A preliminary two-dimensional model for in-situ underground coal gasification is presented. The model describes cavity formation from the injection well end during forward gasification, as well as link zone burn up, when the initial link zone geometry is assumed. Cavity growth is predicted via an integral boundary layer analysis with boundary conditions determined by oxygen mass transfer to the wall for forced and natural convection. Preliminary results are based on the complete oxidation of carbon to carbon monoxide and the water-gas reaction, but exclude reaction rate effects. The effect of water influx is discussed and limits to the amount of water which can react with the coal are presented. A comparison of Eastern and Western coals is presented, as well as dimensionless plots which indicate similarity solutions for various blast flow rates.