THE SOURCE ROCKS OF HONGSHUIZHUANG FORMATION IN LINGYUAN AREA OF LIAOXI DEPRESSION: Petroleum Geology and Hydrocarbon Generation Potential

The shale of Hongshuizhuang Formation is the dominant source rock of Yanliao rift belt with good hydrocarbon generation potential. However, the study of Hongshuizhuang Formation in Liaoxi Depression is relatively weak, which restricts the study of Meso-Neoproterozoic oil-gas geological conditions and exploration in this area. To reveal the hydrocarbon generation potential and oil-gas preservation conditions of source rocks in the area, geochemical analysis is carried out for samples from LLD2 well and 3 sections in Lingyuan area. The results show that the source rocks of Mesoproterozoic Hongshuizhuang Formation generally have high organic abundance and good hydrocarbon-generating material basis. The organic matter is mainly Ⅰ-Ⅱ₁ type, partly Ⅱ₂ and Ⅲ types. The R_o distribution ranges from 1.15% to 2.26%, belonging to mature-high mature stage, and some samples are over-mature, which are comprehensively evaluated as medium-good source rocks with good hydrocarbon generation potential. The Hongshuizhuang Formation in Lingyuan area serves as source bed located in favorable reservoir facies belt and can compose two sets of complete source-reservoir-cap assemblages, showing good oil-gas exploration prospects.