Oil & Gas Geology ›› 1991, Vol. 12 ›› Issue (2): 136-142.doi: 10.11743/ogg19910205

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DISTRIBUTION OF PORPHYRIN IN JIANGHAN AND BIYANG BASINS

Chen Junhong1, Fu Jiamo1, Sheng Guoying1, R. P. Philp2   

  1. 1. Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou;
    2. School of Geology and Geophysics, University of Oklahoma, U. S. A.
  • Received:1990-12-27 Online:1991-06-25 Published:2012-01-16

Abstract:

The distribution of porphyrin in oils from Jianghan and Biyang Basins, China, was studied. The high contents of C32 and C33 DPEP porphyrin isomers with a additional methyl group in five-membered isocyclic ring is the indicator of an unusual type of porphyrin precusor or input occurred in sedimentary environment with very high salinity and low maturity of oils. The major changes of porphyrins under maturity are the gradual decreases of DPEP/(DPEP+ETIO)% and dealkylation/alkylation within ETIO porphyrins. The ratios of DPEP/ETIO or DPEP/(DPEP+ETIO)%, C31 ETIO-A/C28ETIO-B and ETIO-A C31/C30 can be used as thermal maturity parameters.