Water interaction and hydrogeochemistry during the injection of oil production brines in the West Lithuanian oilfields
Aurelija Baublyte, Vilnius University, Faculty of Natural Sciences, Department of Hydrogeology and Engineering Geology, Lithuania, [email protected]
The main goal of the study is analysis of the distribution of groundwater hydrochemical facies in natural circumstances and investigation of the impact on them during the injection of the brine into the above layered aquifer systems. The oil production is proceeding in the West Lithuania, where the Middle Cambrian is the main productive horizon, exploited now. Currently the brine is injected into the same horizon. However the permeability of this layer is not very high, consequently the acceptance of the water is low. Moreover, the volume of the groundwater in this aquifer and the difficulty of the oil extraction increase. So the Cambrian brines could be injected into the above layered Lower Devonian or Upper Permian aquifer systems because of higher permeability. A large quantity of water containing high concentration of dissolved salts is produced as a byproduct of oil extraction from the wells. The discharge of brines can cause a threat to groundwater and surface quality. Based on water chemical analysis, rock cores and modeling codes we develop conceptual model of groundwater flow and solute transport mechanisms and thermodynamics.
A combination of groundwater flow and transport modeling would: gain a better understanding of the thermodynamics in the aquifer systems; help in getting larger knowledge of obtaining new trace elements and thermodynamic data to geochemical modeling; result better understanding of the chemical reactions during the injection and mixing of different types of groundwater.
AAPG Search and Discovery Article #90060©2006 AAPG Foundation Grants-in-Aid