Hydrocarbon accumulation features and exploration potentials in Anshun Sag, Southern Guizhou Depression

The potential petroleum accumulation types, features and forecasts of the Anshun Sag in the Southern Guizhou Depression have been discussed based on seismic interpretations and previous studies. In the lower formations of the sag, "Majiang paleo-reservoirs" have been found. In the upper formation, there exist "reef-flat" and "unconformity surface or regolith" reservoirs. Meanwhile, source rocks are well-developed and the sag is the long-term target zone for hydrocarbon migration. Good cap rocks provide good regional hydrocarbon preservation conditions. The Puding synclinorium is the most favorable exploration target in the Anshun Sag.