STUDY ON THE SIMULATED BIODEGRADATIED STERANE IN CRUDE OIL

The biodegradation of regular sterane and rearranged sterane in crude oil was studied on the basis of simulated biodegradation experiment to the crude oil.The biodegradation products were analyzed by GC-MS.Research shows that the biodegradation of regular sterane is early than that of rearranged sterane.The biodegradation ability of sterane is C₂7>C₂8>C₂9.Before the great biodegradation of the sterane,those maturity indicators such as isomerization of C₂9 steranes at C₂0 vary slightly.But some biomarker indicators used for the researches on oil-source correlation,oil source and sedimental environment will probably change.These indicators include ratio of regular steran to 17α(H)-hopane,C₂7-C₂8-C₂9 sterane,C₂7-C₂8-C₂9 rearranged sterane,ratio of rearranged sterane to regular sterane,and so on.