LA-ICPMS in-situ U-Pb Geochronology of Low-Uranium Carbonate Minerals and Its Application to Reservoir Diagenetic Evolution Studies

Abstract

Reconstruction of the diagenetic evolution of reservoirs is one of the most significant tasks in oil and gas exploration and development. Assessing the accurate timing of diagenetic events is critical to better understand the process of reservoir evolution, but the isotope dating of diagenetic events is technically challenging. This paper uses three case studies in the sedimentary basins in China to demonstrate the promising application of recently developed LA-(MC)-ICPMS in-situ U-Pb geochronology. Our results show that the new U-Pb dating method provides a reliable and efficient chronological approach to determine the absolute ages of diagenetic events. For example, the U-Pb age data of the Cambrian carbonate reservoir in the Tarim Basin reveals three diagenetic events at 526±14, 515±21, and 481±4.6 Ma, respectively. It is worth noting that microscopic observations are particularly important for improving the success rate of U-Pb dating. In addition, the recent progress and future prospects in the in-situ U-Pb dating method are also discussed in this study, suggesting that this method is currently hindered by the lack of international carbonate standards for data correction.