Degradation Rate of Flowback and Produced Waters

FPW, Degradation, Toxcicity

Alejandro Escobar-Lopez (he/him), Degradation Rate of Flowback and Produced Waters

Horizontal hydraulic fracturing is a common practice in the oil and gas industry involving injection of water mixed with various compounds into the ground, with the intent of fracturing and releasing oil and gas products from the surrounding strata. Following injection, pressure in the fracture is allowed to build up, and once released, flowback fluid and produced waters return to the injection well. Flowback fluid is generally considered fluid that returns soon after injection, and produced waters is the fluid that returns later. This differentiation is poorly defined, with both fluids often mixing, and as a result this mixture is called flowback and produced water (FPW). During transportation, spills may occur and FPW may flow into the environment. Relatively little is known about the toxicity of FPW and its impact on the environment. Even less is known about how degradation affects the toxicity of FPW. Salts and metals present in FPW do not degrade, but organic substances within it do. D. magna has been previously characterized as being highly sensitive to FPW concentrations in water and is a key organism that exists in many North American aquatic ecosystems. To examine how toxicity changes over time, FPW from the same well was used biweekly in lethal concentration experiments. The concentration of FPW at which 50% of organisms died is compared to initial results to determine FPW degradation rate. Preliminary results indicate a slow but constant reduction in toxicity over time. A better understanding of FPW degradation is key to understanding the long-term effects of FPW spills in the ecosystem and how unproperly cleaned spills may affect the environment. Because organics are constantly degrading in FPW, research into this field provides insight for any researchers, environmentalists, oil companies or otherwise looking to get a better understanding of what influences FPW toxicity.