Full text loading...
-
Chlorine and Bromine Stable Isotope Compositions and Formation Water Characterisation
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, EAGE Workshop on Petroleum Geochemistry in Operations and Production, Oct 2016, Volume 2016, p.1 - 5
Abstract
While most chemical tracers are prone to changes upon water-rock reaction, chlorine and bromine are though to be conservative. This is why the stable isotope compositions of both elements can provide information not only about the origin of formation waters but also about solutes transport processes occurring in sedimentary basins in general and hydrocarbon fields in particular.
We review here the present knowledge about the mechanisms responsible for variations in Chlorine and Bromine isotope compositions observed in formation waters: salt precipitation, diffusion, ion filtration and possibly redox reactions involving organo-Br, and we present new experimental results from our team. The present knowledge still appears insufficient to fully understand all the information locked in the stable isotope compositions of both elements, but because they are not affected by fluid-mineral exchanges but are fractionated by diffusion and ion filtration, they are expected in some cases to show variations while the overall chemistry remains unchanged. They have thus the potential to refine the characterisation of field compartmentalization, inter-well communications and to help in the identification of the source of water breakthrough at oil producer well.