THE MODEL FOR FORMATION RESERVOIR IN HALF GRABEN MODE OF FAULT-DEPRESSION BASIN——TAKING THE LISHU FAULT DEPRESSION IN SONGLIAO BASIN AS AN EXAMPLE

The half graben mode is a main type of depth fault depression of Songliao basin and it is the target for oil-gas exploration. Taking the Lishu fault depression as an example, according to the developed character of tectonics and sequence strata, and the cooperation regularity of sourcereservoircap six reservoir types were recognised. There are rollover anticline reservoir, fault reservoir, faultblock reservoir,updip pinchout lithology reservoir in overlap mode, updip pinchout lithology reservoir in phase transition mode, lenticular lithology reservoir and buried hill reservoir. The model for formation of reservoir in half graben mode faultdepression basin was discussed.