Abstract:

New discovery of oil and gas in the flank of Balingshan-Huayuan anticline structure in the recent years makes it necessary to have a further understanding of its structural nature. Based on the interpretation of seismic profiles, it is considered that K2y-Ex is the superimposition of salt and mud tectonics, and can be divided into salt dome salt pillar multi layered superimposed structure, salt mud dome salt mud pillar structure and salt mud dome structure. The formation of salt mud tectonics was the superposition effect of plasticized salt mud stone bedding creep which led to thickening of the single layer and the multi layer cumulation. Reverse fault was formed by the salt mud intrusion along the early hanging wall of fault and the diapirism, thus the fault had the characteristics of the upper bed showing reverse and the lower showing normal. Differential loading and volcanic thermal convection were the dominant dynamic mechanisms. The salt dome-salt pillar of K2y Lower Es occurred at the Middle Eocene with the main formation stage of the Late Oligocene, the salt mud tectonics of upper Es-Ex occurred at the Late Oligocene, and both of them finalized basically in Pleistocene. The salt mud tectonic wing strata-salt mud sealing barrier trap and the lithologic updip pinch out salt mud sealing barrier trap are the potential oil and gas reservoir exploration types.

Key words: BalingshanHuayuan area, salt and salt mud tectonics, structure assemble, formation mechanism