Suman George

Terrestrial exposure of oilfield flowline additives diminish soil structural stability and remediative microbial function

Onshore oil production pipelines are major installations in the petroleum industry, stretching many thousands of kilometres worldwide which also contain flowline additives. The current study focuses on the effect of the flowline additives on soil physico-chemical and biological properties and quantified the impact using resilience and resistance indices. Our findings are the first to highlight deleterious effect of flowline additives by altering some fundamental soil properties, including a complete loss of structural integrity of the impacted soil and a reduced capacity to degrade hydrocarbons mainly due to: (i) phosphonate salts (in scale inhibitor) prevented accumulation of scale in pipelines but also disrupted soil physical structure; (ii) glutaraldehyde (in biocides) which repressed microbial activity in the pipeline and reduced hydrocarbon degradation in soil upon environmental exposure; (iii) the combinatory effects of these two chemicals synergistically caused severe soil structural collapse and disruption of microbial degradation of petroleum hydrocarbons.

Baseline characterisation and monitoring protocols for development of shale and tight gas resources, northern Perth Basin

CSIRO, in collaboration with Latent Petroleum, AWE Limited, Origin Energy, Norwest Energy and the WA Department of Mines and Petroleum (DMP) have established a research program into methods of calculating baseline values of environmental indicators and monitoring techniques during development of tight gas resources in the northern Perth Basin. As part of the project, a desktop review of available groundwater monitoring data around the sponsors’ permit areas was conducted, along with measurements of ambient methane (CH4) concentrations. The groundwater study indicated a lack of monitoring wells within the permit areas, apart from those being monitored by explorers, and provides a valuable update to the regional groundwater models built by the WA Department of Water (DoW). The mobile CH4 survey measured ambient levels of CH4 across the basin, and CH4 concentrations were close to those measured at the Cape Grim atmospheric research station (Tasmania). The soil-gas flux survey measured very low or negative CH4 flux, closely associated with carbon dioxide (CO2) levels, indicating the flux rate was controlled by microbial action. The outcomes of the project are intended to assist operators to address community assurance, adhere to or surpass regulatory requirements and establish industry best practice standards.