## 6 Conclusions  
This study conducted a detailed study on the high-resolution sequence stratigraphy and sedimentary evolution of the Guantao Formation in the Binxian area of Bohai Bay Basin in China. The controlling effect of sequence stratigraphy on sedimentary filling and its significance for oil and gas exploration and development were analyzed.  
(1) According to a combination method using seismic data, well log data, WTT, and INPEFA methods, the Guantao Formation in the study area was divided into one long-term cycle (LNG), four mid-term cycles (MNG1-MNG4, from bottom to top), and eleven short-term cycles (SNG1-SNG1, from bottom to top).  
(2) The sedimentary facies types of the Guantao Formation exhibited a regular variation with the fluctuation in the base-level. The sequence stratigraphic style of the study area had a significant controlling effect on sedimentation and sand body distribution. Different levels of cycles had different impacts on the sedimentary facies/microfacies type, the development degree of each sedimentary microfacies, and the sand body distribution. The long-term cycle controlled the distribution of sedimentary facies, while the mid-term and short-term cycles controlled the distribution of sedimentary microfacies. During the rising semi-cyclical period of the LNG, the area was mainly filled by alluvial fan and braided fluvial facies. As the base-level rose, the alluvial fan gradually evolved into braided fluvial and then into meandering fluvial facies. During the descending semi-cyclical period of the LNG, the area was mainly filled by braided and meandering fluvial facies. As the base-level decreased, the width of meandering fluvial channels and the distribution range of sand bodies increased.  
(3) The bottom interface of the Guantao Formation (T1) served as the dominant migration channel in the study area, connecting the reservoir and source rocks. When the base-level was at a low level (MNG1), a large amount of sand bodies developed, which can form favorable reservoirs for petroleum. The interlayers at the top of the long- and mid-term cycles served as seal layers to prevent the oil and gas from escaping. Therefore, the MNG1 cycle exhibited a good combination of reservoir and seal, resulting in the accumulation of oil and gas in the MNG1 cycle, which became the main oil- and gas-producing layer in the area.  
This study analyzed the Guantao Formation in the Binxian uplift in order to clarify the impact of the Guantao Formation sequence stratigraphy on sedimentary filling styles. The study results can provide effective guidance for future prediction of the distribution of sand bodies and high-quality reservoirs.  
Conceptualization, Q.L.; methodology, X.Y.; software, Y.Z. and Y.H.; formal analysis, R.T. and J.L.; investigation, Q.L.; writing--original draft preparation, Q.L.; review, X.Y.; funding acquisition, Q.L. and X.Y. All authors have read and agreed to the published version of the manuscript.  
This study was financially supported by the National Natural Science Foundation of China (Grant No. 42372146 and 41972107) and the Strategic Cooperation Technology Projects of CNPC and CUPB (ZLZX 2020-02).  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the authors on request.  
We extend gratitude to the Exploration and Development Research Institute of Shengli Oilfield for providing the samples and data access, and for granting permission to publish the results.  
The authors declare no conflicts of interest.