Volcanic reservoir features and exploration potential of Changling faulted depression in the southern Songliao Basin, China

Volcanic reservoirs are well developed in deep area of Changling faulted depression. The formation of volcanic rock reservoirs was divided into two stages, the initial diagenesis stage and later diagenesis stage. The initial diagenesis formed primary porosity; The later diagenesis formed secondary porosity; Tectonism was throughout the whole process of the diagenesis, forming various primary and secondary cracks. Those cracks are key that the volcanic formates becomes reservoir. Volcanic edifice stacked horizontally side by side. Volcanics which have big thinkness and multi-cycle development characteristics are the main reservoir of deep area. Widely developed thick layer of volcanic reservoir in the deep basin, combined with source rocks, and big-deep faults, formed favorable exploration targets, which have huge exploration potential.