Factor analysis of gas wells’ operating parameters

Abstract

The paper discusses methodological approaches to the use of deterministic factor analysis for identifying the sources of changes in gas wells’ parameters under steady-state gas inflow obeying linear and non-linear filtration laws. Factor analysis methods make it possible to quantify the degree of influence of individual factors on the deviation of the indicator under study. In accordance with the methodology of factor analysis, mathematical models of the factor system were substantiated for linear and non-linear gas filtration, a set of factors of influence was determined, and ready-made solutions for factor analysis of gas wells’ operating parameters were obtained. In the paper, the method of weighted finite differences was substantiated and investigated with the aim of factor analyzing gas wells’ mode of operation and obtaining formulas to calculate the increment in gas production caused by changes in factors. Approbation of working formulas for assessing the degree of influence of factors on either positive or negative deviations in the gas flow rate was carried out with respect to the parameters of the wells of underground gas storages in the cycles of withdrawal and injection. The obtained formulas for factor analysis of gas wells make it possible to quantify the influence of such factors as reservoir and bottomhole pressures, filtration resistance coefficients, on the deviation of gas flow rate. Further ranking of wells by factors constitutes the basis for managing gas withdrawal (injection) processes and for well interventions planning.