Research project

Project fact sheet

Understanding carbonate mineralization in fractures using novel geochemical methods

Project researcher(s): 
Adhipa Herlambang
Project supervisor(s): 
Dr C├ędric M. John
Project supervisor(s): 
Professor John Cosgrove
Duration: 
June, 2017 - May, 2021
Funding

This project, sponsored by the Indonesia Endowment Fund for Education (LPDP Scholarship), is addressing fondamental questions in structural diagenesis. 

Fractures in rocks are ideal conduits for fluids in the subsurface. This includes hydrocarbons, but also formation waters and other fluids. When water circulates through the fractures, it often can lead to the precipitation of mineral phases. This is notably the case in carbonate settings, where the supersaturation of subsurface fluids with respect to carbonates can be very high.

Our goal in this research project is to improve our understanding of the mechanisms that lead to carbonate precipitation in fractures, notably to understand why some fracture network may not be opened in the subsurface. Fundamental questions will include why carbonate precipitates, by exactly what mechanisms, and when. In order to obtain this information, we plan on deploying a range of modern analytical techniques to mineralized fractured zones. This will include clumped isotopes paleothermometry, as the latter allows us to determine both the temperature at which the minerals form, but also the isotopic composition from the parent fluid.

 

 

 

 

 

There remain however some challenges with clumped isotopes, such as for instance sample size. In this project, we will try to reduce sample size as much as possible by using a combination of techniques that were previously published, with the addition of new methods developed in house. We will also address the question of equilibrium versus kinetic precipitation in fractures, and how we can determine this using geochemical techniques. A range of case studies will be investigated.