A new method of deliverability prediction by steady point in gas wells

Calculating the absolute open flow potential timely and investigating production capacity so as to adjust working system of production wells is one of main means to effectively recovery gas reservoirs during intermediate and late development stage. In order to obtain the open flow potential of gas wells accurately, a new method which utilized a single steady point was proposed in this research, which was based on deliverability formula of a gas well in pseudo-steady state flow with pseudo-pressure form. The influence on factor B in binomial productivity equation caused by the changed permeability was taken into consideration. According to the stable production data, reservoir permeability K can be determined by iterative method firstly, and the coefficient A, B in binomial productivity equation can be calculated with the open flow potential subsequently. It illustrated clearly by a practical example that the new method was suitable for gas wells especially when the producing pressure drop is large. Additionally, the error between the open flow potential value and interpretation result from the multi-point test was small, which proved it to be more simple, economic and effective than the common one.