Evaluating Hydrologic Reservoir Constraint in Coal Seams and Shale Formations

摘要

Methods and apparatus suitable for quickly and accurately measuring ¹³C levels and supporting data in an aqueous fluid reservoir. Interpreting the resulting data to indicate key factors regarding a reservoir and completion methods, including reservoir constraint, gas producibility, and completion success. A sensor and to a sensing method that evaluates the level of hydrologic constraint in aquifers occurring in unconventional reservoirs, such as shales and coals is disclosed. Specifically, Raman spectroscopy is disclosed as a sensor and a sensing method that measures the level of naturally-occurring ¹³C in an aqueous reservoir and compares the level of ¹³C to the levels typical for highly constrained and highly unconstrained reservoirs. The disclosed sensor and sensing method also monitors the level of naturally-occurring ¹³C in a reservoir. Also disclosed is a method of using δ¹³C_Dic to evaluate geographic areas of coal bed reservoir water having biologic methanogenic activity.