Utilization of a 16S rRNA Gene Microarray (PhyloChip) to Analyze the Efficacy of Oil and Gas Industry Bacteria Culture Media

Bacterial biofouling in the oil and gas industry is the direct cause of microbially-induced corrosion (MIC) and microbially-induced souring (MIS).  In addition, bacteria and their by-products may cause emulsion problems, oil carryover, plugging of filters and other equipment, and scale deposition.  It is estimated that bacteria-related issues cost the industry billons of dollars a year in the United States alone.   

Current techniques commonly employed to enumerate oilfield bacteria and test the efficacy of biocides focus on serial-dilution culture methods (NACE TMO 194-2004). However, media formulations utilize standard recipes that allow the growth of only a portion of the field population that is actually present, and do not support the growth of potentially significant bacterial species.  Current reports estimate that less than 10% of oilfield populations can be cultured.  To date, no investigations have focused on elucidating culturing efficacy of oilfield culture-analysis formulations.

In this study, genetic profile analysis of microbial communities present in produced-water samples were compared to those that were derived from culturing the produced water.   Genetic analyses utilized the Affymetrix G2 PhyloChip microarray, which can detect approximately 8500 operational taxonomic units (OTUs) in a single test to estimate bacterial diversity.  The results are presented and discussed with emphasis on the need to develop more rapid and reliable methods for the detection and monitoring of problematic bacteria in oilfield systems.