A quantitative hydrodynamic evaluation method based on shelf sand ridge morphology

Abstract

This invention discloses a quantitative hydrodynamic evaluation method based on shelf sand ridge morphology, including: acquiring relevant data characterizing the shelf sand ridge features of the target work area; conducting seismic stratigraphic interpretation of sand bodies; dividing the target shelf sand ridge into different systems tracts; performing correlation analysis between seismic attributes and sand body thickness, optimizing seismic attributes, and characterizing striped sand sedimentary facies; statistically analyzing relevant physical parameters of the shelf sand ridge; statistically analyzing the morphological parameters of the shelf sand ridge in different systems tracts; classifying the shelf sand ridge morphology according to different systems tracts; calculating the hydrodynamic index of different systems tracts based on the morphological characteristics of the shelf sand ridges; and determining the hydrodynamic influence type of different systems tracts based on the morphological type of the shelf sand ridge and the hydrodynamic index of different systems tracts. This invention defines the hydrodynamic index for the formation of shelf sand ridges in different systems tracts by characterizing the planar morphological parameters of the shelf sand ridges, which can help promote the exploration and development of subsequent lithologic oil and gas reservoirs.

Description

Technical Field

[0001] This invention relates to a quantitative hydrodynamic evaluation method based on shelf sand ridge morphology, belonging to the field of petroleum exploration and development technology. Background Technology

[0002] With fewer and fewer structural oil and gas reservoirs being discovered, lithologic oil and gas reservoirs, such as updip pinch-out sand bodies and lenses, are gradually becoming important exploration targets for increasing oil and gas reserves in my country. On shallow marine shelves tens or hundreds of kilometers from the coastline, sand bodies with linear or radial planar morphologies are often distributed; these sand bodies are called shelf ridges (tidal ridges, beach ridges, or banded sands). Shelf ridges mostly extend parallel to the coastline and are often enclosed by shelf mudstone to form lenticular lithologic traps. They are connected to the underlying source rocks through faults or sand body networks, possessing excellent conditions for oil and gas accumulation and making them important targets for lithologic exploration and development in my country.

[0003] However, shallow marine shelf sand ridges are subjected to complex hydrodynamic forces during their formation, including tides and coastal currents. The mixed hydrodynamic processes on shallow marine shelves are complex, with variations in hydrodynamic forces at different times within the same region, and different facies zones experiencing varying intensities of hydrodynamic alteration during the same period. This results in rapid morphological and lateral facies transitions in shelf sand ridges, leading to strong heterogeneity in reservoir thickness and properties, and significant differences in oil (gas) content. For a long time, the evaluation of the hydrodynamic impact of shelf sand ridges has primarily relied on bedding analysis of core records. However, in offshore oil and gas exploration, core sampling is often scarce, making it difficult to accurately determine the types of hydrodynamic impacts and evaluation methods, greatly increasing the difficulty of exploring and evaluating such lithological traps. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the prior art by providing a quantitative hydrodynamic evaluation method based on shelf sand ridge morphology.

[0005] The technical solution provided by this invention to solve the above-mentioned technical problems is: a method for quantitative evaluation of hydrodynamics based on shelf sand ridge morphology, comprising the following steps:

[0006] Step S10: Obtain relevant data on the characteristics of the continental shelf sand ridges supporting the target work area;

[0007] Step S20: Based on the seismic data of the target work area and the shelf sand ridge stratigraphic interpretation scheme, carry out seismic stratigraphic interpretation of the sand body;

[0008] Step S30: Based on the seismic reflection termination relationship and the accommodation space sequence method, identify the sequence boundary and system tract interface, and divide the target shelf sand ridge into different system tracts according to the identified interface.

[0009] Step S40: Using the seismic horizon of the sand body as a constraint, extract various conventional seismic attributes, and extract the sand body thickness of a single well based on well logging data and the Direct software module; then perform correlation analysis between the seismic attributes and the sand body thickness, select the best seismic attributes, and characterize the strip sand sedimentary facies.

[0010] Step S50: Based on core and thin section data, and constrained by the system tract division scheme, statistical analysis of shelf sandstone and ridge lithology is conducted according to different system tracts;

[0011] Step S60: Based on physical property data and constrained by the system tract division scheme, statistically analyze the relevant physical property parameters of shelf sand ridges according to different system tracts;

[0012] Step S70: Based on the characterized sedimentary microfacies, use CorelDraw software and VB to write a program to statistically analyze the morphological parameters of shelf sand ridges in different system tracts;

[0013] Step S80: Comprehensively analyze and statistically analyze the morphological parameters of the shelf sand ridges, and classify the shelf sand ridge morphology according to different system domains;

[0014] Step S90: Calculate the hydrodynamic index of different system tracts based on the morphological characteristics of shelf sand ridges;

[0015] Step S100: Determine the hydrodynamic influence type of different system tracts based on the morphology type of the shelf sand ridge and the hydrodynamic index of different system tracts.

[0016] A further technical solution is that the relevant data includes seismic data, well logging data, core / thin section data, physical property data, and regional geological data.

[0017] A further technical solution is that, in step S20, when interpreting the seismic stratigraphic position of the sand body, the principles of isochronous comparison, hierarchical control, and model guidance are followed, and a combined well-seismic approach is adopted, with interaction between planar and cross-sectional views, to achieve closed interpretation of the sand body stratigraphic position.

[0018] A further technical solution is that the specific process of step S30 includes:

[0019] Step S31: Identify sequence boundaries based on seismic reflection termination relationships and sequence stratigraphy theory and methods;

[0020] Step S32: Identify system tract interfaces based on seismic reflection termination relationships and the accommodative space sequence method;

[0021] Step S33: Divide the shelf sand ridges into different systems tracts according to sequence boundaries and systems tract interfaces.

[0022] A further technical solution is that the specific process of step S40 includes:

[0023] Step S41: Using the seismic horizon of the sand body as a constraint, extract various conventional seismic attributes, including amplitude, statistical, signal, and waveform attributes;

[0024] Step S42: Based on the logging data, extract the thickness of the sand body in a single well of the target layer using the Diret software module;

[0025] Step S43: Perform correlation analysis between the extracted seismic attributes and sand body thickness, and optimize the seismic attributes;

[0026] Step S44: Based on the selected seismic attributes and combined with well logging, core and sand body thickness data, characterize the shelf sand ridge sedimentary facies.

[0027] A further technical solution is that the relevant physical properties of the continental shelf sand ridge in step S60 include porosity and permeability.

[0028] A further technical solution is that the morphological parameters of the shelf sand ridge in step S70 include length, maximum width, area, and orientation.

[0029] A further technical solution is that, in step S80, the continental shelf sand ridge morphology is divided into type I, type II, and type III; where type I is wide in the south and narrow in the north; type II is approximately equal in width in the north and south; and type III is slightly wider in the north and narrower in the south.

[0030] A further technical solution is that the formula for calculating the hydrodynamic index in step S90 is:

[0031]

[0032] In the formula: L1 is the maximum width of the northern part of the strip sand body; L2 is the maximum width of the southern part of the strip sand body; Δ is the hydrodynamic index.

[0033] A further technical solution is that, in step S100, when the continental shelf sand ridge is of type I, the hydrodynamic index Δ is 0.62-1.06, and its hydrodynamic influence type is mainly wave action;

[0034] When the shelf sand ridge is of type II, the hydrodynamic index Δ is 0.06-0.2, and its hydrodynamic influence is mainly tidal.

[0035] When the shelf sand ridge is of type III, the hydrodynamic index Δ is 0.25-0.53, and its hydrodynamic influence type is a coastal current-tidal hybrid.

[0036] The beneficial effects of this invention are as follows: By characterizing the planar morphological parameters of shelf sand ridges in different system tracts, this invention defines the hydrodynamic index for the formation of shelf sand ridges in different system tracts, which can help promote the exploration and development of subsequent lithologic oil and gas reservoirs. Attached Figure Description

[0037] Figure 1 Diagram illustrating the interface patterns of system domains identified by the earthquake termination relationship and the accommodative spatial sequence method;

[0038] Figure 2 Seismic profile and interface identification map of the target work area;

[0039] Figure 3 A diagram illustrating the system domain division of the target work area;

[0040] Figure 4 Statistical diagram of the thickness of shelf ridge sand bodies in different system domains;

[0041] Figure 5 This is a root mean square attribute graph;

[0042] Figure 6 Sedimentary facies diagram of shelf sand ridges in the target work area;

[0043] Figure 7 Statistical diagrams of shelf sandstone ridge lithology for different system tracts;

[0044] Figure 8 Statistical diagrams of the physical properties of shelf sand ridges in different system domains;

[0045] Figure 9 Statistical chart of hydrodynamic indices for shelf sand ridges in different system domains. Detailed Implementation

[0046] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] like Figure 1 As shown, the present invention provides a method for quantitative hydrodynamic evaluation based on shelf sand ridge morphology, comprising the following steps:

[0048] Step S10: Obtain relevant data on the characteristics of the continental shelf sand ridge in the target work area, including seismic data, well logging data, core / thin section data, physical property data, and regional geological data;

[0049] Step S20: Based on the seismic data of the target work area and the shelf sand ridge stratigraphic interpretation scheme, carry out seismic stratigraphic interpretation of the sand body;

[0050] Based on the shelf sand ridge stratigraphic division scheme, and referring to typical seismic reflection termination relationships (erosion, top overshoot, top overshoot, bottom overshoot), the seismic stratigraphics are manually interpreted and adjusted, and finally a complete closed three-dimensional seismic interpretation stratigraphic sequence is obtained.

[0051] When interpreting seismic horizons, the principles of "isochronous correlation, hierarchical control and model guidance" are followed, and a combined well-seismic approach is adopted, with interaction between planar and profile views, to achieve closed interpretation of sand body horizons.

[0052] Step S30: Based on the seismic reflection termination relationship and the accommodation space sequence method, identify the sequence boundary and system tract interface, and divide the target shelf sand ridge into different system tracts according to the identified interface.

[0053] Step S31: Identify sequence boundaries based on seismic reflection termination relationships and sequence stratigraphy theory and methods;

[0054] Using sequence stratigraphy theory and methods, as well as previous sequence stratigraphic schemes for the target stratigraphic segment in the target work area, a basis for identifying sequence boundaries is established based on the seismic reflection characteristics of the target work area.

[0055] Sequence boundaries are generally unconformities, which will manifest as seismic inhomogeneity on seismic profiles. They can be identified by the reflection termination of the same phase axis on the seismic profile. Typical seismic unconformities include erosion, top overlap, overlap, and underlap.

[0056] (1) Erosion

[0057] Erosion typically occurs at the top boundary of a sequence, where strata disappear laterally toward the top boundary of the sequence. On a seismic profile, this is manifested as the reflection phase axis terminating laterally toward the top boundary of the sequence, usually caused by erosion and tectonic faulting.

[0058] (2) Top Super League

[0059] Top-over phenomenon often occurs at the top boundary of a sequence stratigraphy, referring to the gradual decrease and eventual disappearance of the reverse dip of previously dipping strata as the thickness of the sequence boundary decreases. On seismic profiles, this manifests as the tangential axis below the interface gradually terminating below it, with significant lateral variations in the thickness of the stratigraphic units below the interface. It is often associated with deltaic complexes and can also be observed in deep-sea sedimentary fans. Top-over phenomenon also serves as evidence of sedimentary hiatuses formed without sedimentary activity.

[0060] It is usually not easy to distinguish between erosion and overcut on seismic profiles. However, there are several differences between them:

[0061] 1. Topsupreme deltas often appear at the top of deltas;

[0062] 2. The thickness of the strata reflected by the top edge varies greatly within a small area, and the strata are gradually eliminated with the top edge of the sequence; the thickness of the eroded strata is often stable over a large area, and the strata axes are approximately parallel to each other.

[0063] 3. Tops and bottoms often occur together;

[0064] (3) Shanghai Super League

[0065] The overlap phenomenon often occurs at the bottom boundary of a sequence stratigraphy. It refers to the overlying strata overlapping a primitive sedimentary slope in the opposite direction. On a seismic profile, this is manifested as the phase axes above the interface terminating one by one at a larger downdip angle from the lower part to the higher part.

[0066] (4) Lower Super

[0067] Underlap often occurs at the bottom boundary of a sequence stratigraphy, where an overlying, dipping stratum overlaps a dipping or horizontal original sedimentary surface along its dip. On seismic profiles, this manifests as axial sedimentary bodies above the interface terminating one by one on a smaller dip axis below the interface. The underlap surface often corresponds to the maximum floodplain, is very thin, but has no sedimentary discontinuities.

[0068] Based on the seismic reflection termination relationship of the sequence boundary, two third-order sequence boundaries, SB1 and SB2, were identified in the target work area of ​​the Zhujiang Formation, segment 3.

[0069] Among them, SB1 shows obvious top supersonic and upper supersonic termination relationships, while the erosion and lower supersonic relationships are not obvious. The in-phase axes generally exhibit low to medium frequency, medium amplitude, and moderate continuity.

[0070] SB2 shows obvious top-overlap, upper-overlap, and lower-overlap termination relationships, but the erosion relationship is not obvious. The in-phase axes generally exhibit low to medium frequency, medium to strong amplitude, and moderate continuity. Figure 2 );

[0071] Step S32: Identify system tract interfaces based on seismic reflection termination relationships and the accommodative space sequence method;

[0072] Based on four types of seismic reflection termination relationships—erosion, top overflow, overflow, and underflow—and the accommodative space sequence method, the system tract interfaces are identified, including the maximum flooding surface (MFS), the maximum regression surface (MRS), and the forced regression surface (FRS).

[0073] The accommodation space sequence method was proposed by researchers at Exxon in 2009. This method suggests that three stratigraphic sequences can be developed sequentially from bottom to top: PA (progradational-aggregate) sequence, R (retrogradational) sequence, and APD (aggregational-progradational-degradational) sequence; among which the APD sequence can be further divided into AP (aggregational-progradational) sequence and PD (progradational-degradational) sequence.

[0074] (1) Maximum flooding surface (MFS): This interface is the boundary between the R (regression) sequence and the AP (accretion-progradation) sequence in the stratigraphic stacking sequence. Above the interface is the AP (accretion-progradation) sequence, and below the interface is the R (regression) sequence. The overlap termination relationship of the same phase axis and the underlap phenomenon of multiple pre-accretionary layers can be identified on the interface.

[0075] (2) Maximum Regression Surface (MRS): This interface is the boundary between the PA (progradational-aggregate) sequence and the R (regressional) sequence in the stratigraphic stacking sequence. Above the interface is the R (regressional) sequence, and below the interface is the PA (progradational-aggregate) sequence.

[0076] (3) Forced Regression Surface (FRS): This interface is the boundary between the AP (accretionary-progradational) sequence and the PD (progradational-degradational) sequence in the stratigraphic stacking sequence. Above the interface is the PD (progradational-degradational) sequence, and below the interface is the AP (accretionary-progradational) sequence.

[0077] Step S33: Divide the shelf sand ridges into different systems tracts according to sequence boundaries and systems tract interfaces;

[0078] Based on the identified system tract boundaries, four distinct system tracts were identified: Early Transgressive System Tract (E-TST), Late Transgressive System Tract (L-TST), Highstand System Tract (HST), and Forced Regressive System Tract (FRST). Figure 2 , Figure 3 ).

[0079] Step S40: Using the seismic horizon of the sand body as a constraint, extract various conventional seismic attributes, and extract the sand body thickness of a single well based on well logging data and the Direct software module; then perform correlation analysis between the seismic attributes and the sand body thickness, select the best seismic attributes, and characterize the strip sand sedimentary facies.

[0080] Step S41: Using the seismic horizon of the sand body as a constraint, extract various conventional seismic attributes, including amplitude, statistical, signal, and waveform attributes;

[0081] The amplitude-related seismic attributes include root mean square amplitude, maximum amplitude, minimum amplitude, half-energy, average positive amplitude, average negative amplitude, average amplitude, and average energy.

[0082] Statistical seismic attributes include the sum of energy, the sum of amplitude, the sum of positive amplitude, the sum of negative amplitude, the threshold value, and the standard deviation of amplitude.

[0083] Seismic signal attributes include average instantaneous amplitude and average instantaneous frequency;

[0084] Waveform-type seismic properties include arc length;

[0085] Step S42: Based on the logging data, extract the thickness of the sand body in a single well of the target layer using the Diret software module;

[0086] When calculating the thickness of sand bodies, only the thickness of fine sandstone and siltstone that are favorable for oil and gas storage is counted.

[0087] like Figure 4As shown, the thickness of the forced regressive systems tract siltstone ranges from 6.8m to 39.3m, with an average thickness of 23.18m. The thickness of the HST siltstone ranges from 2.1m to 13.52m, with an average thickness of 4.76m. The thickness of the L-TST siltstone ranges from 2.1m to 6.2m, with an average thickness of 4.66m. The thickness of the E-TST siltstone ranges from 6.1m to 22.51m, with an average thickness of 14.11m.

[0088] Step S43: Perform correlation analysis between the extracted seismic attributes and sand body thickness, and optimize the seismic attributes;

[0089] Pearson correlation analysis was used to select seismic attributes that were highly correlated with sand thickness.

[0090] The formula for calculating the Pearson correlation coefficient is as follows:

[0091]

[0092] In the formula: x represents the sand body thickness information; y represents the seismic attribute information.

[0093] The strength of the correlation between the seismic attribute information and the lithological information is determined based on the absolute value of the Pearson correlation coefficient.

[0094] When the Pearson correlation coefficient is between 0.8 and 1.0, the correlation is extremely strong.

[0095] When the Pearson correlation coefficient is between 0.6 and 0.8, a strong correlation exists.

[0096] When the Pearson correlation coefficient is between 0.4 and 0.6, the correlation is moderate.

[0097] When the Pearson correlation is between 0.2 and 0.4, the correlation is weak.

[0098] When the Pearson value is between 0.0 and 0.2, the correlation is extremely weak or there is no correlation.

[0099] Based on the Pearson correlation coefficient ranking, the root mean square attribute has the best correlation, and the root mean square seismic attribute is preferred to reflect the shelf sand ridge morphology of the target work area.

[0100] Step S44: Based on the selected seismic attributes and combined with well logging, core and sand body thickness data, characterize the shelf sand ridge sedimentary facies;

[0101] (1) Seismic attributes characterize the outline: The root mean square attribute can better reflect the planar morphology of the shelf sand ridge, and the sand bodies are mostly distributed in the northeast-southwest direction. In the root mean square attribute map, the strong amplitude (reddish color mark) to the weak amplitude (greend color mark) can also reflect the state of the sand body thickness from thick to thin.

[0102] (2) Constraints from well logging, core, and sand thickness data: Using lithological logging curves, core identification reports, and extracted single-well sand body thicknesses, constraints and adjustments are made to the shelf sand ridge boundaries based on attribute characterization.

[0103] Step S50: Based on core and thin section data, and constrained by the system tract division scheme, statistical analysis of shelf sandstone and ridge lithology is conducted according to different system tracts;

[0104] Based on the obtained well core and thin section identification reports, the lithology of the shelf sand ridges was statistically analyzed according to different system tracts. According to the statistical results, the main lithologies are fine sandstone, siltstone, argillaceous siltstone, and silty mudstone.

[0105] like Figure 7 As shown, the main sedimentary lithologies in FRST are fine sandstone and siltstone, with fine sandstone being the dominant lithology, accounting for 80%, followed by siltstone, accounting for 20%. HST also mainly consists of fine sandstone and siltstone, accounting for 66.67% and 33.33% respectively. L-TST mainly consists of siltstone, argillaceous siltstone, and silty mudstone, accounting for 25%, 20%, and 55% respectively, with transitional lithologies accounting for 75%. E-TST contains sediments of fine sandstone, siltstone, argillaceous siltstone, and silty mudstone, accounting for 1.61%, 38.71%, 27.42%, and 32.26% respectively. The transitional lithologies argillaceous siltstone and silty mudstone account for the highest combined proportion of 59.68%, followed by siltstone, with fine sandstone being the least common.

[0106] Step S60: Based on physical property data and constrained by the system tract division scheme, statistically analyze the relevant physical property parameters of shelf sand ridges according to different system tracts;

[0107] The main physical properties of the shelf sand ridges in the target work area are porosity and permeability, which are statistically analyzed separately according to different system domains.

[0108] like Figure 8As shown, the porosity of FRST ranges from 20.1% to 28.2%, with an average of 23.72%; its permeability ranges from 53.7 mD to 606.04 mD, with an average of 442 mD. The porosity of HST ranges from 12.3% to 24.5%, with an average of 19.4%; its permeability ranges from 11 mD to 675 mD, with an average of 223.4 mD. The porosity of L-TST ranges from 8.61% to 15.96%, with an average of 11.74%; its permeability ranges from 0.02 mD to 0.7 mD, with an average of 0.15 mD. The porosity of E-TST ranges from 3.14% to 17.43%, with an average of 13.03%; its permeability ranges from 0.01 mD to 12.04 mD, with an average of 0.90 mD. Based on the statistical physical property data, the degree of physical property quality of shelf sand ridges in different system domains can be obtained as follows: FRST > HST > L-TST > E-TST;

[0109] Step S70: Based on the characterized sedimentary microfacies, use CorelDraw software and VB to write a program to statistically analyze the morphological parameters of shelf sand ridges in different system tracts;

[0110] Based on the characterized sedimentary microfacies, morphological parameters of shelf sand ridges in different system tracts were statistically analyzed using CorelDraw software and VB code. The main morphological parameters analyzed were length, maximum width, area, and orientation. The built-in measurement tools in CorelDraw software can be used to measure the length and maximum width of sand streaks; the area calculation code for closed shapes, written in VB language, can also be used to measure the area of ​​shelf sand ridges when run in CorelDraw software.

[0111] It should be noted that the VB code for measuring area is publicly available online, and its code is as follows:

[0112] Sub Test()

[0113] On Error Resume Next

[0114] ActiveDocument.Unit=cdrMillimeter

[0115] Dim sl As Shape,xSel As ShapeRange,m As Double,n As Double

[0116] Set xSel=ActiveSelectionRange

[0117] If ActiveSelectionRange.Count>1Or ActiveSelectionRange.Count=0Then

[0118] MsgBox: "Please select one curve first."

[0119] Exit Sub

[0120] End If

[0121] m=xSel.Shapes(1).Curve.Length

[0122] n = xSel.Shapes(1).Curve.Area

[0123] MsgBox "Curve length L (mm): "&Format(m,"0.0000")&Chr(13)&"Curve area S (mm2): "&Format(n,"0.0000")

[0124] End Sub

[0125] Step S80: Comprehensively analyze and statistically analyze the morphological parameters of the shelf sand ridges, and classify the shelf sand ridge morphology according to different system domains;

[0126] The shelf sand ridge morphology is divided into three types: Type I, Type II, and Type III. Type I is wider in the south and narrower in the north; Type II is approximately equal in width between the north and south; and Type III is slightly wider in the north and narrower in the south.

[0127] The shelf sand ridge morphology of the forced marine regression system domain is mostly Type I (wider in the south and narrower in the north); the early marine transgression system domain is mainly Type II (approximately equal width in the north and south), with some Type III (slightly wider in the north and narrower in the south); the late marine transgression system domain is mainly Type III (slightly wider in the north and narrower in the south), with some Type II (approximately equal width in the north and south).

[0128] Step S90: Calculate the hydrodynamic index of different system tracts based on the morphological characteristics of shelf sand ridges;

[0129] During the deposition of the target shelf sand ridge, the target work area was subjected to prolonged NE-SW tidal forces and SSW coastal currents. Due to the bidirectional nature of tidal flow, the planar morphology of the sand bodies was easily modified to a relatively symmetrical form, i.e., Type II or Type III sand bodies; while the coastal current tended to unidirectional modification, easily forming Type I sand bodies that converged in the north and diverged in the south. To highlight the morphological differences caused by different hydrodynamic influences, a hydrodynamic index (Δ) was defined for semi-quantitative characterization, and its expression is:

[0130]

[0131] In the formula: L1 is the maximum width of the northern part of the strip sand body; L2 is the maximum width of the southern part of the strip sand body; Δ is the hydrodynamic index;

[0132] When the hydrodynamic index Δ is close to 0, it indicates that the sand body is mainly affected by tidal forces; conversely, the more the value deviates from 0, the more the sand body is affected by coastal currents.

[0133] During the measurement, all shelf sand ridges were approximated as symmetrical strips, and the axis of symmetry of the sand bodies was roughly located. The maximum values ​​were measured along the axis of symmetry towards the south and north respectively.

[0134] Statistical results show that during the FRST period, Type I sand bodies were the most numerous, with a hydrodynamic index ranging from 0.47 to 1.08 and an average of 0.70; Type II sand bodies had a hydrodynamic index ranging from 0.11 to 0.31 and an average of 0.19; and Type III sand bodies had a hydrodynamic index ranging from 0.47 to 0.60 and an average of 0.53. During the HST period, Type II sand bodies were the most numerous, with a hydrodynamic index ranging from 0.01 to 0.50 and an average of 0.18; Type I sand bodies had a hydrodynamic index ranging from 0.55 to 0.68 and an average of 0.62; and Type III sand bodies had a hydrodynamic index ranging from 0.14 to 0.55 and an average of 0.32. During the L-TST period, Type III sand bodies were the most numerous, with a hydrodynamic index ranging from 0.10 to 0.71 and an average of 0.25; Type I sand bodies had a hydrodynamic index ranging from 0.44 to 0.96 and an average of 0.65; and Type II sand bodies had a hydrodynamic index ranging from 0.02 to 0.09 and an average of 0.06. During the E-TST period, Type II sand bodies were the most numerous, with a hydrodynamic index ranging from 0.01 to 0.55 and an average of 0.20; and Type I sand bodies had a hydrodynamic index ranging from 0.64 to 1.37 and an average of 1.06. Figure 9 ).

[0135] Overall, the hydrodynamic index of Type I sand bodies, which are mainly modified by waves, is greater than that of Type II and Type III sand bodies, which are mainly modified by tides. The average hydrodynamic index of Type I sand bodies is 0.73, while the average hydrodynamic indexes of Type II and Type III sand bodies are 0.16 and 0.30, respectively.

[0136] Step S100: Determine the hydrodynamic influence type of different system tracts based on the morphology type of shelf sand ridges and the hydrodynamic index of different system tracts;

[0137] When the shelf sand ridge is of type I, the hydrodynamic index Δ is 0.62-1.06, and its hydrodynamic influence is mainly wave action;

[0138] When the shelf sand ridge is of type II, the hydrodynamic index Δ is 0.06-0.2, and its hydrodynamic influence is mainly tidal.

[0139] When the shelf sand ridge is of type III, the hydrodynamic index Δ is 0.25-0.53, and its hydrodynamic influence type is a coastal current-tidal hybrid.

[0140] Characterizing the shelf sand ridge features of different system tracts using comprehensive lithology, physical properties, morphological parameters, morphological types, quantitative relationships, and hydrodynamic indices:

[0141] (1) Forced Marine Retreat System Domain (FRST)

[0142] The banded sandstone is mainly composed of fine sandstone and siltstone; the porosity ranges from 20.1% to 28.2%, with an average of 23.72%; the permeability ranges from 53.7 mD to 606.04 mD, with an average of 442 mD; the length ranges from 4.36 to 21.16 km, with an average of 13.92 km; the maximum width ranges from 1.56 to 6.07 km, with an average of 3.43 km; and the area ranges from 9.82 to 59.15 km². 2 The average is 33.45 km. 2 The trend is mainly northeast-southwest; the morphology is mainly type I (wider in the south and narrower in the north); the hydrodynamic type is mainly coastal current, with a hydrodynamic index ranging from 0.47 to 1.08 and an average value of 0.70.

[0143] (2) High-level system domain (HST)

[0144] The banded sandstone is mainly composed of fine sandstone and siltstone; the porosity ranges from 12.3% to 24.5%, with an average of 19.4%; the permeability ranges from 11 mD to 675 mD, with an average of 223.4 mD; the length ranges from 2.54 to 20.1 km, with an average of 6.52 km; the maximum width ranges from 0.88 to 3.19 km, with an average of 1.70 km; and the area ranges from 1.91 to 52.35 km². 2 The average is 14.56 km. 2 The orientation is mainly northeast-southwest; the morphology is mainly type II (wider in the south and narrower in the north); the hydrodynamic type is mainly tidal, with a hydrodynamic index ranging from 0.01 to 0.50 and an average value of 0.18.

[0145] (3) Late-Temporal Transgression System Tract (L-TST)

[0146] The banded sandstone is predominantly transitional rock, followed by siltstone; porosity ranges from 8.61% to 15.96%, with an average of 11.74%; permeability ranges from 0.02 mD to 0.7 mD, with an average of 0.15 mD; length ranges from 2.84 to 13.32 km, with an average of 8.79 km; maximum width ranges from 0.86 to 4.57 km, with an average of 1.9 km; and area ranges from 2.78 to 26.83 km². 2The average is 12.96 km. 2 The morphology is mainly type III (slightly wider in the north and narrower in the south); the hydrodynamic type is mainly tidal, with a hydrodynamic index ranging from 0.10 to 0.71 and an average value of 0.25.

[0147] (4) Early transgressive systems tract (E-TST)

[0148] The banded sandstone is dominated by siltstone with a high content of transitional rocks; porosity ranges from 3.14% to 17.43%, with an average of 13.03%; permeability ranges from 0.01 mD to 12.04 mD, with an average of 0.90 mD; length ranges from 2.54 to 19.89 km, with an average of 9.48 km; maximum width ranges from 0.76 to 3.73 km, with an average of 2.04 km; and area ranges from 3.63 to 31.31 km². 2 The average is 14.56 km. 2 The orientation is mainly northeast-southwest; the morphology is mainly type II (approximately equal width between north and south); the hydrodynamic type is mainly tidal, with a hydrodynamic index ranging from 0.01 to 0.55 and an average value of 0.20.

[0149] The above description is not intended to limit the present invention in any way. Although the present invention has been disclosed through the above embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A quantitative hydrodynamic evaluation method based on shelf sand ridge morphology, characterized in that, Includes the following steps: Step S10: Obtain relevant data on the characteristics of the continental shelf sand ridges supporting the target work area; Step S20: Based on the seismic data of the target work area and the shelf sand ridge stratigraphic interpretation scheme, carry out seismic stratigraphic interpretation of the sand body; Step S30: Based on the seismic reflection termination relationship and the accommodation space sequence method, identify sequence boundaries and system tract interfaces, and divide the target shelf sand ridge into different system tracts based on the identified interfaces. Step S40: Using the seismic horizon of the sand body as a constraint, extract various conventional seismic attributes, and extract the sand body thickness of a single well based on well logging data and the Direct software module; then perform correlation analysis between the seismic attributes and the sand body thickness, select the best seismic attributes, and characterize the strip sand sedimentary facies. Step S50: Based on core and thin section data, and constrained by the system tract division scheme, statistical analysis of shelf sandstone and ridge lithology is conducted according to different system tracts; Step S60: Based on physical property data and constrained by the system tract division scheme, statistically analyze the relevant physical property parameters of shelf sand ridges according to different system tracts; Step S70: Based on the characterized sedimentary microfacies, use CorelDraw software and VB to write a program to statistically analyze the morphological parameters of shelf sand ridges in different system tracts; Step S80: Comprehensively analyze and statistically analyze the morphological parameters of the shelf sand ridges, and classify the shelf sand ridge morphology according to different system domains; The shelf sand ridge morphology is divided into three types: Type I, Type II, and Type III; Type I is wider in the south and narrower in the north; Type II is approximately equal in width in the north and south; and Type III is slightly wider in the north and narrower in the south. Step S90: Calculate the hydrodynamic index of different system tracts based on the morphological characteristics of shelf sand ridges; In the formula: L 1 represents the maximum width of the northern part of the strip sand body; L 2 represents the maximum width of the southern part of the strip sand body; Hydrodynamic index; Step S100: Determine the hydrodynamic influence type of different system tracts based on the morphology type of shelf sand ridges and the hydrodynamic index of different system tracts; In step S100, when the shelf sand ridge is type I, the hydrodynamic index... The value ranges from 0.62 to 1.06, and the hydrodynamic influence is mainly wave action. When the shelf ridge is type II, the hydrodynamic index is... The value is 0.06-0.2, and its hydrodynamic influence is mainly tidal. When the shelf sand ridge is type III, the hydrodynamic index is... The value is 0.25-0.53, and its hydrodynamic impact type is a coastal current-tidal hybrid.

2. The method for quantitative hydrodynamic evaluation based on shelf sand ridge morphology according to claim 1, characterized in that, The relevant data include seismic data, well logging data, core / thin section data, physical property data, and regional geological data.

3. The method for quantitative hydrodynamic evaluation based on shelf sand ridge morphology according to claim 1, characterized in that, In step S20, when interpreting the seismic stratigraphic position of the sand body, the principles of isochronous correlation, hierarchical control, and model guidance are followed. A combined well-seismic approach is adopted, with interaction between planar and cross-sectional views, to achieve closed interpretation of the sand body stratigraphic position.

4. The method for quantitative hydrodynamic evaluation based on shelf sand ridge morphology according to claim 1, characterized in that, The specific process of step S30 includes: Step S31: Identify sequence boundaries based on seismic reflection termination relationships and sequence stratigraphy theory and methods; Step S32: Identify system tract interfaces based on seismic reflection termination relationships and the accommodative space sequence method; Step S33: Divide the shelf sand ridges into different systems tracts according to sequence boundaries and systems tract interfaces.

5. The method for quantitative hydrodynamic evaluation based on shelf sand ridge morphology according to claim 1, characterized in that, The specific process of step S40 includes: Step S41: Using the seismic horizon of the sand body as a constraint, extract various conventional seismic attributes, including amplitude, statistical, signal, and waveform attributes; Step S42: Based on the logging data, extract the thickness of the sand body in a single well of the target layer using the Diret software module; Step S43: Perform correlation analysis between the extracted seismic attributes and sand body thickness, and optimize the seismic attributes; Step S44: Based on the selected seismic attributes and combined with well logging, core and sand body thickness data, characterize the shelf sand ridge sedimentary facies.

6. The method for quantitative evaluation of hydrodynamics based on shelf sand ridge morphology according to claim 1, characterized in that, The relevant physical properties of the continental shelf sand ridges in step S60 include porosity and permeability.

7. The method for quantitative hydrodynamic evaluation based on shelf sand ridge morphology according to claim 1, characterized in that, The morphological parameters of the shelf sand ridge in step S70 include length, maximum width, area, and orientation.

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