Because the primary control factors of the high-quality Putaohua Oil Reservoir in the South Gulong Area of the Songliao Basin are uncertain, this research focused on the primary factors influencing the lithology, pore types, surface porosity characteristics, and pore development in this high-quality oil-bearing reservoir. The results show that various types of pores developed in the Putaohua Oil Reservoir including primary intergranular pores, intergranular corrosion-expanding pores, intergranular dissolution pores, intercrystalline pores, and microfractures; the corrosion pores account for 57.40% of all pore types. Differences in pore types and surface porosities exist in various types of sedimentary microfacies:sheet sand has the most developed pores, primarily carbonate cement dissolution pores and feldspar dissolution pores; estuary bar sandbodies are second, with the surface porosity of primary intergranular pores and dissolution pores of river mouth bar sandbodies accounting for 7.42% and 5.33%, respectively; natural embankments and crevasse splay sandbodies have the least developed pores. Sedimentation cementation and organic act dissolution are the primary factors controlling the development of the high-quality Putaohua Reservoir. The high content of rigid material and high structural maturity are beneficial for the development and preservation of primary intergranular pores. A high content of feldspar, carbonate, and other soluble materials is beneficial for the development of dissolution pores. Dissolution is the most important factor for the improvement of physical reservoir properties.
