Based on the drilling,logging and geochemical data from 32 wells,the deposit and tectonic evolution feature of the Tangyuan fault depression were studied,and the gas accumulation conditions and gas reservoir types were analyzed.

The oil/gas reservoir types in Wuerxun-Beier faulted-down depression and their exploration methods;

Furtherly,according to structural positions and related reservoir types,hydrocarbon accumulation models can be divided into five types,including the main uplift body,the uplift steep slope,the uplift gentle slope,the inter(intro)-sag highland and th.

The main reservoir types were anticlinal reservoir, fault reservoir, lithologic reservoir, heavy-oil sealing reservoir and composite reservoir in Wuerhe-Xiazijie Area, and heavy-oil sealing reservoir was a typical one.

Based on investigations of accumulation types and distribution regularities in the Dawanqi oilfield,it is pointed out that,this oilfield is controlled by various geo-factors and characterized by multiple trap and reservoir types.

The results indicate that there is noticeable otherness in the characteristics of source rock,reservoir rock and forming mechanism of oil pools,though reservoir types both of them are all lithologic or structural-lithologic.

Its source conditions, reservoir properties, caprock conditions, structural conditions and type of reservoir formation are analyzed.