American Petroleum Institute

Recommended Practice for Analysis of Oilfield Waters - THIRD EDITION
 N RP 45

Annotation

This document is directed toward the determination of dissolved and dispersed components in oilfield waters (produced water, injected water, aqueous workover fluids, and stimulation fluids). Bacterial analyses, bioassay (toxicity tests for marine animals), NORM determination, and membrane filter procedures are outside the scope of this document.

Biological determination of the species and concentration of bacteria are covered in NACE TM0194-94, Field Monitoring of Bacterial Growth in Oilfield Systems .

Determinations of Naturally Occurring Radioactive Materials (NORM) in oilfield waters is discussed in API Bulletin E2, Bulletin on Management of Naturally Occurring Radioactive Materials (NORM) in Oil and Gas Production

Membrane filter procedures are covered in NACE TM01- 73, Test Methods for Determining Water Quality for Subsurface Injection Using Membrane Filters .

Analyses for residuals of proprietary organic treatment chemicals, such as corrosion inhibitors, demulsifiers, scale inhibitors, water clarifiers, biocides, etc. are also outside the scope of this document. However, analyses for generic components of proprietary chemicals, such as phosphate (scale inhibitor), are included in this document.

Lastly, analyses of nonhazardous oilfield waste (NOW), such as drilling fluid, soil, cores, etc. are outside the scope of this document. However, analyses of separated water (including filtrates) from such sources are within the scope.

The analytical methods presented in this document were selected for their accuracy, reproducibility, and applicability to oilfield systems. For most constituents, several methods of varying degrees of complexity and accuracy are presented to provide the analyst with the opportunity to choose the most appropriate and cost effective method pertinent to his/her needs.