USE OF GAUSSIAN DISTRIBUTION FOR ESTIMATION OF GOB GAS DRAINAGE WELL PRODUCTIVITY

Abstract

This paper describes the development and application of new mathematical models for estimation of well productivity during drainage of methane gob gas associated with coal extraction. It is established that the relationship between methane emission from surface gob gas wells and the duration of well production can be described by Gaussian (normal) distribution. Mathematical models based on using the Gaussian error distribution function and the Gaussian density function were proposed to describe the correlation between parameters of methane emission from gob gas wells, duration of well production, and time coordinate of maximum gas emission. These models allow prediction of the total volume of gas which can be extracted for the entire period of well production, the maximum volumetric flow rate of gas emission and the time coordinate of maximum gas emission using at least three measurement of gas volumetric rate (or gas volume) from a gas well at any time during the well production period.