Resources

Stable Isotope Hydrology
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Roger E. Diamond
The book begins by explaining what isotopes are, how they behave (fractionation, distillation, etc.) and how they are measured and reported in the delta notation. Then follow sections on calculation and significance of meteoric water lines, isotopic effects like the temperature or altitude effect, use of the deuterium excess parameter, and methods like mass balance and hydrograph separation. Several case studies are included to illustrate the application to problems like recharge estimation, leakage of surface water into groundwater and residence time of groundwater. Finally, there are some tips on water sampling for stable isotopes and some exercises with worked answers.

Fingerprinting Formation – Waters Using Stable Isotopes
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B.J. Rostron, C. Holmden
Hydrogen and oxygen isotope compositions of formation-waters from the Williston Basin are reported from produced waters and drill stem tests for a vertical stratigraphic section near Midale, Saskatchewan. These new data, in conjunction with data from the literature, show that Williston Basin formation-waters vary substantially in isotopic composition between aquifers in the stratigraphic section and within the same aquifer regionally. These large isotopic variations enable the use of H and O isotopes in Williston Basin formation-waters to fingerprint sources of contaminant water encountered during drilling and production of hydrocarbons. q2000 Elsevier Science B.V. All rights reserved.

Regional Variations In Oxygen Isotopic Compositions
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B.J. Rostron, C. Holmden
Oxygen isotope compositions of formation waters from drill stem tests and produced waters are reported from the Yeoman and Duperow aquifers across the Williston basin. Mapped isotopic distributions vary across the basin from <–24‰ δ18O to values over +9.4‰ δ18O, relative to Standard Mean Ocean Water (SMOW). Areal distributions of oxygen isotopes support a complex model of paleohydrogeology of the basin. They can be used to trace meteoric recharge into the basin, identify slow or stagnant brine-flow areas, and the presence of glacially induced recharge water deep in the subsurface. D 2003 Elsevier Science B.V. All rights reserved.

Fingerprinting Stray Formation Fluids Associated with Hydrocarbon Exploration and Production
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B.J. Rostron, S. Arkadakskiy
Formation water or hydrocarbons occurring at surface and subsurface locations away from their point of origin are often referred to as “stray fluids.” Efforts to identify the sources of these fluids have provided important insights for optimizing hydrocarbon exploration and production. With the rapid growth in hydraulic fracturing operations, the source of associated fluids is becoming the focus of scientists and environmental regulators. Many geochemical techniques are available for fingerprinting stray fluids, but the information from traditional approaches can be difficult to interpret in some oil and natural gas settings. New isotopic techniques, using signatures of 18O, 2H, 13C, 87/86Sr, and others, are now placing better constraints on the interpretation of stray-fluid origins. These new isotopic fingerprinting methods are being used by the hydrocarbon industry to solve problems and safeguard public health. 

Stable Isotope Geochemistry Helps in Reducing Out-of-Zone Hydraulic Fracturing
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S. Arkadakskiy, B.J. Rostron
This presentation outlines 3 major studies undertaken by Isobrine using stable isotope geochemistry to characterize the sources of co-produced brines in oil and gas wells drilled in the Bakken Formation. Isotopes identified that many wells contained significant quantities of external fluids from nearby water-rich zones, as a result of inefficient hydraulic fracturing programs. These projects helped clients to minimize unwanted brine production and increase hydrocarbon yields in future wells by modifying their drilling programs to optimize the size, number, and/or distribution of hydraulic fracturing sites along the well bores.