A method and system for predicting deepwater gravity flow hydrocarbon reservoirs

Abstract

The application discloses a kind of deepwater gravity flow oil and gas reservoir prediction method and prediction system, and prediction method includes steps: astronomical cycle signal extraction, according to the GR logging of at least two single wells in target block, four levels of astronomical cycle signals of eccentricity, slope, long eccentricity, short eccentricity are extracted by Milankovitch cycle analysis;Astronomical cycle signal identification, link the astronomical cycle formation framework between each well, compare and identify the astronomical cycle signal of each single well between multiple wells, establish astronomical cycle formation framework;Deepwater gravity flow oil and gas reservoir determination, according to the eccentricity of the astronomical cycle formation framework, the slope, the long eccentricity, the short eccentricity accurately determine the deepwater gravity flow oil and gas reservoir.The present application establishes higher precision astronomical formation framework based on astronomical cycle, and carries out high-precision isochronous stratigraphic correlation analysis of deepwater gravity flow oil and gas reservoir, to realize high-precision prediction.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas exploration, and in particular to a deep-water gravity flow oil and gas reservoir prediction method and system. BACKGROUND

[0002] With the vigorous development of deep-water gravity flow sand body oil and gas exploration and development in recent years, it is particularly important to identify the high-precision spatial and temporal distribution of deep-water thin interbedded gravity flow oil and gas reservoirs. Sequence stratigraphy is a common means of analyzing the spatial and temporal distribution and evolution of sedimentary rocks. It is based on the rise and fall of the horizontal plane, and identifies sequence boundaries through unconformities and corresponding conformities. As shown in the deep-water environment diagram, the water depth during the deposition of deep-water oil and gas reservoirs is large, and thus it is not sensitive to water depth changes, making it difficult to use sequence stratigraphy alone to achieve high-precision spatial and temporal distribution of deep-water thin interbedded gravity flow oil and gas reservoirs. Figure 1

[0003] There are two main types of existing deep-water gravity flow oil and gas reservoir prediction methods: using sequence stratigraphy and using seismic data.

[0004] Prior Art One:

[0005] Using sequence stratigraphy for prediction, sequence stratigraphy is a common means of analyzing the spatial and temporal distribution and evolution of sedimentary rocks. It is based on the rise and fall of the horizontal plane, and identifies sequence boundaries through unconformities and corresponding conformities. Its theoretical basis is that water depth changes control lithology and lithofacies changes, and through seismic, logging and well logging data, lithology and lithofacies changes can be identified to predict reservoirs. However, this method is only applicable to shallow sandstone and gravel environments (water depth of several to tens of meters), because the water depth of shallow sandstone and gravel environments is relatively shallow, and it is sensitive to water depth changes, resulting in very obvious lithology and lithofacies changes, which can be identified through seismic, logging and well logging data. The water depth during the deposition of deep-water oil and gas reservoirs is large, and the water depth of deep-water gravity flow thin interbedded oil and gas reservoirs is several hundred to several thousand meters. Therefore, the general scale changes of sea (lake) level (several to tens of meters) have little effect on deep-water environments, making it difficult for traditional methods to depict the spatial and temporal distribution of deep-water thin interbedded oil and gas reservoirs.

[0006] As shown in the deep-water environment diagram, the water depth during the deposition of deep-water oil and gas reservoirs is large, and thus it is not sensitive to water depth changes, making it difficult to use sequence stratigraphy alone to achieve high-precision spatial and temporal distribution of deep-water thin interbedded gravity flow oil and gas reservoirs. Figure 2 ​The lithofacies of the glutenite strata system changes obviously, so the strata can be divided by using sequence stratigraphy, and then the distribution rule can be analyzed. The existing research on the spatiotemporal distribution rule of the deepwater gravity flow sand body oil and gas reservoir depends on sequence stratigraphy. The basis for the strata division by sequence stratigraphy is the water depth change, that is, based on the theory that the water depth change controls the lithology and lithofacies change, the strata division is carried out. Sequence stratigraphy identifies the lithology and lithofacies change through seismic, logging and mud logging data. This is applicable to the shallow water sandstone and glutenite environment, because the water depth of the shallow water sandstone and glutenite environment (a few meters to tens of meters) is small, and the water depth change is sensitive, resulting in obvious lithology and lithofacies change. Therefore, the lithology and lithofacies change can be identified through seismic, logging and mud logging data, and then the spatiotemporal distribution rule of the shallow water sandstone and glutenite can be analyzed.

[0007] The defect of the prior art 1 is that the sequence stratigraphy technology depends too much on the lithology and lithofacies change caused by the water depth change, and needs to identify these lithology and lithofacies changes on seismic, logging and mud logging data. However, the water depth of the deep water environment is large, resulting in that it is not sensitive to the relative water depth change, so it is difficult to solve this problem only by using sequence stratigraphy.

[0008] The prior art 2 is:

[0009] The deepwater gravity flow sand body is identified by using seismic data for prediction, through interpreting seismic profiles, extracting seismic attributes or seismic inversion technology.

[0010] The defect of the prior art 2 is that the cost of seismic data acquisition is high, and there is no seismic data in many sedimentary basins; and the research precision of the seismic data is limited by the quality of the seismic data, resulting in that the research precision of the deepwater gravity flow sand body is insufficient, and it is difficult to achieve the fine description of the meter-level deepwater gravity flow sand body.

[0011] Therefore, the current deepwater gravity flow oil and gas reservoir prediction method cannot achieve high-precision prediction in the deepwater environment, and in the field of deepwater gravity flow oil and gas reservoir prediction, new theories and technologies are urgently needed to solve the problem of low prediction precision of the spatiotemporal distribution of deepwater thin interbedded oil and gas reservoirs. SUMMARY

[0012] In order to overcome one or more of the above technical problems, the purpose of the present application is to provide a deepwater gravity flow oil and gas reservoir prediction method and prediction system, which uses well logging curves to analyze astronomical cycles, identifies multi-scale astronomical cycle signals including super-long eccentricity, slope, long eccentricity and short eccentricity, and then analyzes the spatiotemporal distribution rule of the deepwater thin interbedded oil and gas reservoir by using the astronomical cycle signals, so as to solve the problem of low prediction precision of the deepwater gravity flow oil and gas reservoir in the prior art.

[0013] In a first aspect, the present application provides a deepwater gravity flow oil and gas reservoir prediction method, characterized in that it comprises the following steps:

[0014] extracting the astronomic cycle signals, according to the Milankovitch cycle analysis of GR logging curves of at least two single wells in the target block, extracting astronomic cycle signals of four levels of super-long eccentricity, slope, long eccentricity and short eccentricity;

[0015] identifying the astronomic cycle signals, connecting the astronomic cycle stratigraphic framework between wells, comparing and identifying the cycles of super-long eccentricity, slope, long eccentricity and short eccentricity of each single well among multiple wells, and establishing the astronomic cycle stratigraphic framework;

[0016] determining the deepwater gravity flow oil and gas reservoir, according to the astronomic cycle stratigraphic framework, and according to the super-long eccentricity, the slope, the long eccentricity and the short eccentricity of the deepwater thin interbedded reservoir, accurately determining the deepwater gravity flow oil and gas reservoir.

[0017] Further, the extraction of the astronomic cycle signals includes the following steps:

[0018] In the Milankovitch cycle analysis, the extraction of each level of cycle signal is super-long eccentricity, slope, long eccentricity and short eccentricity in turn, and the duration ratio is 240:120:40:10.

[0019] Further, the identification of the astronomic cycle signals includes the following steps:

[0020] According to the anchor point age or marker layer calibration of the single well, connecting the astronomic cycle stratigraphic framework of each well, and comparing and identifying the cycles of super-long eccentricity, slope, long eccentricity and short eccentricity among multiple wells.

[0021] Further, the determination of the deepwater gravity flow oil and gas reservoir includes the following steps:

[0022] Using the super-long eccentricity with a duration cycle of 2.4 million years to identify the lithofacies assemblage type;

[0023] Using the slope with a duration cycle of 1.2 million years to predict the scale of the thin interbedded reservoir;

[0024] Using the internal cycle of the long eccentricity with a duration cycle of 400,000 years to predict the long and short eccentricity cycles controlling the frequency, period and component of felsic sandstone+shale in turn;

[0025] Using the internal cycle of the short eccentricity with a duration cycle of 100,000 years to predict the secondary cycle of frequency, period and component of felsic sandstone+shale and TOC content.

[0026] In the above embodiments, the lithofacies assemblage type is a genetic type of rock, for example including flood-type lithofacies assemblage and slump-type lithofacies assemblage; the scale of thin interbedded reservoir is the cumulative stacking thickness of sand bodies, for example including sand bodies with a thickness of several meters to tens of meters; the felsic sand+shale frequency, phase, and component are trigger time interval, single-phase thickness, and mineral component (i.e., brittleness), respectively; the felsic sand+shale frequency, phase, and component of the secondary cycle and TOC content are secondary trigger time interval, single-phase thickness, mineral component (i.e., brittleness), and organic matter abundance.

[0027] In a second aspect, the present application further provides a deepwater gravity flow oil and gas reservoir prediction system, characterized in that it comprises:

[0028] a time scale extraction module configured to extract four levels of astronomical cycle signals of super-long eccentricity, slope, long eccentricity, and short eccentricity according to Milankovitch cycle analysis of GR logging curves or the like of at least two single wells in a target block, and establish an astronomical cycle stratigraphic framework;

[0029] a time scale identification module configured to link the astronomical cycle stratigraphic frameworks between wells, and compare and identify the cycles of super-long eccentricity, slope, long eccentricity, and short eccentricity of each single well between multiple wells;

[0030] a deepwater gravity flow oil and gas reservoir determination module configured to accurately determine deepwater gravity flow oil and gas reservoirs according to the astronomical cycle stratigraphic framework and the super-long eccentricity, slope, long eccentricity, and short eccentricity of deepwater thin interbedded reservoirs.

[0031] Further, the time scale extraction module has a ratio of super-long eccentricity, slope, long eccentricity, and short eccentricity duration of 240:120:40:10; the time scale identification module links the astronomical cycle stratigraphic frameworks between wells according to the anchor point age or marker layer calibration of the single well, and compares and identifies the cycles of super-long eccentricity, slope, long eccentricity, and short eccentricity of each single well between multiple wells.

[0032] Still further, the deepwater gravity flow oil and gas reservoir determination module includes a super-long eccentricity cycle module, a slope cycle module, a long eccentricity cycle module, and a short eccentricity cycle module.

[0033] The super-long eccentricity cycle module is configured to identify the lithofacies assemblage type according to the cycle of super-long eccentricity of 2.4 million years.

[0034] The slope cycle module is configured to predict the scale of thin interbedded reservoirs according to the cycle of slope of 1.2 million years.

[0035] The long eccentricity cycle module predicts long felsic sandstone + mudstone frequency, period and component according to the long eccentricity cycle of 400,000 years and the short eccentricity cycle of 1,000,000 years.

[0036] The short eccentricity cycle module predicts the frequency, period and component of the secondary cycle of long felsic sandstone + mudstone and the TOC content according to the short eccentricity cycle of 1,000,000 years.

[0037] Compared with the prior art, the present application has the following beneficial effects:

[0038] The deep water gravity flow oil and gas reservoir high-precision prediction method and prediction system provided by the present application first identify the astronomical cycles of super-long eccentricity, slope, long eccentricity and short eccentricity of at least two single wells, and establish a high-precision astronomical cycle stratigraphic framework of the target block according to these astronomical cycle signals, because the precision of the sequence stratigraphic framework established based on the astronomical cycle is much higher than that of the sequence stratigraphic framework established by the traditional method. Under the constraint of the high-precision cycle stratigraphic framework, high-precision isochronous stratigraphic correlation of the deep water gravity flow oil and gas reservoir is carried out, thereby realizing high-precision prediction. At the same time, the present application also realizes the prediction of the frequency, period and component of long felsic sandstone + mudstone, which cannot be realized by the traditional sequence stratigraphy method. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 Deep water environment schematic diagram.

[0040] Figure 2 Single well shallow water sandstone and gravel layer division schematic diagram based on sequence stratigraphy.

[0041] Figure 3 Distribution rule of deep water gravity flow sand body in super-long eccentricity stratigraphic framework.

[0042] Figure 4 Different long eccentricity sand ratio contour map within a slope.

[0043] Figure 5 Long eccentricity and short eccentricity gradually control sand and mud distribution rule diagram.

[0044] Figure 6 Flowchart of embodiment 1 of the present application.

[0045] Figure 7 Schematic diagram of the determination step of the deep water gravity flow oil and gas reservoir of embodiment 1 of the present application.

[0046] Figure 8 Schematic diagram of the deep water gravity flow oil and gas reservoir prediction system of embodiment 2 of the present application.

[0047] Figure 9Figure 3 is a well FS1 astrocycle and gravity flow reservoir relationship chart for embodiment 3 of the present invention.

[0048] Reference signs in the drawings are:

[0049] 1, time scale extraction module; 2, time scale identification module; 3, deepwater gravity flow oil and gas reservoir determination module; 31, super-long eccentricity cycle module; 32, slope cycle module; 33, long eccentricity cycle module; 34, short eccentricity cycle module. DETAILED DESCRIPTION

[0050] The present invention will be further described below in conjunction with the accompanying drawings, so that those skilled in the art can implement it according to the description.

[0051] The terms "first", "second", "third", "fourth" in the embodiments of the present application are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", "third", "fourth" can be explicitly or implicitly included at least one of the features. It should be noted that in the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited. In addition, the directions or position relationships indicated by "up", "down", "top", "bottom", "inner", "outer" are based on the directions or position relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the devices or apparatuses referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present invention. Furthermore, the terms "include" and "provided with" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0052] In addition to the above, it is still emphasized that the reference to "embodiments" in this document means that the specific features, structures or characteristics described in conjunction with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily refer to the same embodiment, nor is it independent or alternative to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0053] Embodiment 1

[0054] As Figure 6 shown, a deepwater gravity flow oil and gas reservoir prediction method includes the following steps:

[0055] S1: Extraction of astronomical cycle signals, according to Milankovitch cycle analysis of GR logging curves and the like of at least two single wells in the target block, astronomical cycle signals of four levels of super-long eccentricity, slope, long eccentricity and short eccentricity are extracted, and an astronomical cycle stratigraphic framework is established;

[0056] More specifically, according to Milankovitch cycle analysis of multiple single well GR logging curves of the deep water thin interbedded reservoir, cycle signals of each level are extracted, and four parameters with duration ratios of 240:120:40:10 are selected, namely super-long eccentricity, slope, long eccentricity and short eccentricity;

[0057] An astronomical cycle stratigraphic framework of four parameters of super-long eccentricity (period of 2.4 million years), slope (period of 1.2 million years), long eccentricity (period of 0.4 million years) and short eccentricity (period of 0.1 million years) of the deep water thin interbedded reservoir is established.

[0058] S2: Identification of astronomical cycle signals, connecting the astronomical cycle stratigraphic framework between wells, and comparing the super-long eccentricity, slope, long eccentricity and short eccentricity cycles of each single well between multiple wells. More specifically, according to the anchor point age or marker layer calibration of the single well, the astronomical cycle stratigraphic framework of each well is connected, and each super-long eccentricity, slope, long eccentricity and short eccentricity cycle is compared between multiple wells.

[0059] Through the above S1 and S2 steps, high-precision isochronal stratigraphic correlation of the deep water oil and gas reservoir in the target block is realized.

[0060] S3: Determination of deep water gravity flow oil and gas reservoir, according to the astronomical cycle stratigraphic framework, the super-long eccentricity, slope, long eccentricity and short eccentricity of the deep water thin interbedded reservoir are used to determine the deep water gravity flow oil and gas reservoir.

[0061] The deep water gravity flow oil and gas reservoir has a large water depth, and with the change of water depth (meter level), the lithology and lithofacies change is not sensitive, resulting in that the lithology and lithofacies change is not obvious, so that the lithology and lithofacies change cannot be identified through seismic, logging and logging data. Through the steps S1, S2 and S3 of the embodiment, the logging curves are used for astronomical cycle analysis, the multi-scale astronomical cycle signals including super-long eccentricity, slope, long eccentricity and short eccentricity are identified, and then the astronomical cycle signals are used to more accurately predict the space-time distribution rule of the deep water thin interbedded oil and gas reservoir in the target block.

[0062] Specifically, in some embodiments, the determination of the deep water gravity flow oil and gas reservoir in the S3 step includes the following steps:

[0063] S3-1: Use the super-long eccentricity with a duration period of 2.4 million years to identify the lithofacies assemblage type, such as Figure 3Among them, flood-type sandstone assemblages are mainly distributed in the middle of the ultra-long eccentricity, while landslide-type sandstone assemblages are distributed at the top and bottom of the ultra-long eccentricity.

[0064] S3-2: Predicting the size of thin interbedded reservoirs using a slope with a duration of 1.2 million years. One 1.2 million-year slope cycle includes three long eccentricity cycles with a duration of 400,000 years. Among these three long eccentricity cycles, the thin interbedded reservoirs are more developed in the middle long eccentricity cycle. For example... Figure 4 The slope is such that the long eccentricity 2 in the middle section indicates a high sand-to-soil ratio and a large sandstone thickness. In the left figure, the long eccentricity is 1 at the bottom; in the middle figure, it is 2 in the middle; and in the right figure, it is 3 at the top. The vertical colored bars in the figure represent the percentage of sandstone thickness (sand-to-soil ratio).

[0065] S3-3: By utilizing the interior of a long eccentricity cycle with a duration of 400,000 years, the frequency, phase, and composition of felsic sandstone + mudstone are predicted to be controlled stepwise by the long eccentricity cycle and the short eccentricity cycle. A method is proposed to comprehensively predict the frequency, phase, and composition of felsic sandstone + mudstone using the long eccentricity cycle and the short eccentricity cycle.

[0066] S3-4: Utilizing the interior of a short eccentricity cycle with a duration of 100,000 years, the middle part of the cycle (low-value stage) shows sandstone thickness, high frequency, high felsic content, and low TOC. Therefore, the 100,000-year short eccentricity cycle is a secondary cycle for predicting sandstone thickness, frequency, and felsic mineral content. Figure 5 The diagram shows the gradual control of sand and mud distribution by long and short eccentricities.

[0067] like Figure 7 The predictions shown are obtained after steps S3-1, S3-2, S3-3, and S3-4. Figure 7 In the middle section, the 2.4 million-year ultra-long eccentricity cycle predicted that the top layer was a slump-type sandstone and the middle layer was a flood-type sandstone; the 1.2 million-year slope cycle predicted that the top and bottom layers had less slope sandstone and the middle layer had more slope sandstone; the 400,000-year long eccentricity cycle predicted that the top and bottom layers had thin felsic material, low frequency, and low brittleness, while the middle layer had thick felsic material, high frequency, and high brittleness; the 100,000-year short eccentricity cycle predicted that the top and bottom layers had thin felsic material, low frequency, low brittleness, and high TOC, while the middle layer had thick felsic material, high frequency, high brittleness, and low TOC.

[0068] Example 2

[0069] like Figure 8 As shown, the present invention also provides a deepwater gravity flow oil and gas reservoir prediction system, which includes a time scale extraction module 1, a time scale identification module 2, and a deepwater gravity flow oil and gas reservoir determination module 3.

[0070] Specifically, the time scale extraction module 1 is used to extract four levels of astronomical cycle signals of super-long eccentricity, slope, long eccentricity and short eccentricity according to the Milankovitch cycle analysis of GR logging curves of at least two single wells in the target block, and to establish an astronomical cycle stratigraphic framework; the time scale identification module 2 is used to link the astronomical cycle stratigraphic frameworks between wells, and to compare and identify the cycles of super-long eccentricity, slope, long eccentricity and short eccentricity of each single well among multiple wells; and the deepwater gravity flow oil and gas reservoir determination module 3 is used to accurately determine the deepwater gravity flow oil and gas reservoir according to the astronomical cycle stratigraphic framework and the super-long eccentricity, slope, long eccentricity and short eccentricity of the deepwater thin interbedded reservoir.

[0071] Further, the duration ratio of super-long eccentricity, slope, long eccentricity and short eccentricity in the time scale extraction module 1 is 240:120:40:10; the time scale identification module 2 is calibrated according to the anchor point age or marker layer of a single well, links the astronomical cycle stratigraphic frameworks of each well, and compares and identifies the cycles of super-long eccentricity, slope, long eccentricity and short eccentricity of each single well among multiple wells.

[0072] Further, the deepwater gravity flow oil and gas reservoir determination module 3 includes a super-long eccentricity cycle module 31, a slope cycle module 32, a long eccentricity cycle module 33 and a short eccentricity cycle module 34.

[0073] The super-long eccentricity cycle module 31 is used to identify the lithofacies assemblage type according to the 2.4 million-year super-long eccentricity cycle.

[0074] The slope cycle module 32 is used to predict the scale of thin interbedded reservoirs according to the 1.2 million-year slope cycle.

[0075] The long eccentricity cycle module 33 is used to control the frequency, period and composition of felsic sandstone+shale in stages according to the 400,000-year long eccentricity cycle and the 100,000-year short eccentricity cycle, and to propose the use of long eccentricity cycle and short eccentricity cycle to predict the frequency, period and composition of felsic sandstone+shale, wherein the middle part of the 400,000-year cycle, i.e. the low value stage, has large sandstone thickness, high frequency, high felsic content and low TOC.

[0076] The short eccentricity cycle module 34 is used to predict the secondary cycle of frequency, period and composition of felsic sandstone+shale and TOC content according to the 100,000-year short eccentricity cycle, wherein the middle part of the 100,000-year short eccentricity cycle, i.e. the low value stage, has large sandstone thickness, high frequency, high felsic content and low TOC.

[0077] Embodiment 3

[0078] Based on publicly available information from an oilfield, the gravity flow reservoir prediction method for the drilled well FS1 was used according to this invention. An astronomical cycle framework was established using GR logging curves, thereby enabling reservoir prediction. Figure 9 As shown in the figure, the type of gravity flow sand body reservoir was predicted using the ultra-long eccentricity cycle curve of 2.4 million years, and the slump-type gravity flow reservoir was identified at the top and bottom of its cycle. Figure 9 (Numbers 1 and 4), flood-type gravity flow reservoirs were identified in the middle of their cycles ( Figure 9 (Numbers 2 and 3). Furthermore, using a 1.2 million-year slope to predict the size of gravity flow reservoirs, gravity flow reservoirs located at the top and bottom of the slope were found, with thin individual reservoir layers. Figure 9 Number 3, with a single layer less than 5 meters thick, while the gravity flow reservoir located in the middle of the slope has a large single layer thickness. Figure 9 (Numbered 1-2, 4; single layer thickness 15 meters). Furthermore, using a 400,000-year long eccentricity cycle to predict the felsic mineral composition, it was found that the felsic mineral content was high and the TOC was low in the middle of the long eccentricity. Using a 100,000-year short eccentricity cycle to predict the secondary cycles and TOC cycles of felsic minerals, it was found that the felsic content was high and the TOC was low in the middle of the short eccentricity.

[0079] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method of predicting deepwater gravity flow hydrocarbon reservoirs, characterized by, The method comprises the following steps: astronomical cycle signal extraction, extracting four levels of astronomical cycle signals of super-long eccentricity, slope, long eccentricity and short eccentricity according to Milankovitch cycle analysis of GR logging curves of at least two single wells in a target block, and establishing an astronomical cycle stratigraphic framework; astronomical cycle signal identification, connecting the astronomical cycle stratigraphic framework between wells, and comparing and identifying the cycles of super-long eccentricity, slope, long eccentricity and short eccentricity of each single well among multiple wells to establish an astronomical cycle stratigraphic framework; determination of deepwater gravity flow oil and gas reservoir, accurately determining the deepwater gravity flow oil and gas reservoir according to the super-long eccentricity, the slope, the long eccentricity and the short eccentricity of the deepwater thin interbedded reservoir according to the astronomical cycle stratigraphic framework; the determination of the deepwater gravity flow oil and gas reservoir comprises the following steps: using the super-long eccentricity with a continuous period of 2.4 million years to identify lithofacies assemblage types; using the slope with a continuous period of 1.2 million years to predict the scale of thin interbedded reservoirs; using the long eccentricity with a continuous period of 400,000 years to predict the long and short eccentricity cycles controlling the frequency, period and composition of felsic sandstone and mudstone in turn; using the short eccentricity cycle with a continuous period of 100,000 years to predict the secondary cycle of the frequency, period and composition of felsic sandstone and mudstone and the TOC content.

2. The method of claim 1, wherein, The astronomical cycle signal extraction comprises the following steps: In the Milankovitch cycle analysis, the extraction of each level of cycle signal is super-long eccentricity, slope, long eccentricity and short eccentricity in turn, and the duration ratio is 240:120:40:

10.

3. The method of claim 2, wherein, The astronomical cycle signal identification comprises the following steps: According to the anchor point age or marker layer calibration of the single well, the astronomical cycle stratigraphic framework of each well is connected, and the cycles of super-long eccentricity, slope, long eccentricity and short eccentricity are compared and identified among multiple wells.

4. A deep water gravity flow reservoir prediction system, characterized by, It comprises: a time scale extraction module for extracting four levels of astronomical cycle signals of super-long eccentricity, slope, long eccentricity and short eccentricity according to Milankovitch cycle analysis of GR logging curves of at least two single wells in a target block, and establishing an astronomical cycle stratigraphic framework; a time scale identification module for connecting the astronomical cycle stratigraphic framework between wells, and comparing and identifying the cycles of super-long eccentricity, slope, long eccentricity and short eccentricity of each single well among multiple wells to establish an astronomical cycle stratigraphic framework; a deepwater gravity flow oil and gas reservoir determination module for accurately determining the deepwater gravity flow oil and gas reservoir according to the super-long eccentricity, the slope, the long eccentricity and the short eccentricity of the deepwater thin interbedded reservoir according to the astronomical cycle stratigraphic framework; The deepwater gravity flow oil and gas reservoir determination module comprises a super-long eccentricity cycle module, a slope cycle module, a long eccentricity cycle module and a short eccentricity cycle module; The super-long eccentricity cycle module identifies lithofacies assemblage types according to the super-long eccentricity cycle with a period of 2.4 million years. The slope cycle module predicts the scale of thin interbedded reservoirs according to the slope cycle with a period of 1.2 million years. The long eccentricity cycle module predicts the frequency, period and component of the long felsic sandstone+ mudstone according to the long eccentricity cycle of 400,000 years and the short eccentricity cycle of 1,000,000 years. The short eccentricity cycle module predicts the frequency, period, component, secondary cycle and TOC content of the long felsic sandstone+ mudstone according to the short eccentricity cycle of 1,000,000 years.

5. The deep water gravity flow hydrocarbon reservoir prediction system of claim 4, wherein, The ratio of the duration of the ultra-long eccentricity, slope, long eccentricity, short eccentricity in the time scale extraction module is 240:120:40:10; the time scale identification module is calibrated according to the anchor point age or marker layer of the single well, links the astronomic cycle stratigraphic framework of each well, and compares and identifies the cycle of the ultra-long eccentricity, slope, long eccentricity and short eccentricity of each single well among multiple wells.

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