High-Quality Source Rock Thickness Prediction of Xujiahe Formation in the Western-Central Transition Zone of Sichuan Basin

Summary The Xujiahe formation in the western-central transition zone of Sichuan Basin are divided into six members. Source and reservoir are stacked vertically. The first，third，and fifth members are source rocks. In this context，the distribution of high-quality source rock is one of the major determinants of tight gas exploration. The total organic carbon (TOC) is an important parameter to predict the distribution of high-quality source rock. The multi-attribute inversion method is selected optimally to predict the TOC distribution. There are too many 2D seismic lines in study area. According to the prior works, the multi-attribute inversion must be performed line by line. This leads to the following problems：1. It is a heavy and time-consuming workload; 2. The 2D seismic line which is far from the well is impossible to perform multi-attribute inversion. In the view of above, this paper establishes a pseudo-3D seismic survey grid to form pseudo-3D seismic data. Based on this，multi-attribute inversion is used to predict the TOC distribution effectually. The method can improve the utilization ratio of 2D seismic data and greatly reduce the workload. Prediction results shows: the high-quality source rocks of the first, third and fifth member of Xujiahe formation are overall development in study area.