Natural Gas

PI: Hamid Arastoopour (ChBE/MMAE)

Global estimates of resource-grade natural gas from hydrates range from 10,000 trillion cubic feet (tcf) to greater than 100,000 tcf. In recent years, the 570 tcf of technically recoverable shale gas resources has provided the United States with considerable economic stimulus and the affordable means of decreasing coal consumption. This means the potential impact of hydrate resources will result in very significant international economic growth. To obtain a better understanding of methane production from hydrate reservoirs, the development of numerical simulation tools to predict gas and water flow patterns in the reservoir is needed. The major challenge in developing reliable governing equations and simulation code is that the hydrate reservoirs are unconsolidated. Currently available reservoir simulators are based on consolidated reservoirs and are not applicable to hydrate reservoirs. In this research project, we have developed a novel four-phase flow model and numerical simulation. Constitutive models for the solid viscosity and solid pressure have been developed to model the change in the strength of the sediment as hydrate dissociates and sand flows. Additionally, pore-scale inhomogeneity intrinsic to the reservoir is magnified during the hydrate dissociation and sand production processes, causing homogeneous permeability models to deviate significantly from experimental results. Therefore, another constitutive model has been developed to quantify the pore-scale inhomogeneity and simulate the evolution of high-permeability regions in the reservoir. Our numerical simulation prediction of the methane production compared well with the production data from the JOGMEC Mallik 2L-38 well in Alaska.

PI: Hamid Arastoopour (ChBE/MMAE)

Natural gas storage can be accomplished in three ways: compressed natural gas (CNG) with low capacity and fast discharge; adsorbed natural gas (ANG) with higher capacity and low rate of desorption; and liquefied natural gas (LNG) with very high capacity and high cost, with some challenges in handling, transportation, and safety. We have constructed an experimental setup capable of measuring the rate and extent of natural gas adsorption on different porous materials (ANG) at elevated pressures using different materials including activated carbon. Our experimental results have shown that, at the same pressure, the adsorbed natural gas on activated carbon has more than twice the capacity of compressed natural gas.

PI: Carrie Hall (MMAE)

This project deals with examining methods of enabling efficient and clean use of natural gas for transportation through the implementation of high-efficiency internal combustion engine concepts. In particular, this group has investigated strategies for using natural gas in a dual-fuel engine architecture in which natural gas can be run simultaneously with a conventional diesel or gasoline fuel. Such strategies can enable more efficient use of natural gas but can lead to challenging variations in the combustion process. Understanding and controlling these problematic combustion variations with natural gas has been a main focus of this work.