This paper demonstrates the importance of providing a guide model for distributing log properties in 3D. This analysis involved building geo-cellular models with varying degrees of geologic complexity and testing for the accuracy of predictions at two blind wells. The results at the two wells show that by accounting for stratigraphic complexity, an optimal number of stratigraphic layers can be found to improve the accuracy of predicted porosity.
Using more stratigraphic layers to define geologic detail is more time-consuming, so knowing the optimal layering for property modeling by using the suggested workflow saves time while improving the quality of the resulting predictions. Having an accurate 3D log property distribution has a direct impact on sweet-spot identification, resource-in-place calculations, high-resolution velocity modeling, and geomechanical modeling for unconventional reservoirs.
Geo-cellular modeling has been an important process in understanding the heterogeneities, uncertainties and complexities of conventional reservoirs all over the world since the mid-1990s. Although geomodels have become widely accepted for guiding reservoir characterization in conventional reservoirs, they have been under-utilized in unconventional reservoirs. The assumption is often made that unconventional reservoirs can be modeled without the use of facies models or sequence stratigraphic concepts; however, this assumption can lead to inaccurate models.
This study attempts to quantify the value of incorporating detailed geologic information into geomodels for unconventional reservoirs.