Permian Formation Characteristics and Petroleum Geological Significance of Well MSD1 in Suhongtu Depression, Yin’e Basin

For a long time, due to the unclear understanding of the characteristics of Permian residual strata in the coverage area of yin'e basin, the geological age of oil and gas production layers revealed by drilling in the basin is controversial. In this study, palynology, mineralogy, zircon chronology and other research work were carried out by using the core samples of the lower well section of well msd1 in Suhongtu depression of yine basin, and stratigraphic correlation was carried out in combination with the drilling, seismic survey line and surface outcrop data in the basin. The following understandings were obtained: ① sporopollen molecules such as florinites, vesicaspora, stratoabieites, vittatina and hamiapollenites found in the 2669.00～2726.00 m well section of well msd1 in Suhongtu depression, The scattered bioclastic distribution of brachiopods, crinoids and bryozoans can be seen under the thin section microscope of clastic rock, indicating that the stratum of this section is the upper Permian halsuhai formation, which is in the Late Permian. ② Combined with drilling time depth calibration and seismic horizon tracking, it is clear that the Permian in yine basin is widely distributed in the coverage area of the basin. The seismic reflection of the Permian presents the characteristics of weak reflection blank reflection, medium weak amplitude, poor continuity in the layer and occasional strong amplitude continuous boundary at the bottom, reflecting that the Permian has experienced multi-stage structural transformation after sedimentation. ③ Two sets of oil and gas systems of Cretaceous and Permian have been found in many wells in the basin. The geochemical characteristics of drilling source rocks show that the Permian in yine basin has rich oil and gas exploration potential. It is comprehensively considered that the Permian prototype basin in yine basin has a wide distribution range, rich oil and gas resource potential, strong zoning of late structural transformation, and serious structural damage in some areas. The discovery of Permian paleontostratigraphic evidence in well msd1 further strengthens the exploration prospect of Permian.