Abstract: Two oil samples with different maturities from a basin in western China are selected, mixed and separated by group composition in order to properly estimate the allocation of single well productivity with geochemical method. The saturated hydrocarbons are analyzed by gas chromatography. The result shows that both linear and nonlinear changes occur in fingerprint indicator ratio and mixed ratio of the mixed sample. The reason is that the process of mixture is not pure physical one, but a physicochemical one. Through linear match, the error can be greatly reduced by recalculation of it after removing those imperfect fingerprints in linear correlation. Also, the error could be decreased by using presumed the single layer fingerprint ratio rather than the initial single layer value. The study could be as a guide for selection of peak fingerprint and optimization of related calculation method for productivity monitoring.

Key words: commingling production, production calculation, geochemistry, experiment, test