Abstract:

Baohai Bay basin, a typical extensional rift basin, and Ordos basin, an intracraton downwarped basin, are two important types of basins in China. The main control factors for high quality reservoirs are different because of their respective basin features. In Bohai Bay basin, the sandbody types are abundant and various, the distribution of sandbodies is separated seriously, and the high quality reservoirs are related with secondary pores and abnormal pressure vertically. In Ordos basin, the sandbody types are relatively monotonous，sandbodies have a good continuity, and the reservoirs are mainly controlled by the diagenetic differentiation caused by differential sedimentation inside the sandbodies, so the zonation of reservoir is not obvious vertically. In Bohai Bay basin, the oil and gas exploration should be based on sedimentary facies analysis, and focus on the favorable diagenetic zones and formations. However, in Ordos basin, the focus should be put on the relatively high permeability sandstones in the generally low permeable sandstone backgrounds.

Key words: high quality reservoir, sandbody type, diagenesis, control factor