普光气田重力异常的视密度反演

普光气田是我国近年发现的最大气田．根据气田储层和盖层的岩石密度，估算普光气田上约有零点几毫伽量级的重力异常．但由于区域场和其他岩石的影响，气田的负异常受到严重的干扰．我们使用基于位场切割分离和位场大深度向下延拓的视密度反演新方法，在普光气田上得到明显的负密度异常．在川东北其他一些气田上，也得到负密度异常．根据视密度反演结果，对川东北的含气远景区做了预测．

Apparent density inversion of gravity anomalies of Puguang gas field

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.