Titre du document / Document title

Use of radium isotopes to determine the age and origin of radioactive barite at oil-field production sites

Auteur(s) / Author(s)

ZIELINSKI R. A. ⁽¹⁾ ; OTTON J. K. ⁽²⁾ ; BUDAHN J. R. ⁽³⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ US Geological Survey, Denver Federal Center, Mail Stop 973, Denver, CO 80225, ETATS-UNIS
⁽²⁾ US Geological Survey, Denver Federal Center, Mail Stop 939, Denver, CO 80225, ETATS-UNIS
⁽³⁾ US Geological Survey, Denver Federal Center, Mail Stop 974, Denver, CO 80225, ETATS-UNIS

Résumé / Abstract

Radium-bearing barite (radiobarite) is a common constituent of scale and sludge deposits that form in oil-field production equipment. The barite forms as a precipitate from radium-bearing, saline formation water that is pumped to the surface along with oil. Radioactivity levels in some oil-field equipment and in soils contaminated by scale and sludge can be sufficiently high to pose a potential health threat. Accurate determinations of radium isotopes (²²⁶Ra +²²⁸Ra) in soils are required to establish the level of soil contamination and the volume of soil that may exceed regulatory limits for total radium content. In this study the radium isotopic data are used to provide estimates of the age of formation of the radiobarite contaminant. Age estimates require that highly insoluble radiobarite approximates a chemically closed system from the time of its formation. Age estimates are based on the decay of short-lived ²²⁸Ra (half-life = 5.76 years) compared to ²²⁶Ra (half-life = 1600 years). Present activity ratios of ²²⁸Ra/²²⁶Ra in radio-barite-rich scale or highly contaminated soil are compared to initial ratios at the time of radiobarite precipitation. Initial ratios are estimated by measurements of saline water or recent barite precipitates at the site or by considering a range of probable initial ratios based on reported values in modern oil-field brines. At sites that contain two distinct radiobarite sources of different age, the soils containing mixtures of sources can be identified, and mixing proportions quantified using radium concentration and isotopic data. These uses of radium isotope data provide more description of contamination history and can possibly address liability issues.

Revue / Journal Title

Environmental pollution   ISSN 0269-7491   CODEN ENVPAF 

Source / Source

2001, vol. 113, n^o3, pp. 299-309 (39 ref.)

Langue / Language

Anglais

Editeur / Publisher

Elsevier, Oxford, ROYAUME-UNI  (1987) (Revue)

Mots-clés anglais / English Keywords

Oil field ; Oil industry ; Industrial waste ; Barite ; Brackish water ; Soil pollution ; Radioactive pollution ; Radium 226 ; Radium 228 ; Isotopic analysis ; Radioisotope ; Radioactivity measurement ; Isotope dating ; Geochemistry ;

Mots-clés français / French Keywords

Champ pétrole ; Industrie pétrolière ; Déchet industriel ; Barytine ; Eau saumâtre ; Pollution sol ; Pollution radioactive ; Radium 226 ; Radium 228 ; Analyse isotopique ; Radioisotope ; Mesure radioactivité ; Datation isotope ; Géochimie ;

Mots-clés espagnols / Spanish Keywords

Campo petróleo ; Industria petrolera ; Desperdicio industrial ; Baritina ; Agua salobre ; Polución suelo ; Polución radioactiva ; Análisis isotópico ; Radionúclido ; Medición radioactividad ; Datación isotópica ; Geoquímica ;

Localisation / Location

INIST-CNRS, Cote INIST : 15173, 35400009638298.0070