عنوان مقاله [English]
Underground coal gasification (UCG) is a procedure in which in-situ coal is converted to gas. This process forms a cavity (panel) in the coal seam. The panel width will vary with thickness of the coal, energy in the coal and amount of groundwater that runs into the reactor. Unsuitable deign of panel width directly impacts the economic and environmental factors. Therefore, in this research a new method for estimating panel width has been developed using non-linear regression analysis based on data gathered from the 6 UCG field trials which gasified by Controlled Retraction Injection Point (CRIP) method.
There is currently no empirical equation for estimation of panel width in UCG design. In this study, at the first stage, a series of simple regression analysis between the independent variables and the dependent variable (panel width) using the data of 6 UCG field trials were implemented. Regression analysis was carried out using SPSS software. The result of this stage revealed that obtaining a reliable relation for the estimation of the panel width using a unique variable is almost impossible. At the second stage, the multiple linear regression analysis was implemented to obtain a relation between panel width and independent variable. Findings showed no reliably relation for estimation of panel width. Finally, the non-linear regression analysis was implemented for development of an empirical model. The results of this study showed a better relationship between independent variables and panel width.
Methodology and Approaches
In this study, non-linear regression analysis has been employed based on data gathered from the 6 UCG field trials and then empirical model has been developed. For this purpose the SPSS21 software has been used.
Results and Conclusions
In this paper, a new empirical model developed by non-linear multiple regression method for predication of the panel width in UCG design. During the analysis, five possible independent variables coal seam thickness, coal seam depth, operation pressure, coal seam permeability and coal calorific value are used to predict the panel width in UCG. The results of this study show that the developed empirical model can reliably predict the panel width in UCG process. The most important application of this model is to predict panel width before the construction of a UCG pilot. Base on this model, the panel width is estimated 45 m in Tabas Mazino coal deposit.