The first decade of scientific insights from the Deepwater Horizon oil release

What Was Released? Assessing the Physical Properties and Chemical Composition of Petroleum and Products of Burned Oil

“…It required a combination of measurements, calculations, and mathematical modeling. According to the information provided in the review by Kujawinski et al (2020), the broken well released 530,000 tonnes of oil (defined as hydrocarbons with six or more carbon atoms that are liquid at ambient pressure). In addition, 170,000 tonnes of natural gas (hydrocarbons with five or less carbon atoms that are gases at ambient pressure) escaped near the seafloor, in 1,500 m water depth at high pressure and with a temperature of about 100°C, into the overlying cold water column (Reddy et al, 2012; note that these amounts are approximate, and slightly different numbers can be found elsewhere in the literature; according to Lee et al, 2018, a federal court ruled in January 2015 that "BP was liable for 3.19 M barrels of crude oil that leaked into the Gulf " of Mexico).…”

“…c Estimated from Mango ratios (Jarvie et al, 2015) using the composition of 2-and 3-methyl pentanes and 2-and 3-methyl hexanes in MW-1 oil ( responders decided to convert the larger, faster-rising oil droplets into small droplets that would remain in the deep sea applied chemical dispersants directly at the outflow near the seafloor. Overton et al (2016), Kujawinski et al (2020), and Oldenburg et al (2020) included bulk and molecular information on the Macondo oil in their reviews of the chemical analysis of original and transformed petroleum spilled during the DWH incident at mid-term and toward the end of the Gulf of Mexico Research Initiative (GoMRI), respectively. Petroleum sampled directly above the Macondo well during the blowout ("live oil"; Table 2) was determined to have a GOR of 1,600 standard cubic feet per barrel petroleum (Reddy et al, 2012).…”

“…As summarized by Kujawinski et al (2020), dioctyl sodium sulfosuccinate (DOSS) was used to track the fate of the deep-sea dispersants applied for spill mitigation during the DWH disaster; this compound was selected because it comprises a large and relatively constant fraction of Corexit and other dispersant formulations, and it was amenable to existing analytical protocols. Samples taken during and a few months after the disaster indicated that DOSS persisted in the subsurface intrusion and was not degraded (Kujawinski et al, 2011), contrary to expectations based on laboratory experiments performed under surface conditions (Baelum et al, 2012).…”

“…Similar molecular information is available for all other nominal masses in the mass spectrum. Reprinted from Kujawinski et al (2020) with permission from Springer Nature; panels a-c were adapted from Aeppli et al (2012) with permission from the American Chemical Society ature compilation of different oil burning experiments using various substrates (Booher and Janke, 1997, mostly based on the work of D.D. Evans, National Institute of Standards and Technology, in the early 1990s), products of burning oil, excluding water, are about 92% carbon dioxide, 3.2% carbon monoxide, 4.6% smoke (soot/black carbon), 0.03% PAHs, and 0.27% volatile organic chemicals (VOCs).…”

Marine Oil Snow, a Microbial Perspective

“…In order to respond effectively to crude oil released to the marine environment it is imperative to understand the interplay between the physical, chemical, and biological factors that determine petroleum fate, transport, and impact on the biota and surrounding environment. Marine snow (MS) came to prominence as a vehicle for transporting oil to the benthos during the 2010 Macondo spill (hereafter referred to as the MC-252 spill, because the Macondo Prospect is located in Mississippi Canyon Block 252 of the Gulf of Mexico), and has stimulated a lot of research to determine its quantitative importance, resulting in several reviews on the topic (e.g., Daly et al, 2016;Passow and Ziervogel, 2016;Quigg et al, 2016Quigg et al, , 2020Decho and Gutierrez, 2017;Brakstad et al, 2018b;Burd et al, 2020;Kujawinski et al, 2020;Passow and Overton, 2021).…”