On-Site Fluids and Solids Characterization with Benchtop XRF Analyzer

Abstract

Water, oil and solid field sample characterizations are essential to scale management, corrosion and flow assurance surveillance. From sample collection to getting lab test results take weeks to even months for off-shore locations, while operation changes can happen in hours or days. During the sample transportation process, water and solid samples are often oxidized with iron species dropped out of solution or changed to oxide. For fast operational feedback and "freshest" sample measurement, on-site composition analyses are highly desirable. Typical lab analyzers, such as ICP (inductively coupled plasma) and IC (Ion Chromatography), are highly specialized and requires regular chemical supplies and maintenance. So many lab analyzers are not suitable for on-site use. This paper reports the development of test methods using a benchtop X-Ray Fluorescence (XRF) analyzer for oil field samples and field application at Gulf of Mexico offshore locations. The Benchtop XRF analyzer is very user-friendly, requires minimal sample preparation, and leaves little room for human error. Once set up, the analyzer provides fast on-site feedback at low cost, and can work with all non-gas samples. With calibrated methods, this analyzer can provide quantitative measurement for elements in water or oil. For other sample types, such as solid, slurry, mix and metals, this analyzer can be used to do qualitative measurements for trending and component identification. This on-site surveillance tool has proven to be able to provide fast and accurate data on key elements for scale, corrosion and flow assurance management at a low cost. Examples of operation decisions based on this analyzer results will be presented. This tool has demonstrated the ability to provide timely data for preventing plugging/fouling, checking chemical effectiveness, improved integrity surveillance and well flowback surveillance. Use of this tool during maintenance/turnaround helps to build up a better picture on areas with various deposits.