0122 Environmental and human health impact assessment condensate spill

OIL & GAS Environmental and Human Health Impacts Evaluation of a Condensate Spill Natural Gas Processing Facility, Bangladesh

Project Summary

Environmental and Human Health Impacts Evaluation of a Condensate Spill Natural Gas Processing Facility, Bangladesh

Key Project Elements  Environmental Impact and Human Health Evaluation  Semi-quantified Risk Assessment  Air Dispersion Modelling

 Water Dispersion Modelling  Explosion Risk

CRA was commissioned to undertake an evaluation of environmental and human health risk resulting from a condensate spill for a leading oil and gas producer. The spill occurred during the export by road tanker of condensate produced at a natural gas processing facility in central Bangladesh.

Condensate by-product from the gas processing facility is sold and collected on behalf of the purchaser by a transport contractor. Although the gas processing facility operator had no responsibility for the fate of the condensate once it had been collected, the client wanted to understand the risks resulting from an incident involving a road tanker in the vicinity of the site. The two principal risk scenarios were identified as the release of condensate vapour affecting humans and the release of liquid condensate having an impact on soil and water. The assessment assumed a worst case scenario of a rapid release of tanker contents following a collision or overturning.

The potential impacts from the release of vapour were modelled using SAFER TRACE to determine the distance from the spill that potentially explosive atmospheric concentrations would occur. This took account of the output of a mixture model algorithm, the Peng-Robinson equation of state, which is commonly used to estimate the volatility of liquid mixtures.

The soil and water impact assessment addressed three different scenarios, based on seasonal monsoon flooding: dry soil, intermediate flooding of individual paddy fields and full flooding across paddies. The outputs included estimates of soil contamination volumes for the dry season and the surface extent of water pollution during flooding. This allowed the client to prepare emergency response plans for the various scenarios.

Ref: PS0122