Richard Berka explains how a moisture audit can optimise plant processes and prevent unscheduled shutdowns in areas where it is considered a contaminant.
Moisture audits are especially relevant in the oil and gas sector where the risk of hydrate formation and pipeline corrosion is a significant safety concern where moisture levels need to be tightly monitored to ensure least risk to people, plant or processes.
In the transition from oil to a gas driven economy, the use of higher pressures and colder distillation temperatures is forcing ever tighter constraints on gas production processes.
Moisture measurements are being demanded at sub ppm levels, but for these to be proven against traceable standards requires a process of checks and balances that often lags behind the needs of an ever changing industry.
MCM has the capability to offer customers a mass traceable moisture validation service down to sub ppm levels, today. It can provide a highly cost effective testing service to independently determine the moisture concentrations at key process points around a plant, rig or FPSO. This is particularly useful on LNG plants where moisture levels in the sub ppm range can result in a process shutdown, but where routine validation of potentially contaminated on line analysers has been too uncertain to provide meaningful data.
The polar 'stickiness' of water, combined with its abundance in nature and superb solvent characteristics means trying to keep water out of processes is always problematic and perhaps explains why moisture is considered to be one of the hardest parameters to measure with a high degree of certainty.
Significant investment in developing mass traceable calibration standards has been coupled with repeated iterations of instrument design over many years. This has resulted in a range of instrumentation that minimises the effects of hysteresis, drift and slow response so commonly experienced with less advanced designs. Careful handling techniques and validation methodologies ensure fast, reproducible, and above all, traceable measurements.
MCM's portable hygrometers are highly reproducible, fast and impervious to temperature changes with a rapid sensor drying feature and error correcting features.
The company's validation service includes the provision of freshly calibrated portable and on line moisture analysers (ATEX certified), dry gas generators and reference hygrometers together with an engineer to establish an on-site validation system and to perform site tests.
This approach provides quick and reliable results with the certainty and documentary evidence of laboratory traceability and skilled technicians trained in sample handling.
Such validation services have been successfully used by BP, Shell, Conoco Philips and others to investigate moisture conditions on plants and offshore installations, and in each case positive savings have been realised.
Offshore glycol dehydration processes have been optimised using such services resulting in reduction of methane use by 11 tonnes/day on just one dehydrator.
The service can be mobilised within 72 hours and is costed on a day rate.
For more information visit www.engineerlive.com/iog
Richard Berka is with Moisture Control & Measurement Ltd, Wetherby, West Yorkshire, England. www.mcm-moisture.com