Abstract: The pyrolith reservoir of Saihantala sag in Erlian Basin is an important exploration area and has been given high priority in recent years. Jurassic andesite and basalt of the area are the main drilling target. It is one of the exploration difficulties to predict the distribution of pyrolith reservoir effectively. Aiming at the lava reservoir characteristics and difficulties in prediction, some methods are used to predict the spatial distribution patterns and the thickness changes of andesite and basalt, such as nature gamma analog acoustic wave inversion, nature gamma reservoir parameter inversion, and seismic attributes. According to the primal physiognomy of lava, characteristics of the fracture structure, seismic facies, the cause formation method and attributes predicting method are used to predict the characteristics of volcanic rock. The volcanic facies is predicted by synthesizing the volcanic lithology and the result of inversion prediction, in combination with core data. The development areas of fracture and volcano slopes which are at a middle distance from the volcano center are considered to be favorable reservoirs.

Key words: volcanic rock, seismic inversion, seismic attributes, seismic facies, reservoir prediction, Saihantala sag