Apparent density inversion of gravity anomalies of Puguang gas field
普光气田重力异常的视密度反演

The Puguang gas field is the largest gas field found in recent years. The estimated gravity anomalies of Puguang gas field based on the density of reservoir rock and cap rock are less than 1 mGal. However, the negative gravity anomalies are interfered by regional field and other rocks. The distinct negative density anomalies are obtained by the novel method which called apparent density inversion, based on the separation of potential fields by cutting method and much deeper downward continuation of fields. The negative density anomalies are also obtained from the gravity data of other gas fields in the northeast of Sichuan basin. The gas-prospective areas in northeast of Sichuan basin are predicted according to the results of apparent density inversion.