An IR-Based Field Analytical Method for Total Petroleum Hydrocarbon Measurement- Field Deployment and Performance Evaluation

Field Sampling, Measurement and Sensor Technology
Oral Presentation

Presented by T. Vidra
Prepared by , S. Mcmillen

Contact Information: [email protected]; 510-242-1654


ABSTRACT

Total Petroleum Hydrocarbons (TPH) in soil is often measured to determine if soils have been impacted by crude oil. Chevron Pacific Indonesia (CPI) operates several oil fields in Sumatra and during site decommissioning, soil samples must be analysed. Traditional laboratory methods require three to four days to analyse for TPH in soil and commercial labs often take two to four weeks before reporting results. This timing results in delays in decision-making regarding site soil delineation and excavation as well as in determining when soil remediation has been completed. In the two pilot studies, a portable handheld infrared (IR) instrument was pilot tested with over 300 soil samples from variable CPI sites. These samples covered a wide range of soil type, oil content, and moisture content, and should therefore be representative of most CPI sites. The US EPA 8015 TPH-Gas Chromatography (GC) analytical method data of those soil samples were used to create two site-specific models with 15-20 double-blinded samples to validate the modeling work. The validated models have been loaded onto the individual instrument for field deployment. This non-destructive IR technology was the first time deployed in CPI fields in July 2016. This rapid portable IR method provided TPH results that correlated well with standard TPH-GC results at different concentration levels. The advantage of this rapid IR method is that the soil samples do not have to be extracted with a solvent, so no chemical wastes are generated in the field. The rapid IR method provides TPH results in a few minutes rather than in days or weeks from a lab. A continuously monitoring incoming soil types vs. data accuracy has been set up to evaluate the performance of this instrumentation at variable field conditions. This paper describes the results from the two pilot studies, field deployment and field evaluation of this technology.