Publications Related to this Project
The Dengying Formation of China hosts extensive gas fields in dolomitized units of the Sichuan Basin. Textural and isotopic data from previous research on these units suggest that dolomitization was syndepositional and formed from fluids with seawater compositions, however other researchers cite a hydrothermal origin for dolomite and the associated textures.
Our research will assess the role of microorganisms in kinetic and mechanistic controls on both low-temperature primary dolomite precipitation and dolomitization, using controlled laboratory experiments representing the range and complexity of seawater-to-evaporated seawater environments present in the Dengying system and typical of other restricted platform facies.
Following quantification of controls, additional experiments will be conducted for longer time periods and with increasing volume to (i) assess macroscale factors and (ii) compare their isotopic signatures, geochemistry, and petrography with modern and ancient examples. Further, biomarker signatures of ancient samples will be used to further interpret microbial processes contributing to hydrocarbon generation and modification.
Our results are designed to directly address the controls on low-temperature dolomitization in dolomite reservoirs, such as the restricted platform facies of Central Sichuan Basin, and provide critical conceptual and kinetic data to better model the extent of dolomitization in these types of reservoirs.
Collaborators: Alison Olcott, University of Kansas; Bryan Rodriguez-Colon, University of Kansas; Adrianne Seiden, University of Kansas
Funding: PetroChina, KICC