Controlling Factors on Reservoir Quality of the Miocene in the Northern Yinggehai Area, Yinggehai Basin

With the increasing maturity of exploration in proven areas and main pay zones of the Yinggehai Basin, frontier zones and new formations have progressively become the focus of attention. The Northern Yinggehai area, situated on the northern margin of the Yinggehai Depression, possesses significant exploration potential; however, it remains under-explored, and systematic studies on its depositional systems and reservoir development are still lacking. Based on core observations, thin-section petrography, well-logging and mud-logging data, and geochemical analyses, reservoir characteristics of the HK2 and LG35 blocks were investigated to elucidate the principal controls on reservoir development. The results indicate that late-stage high-temperature and rapid burial compaction, together with authigenic clay minerals and carbonate cementation, represent the dominant factors governing reservoir quality evolution.