Development of a Heterogeneous Earth Model in Unconventional Reservoirs, for Early Assessment of Reservoir Potential

In this paper, we describe a large effort to develop an integrated Heterogeneous Earth Model for a large region of the Haynesville play. The work includes a comprehensive geologic and petrologic study, based on the evaluation of multiple cores, analysis of a large number of well logs in the region and integration with seismic data. The work also includes extensive characterization of mechanical, geochemical and reservoir properties via laboratory testing. The result is a model that scales seismic data with log data, and with core data, based on fundamental measurements that respond to changes in texture and composition at these various scales. Results provide the volumetric distribution of rock classes or regions with similar and dissimilar texture and composition. This classification defines the geometric heterogeneity of the system. Results also provide rock physics models for propagating measured properties on core samples to measured log data and seismic data. Thus continuous distributions of all core measured properties are possible at the log scale and also at the seismic scale. The advantage of integration with measured properties on core is that we can populate the model with necessary complex properties not otherwise independently obtainable from seismic data alone. For example, anisotropic elastic properties, anisotropic strength, creep, organic content, hydrocarbon filled porosity, rock fluid sensitivity, and others. The distribution of this array of relevant properties to each rock class, allows us to evaluate the real distribution of reservoir quality and completion quality in the region, and assess the variability in reservoir potential. This information is fundamental for early exploration and for the effective planning of field development.