Abstract
This issue contains 24 papers. The first 5 papers deal with the basic science and studies on the coal-gas interaction, the causes and consequences of errors in determining sorption capacity, the kinetics of sorption for gas mixtures in coal and the imbibition and wettability characteristics of coal as a reservoir. The next seven papers are concentrated on the novel instrumental techniques, such as SAXS, SANS, acoustic emission, x-ray micro tomography, optical imaging and pressure transient techniques that can be used to characterize gas sorption mechanisms, their kinetics, the resultant strains and the permeability of coal. Permeability change in coals due to gas sorption is certainly one of the major issues related to field applications. In the 13th and 14th papers of, this issue is discussed with examples and improved analytical modeling approaches. These papers are followed by two papers (15th and 16th), which deal with the numerical formulation issues of gas sorption and transport in coal micro-structure and with the modeling issues of CO2 sequestration and enhanced coalbed methane recovery. The next group of papers (17th and 18th) is on parametric simulations on two different coal fields: Huntly field in New Zealand and Zonguldak Basin in Turkey. Beside the difference in coalfield, these studies used two different simulators for evaluations of methane production and CO2 injection. These are followed by three papers (19th-21st) that evaluate the results of two actual field tests (in Europe and in the U.S.) and the assessment of coal swelling and shrinkage based on rank-dependent properties of coals. In the last three papers of this issue, a study to improve CO2 injectivity in a coal reservoir, a new model coupling of flow and geomechanics of coals, and the economics of CO2 sequestration are presented.