Abstract
This research aims to evaluate the groundwater composition in oil and gas fields, specifically within the Devonian terrigenous horizon. A comprehensive analysis was conducted on 166 produced water samples collected from different tectonic structures. The primary objectives encompassed anionic and cationic composition analysis, elemental composition examination, distribution mapping of key elements, and exploration of the feasibility of extracting valuable components.
Results elucidated substantial variations in the anionic and cationic composition of groundwater within the Devonian horizon, manifesting noticeable difference in salinity (TDS) ranging from 19 g/l to 276 g/l. These variations were attributed to the injection of fresh water into the reservoir during the early stages of field development. Distinct patterns were observed within each tectonic structure, highlighting the presence of a large amount of valuable elements in the northern part of the study area and deep regions. This phenomenon was ascribed to the greater depths of formation water in these areas, coupled with brines geochemical metamorphization. These zones were deemed more promising for the extraction of hydromineral raw materials. Notably, for lithium extraction, the Mg/Li ratio played a significant role, with a critical impact on the choice of extraction methods. In studied brines the Mg/Li ratio varies from 415 to 3960. Consequently, membrane methods and concentration precipitation were deemed unsuitable for lithium extraction. Instead, the use of sorbents selectively targeting lithium ions, followed by desorption and concentration, emerged as a promising alternative.
Calculation of the annual volumes of salts produced from the studied wells revealed significant potential. An inherent advantage of utilizing produced waters as a source of mineral raw materials lies in the cost-effectiveness of the product. Additionally, there is no need for the construction of additional production wells or expensive mining developments.
The extraction of additional components from produced water assumes heightened significance, particularly in mature fields at advanced stages of development characterized by substantial volumes of produced water. This research underscores the potential for sustainable resource extraction from oil and gas fields, with implications for both economic and environmental considerations.
