Natural gas plays an increasingly important role as a clean energy source. It is estimated that 10% of the produced gas comes in the form of methane from coal seams and the contribution of gas from coal is expected to increase to 20% in the next 10 years. There is a need to develop more gas wells that are managed efficiently. The inherent problem is the maximization of production with minimum cost. The maximum production is a function of gas content controlled by the coal properties such as porosity, permeability, pressure, desorption time and ash content. The recent trend is to develop horizontal wells to increase the recovery times by quickly dewatering the seams and to obtain gas production early in the life of the well. Developing horizontal wells in thin coal seams are expensive and the prospects need to be evaluated properly in order to maximize gas production.
Many factors affect the methane production capacity of a coal seam and to find the best well planning and design is a challenge. Many characteristics of coal such as gas content, pressure and saturation are determined. On the other hand, decisions regarding the number, location, and type of wells, completion methods, hole size and similar decisions depend on the properties of coal.
In this paper, we presented the results of a study conducted to investigate the methane gas production strategies for different coal seams. A main goal of this study is to optimize methane gas production from coal seams. Presented in this study are the effects of reservoir properties on the efficiency of selected well design.