Abstract: The empirical equation of ascertaining reasonable well spacing density of gas field is given by Literatures [1] to [3] in this paper using reserves abundance calculating method. When applying them to calculate well spacing density of SZ gas field in Daqing field, big errors are found. Combined with economic appraisal method, single well deliverability method and reasonable gas production velocity method, this paper presents the modified reserves abundance calculation method suitable to SZ gas field, following finding out the reason for such errors caused by the empirical equation of reserves abundance calculating method.

Key words: well spacing density, gas field, reserves, abundance