Evaluation of strategies for fracture modeling: A case study at Teapot Dome, Wyoming

Abstract

The characterization of fractured reservoirs is complex. Fracture modeling is often based on very limited well data and therefore is subject to high uncertainty. Typically, the standard modeling workflow uses interpolation algorithms to predict the fracture spatial distribution. This thesis shows an alternative workflow for improving fracture modeling between wells through the use of seismic attributes. The standard and the alternative workflows are applied to a public dataset from the Teapot Dome in central Wyoming, USA. The Teapot Dome is a basement-cored anticline above a thrust. The main objective of the thesis is to compare fracture models of the anticline guided by the two approaches: the standard interpolation based approach, and the seismic based approach using attributes sensitive to faults. The generated models differ mainly in the way of modeling the fracture intensity. The evaluation and uncertainty assessment of these techniques is based on the reservoir permeability derived from fracture models. A comparison of these two methods provides insight into the complexity and uncertainty involved in fracture modeling. In addition, the results show the disadvantages of models guided by the interpolation algorithms, Kriging and Gauss simulation. On the other hand, the seismic based workflow delivers fracture models that are more reliable. Although the seismic based fracture models give a similar permeability distribution like the interpolation methods, they show differences associated with the spatial distribution and connectivity of high permeability zones.