3D In-Situ Shale Characterization via Lithofacies-Seismic Coupling
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Solution Overview
Problem
Current methods for accurately characterizing the heterogeneity of shale oil and gas generating and reserving performance parameters in a 3D space are inadequate, particularly due to limitations in integrating vertical and horizontal well data and the lack of reliable TOC and porosity value interpretation, leading to errors in shale oil and gas exploration and development.
Innovation Solution
A 3D in-situ characterization method is developed, involving logging and seismic coupling, with steps including establishing in-situ interpretation models, creating spatial frameworks, and using multi-mesh approximation algorithms to accurately model top and bottom surfaces, and employing 3D visualization and simulation techniques to integrate lithofacies and seismic attributes for precise TOC and porosity characterization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If deterministic modeling algorithm or stochastic modeling algorithm is used to establish 3D model of TOC content and porosity, then 3D distribution characteristics can be described, but large errors exist between logging interpretation results and actual TOC content and porosity values
Solution Approach 1:
The patent introduces lithofacies type as an intermediary to connect logging data with TOC content and porosity values. By establishing lithofacies-lithofacies-well coupling interpretation models, the method uses lithofacies classification as a mediator to improve the accuracy of TOC and porosity interpretation, reducing the direct error between logging results and actual values through this intermediate classification layer.
Solution Approach 2:
The patent changes the interpretation approach by introducing lithofacies-based parameter control. Instead of direct logging interpretation, it transforms the parameters through lithofacies classification, where different lithofacies types have different interpretation parameters and ranges. This parameter transformation through lithofacies classification improves the accuracy of TOC content and porosity values.
2Ease of manufacture
If 3D model is established mainly using hierarchical data of vertical well, then modeling can be completed, but spatial extension characteristics of horizontal well section trajectory cannot be truly reflected
Solution Approach 1:
The patent merges vertical well data with horizontal well data to establish a comprehensive 3D model. By combining hierarchical data from vertical wells with trajectory data from horizontal wells, the method achieves both modeling efficiency and accurate representation of spatial extension characteristics. The merging of different well type data allows the model to reflect both vertical and horizontal spatial relationships.
Solution Approach 2:
The patent adds the horizontal dimension to the traditional vertical well-based 3D modeling. By incorporating horizontal well trajectory data, the method transitions from a primarily vertical-dimensional model to a true three-dimensional model that accurately represents spatial extension in all directions. This dimensional enhancement allows the model to reflect the actual spatial distribution characteristics of the reservoir.
3Productivity
If lithofacies types are not used to control and restrict interpretation parameters, then logging interpretation can be performed directly, but large errors occur between interpretation results and actual TOC content and porosity values
Solution Approach 1:
The patent applies local quality control by assigning different interpretation parameters and ranges to different lithofacies types. Each lithofacies classification has its own specific interpretation characteristics, allowing the interpretation process to adapt to local geological conditions. This localized parameter control significantly improves the accuracy of TOC content and porosity values while maintaining interpretation efficiency through automated classification.
Data Source
AI summary
The present invention discloses a three-dimensional in-situ characterization method for heterogeneity in generating and reserving performances of shale. The method includes the following steps: establishing a logging in-situ interpretation model of generating and reserving parameters based on lithofacies-lithofacies-well coupling, and completing single-well interpretation; establishing a 3D seismic in-situ interpretation model of generating and reserving parameters by using well-seismic coupling; establishing a spatial in-situ framework of a layer group based on lithofacies-well-seismic coupling, and establishing a spatial distribution trend framework of small layers of a shale formation by using 3D visualized comparison of a vertical well; and implementing 3D in-situ accurate characterization of shale generating and reserving performance parameters by using lithofacies-well-seismic coupling based on the establishment of the seismic-lithofacies dual-control parameter field. The present invention integrates an in-situ technology into shale logging, seismic generating and reserving parameter interpretation, and the establishment of a 3D mesh model of small layers of shale, which realizes the accurate description of the heterogeneity in TOC content and porosity value of shale oil and gas in a 3D space, and provides a reliable technical support for shale oil and gas exploration and development.