Based on the conventional core experiments and pressure-sensitive features of gas reservoirs

it is suggested that the "slip flow of gas" and "threshold pressure" may be caused by pressure sensitivity of gas reservoir.This paper takes the overpressured tight gas reservoir in the shallow Upper Jurassic Penglaizhen Formation

Xinchang gas field

Sichuan province

as a research object

analyses the data collected from gas single-phase percolation experiments on its rock samples

and discusses the causes of the sophisticated percolation process with the coexistence of "slip flow of gas" phenomena and "threshold pressure" features.It proposes that the percolation process be induced by pressure sensitivity rather than by traditional Klinkenberg effect or low rate non-Darcy mechanism.The experiments also indicate that the Penglaizhen gas reservoirs in Xinchang gas field shows strong pressure sensitivity

and its fitting factor ranging between 0.3 to 1.9 and permeability reduction magnitude varying from 10% to 80%.