Abstract

Produced waters are generated from hydrocarbon and geothermal reservoirs during field development. Basinal brine is traditionally referenced as deep saline groundwater that is predominantly disposed of during oil and gas production, but should instead be valued as a natural resource. Produced waters contain virtually every naturally occurring element and can exhibit salinities several times that of sea-water. Currently, there are areas where mineral commodity extraction and beneficial uses of produced waters are being implemented. Demand is increasing to reduce produced water waste, constrain expenditures, and improve development for recycling or reusing basinal brines in oil and gas field operations. Exploration in basinal brines provides an opportune source to ascertain a new potential mineral and energy resources (e.g., lithium for batteries).

A comprehensive, national evaluation of the mineral commodity potential of produced waters will be presented. This investigation utilizes the United States Geological Survey (USGS) produced waters geochemical database (Version 2.1), which is a compilation of records from approximately 160,000 samples providing major and trace element data for produced waters from hydrocarbon and geothermal wells.

Based on geologic history, structure, lithology, and fluid origins, produced waters from individual basins have unique geochemical signatures. Compiled national maps show spatial differences in concentrations for constituents of interest, estimated economic values, and correlation among potential mineral commodity sources. Economic values for raw elemental commodities for each data point are taken as the product of mineral commodities value estimates from USGS mineral commodity summary reports, and corresponding produced water concentration data for each element. More complete economic assessment evaluates the viability of the proposed mineral commodity for exploration, extraction, and development. Examination of mineral commodities in produced water can serve as a powerful tool for exploration or extraction of strategic elements; results from statistical outlier analysis will narrow the focus for mineral commodity exploration potential. Byproduct wastewater that is returned after mineral extraction, is another available commodity from this process and can be re-used for oil and gas field operations.

There is a rise in demand for energy resource development and a national push for water conservation. This effort highlights an opportunity for extracting mineral commodity resources and improving water sustainability management in hydrocarbon and geothermal operations.