Model Calibration and Upscaling
By focusing on effective rock typing, characterization of petrophysical heterogeneity, and data integration at an early stage, core measurements data can be integrated and upscaled to borehole, well-log and reservoir scale geological, petrophysical, and geo-mechanical models.
As an example, the minimum required data set to complete the characterization for wellbore stability modeling includes multistage triaxial tests on vertical plugs for matrix cohesion and friction angle, and on angled plugs for weak plain strength characterization.
The first step in model deployment is to establish predictive correlations between the results from the core plug testing and the continuous core scanning with plug scale strength data. This data is integrated with welllogs and in-situ stress data into an integrated mechanical earth model. Various strategies have been employed by different groups. Generation of continuous model parameters with depth are used to provide inputs to numerical models at each depth of interest. As an example we show a modeling workflow, starting with calibration to plug scale properties and screening via analytical models, and ending with numerical simulations of wellbore damage as a function of decreasing mud weight.
Illustration of the wellbore stability modeling application. Analytical and Numerical Models use calibrated properties as input to assess near wellbore damage patterns. Contours show maximum principal stress distribution around a horizontal wellbore with varying mud weights. Black lines indicate discrete fractures emerging from the models dictated by stress, material state and mud weight.
As a second example, plug-scale FDEM models calibrated to laboratory data are used as inputs to borehole scale models of stimulation potential for EGS and Geologic Hydrogen applications.
Illustration of multiscale geomechanical modeling to reservoir engineering for geothermal and geologic hydrogen applications. Numerical Models use calibrated properties as input to assess near wellbore damage patterns to optimize near borehole stimulations for complex reservoir engineering applications such as enhanced geothermal, closed loop geothermal, and geologic hydrogen.
