Abstract: The Qintong sag in the North Jiangsu Basin is a typical minor faulted basin. Over years of exploration, undiscovered structural oil and gas reservoirs with high abundance have become less and less, but large lithologic reservoirs with low abundance are prospective for exploration. During the 12th Five-Year Plan, some new technologies and methods of sequence stratigraphy and seismic sedimentology were deployed to promote reserve discoveries in the Qintong sag. Among these discoveries, lithologic reservoirs took a relatively high proportion. For example, the overlapping and pinchout lithologic reservoir in the Ed-1 Member of the Shuaiduo-Chenjiashe area on the Western Slope Belt and two structural-lithologic reservoirs with reserves of ten million tons in the Yuduo-Huazhuang are and the Ef-3 Member of the Shuaiduo area were discovered successively. In addition, favorable signs were observed during exploration of lithologic reservoirs related to volcanic formations. Research results show that phase-controlling traps can be seen as the foundation, fault-sand body conductivity system as the key and preservation conditions as the core for the formation of lithologic reservoir in the Ed-1 Member . Moreover, the structural-lithologic reservoir in the Ef-3 Member are characterized by three controlling factors, i.e. near-source accumulation, control of phase belt, and conductivity of faulting systems. The research results may provide necessary guidance for future exploration operations. Exploration findings related to lithologic reservoirs in the Qindong sag made during the 12th Five-year Plan reveal that lithologic reservoirs in the Ed-1 and Ef-3 Members, together with those related to volcanic rocks, will remain as key exploration targets for lithologic reservoirs in the Qintong sag, North Jiangsu Basin.

Key words: Qintong sag, lithologic reservoir, hydrocarbon accumulation pattern, exploration revelation, exploration potential