RELATIONSHIP OF RESERVOIR FORMATION WITH UNCONFORMITIES AND THEIR GEOPHYSICAL RESPONDENCE IN THE JUNGGAR BASIN

Several unconformities were formed as a result of several tectonic movements in the Junggar Basin. Five types of unconformity were recognized, with different reflection characters in seismic sections for each one. Unconformity structures are vertically divided into three layers, and every layer is consisted of several kinds of rocks with different logging responses in electrofacies. These unconformities not only are the pathways for oil and gas migration, but also provide accommodation for oil and gas accumulation. Although reservoir-forming conditions of the unconformity have the similar parts, the different types of unconformity show different oil and gas reservoir-forming patterns due to different stress behaviours and deformation levels when the unconformities were formed.