A New Integrated Tectonic Synthesis of the Piceance Basin: Implications for Fractured Reservoir Detection and Characterization: ABSTRACT

Abstract

Detailed reservoir characterization of Piceance Basin thin-skinned structural traps reveals the importance of fracture-controlled gas production. A complete understanding of basin fracture genesis can be achieved through determination of the regional tectonic evolution. To understand the evolution of thin-skinned and basement-involved structures, high-resolution aeromagnetic data, seismic data, remote sensing imagery analysis, and production history analyses have been integrated with conventional subsurface and surficial dynamic structural analyses. Examination of structural trends in rocks ranging in age from the Precambrian through Holocene show the importance of pre-existing anisotropies in partitioning younger tectonic strain. Because of this strain partitioning, many Laramide structures show complex reactivation histories that obscure older Precambrian and Paleozoic tectonic events. An excellent example of this reactivation and partitioning is provided by NW-trending Precambrian-age structures on the Uncompahgre Uplift that were reactivated during Pennsylvanian-age deformation (Ancestral Rockies) and Laramide events. Because of its importance to reservoir engineering problems such as hydraulic stimulation design and drainage efficiency calculations for fractured reservoirs, the modern stress state throughout the basin has been determined and data suggest that there is significant variability in principal stress orientations throughout the basin. This interpretation demonstrates the complex evolution of multiply-reactivated tectonic structures and the relationship between productionmore » trends, structure, and fractured reservoirs. Most importantly, the integrated exploration approach demonstrates the power of an integrated basin analysis as a deterministic tool for understanding and predicting fractured reservoir conditions in advance of drilling.« less