Simulated experiment evidences of the corrosion and reform actions of H2S to carbonate reservoirs: an example of Feixianguan Formation, east Sichuan

摘要

The reservoir of Feixianguan Formation of the Lower Trlassic in the Sichuan Basin is the deepest buried carbonate reservoir in China, with developed secondary corrosion holes, high quantities carbonate reservoir, maximum effective carbonate reservoirthickness. Also Feixianguan gas reservoir has the highest quantities of H_2S. Research discovers that there are close relationships between the formation of reservoir and H_2S. The mutual actions between acidity fluid and carbonate promoted the forming of secondary carbonate holes. Through the experiment of corrosion of the samples of Feixianguan carbonate reservoir in saturated aqueous solution of hydrogen sulfide, the porosity and permeability increased greatly, porosity increased 2% and permeabilityincreased nearly two quantity degrees, also the density became light, which confirm the corrosion and reform actions of H_2S to carbonate.