Inter‐laboratory test for oxygen and hydrogen stable isotope analyses of geothermal fluids: Assessment of reservoir fluid compositions

Abstract

The measured and calculated δ O and δ H values of water sampled at the weir box, separator and wellhead of geothermal wells suggest the existence of hydrogen and oxygen isotope-exchange equilibrium between the liquid and vapor phases at all sampling points in the well. Thus, both procedures for calculating the isotopic compositions of the deep geothermal reservoir fluid - using either the analytical data of the liquid phase at the weir box together with those of vapor at the separator or the analytical data of liquid and vapor phases at the separator -are equally valid.

An international intercomparison of stable carbon isotope composition measurements of dissolved inorganic carbon in seawater

“…A more direct assessment of measurement reproducibility can be derived from intercomparison exercises in which identical replicate samples are sent to multiple labs for analysis (a so‐called “ring‐test” or “round robin test”). Intercomparisons of this type have been conducted for oxygen and hydrogen stable isotope compositions of water ( δ 2 H‐H 2 O and δ 18 O‐H 2 O; e.g., Walker et al ; Wassenaar et al ; Verma et al ), seawater nutrient concentrations (Aoyama et al ), and seawater DIC and alkalinity concentrations (Bockmon and Dickson ; Verma et al ). However, to the authors’ knowledge, there has been only one published interlaboratory comparison study of δ 13 C‐DIC measurements on natural waters (van Geldern et al ).…”

Interlaboratory test for stable carbon isotope analysis of dissolved inorganic carbon in geothermal fluids

“…Figure shows a schematic diagram of a geothermal production well . A mixture of vapor and liquid phases reaches the wellhead from the subsurface geothermal reservoir.…”

“…Location of sampling points in the geothermal production well [Color figure can be viewed at wileyonlinelibrary.com]…”