Method and device for recovering ancient landform of carbonate rock stratum by coupling multiple information

Abstract

The invention discloses a method and device for recovering the ancient landform of a carbonate rock stratum by coupling multiple information, and the method comprises the steps: carrying out the sequence interface recognition through the geological information of a research region and the logging information of all drilling wells in the research region, and building a carbonate rock stratum framework of a preset horizon in the research region; carrying out cycle stratigraphic analysis by using the well logging information of the well drilling in the research area to obtain a preset horizon deposition rate of the well drilling in the research area; according to the preset horizon deposition rate of the well drilling position in the research area, the denudation stratum thickness of the preset horizon of the well drilling position in the research area is calculated; and through an interpolation algorithm or a machine learning algorithm, according to the carbonate rock stratigraphic framework of the preset horizon in the research area and the denudation stratum thickness of the preset horizon at the well drilling position in the research area, recovering the ancient landform of the preset horizon in the research area. According to the method, the precision of recovering the denudation amount of the carbonate rock stratum can be improved, the ancient landform information of the carbonate rock in the region can be conveniently and quickly obtained, and a basic framework is provided for carbonate rock reservoir prediction.

Description

Technical Field

[0001] The present invention relates to the technical field of petroleum geological exploration, and in particular to a method and device for recovering paleo-geomorphology of carbonate strata by coupling multiple information. Background Art

[0002] This section is intended to provide a background or context to the embodiments of the invention that are recited in the claims. No statement herein is admitted to be prior art by virtue of its inclusion in this section.

[0003] Paleogeomorphological restoration of carbonate strata plays a crucial role in the study of carbonate platform evolution and reservoir prediction, providing a key basis for related geological research and resource exploration. Over time, scholars and practitioners in the field have developed a variety of traditional restoration methods, including residual thickness methods, impression methods, sedimentological analysis methods, sequence stratigraphic restoration methods, and layer flattening methods.

[0004] Traditional paleogeomorphological reconstruction methods typically rely on a single type of data, such as seismic or geological data. However, in some cases, the resolution of seismic data may not be sufficient to accurately identify sequence boundaries, especially in carbonate formations, where seismic reflection characteristics can be affected by lithologic variations and structural complexity. Furthermore, the application of only a single type of data may not fully reflect the complexity of carbonate paleogeomorphology, especially in areas with large variations in sedimentation rates or significant erosion. This can lead to stagnation in paleogeomorphological reconstruction efforts or significant deviations in results. This has significantly restricted the further development of related research and practical work, and new technical solutions are urgently needed to overcome this bottleneck. Summary of the Invention

[0005] The present invention provides a method for restoring paleogeomorphology of carbonate formations by coupling multiple information, which is used to improve the accuracy of restoring the amount of erosion in carbonate formations, conveniently and quickly obtain paleogeomorphological information of carbonate formations in a region, and provide a basic framework for carbonate reservoir prediction. The method includes:

[0006] Sequence boundary identification was carried out using geological information of the study area and logging information of all wells drilled in the study area, and a carbonate stratigraphic framework of the pre-set horizons in the study area was established;

[0007] Using the logging information of the wells drilled in the study area, cyclostratigraphic analysis was carried out to obtain the sedimentation rate of the preset horizon at the wells drilled in the study area; based on the sedimentation rate of the preset horizon at the wells drilled in the study area, the thickness of the eroded strata at the preset horizon at the wells drilled in the study area was calculated;

[0008] Through interpolation algorithm or machine learning algorithm, the paleo-geomorphology of the preset horizon in the study area is restored according to the carbonate rock stratigraphic framework of the preset horizon in the study area and the thickness of the eroded strata of the preset horizon at the drilling site in the study area.

[0009] The present invention also provides a device for recovering paleogeomorphology of carbonate formations by coupling multiple information, which is used to improve the accuracy of recovering the amount of carbonate formation erosion, conveniently and quickly obtain paleogeomorphological information of carbonate formations in the region, and provide a basic framework for carbonate reservoir prediction. The device includes:

[0010] The carbonate stratigraphic framework construction module is used to identify sequence interfaces using geological information of the study area and logging information of wells drilled in the study area, and to establish a carbonate stratigraphic framework for preset horizons in the study area.

[0011] The denuded stratum thickness analysis module is used to: conduct cyclostratigraphic analysis using well logging information from the study area to obtain the sedimentation rate of the preset horizon at the study area; and calculate the denuded stratum thickness of the preset horizon at the study area based on the sedimentation rate of the preset horizon at the study area;

[0012] The paleo-geomorphology restoration module is used to restore the paleo-geomorphology of the preset horizons in the study area through interpolation algorithms or machine learning algorithms, based on the carbonate stratigraphic framework of the preset horizons in the study area and the thickness of the denuded strata at the preset horizons at the wells in the study area.

[0013] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for restoring paleomorphology of carbonate formations by coupling multiple information is implemented.

[0014] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for restoring paleo-geomorphology of carbonate strata by coupling multiple information is implemented.

[0015] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the above-mentioned method of restoring paleo-geomorphology of carbonate strata by coupling multiple information.

[0016] In an embodiment of the present invention, geological information of the study area and logging information of wells drilled in the study area are used to identify sequence interfaces and establish a carbonate stratigraphic framework; cyclostratigraphic analysis is performed using logging information to obtain sedimentation rates; based on the sedimentation rates, the thickness of the eroded strata is calculated; and based on the carbonate stratigraphic framework and the thickness of the eroded strata, the paleogeomorphology of a preset layer in the study area is restored using an interpolation algorithm or a machine learning algorithm. Compared to existing technical solutions that rely on a single data source, have limited paleogeomorphology restoration accuracy, and are not suitable for complex geological conditions, in an embodiment of the present invention, data sources are increased by coupling geological information and logging information; the thickness of the eroded strata is calculated through cyclostratigraphic analysis to improve the accuracy of restoring the amount of stratum erosion; and the paleogeomorphology of the carbonate stratigraphic layers is quickly restored using an interpolation algorithm or a machine learning algorithm, thereby conveniently and quickly obtaining carbonate paleogeomorphology information in the region and providing a basic framework for carbonate reservoir prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0018] Figure 1 This is a flow chart of a method for restoring paleogeomorphology of carbonate strata by coupling multiple information in an embodiment of the present invention;

[0019] Figure 2 The reflection characteristics of the stratum interface in the study area obtained by coupling multiple information in an embodiment of the present invention;

[0020] Figure 3 The results of spectrum analysis and sliding window spectrum analysis in the embodiment of the present invention;

[0021] Figure 4 A floating astronomical age scale established in an embodiment of the present invention;

[0022] Figure 5 This is an analytical diagram of the method for calculating the amount of erosion by astronomical cycles in an embodiment of the present invention;

[0023] Figure 6 This is a line graph of the sedimentation rate of the Longtan-Changxing Formation in a certain basin in the study area in the embodiment of the present invention;

[0024] Figure 7 This is a histogram of sedimentary thickness of the Longtan-Changxing Formation in a certain basin in the study area in the embodiment of the present invention;

[0025] Figure 8 This is a plan view of the actual sedimentary thickness of the Longtan-Changxing Formation in a certain basin in the study area in the embodiment of the present invention;

[0026] Figure 9 This is a plan view of the sedimentation rate of the Longtan-Changxing Formation in a certain basin in the study area in the embodiment of the present invention;

[0027] Figure 10 This is a plan view of the erosion volume of the Longtan-Changxing Formation in a certain basin in the study area in the embodiment of the present invention;

[0028] Figure 11 This is a paleo-geomorphological map of the Longtan-Changxing Formation in a basin in the study area in the embodiment of the present invention;

[0029] Figure 12 Schematic diagram of a device for restoring paleo-geomorphology of carbonate strata by coupling multiple information in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0031] In order to overcome the problems of relying on a single data source, limited accuracy of paleogeomorphology restoration, and unsuitability for complex geological conditions, the embodiment of the present invention proposes a paleogeomorphology restoration method coupled with multiple information. The method aims to improve the accuracy and reliability of paleogeomorphology restoration through collaborative analysis of multi-source data, providing more powerful technical support for geological research and resource exploration. Figure 1 Flowchart of the method for recovering paleogeomorphology of carbonate strata by coupling multiple information in an embodiment of the present invention. Figure 1 As shown, the method includes the following steps:

[0032] Step 101: Use geological information of the study area and logging information of all wells drilled in the study area to identify sequence interfaces and establish a carbonate stratigraphic framework for a preset horizon in the study area;

[0033] Step 102: Perform cyclostratigraphic analysis using well logging information from the wells in the study area to obtain a sedimentation rate at a preset horizon at the wells in the study area; calculate the thickness of the denuded stratum at the preset horizon at the wells in the study area based on the sedimentation rate at the preset horizon at the wells in the study area;

[0034] Step 103: Restore the paleo-geomorphology of the preset horizon in the study area by using an interpolation algorithm or a machine learning algorithm based on the carbonate rock stratigraphic framework of the preset horizon in the study area and the thickness of the denuded strata of the preset horizon at the well in the study area.

[0035] Compared with the technical solutions in the prior art that rely on a single data source, have limited accuracy in paleogeomorphological restoration, and are not suitable for complex geological conditions, in the embodiments of the present invention, data sources are increased by coupling geological information and well logging information; the thickness of the eroded strata is calculated through cyclostratigraphic analysis, thereby improving the accuracy of restoring the amount of stratum erosion; and interpolation algorithms or machine learning algorithms are used to quickly restore the paleogeomorphology of carbonate rock formations, conveniently and quickly obtaining paleogeomorphological information of carbonate rocks in the region, providing a basic framework for carbonate reservoir prediction.

[0036] In recent years, with the advancement of well logging technology, the application of well logging data in geological research has become increasingly widespread. Well logging data can provide detailed information on the physical properties of the formation at the drilling site, such as porosity, permeability, and lithology. This information is invaluable for understanding sedimentary environments and stratigraphic changes. However, existing applications of well logging data are often limited to localized geological analysis, and their potential for large-scale paleogeomorphological reconstruction has yet to be fully realized.

[0037] In the embodiment of the present invention, the geological information of the study area and the logging information of all the wells drilled in the study area are used to carry out sequence interface identification, and a carbonate stratigraphic framework of a preset horizon in the study area is established.

[0038] In one embodiment, sequence interface identification is performed using geological information of the study area to obtain core-scale characteristics of the sequence interface; well logging information of wells drilled in the study area is used to perform sequence interface identification to obtain well logging characteristics of the sequence interface; sedimentary geochemical analysis is performed using geochemical information of the study area to obtain geochemical characteristics of the sequence interface; the core-scale characteristics, well logging characteristics and geochemical characteristics of the sequence interface are analyzed to establish a carbonate stratigraphic framework for a preset stratum in the study area.

[0039] For example, data on the pre-determined horizons to be restored and the study area are obtained, including geological, geochemical, and well logging information. Based on the acquired geological information, core-scale sequence interface identification is first performed, primarily identifying lithofacies transition surfaces and unconformities. Then, based on the acquired well logging information, logging sequence interface identification is performed, primarily through logging and lithologic calibration. Identifying logging boundary transition surfaces facilitates accurate stratigraphic delineation and identification of changes in sedimentary environments. When simple lithofacies transition surfaces are difficult to identify, sedimentary geochemical testing is required, primarily including carbon and oxygen isotopes, strontium isotopes, and major and trace elements. Calibration of these elemental and isotopic events with global events is key to subsequent cyclic stratigraphic studies based on logging information.

[0040] Figure 2 This is the reflection characteristic of the stratum interface in the study area obtained by coupling multiple information in the embodiment of the present invention. Figure 2As shown, the reflection characteristics that change with depth are displayed: natural gamma ray GR curve, uranium U content, thorium TH content, potassium K content, lithology, acoustic time difference AC, compensated neutron CNL, density DEN, flushing zone formation resistivity ROX, true formation resistivity RT, and the formation interface obtained by integrating multi-source information.

[0041] Preliminary single-well cyclostratigraphic analyses were conducted on several key wells in the study area. By analyzing the cyclomatic characteristics of each well, a single-well cyclomatic sequence and stratigraphic framework were established. These single-well cyclostratigraphic analyses can identify periodic sedimentary features within the strata, thereby revealing the influence of astronomical forces on the sedimentary process and their manifestation in the strata. This method allows for a more precise demarcation and understanding of the sedimentary characteristics of individual stratigraphic units, particularly regarding differences in denudation thickness at different well locations, providing a scientific basis for restoring original stratum thickness. By analyzing the cyclostratigraphic characteristics of each well location, we can more clearly understand the temporal and spatial distribution characteristics of regional strata and the evolution of sedimentary environments over different periods of time.

[0042] In one embodiment, sequence interface identification is performed using geological information of the study area and logging information of wells drilled in the study area to obtain a stratigraphic sequence of a preset drilling position; cyclostratigraphic analysis is performed using logging information of wells drilled in the study area to obtain sedimentary cycle units at the drilling site, and the correspondence between the sedimentary cycle units and the strata at the drilling site is determined; based on the correspondence between the sedimentary cycle units and the strata at the drilling site and the period to which the sedimentary cycle units at the drilling site belong, the period to which each stratum at the drilling site belongs is determined; and strata belonging to the same period are associated to obtain a carbonate rock stratigraphic framework for a preset stratum in the study area.

[0043] The key to traditional paleogeomorphological reconstruction lies in identifying seismic interfaces. While well-seismic data can be used for calibration, paleogeomorphological identification based on seismic data is difficult when micro-paleogeomorphological differences are difficult to detect on seismic interfaces and when seismic interfaces lack clear landmarks. Therefore, the present invention focuses on cyclostratigraphic analysis using well logging data.

[0044] In an embodiment of the present invention, cyclostratigraphic analysis is carried out using logging information of wells drilled in the study area to obtain the sedimentation rate of a preset stratum at the drilling site in the study area; based on the sedimentation rate of the preset stratum at the drilling site in the study area, the thickness of the eroded stratum at the preset stratum at the drilling site in the study area is calculated.

[0045] For example, the cyclostratigraphic analysis in the embodiment of the present invention mainly includes the following steps:

[0046] 1. Obtain the logging information of the wells in the study area (including natural gamma ray GR curves, etc.) and carry out noise removal processing.

[0047] 2. Perform spectrum analysis and sliding window spectrum analysis (usually fast Fourier transform FFT, multi-window spectrum analysis method MTM, etc.) on the denoised logging information. Figure 3 Spectrum analysis and sliding window spectrum analysis results in the embodiment of the present invention. Figure 3 As shown in the figure, after the significance test, the appropriate spectrum peak is selected and the spectrum peak is selected as the cyclic frequency of the corresponding formation. Finally, the appropriate eccentricity E and e period, slope O period and precession P period of the Earth's orbit are selected.

[0048] 3. Filter the frequencies corresponding to E and e respectively to obtain cycles with astronomical periods of 405ka and 125ka. Figure 4 It is a floating astronomical age scale established in the embodiment of the present invention. The long eccentricity curve has a clear astronomical periodicity of about 405ka. Combining it with the logging data can provide an accurate time frame for paleo-geomorphological restoration. By analyzing the periodic changes in the logging curve, the sedimentary cycles corresponding to the long eccentricity period are identified, thereby determining the time nodes of paleo-geomorphological formation and evolution, making the restored paleo-geomorphology more accurate and reliable in the time dimension. Figure 4 As shown, the horizontal axis is the time length (million years Ma), showing the detrended GR curve of the time dimension and the long eccentricity filter curve; E1 to E19 marked in the long eccentricity filter curve represent 19 long eccentricity periods; in the embodiment of the present invention, the most stable 405ka astronomical period is selected to establish the astronomical age scale.

[0049] 4. Finally, deep time conversion is performed and further spectrum analysis is performed in the time domain to test whether the main frequency corresponds to the astronomical periods of 405ka, 125ka, 40ka, and 20ka to determine the reliability of the research.

[0050] Astrostratigraphic methods can effectively and quantitatively calculate the duration of stratigraphic deposition. Based on the basic theory of astronomical cycles, a 405-ka long eccentricity filter analysis of two wells in the study area (Chongtan 1 and Yingtan 1) revealed that Chongtan 1 experienced erosion, while Yingtan 1 did not. Figure 5 This is an analytical diagram of the method for calculating the amount of erosion in astronomical cycles according to an embodiment of the present invention. Figure 5 As shown, taking the well that has not suffered erosion as the standard well, the theoretical erosion thickness can be calculated based on the average sedimentation rate obtained by cyclostratigraphic analysis according to the intact stratum where the standard well is located and the thickness of the residual stratum where the well that has suffered erosion is located.

[0051] In one embodiment, cyclostratigraphic analysis is carried out using logging information at the wells in the study area to obtain a sedimentary cycle sequence of a preset stratum at the drilling well; based on the sedimentary cycle sequence of the preset stratum at the drilling well, the cyclomatic characteristics of the preset stratum at the drilling well are obtained; the cyclomatic characteristics include: the sedimentary cycle period of the sedimentary cycle unit and the number of sedimentary cycle units; the cyclomatic characteristics of the preset stratum at the drilling well and the geological information of the study area are analyzed to obtain the sedimentation rate of the preset stratum at the drilling well.

[0052] For example, through spectrum analysis and wavelet analysis, sedimentary cycles of different orders can be identified, and the number of cycles in each stratum can be counted, reflecting the sedimentary periodicity during the formation period. Spectral analysis can also determine the dominant frequency in the well log curve, and then identify the cycle frequencies corresponding to astronomical periods (such as 405 ka, 125 ka, 40 ka, and 20 ka). In other words, the depositional period of each sedimentary cycle unit can be used to measure the stability and frequency of the sedimentary environment.

[0053] In one embodiment, the deposition rate is calculated according to formula (1):

[0054]

[0055] Where V i is the preset horizon sedimentation rate at the i-th well in the study area, H i is the thickness of the preset layer at the i-th well in the study area, m i is the number of sedimentary cycle units at the preset horizon at the i-th well in the study area, is the average sedimentary cycle period of the preset horizon sedimentary cycle unit at the i-th well in the study area.

[0056] Figure 6 This is a line graph of the sedimentation rate of the Longtan-Changxing Formation in a certain basin in the study area of ​​the present invention. Figure 6 As mentioned above, the dotted line on the left represents the theoretical erosion thickness, while the solid line represents the remaining stratum thickness. Calculated by formula (1), the stratum erosion thickness of Chongtan 1 well is approximately 55 m. Analysis shows that Chongtan 1 well only retains part of the stratigraphic cycles (cycles 1 to 3), while cycles 4 and 5 are missing, indicating that this well section has been significantly eroded. The existing stratigraphic thickness of this well is 112 m, and the calculated average sedimentation rate is 6.79 cm / ka. In contrast, the Yingtan 1 well on the right side of the figure does not show obvious signs of erosion, and the stratum is relatively complete, including all 5 cycles, with a stratum thickness of 364 m. This indicates that the area where the Yingtan 1 well is located has not been significantly eroded, and the sedimentary environment is relatively stable. The average sedimentation rate of the Yingtan 1 well is 17.78 cm / ka, which is significantly higher than that of the Chongtan 1 well.

[0057] Figure 7This is a histogram of sedimentary thickness of the Longtan-Changxing Formation in a certain basin in the study area of ​​the present invention. Figure 7 As shown, the theoretical sedimentary thicknesses of Well Zhongjiang 1, Well Chongtan 1, Well Pengyang 1, Well Wutan 1 and Well Yingtan 1 in different strata are displayed.

[0058] comprehensive Figure 6 and Figure 7 The data from the study indicate that the sedimentation rate and thickness of the Longtan Formation are relatively stable across wells, with an average sedimentation rate of less than 10 cm / ky. This indicates that the sedimentary environment during the formation of the Longtan Formation was relatively stable, reflecting relatively consistent sedimentary conditions within the study area. During this period, the basin's sedimentary environment was low-energy, with minimal sedimentation rate and spatial variation, and a smooth sedimentation process.

[0059] The Changxing Formation's stratigraphic thickness increases from west to east, and the sedimentation rate also accelerates. This trend may indicate that the sediment deposition process was influenced by tectonic or environmental gradients. The shift in sediment thickness from west to east is related to changes in the basin's sedimentary environment at the time. Areas with high sedimentation rates may be located within carbonate reefs, while areas with lower sedimentation rates are mostly distributed in the southwestern region of the basin, reflecting severe erosion.

[0060] The sedimentation rate and thickness of the Feixianguan Formation also show relatively stable characteristics, reflecting the relatively stable sedimentary environment during the Feixianguan Formation period.

[0061] By analyzing the number of cycles and sedimentation rates, we can quantitatively estimate the denudation thickness of different wells and thus restore the original sedimentary thickness of each stratum. This method helps to restore the sedimentary history, identify sedimentary facies types and their spatial distribution, and provide key data for lithofacies paleogeographic mapping. Figure 8 This is a plan view of the actual sedimentary thickness of the Longtan-Changxing Formation in a certain basin in the study area of ​​the present invention. Figure 8 As shown in the figure, the overall distribution of sedimentary thickness shows that the strata in the northeast are thicker and the strata in the southwest are thinner. Compared with the theoretical sedimentary thickness, it is generally speculated that the Changxing Formation strata in the southwest of the figure have undergone more serious erosion.

[0062] In one embodiment, the sedimentary cycle sequence at a preset position in the study area is determined as a standard sedimentary cycle sequence; wherein, the preset position has not been eroded and the sedimentary cycle sequence is complete; the sedimentary cycle sequence of the preset horizon at the drilling site is compared and analyzed with the standard sedimentary cycle sequence to obtain the number of missing sedimentary cycle units at the preset horizon at the drilling site; the product of the number of missing sedimentary cycle units and the sedimentation rate of the preset horizon at the drilling site is calculated respectively to obtain the thickness of the eroded stratum at the preset horizon at the drilling site.

[0063] The number of missing sedimentary cycles reflects the number of sedimentary cycles lost due to erosion in a given well section within the study area and is a direct indicator of the extent of erosion. The loss of formation thickness due to erosion can be calculated by multiplying it by the sedimentation rate, which is the rate of sedimentation per unit time.

[0064] For example, the thickness of the eroded stratum at the preset horizon is calculated according to formula (2):

[0065] ΔH i =n i ×V i (2)

[0066] Where ΔH i is the thickness of the eroded stratum at the preset level at the i-th well, n i is the number of missing sedimentary cycle units in the preset horizon at the i-th well.

[0067] Figure 9 This is a plan view of the sedimentation rate of the Longtan-Changxing Formation in a certain basin in the study area of ​​the present invention. Figure 9 As shown in the figure, Shuangtan 107, Longtan 1, Rentan 1, Yingtan 1, Tiandong 23, Longhui 4, Wutan 1, Menxi 3, Pengyang 3, Chongtan 1, Pengtan 3, Zhongjiang 1, and Yunjin 1 all represent drilling wells. The sedimentation rate of each well was calculated by the formula, and an obvious phenomenon can be observed: the sedimentation rate of the Changxing Formation increases from west to east.

[0068] Figure 10 This is a plan view of the erosion volume of the Longtan-Changxing Formation in a certain basin in the study area of ​​the present invention. Figure 10 As shown in the figure, the amount of erosion of the strata at the wells where the cycles are missing is calculated by the number of standard sedimentary cycles and the sedimentation rate. The area with the largest amount of erosion is the southwest region in the figure.

[0069] By combining the number of missing cycles with the sedimentation rate using formulas (1) and (2), the denudation thickness of the target layer can be calculated. This calculation process can accurately and quantitatively restore the original thickness of the stratum before denudation, obtain sedimentary paleo-geomorphology and later karst paleo-geomorphology, and reveal the impact of denudation on stratum thickness, thereby more accurately reflecting the evolution of geological history and sedimentary environment.

[0070] In an embodiment of the present invention, an interpolation algorithm or a machine learning algorithm is used to restore the paleo-geomorphology of a preset layer in the study area based on the carbonate rock stratigraphic framework of the preset layer in the study area and the thickness of the eroded layer at the preset layer at the drilling site in the study area.

[0071] For example, in the process of restoring micro-paleomorphology, the differences between sedimentary paleomorphology and karst paleomorphology can be considered. When restoring sedimentary paleomorphology, it is necessary to use an interpolation algorithm to restore the sedimentary paleomorphology based on the thickness of the restored original strata. The thicker the strata, the higher the landform, while the thinner the strata, the lower the landform. When restoring karst paleomorphology, the thicker the erosion, the higher the karst highlands, while the thinner the erosion, the lower the karst lowlands.

[0072] In one embodiment, when the number of wells drilled in the study area is less than a preset value, a machine learning algorithm is used to restore the paleo-geomorphology of the preset layer in the study area based on the carbonate rock stratigraphic framework of the preset layer in the study area and the thickness of the eroded layer at the preset layer at the drilling site in the study area; when the number of wells drilled in the study area is not less than a preset value, an interpolation algorithm is used to restore the paleo-geomorphology of the preset layer in the study area based on the carbonate rock stratigraphic framework of the preset layer in the study area and the thickness of the eroded layer at the preset layer at the drilling site in the study area.

[0073] Figure 11 This is a paleo-geomorphological map of the Longtan-Changxing Formation in a basin in the study area of ​​the present invention. Figure 11 As shown in the figure, the paleo-geomorphology map of the Changxing Formation in a basin was restored. Combining the actual stratigraphic thickness and the calculated denudation map, the theoretical stratigraphic thickness map of the entire area in the Changxing Formation in a basin was preliminarily restored, thereby restoring the paleo-geomorphology map.

[0074] The present invention also provides an apparatus for restoring paleogeomorphology of carbonate formations by coupling multiple information, as described in the following embodiments. Because the principles underlying the apparatus are similar to those of the method for restoring paleogeomorphology of carbonate formations by coupling multiple information, the implementation of the apparatus can be referenced to the implementation of the method for restoring paleogeomorphology of carbonate formations by coupling multiple information, and any repetitions will not be repeated.

[0075] Figure 12 Schematic diagram of a device for restoring paleo-geomorphology of carbonate strata by coupling multiple information in an embodiment of the present invention.

[0076] like Figure 12 As shown, the device includes:

[0077] The carbonate stratigraphic framework construction module 1201 is used to: identify sequence interfaces using geological information of the study area and logging information of wells drilled in the study area, and establish a carbonate stratigraphic framework for a preset horizon in the study area;

[0078] The denuded stratum thickness analysis module 1202 is configured to: perform cyclostratigraphic analysis using well logging information from the wells in the study area to obtain a sedimentation rate at a preset layer at the wells in the study area; and calculate the denuded stratum thickness at the preset layer at the wells in the study area based on the sedimentation rate at the preset layer at the wells in the study area.

[0079] The paleo-geomorphology restoration module 1203 is used to restore the paleo-geomorphology of the preset layers in the study area by using an interpolation algorithm or a machine learning algorithm, based on the carbonate rock stratigraphic framework of the preset layers in the study area and the thickness of the denuded layers at the preset layers at the wells in the study area.

[0080] In one embodiment, the carbonate formation framework building module 1201 is specifically configured to:

[0081] Sequence interface identification was carried out using geological information of the study area to obtain core-scale characteristics of sequence interfaces;

[0082] The well logging information of the wells drilled in the study area was used to identify the sequence interface and obtain the logging characteristics of the sequence interface;

[0083] Using the geochemical information of the study area to carry out sedimentary geochemical analysis, the geochemical characteristics of the sequence interface were obtained;

[0084] The core-scale characteristics, logging characteristics and geochemical characteristics of the sequence interface are analyzed to establish the carbonate stratigraphic framework of the preset horizons in the study area.

[0085] In one embodiment, the carbonate formation framework building module 1201 is specifically configured to:

[0086] Sequence interface identification was carried out using geological information of the study area and logging information of the wells drilled in the study area to obtain the stratigraphic sequence of the preset drilling horizons;

[0087] Using the logging information of the wells in the study area, cyclostratigraphic analysis was carried out to obtain the sedimentary cyclonic units at the drilling site and determine the correspondence between the sedimentary cyclonic units at the drilling site and the strata.

[0088] According to the corresponding relationship between the sedimentary cycle units and the strata at the drilling site, and the period to which the sedimentary cycle units at the drilling site belong, the period to which each stratum at the drilling site belongs is determined;

[0089] The strata belonging to the same period are correlated to obtain the carbonate stratigraphic framework of the preset horizons in the study area.

[0090] In one embodiment, the denuded formation thickness analysis module 1202 is specifically configured to:

[0091] Using the logging information from the wells in the study area, we conducted cyclostratigraphic analysis and obtained the sedimentary cycle sequence of the preset horizons at the wells.

[0092] According to the sedimentary cycle sequence of the preset horizon at the drilling site, the cycle characteristics of the preset horizon at the drilling site are obtained; the cycle characteristics include: the sedimentary cycle period of the sedimentary cycle unit and the number of sedimentary cycle units;

[0093] The cyclic characteristics of the preset horizon at the drilling site and the geological information of the study area were analyzed to obtain the sedimentation rate of the preset horizon at the drilling site.

[0094] In one embodiment, the deposition rate is calculated according to the following formula:

[0095]

[0096] Where V i is the preset horizon sedimentation rate at the i-th well in the study area, H i is the thickness of the preset layer at the i-th well in the study area, m i is the number of sedimentary cycle units at the preset horizon at the i-th well in the study area, t i is the average sedimentary cycle period of the preset horizon sedimentary cycle unit at the i-th well in the study area.

[0097] In one embodiment, the denuded formation thickness analysis module 1202 is specifically configured to:

[0098] The sedimentary cycle sequence at the preset location in the study area is determined as the standard sedimentary cycle sequence; wherein the preset location has not been eroded and the sedimentary cycle sequence is complete;

[0099] Compare and analyze the sedimentary cycle sequence of the preset horizon at the drilling site with the standard sedimentary cycle sequence to obtain the number of missing sedimentary cycle units in the preset horizon at the drilling site;

[0100] The product of the number of missing sedimentary cycle units and the sedimentation rate of the preset horizon at the drilling site is calculated respectively to obtain the thickness of the eroded stratum at the preset horizon at the drilling site.

[0101] In one embodiment, the paleo-geomorphology restoration module 1203 is specifically configured to:

[0102] When the number of wells drilled in the study area is less than the preset value, a machine learning algorithm is used to restore the paleomorphology of the preset horizons in the study area based on the carbonate stratigraphic framework of the preset horizons in the study area and the thickness of the denuded strata at the preset horizons where the wells are drilled in the study area.

[0103] When the number of wells drilled in the study area is not less than the preset value, the interpolation algorithm is used to restore the paleomorphology of the preset horizons in the study area based on the carbonate stratigraphic framework of the preset horizons in the study area and the thickness of the denuded strata at the preset horizons where the wells are drilled in the study area.

[0104] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for restoring paleomorphology of carbonate formations by coupling multiple information is implemented.

[0105] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for restoring paleo-geomorphology of carbonate strata by coupling multiple information is implemented.

[0106] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the above-mentioned method of restoring paleo-geomorphology of carbonate strata by coupling multiple information.

[0107] In an embodiment of the present invention, geological information of the study area, well logging information from wells drilled in the study area, and geochemical information are used to identify sequence interfaces and establish a carbonate stratigraphic framework. Cyclostratigraphic analysis is performed using well logging information to obtain sedimentation rates. Based on the sedimentation rates, the thickness of the eroded strata is calculated. Using an interpolation algorithm or a machine learning algorithm, paleogeomorphology of a preset horizon in the study area is restored based on the carbonate stratigraphic framework and the thickness of the eroded strata. Compared to existing technical solutions that rely on a single data source, have limited paleogeomorphology restoration accuracy, and are unsuitable for complex geological conditions, in an embodiment of the present invention, by coupling geological information, well logging information, and geochemical information, data sources are increased, the accuracy of stratigraphic interface identification is improved, cyclostratigraphic analysis is used to calculate the thickness of the eroded strata, and the accuracy of restored stratigraphic erosion is improved, thus avoiding the problem of difficulty in identifying stratigraphic interfaces due to interference from seismic information. Using an interpolation algorithm or a machine learning algorithm, carbonate stratigraphic paleogeomorphology is rapidly restored, conveniently and quickly obtaining carbonate paleogeomorphology information within the region, and providing a basic framework for carbonate reservoir prediction.

[0108] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0109] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0110] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0111] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0112] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for restoring paleogeomorphology of carbonate strata by coupling multiple information, characterized in that: include: Sequence boundary identification was carried out using geological information of the study area and logging information of wells drilled in the study area, and a carbonate stratigraphic framework of the preset horizons in the study area was established; Using the logging information of the wells drilled in the study area, cyclostratigraphic analysis was carried out to obtain the sedimentation rate of the preset horizon at the wells drilled in the study area; based on the sedimentation rate of the preset horizon at the wells drilled in the study area, the thickness of the eroded strata at the preset horizon at the wells drilled in the study area was calculated; Through interpolation algorithm or machine learning algorithm, the paleo-geomorphology of the preset horizon in the study area is restored according to the carbonate rock stratigraphic framework of the preset horizon in the study area and the thickness of the eroded strata of the preset horizon at the drilling site in the study area.

2. The method according to claim 1, wherein Sequence boundary identification was carried out using geological information of the study area and logging information of wells drilled in the study area, and a carbonate stratigraphic framework for the preset horizons in the study area was established, including: Sequence interface identification was carried out using geological information of the study area to obtain core-scale characteristics of sequence interfaces; The well logging information of the wells drilled in the study area was used to identify the sequence interface and obtain the logging characteristics of the sequence interface; Using the geochemical information of the study area to carry out sedimentary geochemical analysis, the geochemical characteristics of the sequence interface were obtained; The core-scale characteristics, logging characteristics and geochemical characteristics of the sequence interface are analyzed to establish the carbonate stratigraphic framework of the preset horizons in the study area.

3. The method according to claim 1, wherein Sequence boundary identification was carried out using geological information of the study area and logging information of wells drilled in the study area, and a carbonate stratigraphic framework for the preset horizons in the study area was established, including: Sequence interface identification was carried out using geological information of the study area and logging information of the wells drilled in the study area to obtain the stratigraphic sequence of the preset drilling horizons; Using the logging information of the wells in the study area, cyclostratigraphic analysis was carried out to obtain the sedimentary cyclonic units at the drilling site and determine the correspondence between the sedimentary cyclonic units at the drilling site and the strata. According to the correspondence between the sedimentary cycle units and the strata at the drilling site, and the period to which the sedimentary cycle units at the drilling site belong, the period to which each stratum at the drilling site belongs is determined; The strata belonging to the same period are correlated to obtain the carbonate stratigraphic framework of the preset horizons in the study area.

4. The method according to claim 1, wherein Using the logging information of the wells drilled in the study area, a cyclostratigraphic analysis was conducted to obtain the sedimentation rates of the preset horizons at the wells drilled in the study area, including: Using the logging information from the wells in the study area, we conducted cyclostratigraphic analysis and obtained the sedimentary cycle sequence of the preset horizons at the wells. According to the sedimentary cycle sequence of the preset horizon at the drilling site, the cycle characteristics of the preset horizon at the drilling site are obtained; the cycle characteristics include: the sedimentary cycle period of the sedimentary cycle unit and the number of sedimentary cycle units; The cyclic characteristics of the preset horizon at the drilling site and the geological information of the study area were analyzed to obtain the sedimentation rate of the preset horizon at the drilling site.

5. The method according to claim 4, wherein The deposition rate was calculated according to the following formula: Where V i is the preset horizon sedimentation rate at the i-th well in the study area, H i is the thickness of the preset layer at the i-th well in the study area, m i is the number of sedimentary cycle units at the preset horizon at the i-th well in the study area, is the average sedimentary cycle period of the preset horizon sedimentary cycle unit at the i-th well in the study area.

6. The method according to claim 4, wherein According to the sedimentation rate of the preset horizon at the drilling site in the study area, the thickness of the eroded stratum at the preset horizon at the drilling site in the study area is calculated, including: The sedimentary cycle sequence at the preset location in the study area is determined as the standard sedimentary cycle sequence; wherein the preset location has not been eroded and the sedimentary cycle sequence is complete; Compare and analyze the sedimentary cycle sequence of the preset horizon at the drilling site with the standard sedimentary cycle sequence to obtain the number of missing sedimentary cycle units in the preset horizon at the drilling site; The product of the number of missing sedimentary cycle units and the sedimentation rate of the preset horizon at the drilling site is calculated respectively to obtain the thickness of the eroded stratum at the preset horizon at the drilling site.

7. The method according to claim 1, wherein Through interpolation or machine learning algorithms, the paleo-geomorphology of the preset horizons in the study area is restored based on the carbonate stratigraphic framework of the preset horizons in the study area and the thickness of the eroded strata at the preset horizons where the wells are drilled in the study area, including: When the number of wells drilled in the study area is less than the preset value, a machine learning algorithm is used to restore the paleomorphology of the preset horizons in the study area based on the carbonate stratigraphic framework of the preset horizons in the study area and the thickness of the denuded strata at the preset horizons where the wells are drilled in the study area. When the number of wells drilled in the study area is not less than the preset value, the interpolation algorithm is used to restore the paleomorphology of the preset horizons in the study area based on the carbonate stratigraphic framework of the preset horizons in the study area and the thickness of the denuded strata at the preset horizons where the wells are drilled in the study area.

8. A device for restoring paleo-geomorphology of carbonate strata by coupling multiple information, characterized in that: include: The carbonate stratigraphic framework construction module is used to identify sequence interfaces using geological information of the study area and logging information of wells drilled in the study area, and to establish a carbonate stratigraphic framework for preset horizons in the study area. The denuded stratum thickness analysis module is used to: conduct cyclostratigraphic analysis using well logging information from the study area to obtain the sedimentation rate of the preset horizon at the study area; and calculate the denuded stratum thickness of the preset horizon at the study area based on the sedimentation rate of the preset horizon at the study area; The paleo-geomorphology restoration module is used to restore the paleo-geomorphology of the preset horizons in the study area through interpolation algorithms or machine learning algorithms, based on the carbonate stratigraphic framework of the preset horizons in the study area and the thickness of the denuded strata at the preset horizons at the wells in the study area.

9. The device according to claim 8, wherein Carbonate formation framework building module, specifically used for: Sequence interface identification was carried out using geological information of the study area to obtain core-scale characteristics of sequence interfaces; The well logging information of the wells drilled in the study area was used to identify the sequence interface and obtain the logging characteristics of the sequence interface; Using the geochemical information of the study area to carry out sedimentary geochemical analysis, the geochemical characteristics of the sequence interface were obtained; The core-scale characteristics, logging characteristics and geochemical characteristics of the sequence interface are analyzed to establish the carbonate stratigraphic framework of the preset horizons in the study area.

10. The device according to claim 8, wherein Carbonate formation framework building module, specifically used for: Sequence interface identification was carried out using geological information of the study area and logging information of the wells drilled in the study area to obtain the stratigraphic sequence of the preset drilling horizons; Using the logging information of the wells in the study area, cyclostratigraphic analysis was carried out to obtain the sedimentary cyclonic units at the drilling site and determine the correspondence between the sedimentary cyclonic units at the drilling site and the strata. According to the correspondence between the sedimentary cycle units and the strata at the drilling site, and the period to which the sedimentary cycle units at the drilling site belong, the period to which each stratum at the drilling site belongs is determined; The strata belonging to the same period are correlated to obtain the carbonate stratigraphic framework of the preset horizons in the study area.

11. The device according to claim 8, wherein The erosion layer thickness analysis module is specifically used for: Using the logging information from the wells in the study area, we conducted cyclostratigraphic analysis and obtained the sedimentary cycle sequence of the preset horizons at the wells. According to the sedimentary cycle sequence of the preset layer at the drilling site, the cycle characteristics of the preset layer at the drilling site are obtained; Cycle characteristics include: sedimentary cycle period of sedimentary cycle units, number of sedimentary cycle units; The cyclic characteristics of the preset horizon at the drilling site and the geological information of the study area were analyzed to obtain the sedimentation rate of the preset horizon at the drilling site.

12. The device according to claim 11, wherein The deposition rate was calculated according to the following formula: Where V i is the preset horizon sedimentation rate at the i-th well in the study area, H i is the thickness of the preset layer at the i-th well in the study area, m i is the number of sedimentary cycle units at the preset horizon at the i-th well in the study area, is the average sedimentary cycle period of the preset horizon sedimentary cycle unit at the i-th well in the study area.

13. The device according to claim 11, wherein The erosion layer thickness analysis module is specifically used for: The sedimentary cycle sequence at the preset location in the study area is determined as the standard sedimentary cycle sequence; wherein the preset location has not been eroded and the sedimentary cycle sequence is complete; Compare and analyze the sedimentary cycle sequence of the preset horizon at the drilling site with the standard sedimentary cycle sequence to obtain the number of missing sedimentary cycle units in the preset horizon at the drilling site; The product of the number of missing sedimentary cycle units and the sedimentation rate of the preset horizon at the drilling site is calculated respectively to obtain the thickness of the eroded stratum at the preset horizon at the drilling site.

14. The device according to claim 8, wherein Paleomorphology restoration module, specifically used for: When the number of wells drilled in the study area is less than the preset value, a machine learning algorithm is used to restore the paleomorphology of the preset horizons in the study area based on the carbonate stratigraphic framework of the preset horizons in the study area and the thickness of the denuded strata at the preset horizons where the wells are drilled in the study area. When the number of wells drilled in the study area is not less than the preset value, the interpolation algorithm is used to restore the paleomorphology of the preset horizons in the study area based on the carbonate stratigraphic framework of the preset horizons in the study area and the thickness of the denuded strata at the preset horizons where the wells are drilled in the study area.

15. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

16. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

17. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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