Quantifying Structural Uncertainty in Anisotropic Depth Imaging – Gulf of Mexico Case Study

Quantifying structural uncertainty in the process of anisotropic model building is of paramount importance, especially in volumetrics estimation and drilling risk analysis. The modern concept of geophysical model building is based on integration of various data types and constraining by knowledge databases and targeted numerical modeling. Tomographic inversion of common-image-point gathers is the main engine for building the earth model. However, this inversion alone is very ambiguous, especially in the presence of anisotropy. Therefore, it is necessary to add well information and other measurements like electromagnetics and gravity in a simultaneous joint inversion process. Furthermore, geological knowledge, basin and geomechanical modeling, and lithoclassification are important constraints for model building. This novel methodology using uncertainty analysis delivers an entire suite of models that fit all available data equally well, allowing the user to select the most geologically plausible solution. In other words, uncertainty analysis has the capability to provide a new paradigm for model building. A case study for the Walker Ridge area of the Gulf of Mexico is presented in this paper.