Method for carrying out hydrodynamic test of gas well, opening out a reservoir with low and moderate permeability, and determination on this basis - its permeability and skin effect

摘要

The purpose of the notification is to conduct a hydrodynamic gas well test providing a low and moderate permeability deposit and to determine the permeability and skin effect on the basis of this test. This is characterized by the opening of the borehole where the head pressure of the pg0 gas plus the gas static pressure balances the composite pressure pd0, the borehole head valve is opened and the gas with very high output is operated for a very short period (1 -2 minutes y),and then this valve is closed and, after a few seconds of waiting for the stabilization, new, lower head pressure pg1 is read and, taking the moment of stabilization of the head pressure as t = 0, the recovery of the head pressure is recorded as a function of time, and the filaments shall be positioned in a rectangular coordinate system as measuring points according to the logarithm of the natural dimensionless pressure pD since t and their path shall be approximated by a straight line and its inclination E shall be read, thereby determining permeability; k of the following formula 1 and extending the straight line to the point of intersection with the axle,where the value of the natural pressure logarithm L is determined, and by reading the coordinates of this point, the skin size of the S effect is calculated from the formula 2 below.