The isolation, occurrence and origin of fluorenones in crude oils and rockextracts

A rapid method for the analysis of fluorenones in crude oils and reservoir core extracts based on solid phase extraction and GC-MS is described. A det ailed reservoir study involving analysis of both fluids and core extracts w as performed and variations in the distributions of fluorenones between res ervoir phases are discussed. Concentrations of fluorenones in reservoir cor e extracts are often very high, which may reflect sorption processes after fluorenone production but in general, fluorenone abundance in flowed oils s eems to be sporadic and may be related to sample age and storage history wi th recent production oils having lower fluorenone concentrations than corre sponding older Drill Stem Test oils. While a geochemical origin for fluoren ones cannot be eliminated in some settings, we are concerned that these com pounds may be frequently formed sporadically as a result of post-sampling o xidation. (C) 2000 Elsevier Science Ltd. All rights reserved.