Evaluation method and device for horizontal well section of thin cloud rock reservoir
By using waveform indication inversion and Sekrigin estimation methods in the horizontal well section of the Thin Dolomites reservoir, the high-resolution reservoir model was solved, and the problems of insufficient evaluation accuracy and insufficient fracturing scheme guidance in the existing technology were achieved, and higher recovery rates and single-well production capacity were achieved.
Patent Information
- Application Number
- CN202311777445.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-21
- Publication Date
- 2025-06-24
AI Technical Summary
The evaluation method of horizontal well section of Thin Wanyan reservoir in the prior art is insufficient in accuracy, which is difficult to reflect the longitudinal changes in reservoir parameters in the upper and lower formations of horizontal well trajectory, and cannot effectively guide the fracturing schemes in different parts of the horizontal section.
By obtaining the basic data of the research area and post-stack offset seismic data, inversion was performed using the waveform indication inversion method, a horizontal well area tectonic model was established, and the inversion results were used as inter-well constraints, a high-resolution reservoir model was established using the Xiekerigin estimation method, and the horizontal well section of the Thin Dolomites reservoir was evaluated.
High-precision modeling of the reservoir model is achieved, the longitudinal resolution is significantly higher than the seismic inversion results, and it is better matched with the well drilling results. It can effectively guide the fracturing scheme design in different parts of the horizontal section, and improve recovery rate and single-well production capacity.
Smart Images
Figure CN120195729A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of oil exploration and development, and particularly relates to a method and device for evaluating horizontal well sections of thin dolomite reservoirs. Background Art
[0002] Currently, the evaluation of horizontal well sections of thin reservoirs at home and abroad usually directly adopts the method of combining seismic inversion results with horizontal well interpretation results, and comprehensively guides the design of fracturing schemes based on the planar development of natural fractures.
[0003] In marine strata, carbonate reservoirs with low porosity and low permeability, such as thin dolomite reservoirs, are widely distributed. The horizontal well drilling technology can better reveal such thin reservoirs and improve production capacity. Horizontal wells belong to a special type of well, with a well deviation of up to 90°, and can achieve a horizontal well trajectory distribution within a certain length of the target layer. Due to the quasi-parallel relationship between horizontal wells and the formation, compared with vertical wells, they can increase the contact area between the well and the oil and gas layer and penetrate the natural fracture zone, which can improve the oil and gas recovery rate and the production capacity of a single well. At the same time, the logging curves of horizontal wells can directly reflect the lateral changes in formation physical properties, and can improve the lateral resolution of seismic inversion results.
[0004] Seismic inversion is an important method for reflecting the target formation structure and rock physical properties by using seismic data received by surface instruments and well data through a series of mathematical algorithms. Currently, seismic inversion in the oil and gas exploration field can be divided into several techniques such as convolution model-based inversion, non-linear inversion, geostatistical inversion, and waveform indication inversion. Due to the characteristics of thin dolomite reservoirs, such as small thickness and large lateral changes, the waveform indication inversion method is often used for prediction, relying on the connection between high-frequency logging information and waveform differences for high-resolution inversion. The evaluation of horizontal well sections of thin dolomite reservoirs is realized by using seismic inversion results and horizontal well interpretation results.
[0005] In the above methods, the seismic identification and evaluation of thin dolomite reservoirs mainly rely on seismic inversion results and horizontal well interpretation results. However, the seismic inversion method is affected by well information, grid parameters, etc., and the resolution of its inversion results is limited. At the same time, due to the congenital conditions of horizontal wells, it is difficult to reflect the longitudinal changes in reservoir parameters in the formations above and below the horizontal well trajectory. Therefore, the above methods have difficulties in analyzing the longitudinal distribution law of reservoirs, affecting the evaluation accuracy of horizontal well sections of thin dolomite reservoirs, and there are potential hazards in guiding fracturing schemes for different parts of the horizontal section. Summary of the Invention
[0006] The present invention provides a method and device for evaluating horizontal well sections of thin dolomite reservoirs to solve the problems in the prior art, such as insufficient accuracy of the evaluation method for horizontal well sections of deep thin dolomite reservoirs, difficulty in reflecting the longitudinal changes in reservoir parameters in the formations above and below the horizontal well trajectory, and inability to effectively guide fracturing schemes for different parts of the horizontal section.
[0007] According to one aspect of the present invention, there is provided a method for evaluating horizontal well sections in thin dolomite reservoirs, comprising: Obtaining basic data of the study area and post-stack migrated seismic data; Based on the basic data and the post-stack migrated seismic data, performing inversion using the waveform indication inversion method to obtain inversion results; According to the basic data, establishing a structural model for the horizontal well area in the study area; On the basis of the structural model, using the inversion results as well-to-well constraints and adopting the co-kriging estimation method to establish a high-resolution reservoir model; Evaluating the horizontal well sections in the thin dolomite reservoir of the study area according to the basic data and the high-resolution reservoir model.
[0008] Preferably, the basic data of the study area at least includes: Logging curves, drilling and logging data, well deviation data, core data, stratification data, logging interpretation results, and seismic interpretation horizons.
[0009] Preferably, the method of performing inversion using the waveform indication inversion method based on the post-stack migrated seismic data according to the basic data to obtain inversion results includes: Performing well-seismic calibration on the post-stack migrated seismic data through the drilling and logging data, well deviation data, core data, and stratification data; According to the post-stack migrated seismic data after well-seismic calibration, using the logging curves, logging interpretation results, and seismic interpretation horizons to perform high-resolution dolomite content waveform indication inversion to obtain inversion results.
[0010] Preferably, the method of establishing a structural model for the horizontal well area in the study area according to the basic data includes: Taking the seismic interpretation horizons, logging interpretation results, and stratification data as the model framework, and using the logging curves and logging interpretation results as constraints to perform three-dimensional geological modeling to obtain the structural model for the horizontal well area in the study area; Among them, when setting model parameters, ensure that the structural plane is consistent with the stratification data, and the longitudinal grid of the model is smaller than the minimum single-layer reservoir thickness.
[0011] Preferably, the method of establishing a high-resolution reservoir model using the co-kriging estimation method with the inversion results as well-to-well constraints on the basis of the structural model includes: On the basis of the structural model, using the dolomite content data in the logging interpretation results as hard data and the dolomite content prediction results in the inversion results as soft data to perform variogram analysis, and adopting the co-kriging estimation method to establish a high-resolution reservoir model.
[0012] Preferably, the method for evaluating the horizontal well section of the thin dolomite reservoir in the study area according to the basic data and the high-resolution reservoir model includes: Extract the ant body plan of the horizontal well section according to the post-stack migrated seismic data and the seismic interpretation horizons; Extract the high-resolution reservoir model plan according to the vertical position of the thin dolomite reservoir development; Analyze the development of the thin dolomite reservoir and the interlayer fractures in the horizontal well section and summarize the distribution law according to the extracted ant body plan and the high-resolution reservoir model plan, and complete the evaluation of the horizontal well section of the thin dolomite reservoir in the study area.
[0013] Preferably, before evaluating the horizontal well section of the thin dolomite reservoir in the study area according to the basic data and the high-resolution reservoir model, it further includes: Along the horizontal well profile, compare the logging curves and logging interpretation results with the high-resolution reservoir model, and judge whether the dolomite content in the high-resolution reservoir model is consistent with the dolomite content in the logging results at the corresponding position. If so, the established high-resolution reservoir model meets the requirements.
[0014] Preferably, the basic data further includes: single-well test production data; Before performing inversion using the waveform indication inversion method based on the post-stack migrated seismic data according to the basic data, it further includes: Optimize the wells in the study area according to the single-well test production data to obtain optimized wells; perform waveform indication inversion using the basic data and the post-stack migrated seismic data corresponding to the optimized wells.
[0015] According to one aspect of the present invention, there is provided an apparatus for evaluating the horizontal well section of a thin dolomite reservoir, including: An acquisition unit for acquiring the basic data of the study area and the post-stack migrated seismic data; A seismic data inversion unit for performing inversion using the waveform indication inversion method based on the post-stack migrated seismic data according to the basic data to obtain inversion results; A structural model establishment unit for establishing a structural model of the horizontal well area in the study area according to the basic data; A reservoir model establishment unit for establishing a high-resolution reservoir model using the co-kriging estimation method with the inversion results as the well-to-well constraint on the basis of the structural model; A horizontal well section evaluation unit for evaluating the horizontal well section of the thin dolomite reservoir in the study area according to the basic data and the high-resolution reservoir model.
[0016] The present invention has at least the following beneficial effects: The present invention provides a method and device for evaluating a horizontal well section of a thin dolomite reservoir. Using the prediction result of cloud quality content by waveform indication inversion as an inter-well constraint, a high-precision reservoir model is established based on the co-Kriging estimation method. The longitudinal resolution of the obtained reservoir model is significantly higher than that of seismic inversion results, and it has a better matching with the actual drilling results of the well. Horizontally, it follows the reservoir distribution characteristics predicted by seismic inversion. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings are incorporated herein and constitute a part of this specification. These drawings illustrate embodiments consistent with the present invention and, together with the specification, are used to explain the technical solutions of the present invention.
[0018] Figure 1 FIG. shows a flowchart of a method for evaluating a horizontal well section of a thin dolomite reservoir according to an embodiment of the present invention; Figure 2 FIG. shows an inversion profile of cloud quality content according to an embodiment of the present invention; Figure 3 FIG. shows a schematic diagram of a structural model in a horizontal well area according to an embodiment of the present invention; Figure 4 FIG. shows a schematic diagram of a high-resolution reservoir model in a horizontal well area according to an embodiment of the present invention; Figure 5 FIG. shows a plan view of a high-resolution reservoir model according to an embodiment of the present invention; Figure 6 FIG. shows a plan view of ant body fracture prediction in a horizontal well area according to an embodiment of the present invention. DETAILED DESCRIPTION
[0019] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise specified.
[0020] As used herein, the term "exemplary" means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.
[0021] As used herein, the term "and / or" merely describes an association relationship between associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, or B exists alone. In addition, the term "at least one" as used herein means any one of a plurality or any combination of at least two of a plurality. For example, including at least one of A, B, and C may represent including any one or more elements selected from the set consisting of A, B, and C.
[0022] In addition, for a better illustration of the present invention, numerous specific details are given in the following detailed implementation manners. Those skilled in the art should understand that the present invention can also be implemented without certain specific details. In some instances, methods, means, elements, and circuits well known to those skilled in the art are not described in detail so as to highlight the gist of the present invention.
[0023] Figure 1 The flowchart showing the evaluation method for the horizontal well section of a thin dolomite reservoir according to an embodiment of the present invention; Figure 2 The inversion profile diagram showing the cloud quality content according to an embodiment of the present invention; Figure 3 The schematic diagram showing the structural model of the horizontal well area according to an embodiment of the present invention; Figure 4 The schematic diagram showing the high-resolution reservoir model of the horizontal well area according to an embodiment of the present invention; Figure 5 The plan view showing the high-resolution reservoir model according to an embodiment of the present invention; Figure 6 The plan view showing the prediction of ant-like body fractures in the horizontal well area according to an embodiment of the present invention. As Figures 1-6 As shown, a method for evaluating the horizontal well section of a thin dolomite reservoir includes: Step S01: Obtain the basic data of the study area and the post-stack migrated seismic data; Step S02: Based on the basic data and the post-stack migrated seismic data, perform inversion using the waveform-indicating inversion method to obtain the inversion results; Step S03: According to the basic data, establish the structural model of the horizontal well area in the study area; Step S04: On the basis of the structural model, use the co-Kriging estimation method to establish a high-resolution reservoir model with the inversion results as the inter-well constraints; Step S05: Evaluate the horizontal well section of the thin dolomite reservoir in the study area according to the basic data and the high-resolution reservoir model.
[0024] The evaluation of the horizontal well section of the thin dolomite reservoir provided by the embodiment of the present invention specifically includes the following steps: Step S01: Obtain the basic data of the study area and the post-stack migrated seismic data.
[0025] In the present invention, the basic data of the study area at least includes: logging curves, drilling and logging data, well deviation data, core data, stratification data, logging interpretation results, and seismic interpretation horizons.
[0026] Step S02: Based on the basic data and the post-stack migrated seismic data, perform inversion using the waveform-indicating inversion method to obtain the inversion results.
[0027] In the present invention, the method for obtaining the inversion result by performing inversion on the post-stack migrated seismic data based on the basic data by using the waveform-indicating inversion method includes: performing well-seismic calibration on the post-stack migrated seismic data by using the drilling and logging data, well deviation data, core data, and layer division data; and performing high-resolution waveform-indicating inversion of the dolomite content by using the well-seismic calibrated post-stack migrated seismic data, the logging curves, the logging interpretation results, and the seismic interpretation horizons to obtain the inversion result.
[0028] In an embodiment of the present invention, based on the amplitude-preserved seismic data, i.e., the post-stack migrated seismic data, the waveform-indicating inversion method is used to combine well and seismic data to predict the development of the dolomite content in the area near the horizontal well trajectory. The specific process is as follows: Perform well-seismic calibration on the post-stack migrated seismic data by using the drilling and logging data, well deviation data, core data, and layer division data to make the two consistent.
[0029] Use the amplitude-preserved seismic data based on the dominant offset stacking, i.e., the post-stack migrated seismic data. According to the seismic interpretation horizons, combined with the logging curves, establish the mapping relationship between the seismic waveform structure of the target layer and the high-frequency dolomite content curve structure through dynamic clustering analysis of seismic waveforms; use the lateral similarity of seismic waveforms to drive the high-frequency logging information in the logging interpretation results to achieve high-resolution waveform-indicating inversion of the dolomite content and obtain the inversion result. Among them, the waveform-indicating inversion process is implemented by using SMI software.
[0030] As Figure 2 shown in the cross-section of the inversion result of the dolomite content, predict the development of the dolomite content in the area near the horizontal well trajectory according to the inversion result, that is, the spatial distribution and content level of dolomite in the horizontal well area.
[0031] Step S03: Establish a structural model for the horizontal well area in the study area according to the basic data.
[0032] In the present invention, the method for establishing a structural model for the horizontal well area in the study area according to the basic data includes: using the seismic interpretation horizons, logging interpretation results, and layer division data as the model framework, and using the logging curves and logging interpretation results as constraints to perform 3D geological modeling to obtain the structural model for the horizontal well area in the study area; when setting the model parameters, ensure that the structural horizons are consistent with the layer division data, and the longitudinal grid of the model is smaller than the minimum single-layer reservoir thickness.
[0033] In an embodiment of the present invention, use the seismic structural interpretation results, combined with single-well data, to establish a structural model for the horizontal well area, ensure that the structural horizons are consistent with the drilling layer division, and the longitudinal grid of the model is smaller than the minimum single-layer reservoir thickness. The specific process is as follows: Based on the seismic structure interpretation results, i.e., the seismic interpretation horizons, combined with the logging interpretation results, a three-dimensional geological deterministic modeling is carried out with the fine-layer structure, i.e., the seismic interpretation horizons and the layered data as the model framework, and the parameters varying along the layer obtained from the logging curves and logging interpretation results in the horizontal well logging interpretation as the constraints. The constraint effect is reflected in that the sedimentary cycles can be further divided through the parameters varying along the layer of the horizontal well, such as gamma, resistivity, dolomite content curves, etc., to finely modify the fine-layer structure horizons.
[0034] When setting the structural model parameters, it is necessary to ensure that the structural horizons are consistent with the layered data, and the longitudinal grid of the model is smaller than the minimum single-layer reservoir thickness, so as to establish a three-dimensional structural model in the horizontal well area. Among them, the Petrel software is used to establish the structural model. The final obtained structural model in the horizontal well area is as Figure 3 shown.
[0035] Step S04: On the basis of the structural model, using the inversion results as the inter-well constraints, a high-resolution reservoir model is established by using the co-kriging estimation method.
[0036] In the present invention, the method of establishing a high-resolution reservoir model by using the inversion results as the inter-well constraints and the co-kriging estimation method on the basis of the structural model includes: on the basis of the structural model, using the dolomite content data in the logging interpretation results as the hard data and the predicted dolomite content results in the inversion results as the soft data, performing variogram analysis, and using the co-kriging estimation method to establish a high-resolution reservoir model.
[0037] In the embodiment of the present invention, on the basis of the structural model in the horizontal well area with good well matching, using the logging interpretation dolomite content data as the hard data and the waveform-indicated inversion dolomite content predicted results as the soft data, performing variogram analysis, and using the co-kriging estimation method under the sequential Gaussian simulation algorithm to establish a reservoir dolomite content intensity model, further refining the dolomite distribution range, and forming a high-resolution reservoir model that conforms to the stratigraphic structural model and can match the inversion results. The specific process is as follows: On the basis of the structural model in the horizontal well area with good well matching, i.e., the structural model in the horizontal well area obtained in step S03, using the waveform-indicated inversion dolomite content predicted results, i.e., the dolomite content inversion results obtained in step S02 as the inter-well constraint conditions; using the co-kriging estimation method to perform high-precision reservoir modeling under the constraint conditions; the structural model is the framework model, and the high-precision (high-resolution) reservoir model is established on the basis of the structural model and simulated based on the well data. Among them, the Petrel software is used to establish the high-precision reservoir model. During the high-precision modeling process, the waveform-indicated inversion results of step S02 are input into the software as the reference for model establishment to achieve the constraint effect, further refining the dolomite distribution range, and establishing a high-resolution reservoir model that conforms to the stratigraphic structural model and can match the inversion results.
[0038] As shown Figure 4 in the high-resolution reservoir model established for the horizontal well area. In Figure 4 , TS6 / TS6HC is the well number. Through the thin dolomite reservoir with a visibly identifiable layered distribution longitudinally, that is, the longitudinal distribution of the predicted thin dolomite reservoir is more refined, it is proved that the longitudinal resolution of the obtained high-resolution reservoir model is significantly higher than that of the seismic inversion results, and the matching with the actual drilling results of the well is better. Horizontally, it follows the reservoir distribution characteristics predicted by seismic inversion, and according to the regional geological overview, it is consistent with the development mode of the thin dolomite reservoir in this area.
[0039] Step S05: Evaluate the horizontal well section of the thin dolomite reservoir in the study area according to the basic data and the high-resolution reservoir model.
[0040] In the present invention, the method for evaluating the horizontal well section of the thin dolomite reservoir in the study area according to the basic data and the high-resolution reservoir model includes: extracting the ant body plan of the horizontal well section according to the post-stack migrated seismic data and seismic interpretation horizons; extracting the plan of the high-resolution reservoir model according to the longitudinal position of the development of the thin dolomite reservoir; analyzing the development of the thin dolomite reservoir and interlayer fractures in the horizontal well section and summarizing the distribution law according to the extracted ant body plan and the plan of the high-resolution reservoir model, so as to complete the evaluation of the horizontal well section of the thin dolomite reservoir in the study area.
[0041] In the embodiment of the present invention, according to the prediction result of the reservoir model, that is, the high-resolution reservoir model, a suitable time window near the horizontal well section is selected, the plan of the reservoir model is extracted, and it is compared with the ant body fracture prediction plan extracted from the post-stack migrated seismic data and seismic interpretation horizons to analyze the development status of the reservoir and fractures on both sides of the horizontal well section, so as to guide the determination of the fracturing direction and fracturing scale scheme for different parts of the horizontal section. The specific process is as follows: Based on the amplitude-preserved seismic data (post-stack migrated seismic data) with dominant offset stacking and seismic interpretation horizons, using the upper and lower interpretation horizons of the target interval as the top and bottom surfaces, taking the eigenvalue coherence data as the input, and combining the fracture strike and dip characteristics in the horizontal well area, calculate the fine ant body in this area to form the ant body plan near the horizontal well section, so as to characterize the fracture development situation on both sides of the horizontal well section and its distribution characteristics on the plane.
[0042] Extract the plan of the high-resolution reservoir model according to the longitudinal position of the development of the thin dolomite reservoir, so as to characterize the development situation of the reservoir on both sides of the horizontal well section and its distribution characteristics on the plane.
[0043] According to the extracted reservoir model and the ant body plan view, analyze the development of thin dolomite reservoirs and interlayer fractures on both sides of the horizontal well section, summarize the distribution laws of reservoirs and fractures in the horizontal section, and use this to guide the determination of fracturing directions and fracturing scale schemes for different parts of the horizontal section. For example Figure 6 The figure shows the predicted ant body fracture plan view of the horizontal well area. Compared with the original method of only analyzing through the inversion result plan view and the ant body, the present invention can better evaluate the reservoir by combining the high-resolution reservoir model plan view and the ant body plan view, thereby making the formulation of the fracturing plan more reasonable and effectively improving the productivity of the horizontal well.
[0044] In the present invention, before evaluating the horizontal well section of the thin dolomite reservoir in the study area according to the basic data and the high-resolution reservoir model, it further includes: along the horizontal well profile, comparing the logging curves and logging interpretation results with the high-resolution reservoir model, and judging whether the dolomite content in the high-resolution reservoir model is consistent with the dolomite content in the logging results at the corresponding positions. If so, the established high-resolution reservoir model meets the requirements.
[0045] In an embodiment of the present invention, a high-resolution reservoir model profile is pulled along the horizontal well. According to the logging curves and logging interpretation results, along the horizontal well profile, the logging interpretation results of the horizontal well are finely compared with the high-resolution reservoir model profile. During the fine comparison process, the model data at the well trajectory position in the high-resolution reservoir model is strictly corresponding to the logging curves and interpretation results. Judge whether the dolomite content at the same well section position corresponding to the logging curves and logging interpretation results and the model is consistent. If so, it means that the high-resolution reservoir model data established in step S04 is reliable and can meet the requirements. According to the high-resolution reservoir model after fine comparison, the spatial position relationship between the thin dolomite and the well trajectory can be determined, thereby determining the longitudinal orientation of the development of the thin dolomite reservoir, that is, the spatial distance of the thin dolomite reservoir distributed along the vertical direction of the horizontal well.
[0046] For example Figure 5 The figure shows the high-resolution reservoir model plan view of the horizontal well area, Figure 5 in which the numbers are the labels of different horizontal well sections. The redder the color of the high-resolution reservoir model, that is Figure 5 the darker the color in the figure, the higher the degree of dolomitization, that is, the higher the dolomite content at this position. If the dolomite content at the well position in the high-resolution reservoir model is consistent with the dolomite content result at the corresponding well position analyzed according to the drilling and logging data, core data and logging interpretation results, that is, it corresponds well with the well, then the longitudinal relative relationship between the reservoir development positions at different parts of the horizontal well section and the horizontal well trajectory can be determined. Furthermore, combined with the longitudinal orientation, the dolomite content characteristics of the horizontal well section of the thin dolomite reservoir can be determined. For example, the area around the well is strongly dolomitized, and the area xx meters away from the well is weakly dolomitized, etc.
[0047] In the present invention, the basic data further includes: single well test production capacity data; before performing inversion by using the waveform indication inversion method based on the post-stack migration seismic data according to the basic data, it further includes: optimizing the wells in the study area according to the single well test production capacity data to obtain optimized wells; and performing waveform indication inversion by using the basic data and the post-stack migration seismic data corresponding to the optimized wells.
[0048] In an embodiment of the present invention, the data used in waveform indication inversion is the basic data and the post-stack migration seismic data corresponding to the wells selected after optimizing the wells in the study area through the single well test production capacity data.
[0049] In an embodiment of the present invention, taking a certain study area as an example, the specific process is as follows: Step S01: Collect the basic data of the study area; including: logging curves, drilling and logging data, well inclination data, core data, layer division data, logging interpretation results, seismic interpretation horizons, single well test production capacity data, and post-stack migration seismic data; Step S02: The logging curves show that the average dolomite content in the horizontal well section of the study area is 15 - 20%, and the average porosity is 2.4%, with good reservoir conditions, and seismic inversion prediction can be carried out; the horizontal well data used in inversion is the data corresponding to the wells selected after optimization through the single well test production capacity data; using the amplitude-preserved seismic data based on dominant offset stacking (post-stack migration seismic data), according to the seismic interpretation horizons, combined with the logging curves, establish the mapping relationship between the seismic waveform structure of the target layer and the high-frequency dolomite content curve structure through seismic waveform dynamic clustering analysis; use the lateral similarity of seismic waveforms to drive high-frequency logging information to achieve high-resolution dolomite content waveform indication inversion; predict the development of dolomite content in the area near the horizontal well trajectory according to the inversion results.
[0050] Step S03: Based on the seismic structural interpretation results, combined with the logging interpretation results, taking the sub-divided layer structure as the model framework and the layer-varying parameters obtained from the logging interpretation of the horizontal wells as constraints, use Petrel software to perform three-dimensional geological deterministic modeling; ensure that the structural horizons are consistent with the drilling layer divisions when setting the model parameters, and the longitudinal grid of the model is less than the minimum single-layer reservoir thickness, with the specific unit grid set to 20*20*1 and the total number of grids about 57.29 million, so as to establish a three-dimensional structural model of the horizontal well area in the study area.
[0051] Step S04: Starting from the wellbore data, based on the structural model of the horizontal well area with good well matching, using the prediction result of waveform-indicated inversion of dolomitic content as the inter-well constraint condition; adopting the co-Kriging estimation method for high-precision reservoir modeling, further refining the vertical distribution position of dolomitic content, and establishing a high-resolution reservoir model that conforms to the structural model and can match the inversion results. The obtained reservoir model has a significantly higher vertical resolution than the seismic inversion results and better matches the actual drilling results of the wells, and laterally follows the reservoir distribution characteristics predicted by seismic inversion.
[0052] According to the well logging curves and well logging interpretation results, pull the reservoir model profile along the horizontal well, carefully compare the well logging interpretation results of the horizontal well with the high-resolution reservoir model, and correspond the well trajectory positions of the two; according to the reservoir model, well logging curves and well logging interpretation results, 6 thin dolomite reservoir development sections can be laterally distinguished; determine the vertical orientation of the thin dolomite reservoir development according to the spatial position relationship between the reservoir model and the well trajectory; determine the dolomitic content characteristics of the thin dolomite reservoir according to the matching between the high-dolomitic content well section and the reservoir model.
[0053] Step S05: According to the post-stack migrated seismic data and seismic interpretation horizons, extract the ant bodies near the horizontal well section to characterize the fracture development on both sides of the horizontal well section; according to the vertical position of the thin dolomite reservoir development, extract the plan view of the high-resolution reservoir model to characterize the reservoir development on both sides of the horizontal well section; according to the reservoir and the predicted plan view of the ant body fractures, it is analyzed that the thin dolomite reservoir is relatively developed within 200 m on both sides of the horizontal well section, and the fracture development degree is relatively high, and effective transformation of the thin dolomite reservoir can be achieved.
[0054] It can be understood that the above-mentioned various method embodiments mentioned in the present invention can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present invention will not elaborate further.
[0055] The execution subject of the evaluation method for the horizontal well section of the thin dolomite reservoir can be an evaluation device for the horizontal well section of the thin dolomite reservoir. For example, the evaluation method for the horizontal well section of the thin dolomite reservoir can be executed by a terminal device, a server or other processing devices. Among them, the terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, etc. In some possible implementation manners, the evaluation method for the horizontal well section of the thin dolomite reservoir can be implemented by a processor calling computer-readable instructions stored in a memory.
[0056] Those skilled in the art can understand that in the above methods of the specific embodiments, the writing order of each step does not mean a strict execution order and does not impose any limitation on the implementation process. The specific execution order of each step should be determined according to its function and possible internal logic.
[0057] The present invention also provides an evaluation device for horizontal well sections of thin dolomite reservoirs, including: an acquisition unit for acquiring basic data of the study area and post-stack migrated seismic data; a seismic data inversion unit for performing inversion based on the post-stack migrated seismic data by using a waveform-indicating inversion method according to the basic data to obtain an inversion result; a structural model establishment unit for establishing a structural model of the horizontal well area in the study area according to the basic data; a reservoir model establishment unit for establishing a high-resolution reservoir model by using a co-Kriging estimation method on the basis of the structural model with the inversion result as the inter-well constraint; and a horizontal well section evaluation unit for evaluating the horizontal well sections of the thin dolomite reservoirs in the study area according to the basic data and the high-resolution reservoir model.
[0058] In some embodiments, the functions or the included modules and units of the device provided by the embodiments of the present invention can be used to execute the methods described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.
[0059] The present invention uses the prediction result of the waveform-indicating inversion of the dolomite content as the inter-well constraint to realize high-precision reservoir modeling based on the co-Kriging estimation method. The obtained reservoir model has a significantly higher vertical resolution than the seismic inversion result, better matching with the actual drilling result of the well, and follows the reservoir distribution characteristics predicted by the seismic inversion transversely; based on the high-precision reservoir model, the longitudinal position and dolomite content of the reservoir development in the upper and lower formations of the horizontal well section are determined; by combining the reservoir model with the ant body fracture prediction plan view, the defects of the existing evaluation method for horizontal well sections of deep thin dolomite reservoirs, such as insufficient accuracy and difficulty in effectively guiding the fracturing schemes at different parts of the horizontal section, are solved. The fracturing scheme design at different positions of the horizontal section can be effectively guided by the method of the present invention to ensure the maximization of the fracturing effect.
[0060] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of the technology in the market, or to enable other ordinary skilled persons in the technical field to understand the embodiments disclosed herein.
Claims
1. A method for evaluating a horizontal well section of a thin dolomite reservoir, characterized in that Including: Obtain the basic data of the study area and the post-stack migrated seismic data; Based on the basic data and the post-stack migrated seismic data, perform inversion using the waveform-indicated inversion method to obtain inversion results; Based on the basic data, establish a structural model for the horizontal well area in the study area; On the basis of the structural model, using the inversion results as well-to-well constraints, establish a high-resolution reservoir model using the co-Kriging estimation method; Based on the basic data and the high-resolution reservoir model, evaluate the horizontal well section of the thin dolomite reservoir in the study area.
2. The evaluation method for the horizontal well section of the thin dolomite reservoir according to claim 1, characterized in that The basic data of the study area at least includes: Logging curves, drilling and logging data, well deviation data, core data, stratification data, logging interpretation results, and seismic interpretation horizons.
3. The evaluation method for the horizontal well section of the thin dolomite reservoir according to claim 2, wherein, The method of performing inversion using the waveform-indicated inversion method based on the post-stack migrated seismic data according to the basic data to obtain inversion results includes: Perform well-seismic calibration on the post-stack migrated seismic data through the drilling and logging data, well deviation data, core data, and stratification data; Based on the well-seismic calibrated post-stack migrated seismic data, use the logging curves, logging interpretation results, and seismic interpretation horizons to perform high-resolution dolomite content waveform-indicated inversion to obtain inversion results.
4. The evaluation method for the horizontal well section of the thin dolomite reservoir according to claim 2, characterized in that The method of establishing a structural model for the horizontal well area in the study area based on the basic data includes: Using the seismic interpretation horizons, logging interpretation results, and stratification data as the model framework, and using the logging curves and logging interpretation results as constraints, perform 3D geological modeling to obtain the structural model for the horizontal well area in the study area; Among them, when setting model parameters, ensure that the structural planes are consistent with the stratification data, and the longitudinal grid of the model is smaller than the minimum single-layer reservoir thickness.
5. The evaluation method for the horizontal well section of the thin dolomite reservoir according to claim 2, characterized in that The method of establishing a high-resolution reservoir model using the co-Kriging estimation method with the inversion results as well-to-well constraints on the basis of the structural model includes: On the basis of the structural model, using the dolomite content data in the logging interpretation results as hard data and the predicted dolomite content results in the inversion results as soft data, perform variogram analysis, and use the co-Kriging estimation method to establish a high-resolution reservoir model.
6. The evaluation method for the horizontal well section of the thin dolomite reservoir according to claim 2, characterized in that The method of evaluating the horizontal well section of the thin dolomite reservoir in the study area based on the basic data and the high-resolution reservoir model includes: According to the post-stack migrated seismic data and the seismic interpretation horizons, extract the ant body plan of the horizontal well section; According to the longitudinal position of the development of the thin dolomite reservoir, extract the plan of the high-resolution reservoir model; According to the extracted ant body plan and the plan of the high-resolution reservoir model, analyze the development of the thin dolomite reservoir and interlayer fractures in the horizontal well section and summarize the distribution law to complete the evaluation of the horizontal well section of the thin dolomite reservoir in the study area.
7. The evaluation method for the horizontal well section of the thin dolomite reservoir according to any one of claims 2-6, characterized in that, Before evaluating the horizontal well section of the thin dolomite reservoir in the study area based on the basic data and the high-resolution reservoir model, it also includes: Along the horizontal well profile, compare the logging curves and logging interpretation results with the high-resolution reservoir model, and judge whether the dolomite content in the high-resolution reservoir model is consistent with the dolomite content in the logging results at the corresponding position. If so, the established high-resolution reservoir model meets the requirements.
8. The evaluation method for the horizontal well section of the thin dolomite reservoir according to any one of claims 3-6, characterized in that, The basic data further includes: single well test production capacity data; Before performing inversion using the waveform indication inversion method based on the post-stack migration seismic data according to the basic data, the following steps are also included: Optimizing the wells in the study area according to the single well test production capacity data to obtain optimized wells; and performing waveform indication inversion using the basic data and the post-stack migration seismic data corresponding to the optimized wells.
9. A horizontal well section evaluation device for thin dolomite reservoirs, characterized in that, It includes: An acquisition unit for acquiring the basic data of the study area and the post-stack migration seismic data; A seismic data inversion unit for performing inversion using the waveform indication inversion method based on the post-stack migration seismic data according to the basic data to obtain inversion results; A structural model building unit for building a structural model of the horizontal well area in the study area according to the basic data; A reservoir model building unit for building a high-resolution reservoir model using the co-Kriging estimation method with the inversion results as the inter-well constraint on the basis of the structural model; A horizontal well section evaluation unit for evaluating the horizontal well sections of the thin dolomite reservoir in the study area according to the basic data and the high-resolution reservoir model.