A model for controlling hydrocarbon and predicting favorable exploration zones of the Tazhong palaeouplift in Tarim Basin,NW China

In order to deeply research a model for both controlling hydrocarbons and predicting favorable exploration zones of the Tazhong palaeouplift in Tarim Basin,this paper focused on the tectonic evolution of the Tazhong palaeouplift and the distribution of different reservoirs.A three-epoch tectonic evolution was identified for the Tazhong palaeouplift,i.e the Late Caledonian,Late Hercynian and Himalayan,and a reservoir controlling model for two classes(inner or outside of buried hill) and eight types was established for the Tazhong palaeouplift.Outside the Tazhong palaeouplift buried hills,Carboniferous and Silurian clastic anticline reservoirs,stratigraphic or lithologic reservoirs and fault-block reservoirs occurred at top parts of the palaeouplift and slope,while within the palaeouplift buried hills,Ordovician and Cambrian carbonate weathering-crust reservoirs occurred at the top,reef-flat reservoirs in the lateral margin,and karst and fractured reservoirs at the lower part of the palaeouplift.The mechanism of the reservoir control by the palaeouplift,which contains various traps and carrier systems indicating favorable direction of hydrocarbon migration,was discussed.The research predicted that the Tazhong main horst zone was the most favorable exploration area for fault-block reservoirs,anticline reservoirs and carbonate weathering-crust reservoirs,the Tazhong No.10 structure zone was the favorable exploration area for stratigraphic reservoirs,anticline reservoirs and carbonate karst reservoirs,and the Tazhong No.1 slope break zone was the favorable exploration area for lithologic reservoirs,carbonate karst reservoirs and buried-hill inside fractured reservoirs.