shown to achieve the desired result. In some implementations, multitasking and parallel processing may be advantageous.

[0090] It should be noted that, in this context, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device that comprises a series of elements includes not only those elements but also other elements not expressly listed, or elements that are inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device that comprises the element.

[0091] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for determining the provenance information of sandstone, characterized in that: The method for determining the provenance information of the sandstone includes: obtaining the sandstone, and separating first zircon particles from the sandstone; grinding and polishing the first zircon particles to obtain second zircon particles; Performing imaging processing on the second zircon grains to determine the internal crack development characteristics and magma rhythmic ring development characteristics of the second zircon grains; Based on the internal fissure development characteristics and the magma rhythmic ring development characteristics of the second zircon particles, selecting third zircon particles from the second zircon particles; Performing laser ablation processing on the third zircon particles to determine age information of the third zircon particles; The provenance information of the sandstone is determined based on the age information of the third zircon particles.

2. The method for determining the provenance information of sandstone according to claim 1, characterized in that: The step of performing laser ablation on the third zircon particles to determine the age information of the third zircon particles specifically includes: The third zircon particles are laser ablated by laser ablation inductively coupled plasma mass spectrometry to determine the age information of the third zircon particles.

3. The method for determining the provenance information of sandstone according to claim 1, characterized in that: The step of determining the provenance information of the sandstone according to the age information of the third zircon grain specifically includes: Obtaining the age information of the parent rock of the sandstone; The parent rock age information of the sandstone and the age information of the third zircon grains are compared, and the provenance information of the sandstone is determined according to the comparison result.

4. The method for determining the provenance information of sandstone according to claim 3, characterized in that: The step of obtaining the age information of the parent rock of the sandstone specifically includes: Based on geological data, the spatial distribution characteristics of potential provenance areas around and inside the basin and the age information of the parent rock of the sandstone are determined.

5. The method for determining the provenance information of sandstone according to claim 1, characterized in that: The step of performing imaging processing on the second zircon particles to determine the internal crack development characteristics and magma rhythmic ring development characteristics of the second zircon particles specifically includes: The second zircon particles are subjected to transmitted light imaging and reflected light imaging processing to determine the surface morphological characteristics and the internal crack development characteristics of the second zircon particles.

6. The method for determining the provenance information of sandstone according to claim 5, characterized in that: The step of performing imaging processing on the second zircon particles to determine the internal crack development characteristics and magma rhythmic ring development characteristics of the second zircon particles specifically includes: The second zircon particles are subjected to cathode luminescence imaging processing to determine the development characteristics of the magma rhythmic ring zones of the second zircon particles.

7. The method for determining the provenance information of sandstone according to claim 6, characterized in that: The step of performing cathode luminescence imaging on the second zircon particles further includes: Based on the image information of the third zircon particle generated by cathode luminescence imaging of the second zircon particle, the dot position is determined, and based on the dot position, the third zircon particle is subjected to laser ablation.

8. The method for determining the provenance information of sandstone according to any one of claims 1 to 7, characterized in that: The step of obtaining the sandstone and separating the first zircon particles from the sandstone specifically includes: crushing the sandstone to obtain sandstone fragments; The sandstone fragments are subjected to magnetic separation, flotation and microscope observation to screen out the first zircon particles from the sandstone fragments.

9. The method for determining the provenance information of sandstone according to claim 8, characterized in that: Before performing the step of grinding and polishing the first zircon particles to obtain second zircon particles, the method further includes: The first zircon particles are bonded to an epoxy resin plastic target, and the first zircon particles are ground and polished on the epoxy resin plastic target.

10. The method for determining the provenance information of sandstone according to any one of claims 1 to 9, characterized in that: The step of obtaining the sandstone specifically includes: Acquire the depth of the target well, and determine the position of the target layer according to the depth of the target well; The sandstone is obtained from the target layer location.

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