Abstract: The analyses of binomial equation for gas wells and gas production indicative curves are conducted, and show that to fully utilize in-situ energy, the flowing pressure of gas well corresponding to tilting or upwarping point indicative curve from gas wells should be the reasonable flowing pressure of gas wells, while the production pressure difference at this point can be used as the reasonable production pressure difference. Based on this theory, adopting lab simulation approach and scaled physical mod-eling of petroleum reservoir, this paper presents full simulation of gas producing indicative curves from nearby sidewall under the reservoir conditions, determining reasonable flowing pressure difference, and conversing it to reasonable production pressure differ-ence of gas well. From the lab analyses of 8 wells in Changqing oilfield, it is concluded that the reasonable production pressure differences of gas wells should be controlled within 2.5MPa for Class Ⅰ reservoir, 3.5MPa for Class Ⅱ reservoir and 4.5MPa for Class Ⅲ reservoir.

Key words: gas production, indicative curve, production pressure difference, simulation experiment, scaled analysis