A method for establishing a fan delta front reservoir configuration pattern

Abstract

The application discloses a kind of fan delta front edge reservoir configuration mode establishing methods, comprising the following steps: using artificial observation and identifying the complete constituent unit type of the sand gravel rock mass of the low part of fan delta front edge outcrop to be measured, establish reference feature set;Using unmanned aerial vehicle to shoot the sand gravel rock mass of the high part of fan delta front edge outcrop to be measured, establish the three-dimensional quantitative model of fan delta front edge outcrop to be measured, establish comparison feature set;Comparison feature set and reference feature set are compared, and the complete constituent unit type of the sand gravel rock mass of the high part of fan delta front edge outcrop to be measured is obtained;Establish the constituent unit distribution profile of fan delta front edge outcrop to be measured;The quantitative scale characteristics of the constituent unit of fan delta outcrop to be measured are obtained;According to the quantitative scale characteristics of the constituent unit and the spatial superposition style of the constituent unit, the configuration mode of fan delta front edge outcrop to be measured is established.It can solve the technical problems that it is difficult to establish real and effective fan delta front edge reservoir configuration mode at present.

Description

Technical Field

[0001] This invention relates to the field of petroleum exploration technology, specifically to a method for establishing reservoir configuration models in fan delta fronts. Background Technology

[0002] my country's continental oilfields, which were developed with water injection in the last century, have now generally entered a high water-cut stage, exhibiting prominent development contradictions and abundant remaining oil. The formation of remaining oil is mainly affected by reservoir heterogeneity and development heterogeneity, with reservoir heterogeneity manifested primarily in reservoir configuration and reservoir quality differences. The morphology and scale of reservoir configuration affect fine oil and gas exploration, while spatial stacking patterns influence the deployment of development wells, injection-production relationships, and the tapping of remaining oil potential in the later stages of development. Therefore, in-depth research on reservoir configuration is of significant practical importance for guiding fine oil and gas exploration and development.

[0003] Fan deltas, as an important sedimentary type at the margins of sedimentary basins, are crucial locations for the accumulation of geological and mineral resources such as oil and natural gas. Taking oil and natural gas as an example, several large lacustrine fan delta oil reservoirs have been discovered in basins in eastern and western my country, such as the Wuerhe Formation and Baikouquan Formation fan delta sandstone and conglomerate reservoirs in the Mahu Depression of the Junggar Basin, and the Shahejie Formation fan delta reservoirs in the Huanghua Depression, Jiyang Depression, and Raoyang Depression of the Bohai Bay Basin.

[0004] Fan delta reservoirs exhibit complex morphological characteristics, with significant variations in sand body distribution morphology, quantitative scale, spatial distribution of seepage barriers, and sand body stacking patterns under different geological conditions. Previous studies on fan delta reservoir architecture have largely focused on the plain sediments of fan deltas, which resemble alluvial fans. After an alluvial fan enters a lake, the sediment diffusion pattern changes due to the influence of the lake basin water, resulting in significant differences in the reservoir architecture of the fan delta front compared to the submerged sedimentary bodies.

[0005] Currently, there is limited attention and research on the configuration characteristics of outcrop reservoirs in the fan delta front. Furthermore, manual observation is difficult, risky, and subject to significant subjective influences, making it challenging to establish accurate and effective reservoir configuration models for the fan delta front. Summary of the Invention

[0006] The purpose of this invention is to provide a method for establishing the configuration model of fan delta front reservoirs, which can solve the technical problem that it is currently difficult to establish a real and effective configuration model of fan delta front reservoirs.

[0007] This invention is achieved through the following technical solution:

[0008] A method for establishing the configuration model of a fan delta front reservoir includes the following steps:

[0009] The types of all constituent units of the sandstone and conglomerate body in the low part of the outcrop of the fan delta front under test were identified by manual observation, and the characteristics of each constituent unit type were obtained to establish a reference feature set.

[0010] Using drones to photograph the sandstone and conglomerate body at the high part of the outcrop of the fan delta front to be tested, a three-dimensional quantitative model of the outcrop of the fan delta front to be tested was established, all features of the sandstone and conglomerate body at the high part of the outcrop of the fan delta front to be tested were obtained and labeled in the three-dimensional quantitative model, and a comparison feature set was established.

[0011] By comparing the comparison feature set with the reference feature set, all constituent unit types of the sandstone and conglomerate body at the outcrop high part of the fan delta front to be tested are obtained.

[0012] Based on the aforementioned three-dimensional quantitative model, and combining all the constituent unit types of the sandstone and conglomerate body in the lower part of the outcrop of the fan delta front to be tested and all the constituent unit types of the sandstone and conglomerate body in the higher part of the outcrop of the fan delta front to be tested, a cross-sectional diagram of the constituent unit distribution of the outcrop of the fan delta front to be tested is established.

[0013] Based on the cross-sectional view of the constituent unit distribution of the outcrop at the front of the fan delta to be tested and the three-dimensional quantitative model, the quantitative scale characteristics of the constituent units of the outcrop at the front of the fan delta to be tested are obtained.

[0014] The spatial stacking pattern of the constituent units of the outcrop at the front edge of the fan delta to be tested is obtained;

[0015] Based on the quantitative scale characteristics of the constituent units and the spatial stacking pattern of the constituent units, a configuration pattern of the outcrop at the front edge of the fan delta to be tested is established.

[0016] Optionally, the constituent unit types include: diversion channels, leaf-shaped bodies, and sheet-like sand.

[0017] Optionally, the leaf-like body includes a debris flow tongue-like body and an estuarine bar.

[0018] Optionally, the features include: color, lithology, rhythm, sedimentary structure, and geometry.

[0019] Optionally, the geometric shape includes: a flat-top-convex-bottom shape, a flat-bottom-convex-top shape, and a thin-layer plate shape;

[0020] The lithology includes: conglomerate and sandstone;

[0021] The rhythms include: normal rhythms, homogeneous rhythms, and anti-rhythms.

[0022] Optionally, the step of using unmanned aerial vehicles to photograph the sandstone and conglomerate body at the high part of the outcrop of the fan delta front to establish a three-dimensional quantitative model of the outcrop of the fan delta front includes the following steps:

[0023] The drone was used to cruise and photograph the outcrop at the front edge of the fan delta under test, and several photos with three-dimensional coordinates were obtained.

[0024] The three-dimensional quantitative model is established using the photograph with three-dimensional coordinates;

[0025] in:

[0026] The route of the cruise photography is perpendicular to the distribution profile of the outcrop of the fan delta to be measured.

[0027] The altitude at which the cruise photography was conducted was higher than the highest outcrop height of the outcrop of the fan delta to be measured.

[0028] Optionally, obtaining the quantitative scale characteristics of the constituent units of the outcrop of the fan delta under test based on the cross-sectional view of the constituent unit distribution and the three-dimensional quantitative model includes the following steps:

[0029] Obtain the apparent dip angle data of gravel inside each type of conglomerate body, draw a rose diagram based on the apparent dip angle data, and determine whether the gravel inside each type of conglomerate body has orientation based on the rose diagram;

[0030] Select a directional conglomerate body, measure its dip, and obtain the direction of the main trend line;

[0031] Based on the three-dimensional quantitative model, the apparent width of the constituent unit for each type of constituent unit is measured.

[0032] Based on the mainstream line direction, the apparent width of the constituent unit for each type of constituent unit is corrected to obtain the true width of the constituent unit;

[0033] Based on the true width of the constituent unit for each constituent unit type, the quantitative scale characteristics of the constituent units of the tested fan delta outcrop are obtained.

[0034] Optionally, the formula for calculating the true width of the constituent unit is:

[0035] L = sinα × L';

[0036] in:

[0037] L is the true width of the constituent unit, in meters (m).

[0038] L' is the apparent width of the constituent unit, in meters;

[0039] α is the angle between the cross-sectional distribution direction and the main flow direction.

[0040] Optionally, the quantitative scale characteristics of the constituent unit include: width distribution range, average width, main body thickness distribution range, average main body thickness, width-to-thickness ratio distribution range, and width-to-thickness relationship formula.

[0041] Optionally, the spatial stacking patterns of the constituent units include: lateral-vertical overlapping of diversion channels, deep-cut mouth dam type of diversion channels, lateral overlapping of diversion channels and mouth dams, lateral overlapping of mouth dams, isolated tongue-shaped debris flow bodies, isolated mouth dams, and isolated sheet sand.

[0042] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0043] This invention provides a method for establishing a reservoir configuration model at the front of a fan delta. First, it obtains all constituent unit types of the low-lying sandstone and conglomerate body of the outcrop at the front of the fan delta under test through manual observation. The characteristics of each constituent unit type are analyzed and correlated to establish a reference feature set. Then, it first uses a drone to photograph the high-lying sandstone and conglomerate body of the outcrop at the front of the fan delta under test, taking extensive photos of the high-lying sandstone and conglomerate body, which is difficult to collect manually. A three-dimensional quantitative model of the outcrop at the front of the fan delta under test is established using these numerous photos. Then, all characteristics of the high-lying sandstone and conglomerate body of the outcrop at the front of the fan delta under test are obtained from the photos, establishing a comparison feature set. Finally, by comparing the comparison feature set with the reference feature set, the complete constituent unit types of the high-lying sandstone and conglomerate body of the outcrop at the front of the fan delta under test are deduced through the correlation between the two, thus avoiding direct manual observation of the fan delta under test. This study addresses various challenges faced by the high-lying sandstone and conglomerate bodies in the outcrop of the delta front. Based on this, and using a three-dimensional quantitative model, all constituent unit types of the observed low-lying sandstone and conglomerate bodies in the tested fan delta front outcrop, as well as the inferred constituent unit types of the high-lying sandstone and conglomerate bodies, are marked on the three-dimensional quantitative model. This further establishes a cross-sectional map of the constituent unit distribution of the tested fan delta front outcrop, allowing for the inference of internal parts that cannot be observed, thereby obtaining the constituent unit types from all angles of the tested fan delta front outcrop. Based on this, through the constituent unit distribution cross-sectional map and the three-dimensional quantitative model, the actual quantitative scale characteristics of the constituent units of the tested fan delta front outcrop are measured and calculated. Furthermore, considering the spatial stacking pattern of the constituent units, optimization and correction are performed. Combined with the aforementioned data and models, a true and effective configuration pattern of the tested fan delta front outcrop can be established. Attached Figure Description

[0044] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0045] Figure 1A flowchart of the method for establishing the configuration mode of a fan delta front reservoir provided by the present invention;

[0046] Figure 2 A schematic diagram illustrating the confirmation of the main flow direction in the method for establishing the configuration model of the fan delta front reservoir provided by the present invention.

[0047] Figure 3 This is a schematic diagram illustrating the correction of the apparent width of the constituent units in the method for establishing the configuration mode of the fan delta front reservoir provided by the present invention. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0049] Please refer to Figure 1 This invention provides a method for establishing the configuration model of a fan delta front reservoir, comprising the following steps:

[0050] S1. Using manual observation, identify all constituent unit types of the sandstone and conglomerate body in the low part of the outcrop of the delta front to be measured, obtain the characteristics of each constituent unit type, and establish a reference feature set;

[0051] S2. Use drones to photograph the sandstone and conglomerate body at the high part of the outcrop of the fan delta front to be tested, establish a three-dimensional quantitative model of the outcrop of the fan delta front to be tested, obtain all the features of the sandstone and conglomerate body at the high part of the outcrop of the fan delta front to be tested, and mark them on the three-dimensional quantitative model to establish a comparison feature set.

[0052] S3. Compare the comparison feature set with the reference feature set to obtain all the constituent unit types of the sandstone and conglomerate body at the outcrop high part of the fan delta front to be tested.

[0053] S4. Based on the three-dimensional quantitative model, and combining all the constituent unit types of the sandstone and conglomerate body in the lower part of the outcrop of the fan delta front to be tested and all the constituent unit types of the sandstone and conglomerate body in the higher part of the outcrop of the fan delta front to be tested, establish a cross-sectional map of the constituent unit distribution of the outcrop of the fan delta front to be tested.

[0054] S5. Based on the cross-sectional view of the constituent units of the outcrop at the front edge of the fan delta to be tested and the three-dimensional quantitative model, the quantitative scale characteristics of the constituent units of the outcrop at the front edge of the fan delta to be tested are obtained.

[0055] S6. Obtain the spatial stacking pattern of the constituent units of the outcrop of the front edge of the fan delta to be tested;

[0056] S7. Based on the quantitative scale characteristics of the constituent units and the spatial stacking pattern of the constituent units, establish the configuration pattern of the outcrop at the front edge of the fan delta to be tested.

[0057] The method for establishing the reservoir configuration model of the fan delta front provided by this invention, in step S1, obtains all constituent unit types of the sandstone and conglomerate body in the lower part of the outcrop of the fan delta front under test through manual observation, and analyzes and correlates the characteristics of each constituent unit type to establish a reference feature set; based on this, in step S2, firstly, the sandstone and conglomerate body in the upper part of the outcrop of the fan delta front under test is photographed by drone, taking a large number of photos of the upper part of the sandstone and conglomerate body, which is difficult to collect manually, and establishes a three-dimensional quantitative model of the outcrop of the fan delta front under test through a large number of photos, and then obtains all the characteristics of the sandstone and conglomerate body in the upper part of the outcrop of the fan delta front under test through the photos to establish a comparison feature set; based on this, in step S3, the comparison feature set is compared with the reference feature set, and the complete constituent unit types of the sandstone and conglomerate body in the upper part of the outcrop of the fan delta front under test are obtained by inverse reasoning through the correlation between the two, thereby avoiding direct manual observation of the upper part of the outcrop of the fan delta front under test. The various problems faced by the sandstone and conglomerate bodies are addressed. Based on this, in step S4, using a three-dimensional quantitative model, all constituent unit types of the observed low-lying sandstone and conglomerate bodies in the tested fan delta front outcrop, as well as all inferred constituent unit types of the high-lying sandstone and conglomerate bodies, are marked on the three-dimensional quantitative model. This further establishes a cross-sectional map of the constituent unit distribution of the tested fan delta front outcrop, allowing for the inference of internal parts that cannot be observed, thereby obtaining the constituent unit types from all angles of the tested fan delta front outcrop. Based on this, in step S5, the quantitative scale characteristics of the actual constituent units of the tested fan delta front outcrop are measured and calculated using the constituent unit distribution cross-sectional map and the three-dimensional quantitative model. Based on this, in step S6, the spatial stacking pattern of the constituent units is comprehensively considered, and optimization and correction are performed. Then, in step S7, supplemented by the aforementioned data and models, a true and effective configuration pattern of the tested fan delta front outcrop can be established.

[0058] It should be noted that the above-mentioned "lower part" refers to the part that is exposed at a lower level and can be directly observed with the naked eye; the above-mentioned "higher part" refers to the part that is exposed at a higher level and cannot be or is difficult to be directly observed with the naked eye.

[0059] Furthermore, the constituent unit types include: diversion channels, leaf-shaped bodies, and sheet-like sand.

[0060] Furthermore, the leaf-like body includes: a detrital flow tongue-shaped body and an estuarine bar.

[0061] Furthermore, the features include: color, lithology, rhythm, sedimentary structure, and geometry.

[0062] Furthermore, the geometric morphology includes: flat-top-convex-bottom shape, flat-bottom-convex-top shape, and thin-layered plate-like shape; the lithology includes: conglomerate and sandstone; the rhythm includes: positive rhythm, homogeneous rhythm, and negative rhythm.

[0063] It should be noted that different constituent unit types have different geometric morphological tendencies. For example, distributary channels are generally flat-topped and convex-bottomed, leaf-shaped bodies are generally flat-bottomed and convex-topped, and sheet-like sands are generally thin-layered and plate-like.

[0064] It should be noted that different constituent unit types have different lithological tendencies. For example, distributary channel sediments are coarser in size and are mainly composed of conglomerate, while lobed bodies are mainly composed of conglomerate and sandstone, and sheet sands are mainly composed of sandstone.

[0065] It should be noted that different types of constituent units have different rhythmic tendencies. For example, distributary channels generally have a positive rhythm, clastic flow tongues generally have a homogeneous rhythm, estuary bars generally have a positive or negative rhythm, and sheet sand generally have a homogeneous or negative rhythm.

[0066] Therefore, by identifying the type of constituent unit, its characteristics in various aspects can be obtained more accurately; conversely, by identifying the characteristics within a region, the type of constituent unit of that region can also be analyzed and deduced in reverse.

[0067] Furthermore, the step of using unmanned aerial vehicles to photograph the sandstone and conglomerate bodies at the high part of the outcrop of the fan delta front to establish a three-dimensional quantitative model of the outcrop of the fan delta front includes the following steps:

[0068] S2.1. Use a drone to cruise and photograph the outcrop at the front edge of the fan delta under test, and obtain several photos with three-dimensional coordinates;

[0069] S2.2. Establish the three-dimensional quantitative model using the photograph with three-dimensional coordinates;

[0070] in:

[0071] The route of the cruise photography is perpendicular to the distribution profile of the outcrop of the fan delta to be measured.

[0072] The altitude at which the cruise photography was conducted was higher than the highest outcrop height of the outcrop of the fan delta to be measured.

[0073] It should be noted that the more cruise lines there are, the higher the resolution, but the longer the drone measurement time; the lower the cruise altitude, the higher the resolution.

[0074] Furthermore, obtaining the quantitative scale characteristics of the constituent units of the outcrop of the fan delta under test based on the cross-sectional view of the constituent unit distribution and the three-dimensional quantitative model includes the following steps:

[0075] S5.1 Obtain the apparent dip angle data of gravel inside each type of conglomerate body, draw a rose diagram based on the apparent dip angle data, and determine whether the gravel inside each type of conglomerate body has orientation based on the rose diagram;

[0076] S5.2 Select a directional conglomerate body, measure its dip, and obtain the direction of the main trend line;

[0077] S5.3. Based on the three-dimensional quantitative model, measure the apparent width of each constituent unit type;

[0078] S5.4. According to the direction of the main line, the apparent width of the constituent unit for each type of constituent unit is corrected to obtain the true width of the constituent unit;

[0079] S5.5. Based on the true width of the constituent unit for each constituent unit type, obtain the quantitative scale characteristics of the constituent units of the outcrop of the fan delta to be measured.

[0080] It should be noted that the apparent dip angle data refers to the dip angle of the gravel inside the conglomerate body relative to the rock bedding.

[0081] It should be noted that the rose diagram is one of the joint statistics methods. It can be used to statistically analyze the apparent dip angle data of gravels inside conglomerate bodies. The method is simple, visually striking, and clearly reflects the main dip direction of the gravels, which helps to determine whether the gravels have orientation.

[0082] It should be noted that the apparent width of the constituent unit refers to the width measured from the three-dimensional quantitative model.

[0083] It should be noted that the true width of the constituent unit refers to the cross-sectional width perpendicular to the main line direction.

[0084] Furthermore, the formula for calculating the true width of the constituent unit is:

[0085] L = sinα × L';

[0086] in:

[0087] L is the true width of the constituent unit, in meters (m).

[0088] L' is the apparent width of the constituent unit, in meters;

[0089] α is the angle between the cross-sectional distribution direction and the main flow direction.

[0090] Furthermore, the quantitative scale characteristics of the constituent unit include: width distribution range, average width, main body thickness distribution range, average main body thickness, width-to-thickness ratio distribution range, and width-to-thickness relationship formula.

[0091] Furthermore, the spatial stacking patterns of the constituent units include: lateral-vertical overlapping of diversion channels, deep-cut mouth dam type of diversion channels, lateral overlapping of diversion channels and mouth dams, lateral overlapping of mouth dams, isolated tongue-shaped debris flow bodies, isolated mouth dams, and isolated sheet-like sand.

[0092] Example

[0093] Please refer to Figure 2 and Figure 3 This embodiment provides a method for establishing the configuration model of a fan delta front reservoir, including the following steps:

[0094] Step 0: Select the fan delta to be tested. In this embodiment, the fan delta to be tested is the Lower Cretaceous Xiguayuan Formation fan delta in the Sangyuan section of the Luanping Basin, which is located near Sangyuan Village, Luanping County, Hebei Province.

[0095] Step 1: Identify the constituent units of sandstone and conglomerate bodies in the low-lying outcrops of the fan delta front through manual field measurements.

[0096] Specifically: Different constituent units are identified at lower elevations: Distributary channels are dominated by conglomerate with minor sandstone, exhibiting massive structures, graded bedding, imbricate structures, and cross-bedding. Vertically, they exhibit positive rhythmic characteristics, with scour surfaces visible at the bottom, and a flat-topped, convex-bottom profile. Lobe bodies are dominated by conglomerate and sandstone, with complex vertical grain size variations, exhibiting homogeneous, positive, and negative rhythmic characteristics. In cross-section, they are flat-bottomed, convex-topped. Clastic flow tongue bodies are dominated by medium and fine conglomerate, exhibiting massive structures and visible mudstone lacerations, and exhibiting a homogeneous vertical rhythm. Estuarine bars are dominated by conglomerate and sandstone, exhibiting massive structures, cross-bedding, and parallel bedding, typically composed of multiple accretionary formations. Sheet sands appear as thin, plate-like layers in cross-section, associated with silt and mudstone. The sedimentary thickness is thin, with minimal lateral thickness variation. The sediments are fine-grained, and the lithology is mainly fine sandstone and siltstone. Parallel bedding and wavy cross-bedding are mainly developed, and the vertical direction shows homogeneous rhythm or anti-rhythmic characteristics.

[0097] Step 2: Observe the characteristics of sandstone and conglomerate bodies at high outcrops in the delta front using UAVs, and establish a three-dimensional quantitative model of the outcrops in the fan delta front.

[0098] Specifically: The drone's cruise route, integrated with an oblique camera, was set. Since the mulberry orchard profile's orientation ranges from 258° to 307°, with most areas approaching 300°, the cruise route angle was set at 210°, essentially perpendicular to the profile's orientation. 28 routes were established, ensuring the entire profile was captured. The drone's cruise altitude was also set. Since the highest exposed section of the mulberry orchard is approximately 250 meters above the ground, the cruise altitude was set at 300 meters to avoid collisions caused by the altitude being lower than the exposed mountain height, while also ensuring sufficient resolution. Approximately 6000 coordinate-encoded photos were taken during the cruise, and a 3D quantitative model was created using Context Capture software.

[0099] Small drones were used to take close-up photos of the high-lying sandstone and conglomerate bodies to capture their lithology, grain size rhythm, and sedimentary structures, and these features were then annotated in a three-dimensional quantitative model.

[0100] Step 3: By analogy with high and low sandstone and conglomerate bodies, clarify the distribution of outcrop constituent units in the field of the fan delta front.

[0101] Specifically: By observing the geometric morphology, lithology, rhythm, and sedimentary structures of the high-lying sandstone and conglomerate bodies using drones, and comparing these characteristics with the different constituent unit configurations identified in step 1, the types of constituent units of the high-lying sandstone and conglomerate bodies are identified. Based on the three-dimensional quantitative model, a distribution map of the constituent units of the entire profile is drawn.

[0102] Step 4: Based on the distribution map of constituent units and the three-dimensional quantitative model, clarify the quantitative scale characteristics of the constituent units of outcrops in the field at the front of the fan delta.

[0103] Specifically, the main channel direction varies at different locations on the fan-shaped delta. This example uses measurements of the dip of flattened pebbles in the imbricate conglomerate within different strata of the Sangyuan section to determine the main channel direction during deposition at different strata. The measurement results show that the dip of the flattened pebbles in the imbricate conglomerate is between 300-330°. Figure 2 As shown.

[0104] Based on the cross-sectional orientation at different locations within the mulberry orchard, the cross-section was divided into six segments (A, B, and C). Each segment has a different orientation: segment A has an orientation of 284°, segment B 279°, segment C 286°, segment D 307°, segment E 299°, and segment F 258°. Figure 3As shown. The dip direction of the flat gravel within each segment is taken as the direction of the mainstream line for that segment (if there is no dip data for that segment, the dip direction of the flat gravel in the adjacent segment is taken as the direction of the mainstream line for that segment). Specifically, the mainstream line direction for segment A is 330°, for segment B it is 300°, for segments C and D it is 317°, and for segments E and F it is 330°. Based on the mainstream line direction of each segment, the width of the constituent unit is corrected. The corrected true width of the constituent unit (the cross-sectional width perpendicular to the mainstream line direction) is:

[0105] L A =sinα1×L A ';

[0106] In the formula:

[0107] L A The true width of the unit constituting segment A is in meters.

[0108] L A 'This is the apparent width of the unit that constitutes segment A, in meters;

[0109] α1 is the angle between the cross-sectional distribution direction and the main flow direction.

[0110] Different angles are used to convert different sections of the cross section. If the distribution of the constituent unit is not limited to a certain section, the true width of each unit in each section is calculated and then added together.

[0111] Quantitative analysis of the complete constituent units revealed significant differences in width, thickness, and their relationships among different types of constituent units. Distributary channels ranged in width from 6 to 160 m, with an average width of 33 m; their main body thickness ranged from 0.6 to 28 m, with an average main body thickness of 4.5 m; and their width-to-thickness ratio was 4-25. Debris flow tongue-shaped bodies ranged in width from 66 to 146 m, with an average width of 104 m; their main body thickness ranged from 8 to 15 m, with an average main body thickness of 11 m; and their width-to-thickness ratio was 8-10. Estuarine bars ranged in width from 67 to 203 m, with an average width of 108 m; their main body thickness ranged from 1 to 8 m, with an average main body thickness of 3 m; and their width-to-thickness ratio was 23-67. Sheet-shaped sand formations were mostly wider than 100 m, with a main body thickness of 0.34 to 0.83 m, an average main body thickness of 0.52 m, and a width-to-thickness ratio at least greater than 121. The width-to-thickness relationships of distributary channels, debris flow tongue-shaped bodies, and estuarine bars are as follows:

[0112] y = 5.07x + 10.218 (diversion channel)

[0113] y = 11.21x + 22.063 (detrital flow tongue-shaped body)

[0114] y = 18.74x + 50.013 (Estuary Dam)

[0115] In the formula, y is the true width of the constituent unit, in meters; x is the thickness of the main body of the constituent unit, in meters.

[0116] Step 5: Define the spatial stacking pattern of the outcrops at the front edge of the fan delta.

[0117] Specifically: Based on the distribution diagram of the constituent units of the mulberry garden section drawn in step 3, considering the contact relationship of different constituent units, the spatial stacking pattern of the constituent units of the fan delta front is clarified. Lateral-vertical overlapping type of distributary channels: laterally, the distributary channels migrate frequently, and vertically, multiple distributary channels overlap each other, with vertical and lateral connections between the multiple distributary channels; deep-cut mouth bar type of distributary channels: the distributary channels cut down into the early mouth bars, with vertical connections between different distributary channels and mouth bars; lateral overlapping type of distributary channels and mouth bars: the distributary channels and mouth bars are laterally spliced ​​together and laterally connected; lateral overlapping type of mouth bars: multiple mouth bars are laterally overlapping and laterally connected; isolated type of clastic flow tongue, isolated type of mouth bar, and isolated type of sheet sand: vertically, single-stage clastic flow tongues, mouth bars, and sheet sands are distributed in isolated lenses in the mudstone, with high development of vertical argillaceous interlayers and lateral argillaceous barriers, exhibiting the characteristics of "mud-encased gravel".

[0118] Step 6: Establish the configuration model of the front edge of the fan delta to be tested.

[0119] Specifically, the geometric shape, quantitative scale, and spatial stacking pattern of different constituent units are summarized to establish the configuration pattern of the fan delta front.

[0120] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. 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 within the scope of protection of the present invention.

Claims

1. A method of establishing a fan delta front reservoir architecture pattern, characterized by, Includes the following steps: The types of all constituent units of the sandstone and conglomerate body in the low part of the outcrop of the fan delta front under test were identified by manual observation, and the characteristics of each constituent unit type were obtained to establish a reference feature set. Using drones to photograph the sandstone and conglomerate body at the high part of the outcrop of the fan delta front to be tested, a three-dimensional quantitative model of the outcrop of the fan delta front to be tested was established, all features of the sandstone and conglomerate body at the high part of the outcrop of the fan delta front to be tested were obtained and labeled in the three-dimensional quantitative model, and a comparison feature set was established. By comparing the comparison feature set with the reference feature set, all constituent unit types of the sandstone and conglomerate body at the outcrop high part of the fan delta front to be tested are obtained. Based on the aforementioned three-dimensional quantitative model, and combining all the constituent unit types of the sandstone and conglomerate body in the lower part of the outcrop of the fan delta front to be tested and all the constituent unit types of the sandstone and conglomerate body in the higher part of the outcrop of the fan delta front to be tested, a cross-sectional diagram of the constituent unit distribution of the outcrop of the fan delta front to be tested is established. Based on the cross-sectional view of the constituent unit distribution of the outcrop at the front of the fan delta to be tested and the three-dimensional quantitative model, the quantitative scale characteristics of the constituent units of the outcrop at the front of the fan delta to be tested are obtained. The spatial stacking pattern of the constituent units of the outcrop at the front edge of the fan delta to be tested is obtained; Based on the quantitative scale characteristics of the constituent units and the spatial stacking pattern of the constituent units, a configuration pattern of the outcrop at the front edge of the fan delta to be tested is established. The process of using drones to photograph the sandstone and conglomerate bodies at the high points of the outcrop of the delta front to establish a three-dimensional quantitative model of the outcrop includes the following steps: The drone was used to cruise and photograph the outcrop at the front edge of the fan delta under test, and several photos with three-dimensional coordinates were obtained. The three-dimensional quantitative model is established using the photograph with three-dimensional coordinates; in: The route of the cruise photography is perpendicular to the distribution profile of the outcrop of the fan delta to be measured. The altitude at which the cruise photography was conducted was higher than the highest outcrop height of the outcrop of the fan delta to be measured. The process of obtaining the quantitative scale characteristics of the constituent units of the outcrop of the fan delta under test based on the cross-sectional view of the constituent unit distribution and the three-dimensional quantitative model includes the following steps: Obtain the apparent dip angle data of gravel inside each type of conglomerate body, draw a rose diagram based on the apparent dip angle data, and determine whether the gravel inside each type of conglomerate body has orientation based on the rose diagram; Select a directional conglomerate body, measure its dip, and obtain the direction of the main trend line; Based on the three-dimensional quantitative model, the apparent width of the constituent unit for each type of constituent unit is measured. Based on the mainstream line direction, the apparent width of the constituent unit for each type of constituent unit is corrected to obtain the true width of the constituent unit; Based on the true width of the constituent unit for each constituent unit type, the quantitative scale characteristics of the constituent units of the tested fan delta outcrop are obtained.

2. The method for establishing a fan delta front reservoir architecture pattern according to claim 1, characterized in that, The constituent unit types include: diversion channels, leaf-shaped bodies, and sheet-like sand.

3. The method according to claim 2, wherein, The lobes include detrital flow tongues and estuarine dams.

4. The method according to claim 1, wherein, The characteristics include: color, lithology, rhythm, sedimentary structure, and geometry.

5. The method for establishing the reservoir configuration model of the fan delta front according to claim 4, characterized in that: The geometric shapes include: flat-top-convex-bottom shape, flat-bottom-convex-top shape, and thin-layer plate shape; The lithology includes: conglomerate and sandstone; The rhythms include: normal rhythms, homogeneous rhythms, and anti-rhythms.

6. The method for establishing a fan delta front reservoir architecture pattern according to claim 1, wherein, The formula for calculating the true width of the constituent unit is: L = sinα × L'; in: L is the true width of the constituent unit, in meters (m). L' is the apparent width of the constituent unit, in meters; α is the angle between the cross-sectional distribution direction and the main flow direction.

7. The method for establishing a fan delta front reservoir architecture pattern according to claim 1, wherein, The quantitative scale characteristics of the constituent units include: width distribution range, average width, main body thickness distribution range, average main body thickness, width-to-thickness ratio distribution range, and width-to-thickness relationship formula.

8. The method for establishing a fan delta front reservoir architecture pattern according to claim 1, wherein, The spatial stacking patterns of the constituent units include: lateral-vertical overlapping of distributary channels, deep-cut mouth dam type of distributary channels, lateral overlapping of distributary channels and mouth dams, lateral overlapping of mouth dams, isolated tongue-shaped debris flow bodies, isolated mouth dams, and isolated sheet-like sand.

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