Abstract: Bottom water reservoirs are common in China, in this article, instantaneous point source diffusion equation is established for thin bed bottom water reservoir, using Lord Kelvin point source solution, principle of superposition, mirror response, the basic solution of flow through porous medial differential equation in this types of reservoirs is obtained, Poisson formula is used to simplify the expression, the theory of point source function is used to obtain bottom hole dimensionless pressure response in thin bed bottom water reservoir, the dimensionless pressure is calculated and pressure derivative dual logarithmic theory chart obtained, from this, the character of flow through porous media in vertical well in thin bed bottom water reservoirs and the influence factors are analyzed, well test interpretation software is developed.

Key words: thin bed bottom water reservoir, point source function, character of flow in porous media, influence factors, well test interpretation