Print this pageModeling Pressure Compartments in the Piceance Basin, Colorado
PAYNE, DOROTHY F., JOHN B. COMER, J. MILES MAXWELL, WALID SIBO, and PETER J. ORTOLEVA
Understanding and predicting the geometry and development of pressure compartments in the Piceance Basin of Colorado provides valuable insight into the extent and accessibility of its methane reservoirs. Upper Cretaceous Mesaverde Group units host unconventional, tight gas reservoirs, with fracture controlled permeability. Major producing fields correlate spatially with structure, more than with basin depth, proximity to Tertiary intrusions, or net coal thicknesses. Available production data and modeling results show that major producing fields correlate with observed fluid pressures, which are used to delineate pressure compartments.
Fluid pressure compartments develop as a result of interactions of these processes: pressure solution, tectonics, fracturing, and methane generation. Three-dimensional RTM (reaction-transport-mechanical) modeling is used to capture the coupling of these processes and their relative timing, and to predict subsurface distribution of pressures in a basin. 3-D RTM simulations were conducted for the Piceance Basin in order to gain a better understanding of the compartment structure in the Upper Cretaceous Mesaverde tight gas reservoirs. Available stratigraphic, thermal, and tectonic history were used to constrain the RTM model of the Piceance Basin. Observed fluid pressures and pressure gradients were used to calibrate the model. Results allow predictions of the scales and geometry of these domains, and the location and relative timing of pressure seal formation and fracturing.