STUDY ON THE SEISMIC FACIES OF THE SHAHEZI FORMATION IN XUJIAWEIZI FAULT DEPRESSION IN SONGLIAO BASIN

The Shahezi Formation in the Xujiaweizi Depression in Songliao Basin, formed in the early stage of depression, is largely influenced by the depression. For the situation of less drilling and uneven distribution, based on the seismic reflection termination relationship, the Shahezi Formation is divided into five seismic sequences from Sq1 to Sq5. According to the internal reflection texture and external geometric configuration and in combination with parameters, six seismic facies are identified in the target sequences of the study area, including wedge shaped, parallel sheet, overlap, mound shape, blank and hummocky seismic facies, with detail descriptions of their characteristics. The seismic facies are transformed into sedimentary facies through a comprehensive interpretation. The results show that the target sequences develop the sedimentary systems of braided river delta, fan delta, lake and sublacustrine fan.