Flow rate usually varies greatly in high gas rate wells during flowing,turbulent flow effect and throttling effect etc.

Aimed at the stress sensitivity which exists in view of the gas reservoirs performance history,the stress sensitive effect on gas well productivity is discussed from the angle of gas reservoir engineering.

The productivity prediction equations of conventional gas reservoirs are commonly used to estimate the gas well productivity in low-permeability gas reservoirs at present, without consideration of the threshold pressure gradient, resulting in large discrepancy between the calculations and production realities.

Nowadays, the main method of determining oil and gas well deliverability is steady well test, that is back-pressure testing, isochronal testing, revisionary isochron test and single-point test.