The heat contained in a natural steam field is exploited by drilling a suitable number of Wells down to the reservoir.

The reservoirs in Baota Formation of Middle Ordovician in South Sichuan are characterized by low porosity and low permeability and belong to a fractured type.

Based on the investigation of comprehensive literatures about asphaltene deposition, the physical and chemical deposition mechanism of asphaltene and its plug to pore and throat are summarized.