A Method for Predicting Hydrocarbon Accumulation Period Under Source-Fault-Caprock Configuration and Its Application
To determine hydrocarbon enrichment degree around the faults connecting oil and source rocks in petroliferous basins,based on the study of source rock-fault-caprock configuration,and the hydrocarbon accumulation mechanism,a method for predicting hydrocarbon accumulation period under source-fault-caprock configuration was established,which considers the activity period of the fault connecting oil and source rocks,the hydrocarbon expulsion period of source rock,and the formation period of mudstone caprock.The method was ap-plied to predict the hydrocarbon accumulation period in the lower Sha 1 member within the Qikou sag of the Bohai Bay basin.The results show that during the deposition period of the Guantao formation-Minghuazhen formation,the source rock in Sha 3 member expelled hydro-carbons,the Nandagang fault was opened,and the regional mudstone caprock in the middle Sha 1 member was formed.The source rock,fault and caprock were configured well for a long period,which allowed the hydrocarbons expelled from the source rock in Sha 3 member to effectively accumulate in the lower Sha 1 member.The prediction results are consistent with the exploration results.
Bohai Bay basinQikou sagShahejie formationsource rockfault connecting oil and source rockcaprock sealinghydrocar-bon accumulation