A method for combined development of chemical flooding and straight-line development using high-permeability flow channels
By deploying horizontal wells across a single channel at the top of the oil layer and combining them with chemical drive, the heterogeneity and gravity differentiation problems of the existing well network in the later stages of development were solved, enabling precise tapping of the potential of narrow and complex channels and improving the recovery rate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DAQING OILFIELD CO LTD
- Filing Date
- 2024-11-27
- Publication Date
- 2026-05-29
AI Technical Summary
In the later stages of onshore sandstone reservoir development, the existing well network gradually becomes ineffective due to heterogeneity and gravity differentiation, which causes water injection to surge along high-permeability strips. This makes it impossible to effectively control the remaining oil at the edges of narrow and complex channels, resulting in low recovery rates.
Horizontal wells that traverse a single river channel are deployed at the top of the oil layer. Water is injected into the surrounding vertical wells. Once the water content of the horizontal wells reaches the set value, they are converted into chemical injection wells, and the surrounding vertical wells are converted into oil production wells, forming a three-dimensional well network of horizontal well injection and vertical well production. The sweep volume is expanded by using chemical agents and gravity to tap the remaining oil.
It has enabled precise tapping of the potential of narrow and complex river channels, turning the contradiction between reservoir heterogeneity and gravity differentiation into favorable conditions, improving the recovery rate, and forming an efficient three-dimensional well network structure.
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Figure CN122106513A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of conventional sandstone oilfield technology, specifically to a chemical flooding combined with horizontal development method utilizing high-permeability channels in the case of high-permeability channels caused by the heterogeneity of onshore sandstone reservoirs. Background Technology
[0002] The statements in this section provide only background information in connection with this disclosure and do not constitute prior art.
[0003] my country's high-water-cut old oilfields have reserves of 25.57 billion tons and an annual oil production of 137 million tons, accounting for over 70% of both reserves and production. The water cut is 91.4%, and the recovery rate is 31%, leaving nearly 70% of reserves underground. Water-drive development is the primary method in my country's oilfield development, accounting for about 70%. Water-drive development is the cornerstone of my country's production, but it suffers from severe inefficiency and ineffective circulation. High-permeability channels are widely developed within the reservoirs. In Daqing Changyuan, the calibrated recovery rate for water-drive development is only 45%, with 55% of geological reserves remaining underground. Due to the "three major contradictions" in oilfield development and gravity differentiation, water injection proceeds along high-permeability zones, gradually rendering the existing well network ineffective. This is because conventional vertical well networks primarily consider the control and utilization of sand bodies in the plane. However, in the later stages of development, due to the vertical heterogeneity of the reservoirs, the utilization within or between layers is uneven. For example, in positive rhythmic reservoirs, the bottom water flooding is higher than the top water flooding. This phenomenon becomes more pronounced as water cut increases, assuming the well network remains unchanged. Furthermore, the existing well network cannot effectively control some narrow river channels, resulting in uneven horizontal utilization. Therefore, the existing conventional well network gradually becomes ineffective in the later stages of development.
[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art. Summary of the Invention
[0005] In view of this, this disclosure provides a chemical flooding method for combined vertical and horizontal development using high-permeability channels, which solves the problem that water injection along high-permeability strips and the gradual failure of existing well networks in onshore sandstone reservoirs due to heterogeneity and gravity differentiation.
[0006] To achieve the above-mentioned objective, the method for combined chemical flooding and vertical displacement using high-permeability channels includes:
[0007] Based on the spatial distribution pattern of the remaining oil in the target area, a horizontal well is deployed at the top of the oil layer. The deployment method is to drill a new horizontal well using a high water-cut, high-permeability channel in the later stage, so that the horizontal well crosses at least one single river channel.
[0008] The horizontal well is used as an oil production well, and water is injected into the surrounding vertical wells to tap the remaining oil potential.
[0009] Once the water content of the horizontal well reaches the set value, it is converted into a chemical injection well, and the surrounding vertical wells are converted into oil production wells to continue tapping the remaining oil potential.
[0010] In this disclosure and possible embodiments, the horizontal well is made to cross 3-4 single river channels, and the length of the horizontal well section is greater than 500m.
[0011] In this disclosure and possible embodiments, the method for analyzing the spatial distribution pattern of residual oil in the target area includes:
[0012] The spatial distribution pattern of each sedimentary unit in the target layer of the target area is determined. The method for determining the spatial distribution pattern is based on the core analysis data from inspection wells, well logging data, field outcrops and modern sedimentary data, applying sequence stratigraphy theory to identify sedimentary cycles and sequence boundaries, and dividing sedimentary units by sedimentary cycle method and the principle of correlation of superimposed river sand bodies.
[0013] In this disclosure and possible embodiments, the method for analyzing the spatial distribution pattern of the remaining oil further includes determining the distribution of channel sand bodies, the determination method comprising:
[0014] Based on the spatial distribution patterns of each sedimentary unit, sedimentary microfacies maps of each sedimentary unit are drawn according to well logging data and well logging interpretation data, and the distribution of channel sand bodies is determined using the sedimentary microfacies maps.
[0015] In this disclosure and possible embodiments, the method for analyzing the spatial distribution pattern of residual oil further includes dividing the distribution of individual channels within a composite channel, the division method comprising:
[0016] Based on the distribution of the riverbed sand, the identification markers of individual channels within the composite river are determined, and the distribution of individual channels within the composite river is divided according to the identification markers.
[0017] In this disclosure and possible embodiments, the method for analyzing the spatial distribution pattern of the remaining oil further includes establishing a three-dimensional fine geological model of the target layer in the target area, wherein the method for establishing the geological model includes:
[0018] Based on the distribution pattern of the single river channel, the rhythmicity and heterogeneity of the sand bodies are analyzed, and a three-dimensional fine geological model of the target layer in the target area is established.
[0019] In this disclosure and possible embodiments, the method for analyzing the spatial distribution pattern of the remaining oil further includes determining the spatial distribution pattern of high-permeability channels in the later stage of high water cut, wherein the determination method includes:
[0020] Analyze the dynamic characteristics of the target area to identify abnormal dynamic behaviors that may involve high seepage channels;
[0021] Static analysis using well logging data can identify high-permeability channels in the reservoir.
[0022] Seismic data can be used to identify reservoir continuity and integrity, and to assess potential high-permeability areas.
[0023] A discrimination model for high seepage channels is established, and the areas where high seepage channels may exist are qualitatively identified through the discrimination model;
[0024] Based on the results of dynamic and static analysis, combined with the output of numerical simulation, a spatial distribution map of high seepage channels is drawn.
[0025] In this disclosure and possible embodiments, the method for analyzing the spatial distribution pattern of residual oil further includes quantitative analysis of the spatial distribution pattern of residual oil in the later stage of high water cut, wherein the quantitative analysis method includes:
[0026] Based on the geological model, the spatial distribution pattern of the high water-cut late-stage high-permeability channels, and development dynamic data, the spatial distribution pattern of the remaining oil is obtained by applying numerical simulation methods.
[0027] The beneficial effects of this invention are as follows:
[0028] This invention utilizes a chemical flooding method combining horizontal and vertical wells with high permeability channels. The deployed horizontal well traverses multiple channels and interchannel deposits, precisely tapping into the remaining oil in narrow channels and the edges of complex channels—areas where vertical well networks cannot control. Simultaneously, it leverages natural barriers formed during channel-interchannel phase transitions to achieve segmented development, transforming the inherent contradiction of strong reservoir heterogeneity into a favorable condition for efficient horizontal well development. The horizontal wells' cross-channel development expands the swept volume. Later, horizontal wells are converted to injection, injecting chemical agents at the top of the oil layer for energy replenishment. The use of interlayer barriers and gravity further expands the swept volume of the injected chemical agents, transforming the contradictions of intra-layer heterogeneity and gravity differentiation into favorable conditions for increased swept volume. Finally, high permeability channels at the bottom of the reservoir are used to extract oil from vertical wells, forming a three-dimensional well network of horizontal well injection and vertical well production. This resolves the initial contradictions of intra-layer heterogeneity and gravity differentiation, achieving precise construction of dynamic flow units in both vertical and horizontal directions, truly realizing precise energy replenishment and precise potential tapping. Attached Figure Description
[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the specification, serve to illustrate the technical solutions of this disclosure.
[0030] Figure 1 A flowchart of the chemical flooding direct-flow combined development method utilizing high-permeability channels according to an embodiment of this disclosure;
[0031] Figure 2This is a schematic diagram of the segmented mining profile of a horizontal well that cuts across a river channel in this application example.
[0032] Figure 3 This is a schematic diagram of the segmented injection profile of a horizontal well that cuts across a river channel in an application example disclosed in this publication;
[0033] Figure 4 This is an example diagram of the segmented deployment of horizontal wells that cut across a river channel in this application example. Detailed Implementation
[0034] The present disclosure is described below based on embodiments; however, it is worth noting that the present disclosure is not limited to these embodiments. In the detailed description of the present disclosure below, certain specific details are described in detail. However, those skilled in the art will fully understand the present disclosure for the parts not described in detail.
[0035] Furthermore, unless the context explicitly requires it, the words "comprising," "including," and similar terms throughout the specification and claims should be interpreted as including rather than exclusive or exhaustive; that is, meaning "including but not limited to."
[0036] The core technology of this disclosure is: a chemical flooding method with high permeability channels and a combined direct-flow and horizontal flow approach.
[0037] By utilizing the high permeability channels of reservoirs in the late stage of oilfield development with extremely high water cut, horizontal wells are deployed at the top of the oil layer, wherein the deployment method is such that the horizontal wells cross at least one single river channel.
[0038] The horizontal well is used as an oil production well, and water is injected into the surrounding vertical wells to tap into the remaining oil.
[0039] Once the water content of the horizontal well reaches the set value, it is converted into a chemical injection well, and the surrounding vertical wells are converted into oil production wells to continue tapping the remaining oil potential.
[0040] Based on the above-mentioned core technologies, the following are preferred embodiments provided in this disclosure.
[0041] Figure 1 The flowchart of the chemical flooding direct-flow and horizontal-flow combined development method utilizing high-permeability channels in this embodiment of the present disclosure is as follows:
[0042] Step 1: Finely divide the target area into sedimentary units of the target layer and determine the spatial distribution pattern of each sedimentary unit in the target layer; specifically as follows:
[0043] Based on core analysis data from inspection wells, logging data, field outcrops, and modern sedimentary data, sequence stratigraphy theory was applied to identify sedimentary cycles and sequence boundaries. Through the sedimentary cycle method and the principle of correlation of superimposed river sand bodies, the target layer sedimentary units in the target area were delineated.
[0044] Step 2: Based on well logging data and well logging interpretation data, draw sedimentary microfacies diagrams for each sedimentary unit to determine the distribution of channel sand bodies; details are as follows:
[0045] The type and characteristics of the sedimentary environment in the target area provide a basis for identifying sedimentary microfacies. Using methods such as core observation and well logging analysis, sedimentary microfacies characteristics, such as sand grain size, bedding, and bioturbation, are identified. Based on these characteristics, sedimentary units are divided into different microfacies types, such as distributary channels, abandoned channels, natural levees, and thin-layered overflow sands.
[0046] Step 3: Based on the distribution of sedimentary microfacies, determine the identifying markers of individual channels within the composite channel and delineate the distribution of individual channels within the composite channel:
[0047] The identification markers include the distribution of abandoned channels, differences in sand body size, differences in vertical elevation of sand bodies, interchannel sand bodies, and mudstone deposits; a detailed description of the framework sand bodies within a single channel is required, including their geometry, thickness variations, and connectivity.
[0048] Step 4: Based on the distribution pattern of a single river channel, analyze the rhythmicity and heterogeneity of the sand bodies, and establish a detailed three-dimensional geological model of the target layer in the target area:
[0049] In this embodiment, geological modeling software is used to generate a three-dimensional mesh based on stratigraphic interfaces and geological units, ensuring that the mesh's accuracy and resolution meet modeling requirements. Geological attributes, such as lithology, porosity, and permeability, are assigned to the three-dimensional mesh. Statistical methods and geological knowledge are used to interpolate and extrapolate these attributes to assess model uncertainties, such as data uncertainty and assumptions made during the modeling process. Sensitivity analysis is conducted to determine the parameters that have the greatest impact on the model. The model is validated using actual drilling, logging, and production data. Based on the validation results, the model is adjusted and optimized as necessary.
[0050] The method for establishing a three-dimensional fine geological model as described in this embodiment includes the following specific steps:
[0051] (1) Collect relevant data on the geological area, such as two-dimensional geological maps, drilling data, and seismic interpretation data. Then, conduct detailed analysis and organization of these data to clarify the geological stratification and extract key geological information.
[0052] (2) Geological mapping: Geological mapping is carried out based on the collected data. This includes converting two-dimensional geological maps into three-dimensional geological maps, determining the basic mapping lithostratigraphic units, and collecting, screening and labeling stratigraphic and structural occurrence information.
[0053] (3) Establishing a three-dimensional geological framework: Based on the results of geological mapping, a three-dimensional geological framework is established. Professional software is used to create surfaces and generate solid models. Surfaces can be generated by creating new surfaces and adding the organized point data information files layer by layer, and then the surfaces are extracted into solids to form a geological layer solid model.
[0054] (4) Structural Modeling: Based on the three-dimensional geological framework, structural modeling is performed. This includes establishing fault models and bedding plane models. Establishing fault models involves inputting fault data from seismic interpretation and structural maps, performing fault detection, combination, and 3D meshing. Establishing bedding plane models requires adding the top and bottom surface data of the sandstone formation from seismic interpretation to the fault models, performing time-depth conversion and bedding plane correction, and finally establishing bedding plane models for each sedimentary unit.
[0055] (5) Establishment of facies models: Facies models include sedimentary facies models and lithofacies models. Based on the established three-dimensional geological framework and tectonic model, and combined with actual geological conditions and previous research results, facies models are established and refined.
[0056] Step 5: Based on the water absorption profile, rhythmic distribution, and dynamic data, determine the spatial distribution pattern of high-permeability channels in the later stage of high water cut, and draw a spatial distribution map of high-permeability channels; details are as follows:
[0057] (1) Dynamic characteristic analysis: Analyze the dynamic characteristics of the oilfield, such as water cut change, production index, injection and production pressure distribution, and identify abnormal dynamic manifestations of high permeability channels that may exist in the oilfield.
[0058] (2) Static feature identification: Use well logging data to identify potential high-permeability channels such as high-permeability strips, natural fractures, and faults in the reservoir; use seismic data to identify the continuity and integrity of the reservoir and assess possible high-permeability areas.
[0059] (3) Identification of High-Permeability Channels: Geostatistical methods, fuzzy logic, and pattern recognition techniques are applied to establish a high-permeability channel identification model. This model is then used to partition the oilfield and identify areas where high-permeability channels may exist. The spatial distribution identification steps for high-permeability channels in the later stages of high water cut are as follows:
[0060] ① Data processing is performed on the collected static geological data, dynamic development data, and dynamic monitoring data of the oilfield;
[0061] ② Perform data quality analysis on the data processed in step ① and establish a database;
[0062] ③Based on the established database, conduct research on the production and absorption patterns of liquid between vertical layers, predict the production and absorption ratios and water content of sublayers, and identify the layers with high permeability channels in the vertical direction;
[0063] ④ Based on the established database, perform planar well connectivity analysis and well pressure response analysis to identify the location of planar high-permeability channels;
[0064] ⑤ Based on the established database, vertical rhythm analysis is performed to identify the location of high-permeability channels within the layer.
[0065] (4) Numerical simulation and verification: Establish a reservoir numerical model to simulate the oilfield development process, especially the waterflooding process. Verify the accuracy of the model through historical data matching and adjust the model parameters to better reflect the actual geological conditions.
[0066] (5) Spatial distribution map drawing: Based on the dynamic and static analysis results and combined with the numerical simulation output, a spatial distribution map of high seepage channels is drawn. The spatial distribution of high seepage channels is visualized using geological drawing software.
[0067] Step 6: Based on the geological model, the spatial distribution pattern of high-permeability channels in the later stage of high water-cut development, and development dynamic data, numerical simulation methods are used to quantitatively analyze the spatial distribution pattern of remaining oil in the later stage of high water-cut development; details are as follows:
[0068] (1) Based on the geological model, historical data fitting is performed using historical production data from the oilfield. The model parameters are adjusted to match the simulation results with the actual production data.
[0069] (2) Fluid distribution simulation: Simulate fluid flow during reservoir development, including the distribution changes of oil, water, and gas. Analyze the oil and water distribution at different development stages to identify potential distribution areas of remaining oil.
[0070] (3) Residual oil saturation analysis: Based on the fluid distribution simulation results, the residual oil saturation is calculated. The occurrence state of the residual oil is identified, such as residual oil saturation and oil-water interface.
[0071] (4) Remaining oil potential assessment: Based on the production dynamic data of oil and water wells, assess the remaining oil potential. Quantitatively evaluate the remaining oil potential of different regions and identify high-potential areas.
[0072] (5) Spatial distribution pattern analysis: Using geological information system tools, the distribution of remaining oil saturation is visualized. The spatial distribution pattern of remaining oil is analyzed, such as its relationship with geological structure and the influence of heterogeneity.
[0073] (6) Uncertainty Analysis: Evaluate the impact of model parameter uncertainty on the prediction of remaining oil distribution. Through sensitivity analysis, identify the parameters that have the greatest impact on the prediction of remaining oil distribution.
[0074] Step 7: Based on the spatial distribution pattern of remaining oil, utilizing the high permeability channels existing in the reservoir during the ultra-high water-cut stage of oilfield development, deploy horizontal wells at the top of the oil layer. The deployment method involves ensuring the horizontal wells cross at least one single river channel. These horizontal wells are used as production wells, with water injection from surrounding vertical wells to tap into some of the remaining oil. Once the water cut of the horizontal wells reaches a set value, they are converted into chemical injection wells, and the surrounding vertical wells are converted into production wells to continue tapping into the remaining oil. Details are as follows:
[0075] Horizontal wells are deployed at the top of the oil-bearing formation to reconstruct the three-dimensional well network. The deployment method involves horizontal wells traversing single channels, typically 3-4 single channels, with a horizontal well section length exceeding 500m, thus forming a three-dimensional well network of horizontal injection and vertical production. Since the horizontal well trajectory crosses multiple channels and interchannel sediments, it can precisely tap into the remaining oil in narrow channels and the edges of complex channels that are beyond the control of the vertical well network. Initially, the deployed horizontal wells serve as production wells, while surrounding vertical wells are used for water injection. The injected water flows through high-permeability channels and then into the horizontal wells, tapping into some of the remaining oil. Once the water cut of the deployed horizontal wells reaches 95%, they are converted into chemical injection wells, while the surrounding vertical wells are converted into production wells. The profile control effect of the chemical agents and gravity drive are used to improve the recovery rate at the top of the reservoir.
[0076] Application examples
[0077] Taking a certain oil layer in the Sartu area of the Sabei target zone of Daqing Changyuan Oilfield as the application object, the horizontal well deployment and remaining oil potential tapping are carried out using the vertical-horizontal joint development method disclosed in this invention. The detailed steps are as follows:
[0078] Step 1: Finely divide the sedimentary unit of a certain oil layer in Sartu, Sabei target area of Daqing Changyuan Oilfield, and determine the spatial distribution pattern of each sedimentary unit of the target layer.
[0079] Step 2: Draw sedimentary microfacies maps of the main sedimentary units to determine the distribution of channel sand bodies. Channels are mainly developed in the central and western parts of the target area, see... Figure 4 .
[0080] Step 3: Based on the distribution of sedimentary microfacies, identify the markers of individual channels within the composite channel and delineate the distribution of individual channels within the composite channel. The target area's Sartu target layer sedimentary microfacies map shows four main channel sand bodies. (See attached image) Figure 4 The river channel is between 150 and 450 meters wide.
[0081] Step 4: Establish a detailed three-dimensional geological model of a certain oil layer in Sartu, Sabei target area of Daqing Changyuan Oilfield. Using Petrel geological software, establish a three-dimensional mesh model, structural model, sedimentary facies model, net-to-gross ratio model, porosity model, permeability model, and oil saturation model.
[0082] Step 5: Determine the spatial distribution pattern of high-permeability channels in the later stage of high water cut. Analyze the dynamic characteristics of a certain oil layer in the Sartu reservoir of the Sabei target area of the Daqing Changyuan Oilfield to identify abnormal dynamic manifestations of potentially existing high-permeability channels. Use well logging data to identify high-permeability channels in high-permeability bands within the reservoir and establish a discrimination model for high-permeability channels. Draw a spatial distribution map of high-permeability channels to visualize their spatial distribution. (See...) Figure 2 ,See Figure 3 .
[0083] Step 6: Using numerical simulation, quantitatively analyze the spatial distribution of remaining oil in a high-water-cut oil layer in the Sartu oil reservoir of the Sabei target area of Daqing Changyuan Oilfield during the later stage. (See...) Figure 2 and Figure 3 .
[0084] Step 7: Based on the spatial distribution pattern of remaining oil, reconstruct the three-dimensional well network and implement precise potential tapping. Horizontal well trajectories traverse multiple channels and interchannel sediments, precisely tapping remaining oil in narrow channels and the edges of complex channels that cannot be controlled by the vertical well network, as well as in phase transition areas. Horizontal wells are deployed across a single channel, typically traversing 3-4 single channels, with a horizontal well section length greater than 500m; forming a three-dimensional well network of horizontal well injection and vertical well production; the deployed horizontal wells initially serve as production wells, while surrounding vertical wells are used for water injection. The injected water flows according to a high-permeability channel distribution before flowing into the horizontal wells, tapping some of the remaining oil; once the deployed horizontal wells reach a water cut of 95%, they are converted into chemical injection wells, and surrounding vertical wells are converted into production wells, see [link to relevant documentation]. Figure 2 , Figure 3 and Figure 4 .
[0085] In summary, this invention utilizes the distribution patterns of high-permeability flow channels commonly found in reservoirs during the late-stage ultra-high water-cut phase of oilfield development. It deploys a novel chemical flooding development well network combining vertical and horizontal wells to exploit these high-permeability channels without blocking them. This solves the technical challenges of high well density, complex surface design, and low return on investment caused by dense well network development models in chemical flooding. It forms a method for deploying horizontal wells for chemical flooding that utilizes the distribution characteristics of high-permeability channels. This method is primarily aimed at sandstone reservoirs in the late-stage water-drive or polymer-drive development phases, both domestically and internationally. Based on a detailed description of the spatial distribution patterns of high-permeability channels, it designs a novel well network type combining vertical and horizontal wells to further enhance oil recovery. This effectively improves the control of the infill well network, efficiently taps into the locally enriched residual oil in the ultra-high water-cut phase, and provides an efficient, economical, and convenient well network design approach for further enhancing oil recovery through chemical flooding.
[0086] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.
Claims
1. A method for the combined development of chemical flooding and vertical displacement using high-permeability channels, characterized in that, include: Based on the spatial distribution pattern of the remaining oil in the target area, a horizontal well is deployed at the top of the oil layer. The deployment method is to drill a new horizontal well using a high water-cut, high-permeability channel in the later stage, so that the horizontal well crosses at least one single river channel. The horizontal well is used as an oil production well, and water is injected into the surrounding vertical wells to tap the remaining oil potential. Once the water content of the horizontal well reaches the set value, it is converted into a chemical injection well, and the surrounding vertical wells are converted into oil production wells to continue tapping the remaining oil potential.
2. The method for joint development of vertical and horizontal lines according to claim 1, characterized in that: The horizontal well is designed to cross 3-4 individual river channels, with a horizontal well section length greater than 500m.
3. The method for joint development of vertical and horizontal lines according to claim 1 or 2, characterized in that, The method for analyzing the spatial distribution pattern of remaining oil in the target area includes: The spatial distribution pattern of each sedimentary unit in the target layer of the target area is determined. The method for determining the spatial distribution pattern is based on the core analysis data from inspection wells, well logging data, field outcrops and modern sedimentary data, applying sequence stratigraphy theory to identify sedimentary cycles and sequence boundaries, and dividing sedimentary units by sedimentary cycle method and the principle of correlation of superimposed river sand bodies.
4. The method for joint development of vertical and horizontal lines according to claim 3, characterized in that, The method for analyzing the spatial distribution of remaining oil also includes determining the distribution of channel sand bodies, the determination method including: Based on the spatial distribution patterns of each sedimentary unit, sedimentary microfacies maps of each sedimentary unit are drawn according to well logging data and well logging interpretation data, and the distribution of channel sand bodies is determined using the sedimentary microfacies maps.
5. The method for joint development of vertical and horizontal lines according to claim 4, characterized in that, The method for analyzing the spatial distribution of remaining oil also includes dividing the distribution of individual channels within the composite channel, and the division method includes: Based on the distribution of the riverbed sand, the identification markers of individual channels within the composite river are determined, and the distribution of individual channels within the composite river is divided according to the identification markers.
6. The method for joint development of vertical and horizontal lines according to claim 5, characterized in that, The method for analyzing the spatial distribution of remaining oil also includes establishing a three-dimensional fine geological model of the target layer in the target area. The method for establishing the geological model includes: Based on the distribution pattern of the single river channel, the rhythmicity and heterogeneity of the sand bodies are analyzed, and a three-dimensional fine geological model of the target layer in the target area is established.
7. The method for joint development of vertical and horizontal lines according to claim 6, characterized in that, The method for analyzing the spatial distribution of remaining oil also includes determining the spatial distribution of high-permeability channels in the later stage of high water cut, wherein the method for determination includes: Analyze the dynamic characteristics of the target area to identify abnormal dynamic behaviors that may involve high seepage channels; Static analysis using well logging data can identify high-permeability channels in the reservoir. Seismic data can be used to identify reservoir continuity and integrity, and to assess potential high-permeability areas. A discrimination model for high seepage channels is established, and the areas where high seepage channels may exist are qualitatively identified through the discrimination model; Based on the results of dynamic and static analysis, combined with the output of numerical simulation, a spatial distribution map of high seepage channels is drawn.
8. The method for joint development of vertical and horizontal lines according to claim 7, characterized in that, The method for analyzing the spatial distribution of remaining oil also includes quantitative analysis of the spatial distribution of remaining oil in the later stage of high water cut, wherein the quantitative analysis method includes: Based on the geological model, the spatial distribution pattern of the high water-cut late-stage high-permeability channels, and development dynamic data, the spatial distribution pattern of the remaining oil is obtained by applying numerical simulation methods.