Effects of Porosity and Material Fluctuations on Gas Transport and Sorption Kinetics in Coalbeds Conference Paper uri icon

abstract

  • 2007 Petroleum Society of Canada. Natural gas transport and storage in coal is important for accurate predictions of production rates from coalbeds. Recent investigations based on nondestructive imaging have shown that coals are complex materials exhibiting nonuniform pore structure. Standard approach to describe gas/coal interactions is deterministic and neglects the effects of local spatial heterogeneities in material content and porosity. In this work, adopting a weak-noise approximation, these heterogeneity effects on diffusive gas transport are investigated using a statistical approach in the presence of non-equilibrium (kinetic) gas sorption with random partition coefficient. It is found that the gas-coal system behaves distinctively in the presence of kinetics and that the coal matrix heterogeneities generate multiplicative non-trivial effects on transport. Consequently, average gas concentration field is significantly different than the one obtained using an equivalent yet purely deterministic (i.e., homogeneous) approach. Using fractional gas recovery curves, the results are shown for coals exhibiting Gaussian porosity distributions with varying correlation length scales. A new upscaled deterministic gas mass balance is proposed. The work is a unique approach for understanding coalbed environment and development of sound numerical gas production/storage models.

name of conference

  • Canadian International Petroleum Conference

published proceedings

  • Canadian International Petroleum Conference

author list (cited authors)

  • Fathi, E., Akkutlu, I. Y., & Cunha, L. B.

citation count

  • 0

complete list of authors

  • Fathi, E||Akkutlu, IY||Cunha, LB

publication date

  • January 2007