DISTRIBUTION OF THE ORGANIC REEFS IN THE UPPER PERMIAN CHANGXING FORMATION IN FULING AREA OF NORTHEASTERN SICHUAN

The Changxing Formation, in which organic reefs are well developed, is widely distributed in the Fuling area of the Sichuan Basin. Commercial gas flow has been discovered from the organic reef reservoir in the drilling well of Xinglong No.1 of this region. This paper established a facies model based on 2D and 3D seismic data in combination with the well drilling data, and found that the Changxing organic reefs are characterized by lateral migration and vertical accretion. Through the analysis of the seismic-well response, forward modeling and the study of seismic reflection of the Yuanba reef, the seismic response pattern to reefs in Fuling area were concluded. The distribution pattern of organic reefs was established upon integration of seismic facies, sedimentary facies and well drilling data.