| Songliao Basin ranges from the eastern longitude of 120° to 128°, from northern latitude of 42°20' to 49°20' , 26 × 104km2 in total area, bounded west by Daxing'aniing, northeast by xiaoxing'anling, southeast by Zhangguangcailing, south by hills of Kangping-Faku.Like the other basins in eastern China, Songliao is a two-layered basin, i.e., faulted and depressed. The current geothermal gradient (GG) is a little higher than others basins in the world, and very high in heat flow value (HFV), 42. 8-93. 6mW/m2. The thinnest crust is only 29km; the isoline of 33km accordingly shows the range of the Songliao. The tomographical profiles of Shaoji'an (2000) and Fukao reflect the upwelling of the asthenosphere beneath Songliao. And seismic exploration verifies the existence of listic faults and a deep detachment zone. All these data demonstrate that the extension of the Songliao is caused by the upwelling of the asthenosphere.Tectonically, Songliao is generally divided into 6 1st order tectonic units: the central depression, northern dip-down, northeast uplift, southeast uplift, southwest uplift and west slope. The main study area, Dongtumo is located in the west slope, bounded north by Binzhou railway, west by Nenjiang river, south by Tailai-Taihe and east by Xiaolinke. The total area of Dongtumo is about 4500Km2. In this study area, there are a few low-aptitude structures, such as Dong-10 and Dong-6.In deposition, Quantou Fms III and IV consist of brown red and dark violet red fluvial mudstones intercalated with grey, green and grey white coarse-grained clastics, partly with green, dark grey mudstones and tuffs. They are the minor reservoirs in Dongtumo. Qingshankou Fm I is deep or semi-deep lacustrine deposition and one of the major source rock for Dongtumo. Qingshankou Fm II and III , one of the major reservoirs, were deposited in lake bay and delta environment. The Yaojia Fm, one of the major reservoirs, were deposited in fluvial environment. The Nenjiang Fm I , with a lake shoreline sand bank at its bottom, mainly consists of semi-deep mud. The The Nenjiang Fms II and III, composed of dark and dark grey mudstones, are the regional seal for oil and gas.Since the study area is adjacent to the oil and gas-generating Gulong sag, it is highly possible that the oil and gas migrate within a short distance into the reservoirs sealed by the Nenjiang Fm. The exploration has showed that there are no obvious structures in Dongtumo. The effective way for oil and gas may be sequence stratigraphy.Although sequence stratigraphy was established and applied in the positive continental margin basins, the contribution of Chinese geologists to continental basins has been achieved in sequence stratigraphy, for example, Bohaiway basin, Pearl River Mouth basin, Ordos basin and so on. The application of sequence stratigraphy in Songliao is significant for petroleum exploration.In 1999-2000, the high-resolution seismic exploration and a number of borehole drilling were carried out. This study tries to identify the sequence boundaries, divide sequences and establish the sequence framework.. Combining with analysis of depositional systems and facies, we can obtain the genesis, thickness, position in a sequence and space of sand bodies, and predict the hidden/ lithological petroleum traps.Because the study area is on a gentle slope, and a sequence is a very thin mudstones-interbedded-with-sandstone body, the 2D seismic exploration is hard to differentiate mud beds from sand beds. Hence, special processing of seismic data, such as impedance inversion, seismic trace, instantaneous frequency, instantaneous phase, apparent polarity and reflectance intensity are carried out and the results show that all these methods are effective in differentiating mud and sand, especially the impedance inversion.Some source rock analysis shows that TOC, chloroform "A" and reflectance (R0,) of Qingshankou Fm I are 1.4584, 0.5257, and 0.47, much less than their counterpoints in Gulong sag, the source rock on slope is immature. Therefore, it is assumed that oil and...
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