»Off-Shore Mercury Measurements
There are several methods for performing offshore mercury assessments: process stream sampling and analysis (onsite or offsite analysis), non-destructive-direct measurements (XRF), subsampling (sludges/sediments/equipment scale), or destructive testing (sacrificial flanges, pipe spools, corrosion or test coupons).
Process stream sampling (natural gas, condensate and produced-water) is the primary and essential method for determining contaminate mass and flux of mercury, arsenic and selenium on a continuing basis during the operation of the asset. Process stream sampling, along with system mapping, speciation and partitioning can often provide a near-complete picture of the contaminant loading and allow for targeted assessment of systems (metals equilibration rates, mass loading and distribution are not equal in all sections of processing). Short-term and long-term process stream samples are collected from process under operating conditions and pressures using mercury inert insertion probes and specialized mercury inert sampling and measurement equipment capable of performing sampling/analysis per requirements of ASTM D6350, ISO 6978 and MEPA 30B (co-developed by ISCT members).
ISCT members have advanced mercury and volatile metals measurements in wet gas streams over the last since 2005 and can deploy explosion proof M4 mercury monitoring units from the US Gulf Coast, Australia, New Zealand and South Africa.