The Gigaton Greenhouse Gas Problem: Modeling the Powder River Basin for Carbon Dioxide Sequestration

Jesse Melick

Montana State University, Department of Earth Sciences

Bozeman, MT 59717

[email protected]

The goal of carbon sequestration is to achieve zero-emission of greenhouse gases by helping balance anthropogenic sources, which is accomplished through increasing conservation, enhancing natural sinks for carbon cycle gases, and storing carbon in geologic formations. Because current enhanced oil recovery practices capture only a minute fraction of these enormous requirements (in 2000, the US injected 34 million tons carbon), basin-scale geologic sequestration of gigatons of carbon could help offset this deficit. The immense storage capacities needed to satisfy zero emission requirements and inherent dangers with sequestering these concentrations demand solutions that encompass multiple scales (pores, reservoirs, basins). Building geologic models of sedimentary basins, characterizing the portfolio of geologic storage sites they contain, and simulating pore to field to basin scale permeability distributions, or leakage pathways, can provide insight to this problem.

Modeling the Powder River Basin, a mature petroleum basin with almost 100 years hydrocarbon production, will assess an assortment of storage sites (e.g., carbonate, shoreface, valley fill, mixed carbonate - aeolian clastics, coal bed) and connectivities (e.g., faults, fractures, high permeability pathways) within the regional fluid-flow context. Engaging the petroleum industry with built-in incentives for enhanced oil recovery will help significant expenses of long-term carbon storage to be cost-effectively transferred from the public to the private sector. This holistic evaluation of this basin, where extensive data and infrastructure already exist, permits understanding storage capacity and leakage potential, while reconciling critical logistical and financial issues related to cooptimizing carbon storage with oil recovery, which currently is not being done.

AAPG Search and Discovery Article #90060©2006 AAPG Foundation Grants-in-Aid