THE RELATIONSHIP BETWEEN VITRINITE REFLECTANCE SUPPRESSION AND SOURCE ROCK QUALITY—A CASE STUDY ON SOURCE ROCKS FROM THE DONGYING SAG, BOHAI BAY BASIN

FAMM(fluorescence alteration of multiple macerals) technique is an only effective method for resolving vitrinite reflectance suppression of source rock at present.The FAMM and vitrinite reflectance of various type source rocks are determined in this paper.The relationship between vitrinite reflectance suppression and source rock quality is studied on the basis of measured data and combined with result of predecessors.The studied results show that the levels of vitrinite reflectance suppression are closely related to source rocks quality.The level of vitrinite reflectance suppression is relatively higher in the source rock with better quality.The level of vitrinite reflectance suppression for the source rocks characterized by type Ⅰorganic matter usually ranges from 0.20%～0.35%,average 0.30%;for those characterized by type Ⅱ₁ it usually ranges from 0.15%～0.30%,average 0.22%;for those characterized by type Ⅱ₂ it usually ranges from 0.10%～0.18%,average 0.15% and for those characterized by type Ⅲ it usually ranges from 0.0%～0.05%,i.e.no suppression or slightly suppression.The vitrinite reflectance suppression is affected complexly by many factors.The levels of vitrinite reflectance suppression of the source rocks from Dongying Sag having positive relationship with hydrogen index shows that vi-trinite reflectance suppression is closely related to relatively more perhydrous of source rocks.This is consistent with better quality source rocks with high level of vitrinite reflectance suppression.