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Petroleum: Hydrocarbon Contamination
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Air Quality and Energy Systems, 2020
Svetlana Drozdova, Erwin Rosenberg
Natural seeps are frequently encountered phenomena that occur when crude oil seeps from the geologic strata beneath the seafloor to the overlying water column as a natural process.[10] Recognized by geologists for decades as indicating the existence of potentially exploitable reserves of petroleum, these seeps release vast amounts of crude oil annually. Yet these large volumes are released at a rate low enough that the surrounding ecosystem can adapt and even thrive in their presence; which is not true in case of the catastrophic and accidental impact of a tanker or oil well spill. Natural processes are, therefore, responsible for over 45% of the petroleum entering the marine environment worldwide (Table 2).[11]
Introduction to Oil Spill Behavior
Published in Ozcan Konur, Petrodiesel Fuels, 2021
The formation of tar balls is the ultimate fate of many oils. These tar balls are then deposited on shorelines around the world. The oil may come from spills, but it is also residual oil from natural oil seeps or from deliberate operational releases such as from ships. Tar balls are regularly recovered by machine or by hand from recreational beaches.
Sources and Causes of Oil Spills
Published in M.R. Riazi, Oil Spill Occurrence, Simulation, and Behavior, 2021
According to the National Oceanic and Atmospheric Administration (NOAA), an oil seep is a natural leak of crude oil and gas that migrates up through the sea floor and ocean depths. For example, a natural tar seep offshore of Santa Barbara from the US Geological Survey is shown in Figure 3.30 (NOAA, 2020).
Source identification of PAHs in soils based on stable carbon isotopic signatures
Published in Critical Reviews in Environmental Science and Technology, 2018
Peng Gao, Hongbo Li, Chris P. Wilson, Timothy G. Townsend, Ping Xiang, Yungen Liu, Lena Q. Ma
Most PAHs in the environment result from incomplete combustion and pyrolysis processes of organic matter (OM), including biomass, petroleum, and coals (Gan et al., 2009). Based on their origins, PAHs can come from natural and anthropogenic sources (Buczyńska et al., 2013; Cai et al., 2017; Wang et al., 2015, 2016). Natural sources include oil seeps from crude oil deposits, forest fires, volcanoes, and erosion of ancient sediment. For example, some PAHs such as perylene are produced naturally from the biochemical transformation of OM (Abdel-Shafy & Mansour, 2016). Anthropogenic PAHs are formed either by thermal alteration of OM or its incomplete combustion (Abdel-Shafy & Mansour, 2016; Rothwell & Cooke, 2015). Today, the major sources of PAHs in the environment are from human utilization of petroleum products and incomplete combustion of fossil fuels, biofuels, or other forms of OM, far exceeding natural sources (Cai et al., 2017; Kim et al., 2008). As a result, PAH concentrations are elevated in soils, especially near urban and industrial areas that often have multiple sources of release (Duan et al., 2015).
Oil leaking and seeping site in the Persian Gulf detected and studied by satellite observations
Published in Marine Georesources & Geotechnology, 2021
Andrei Yu. Ivanov, Hadi Gerivani
Natural oil seeps and their surface manifestations often indicate hydrocarbon deposits. Oil seeps detected in offshore sediment basins sometimes indicate the continuation of oil or gas fields in the seabed (e.g., Krajewski et al. 2018; Najoui et al. 2018). Therefore, observation of natural hydrocarbon seeps using SAR and other imaging systems on the sea surface may result in discoveries of hydrocarbon deposits under the seabed. However, due to the complicated relationship between surface manifestations and seafloor sources of hydrocarbons, proper interpretation requires the integration of SAR data with bathymetrical, geological, geophysical, seismic, and hydro-meteorological data.
Characterization of natural hydrocarbon seepage in the South Caspian Sea off Iran using satellite SAR and geological data
Published in Marine Georesources & Geotechnology, 2020
Andrei Yu. Ivanov, Hadi Gerivani, Natalia V. Evtushenko
One of the largest and most intense seepage regions occurs in the south part of the Caspian Sea (Piggott 1996; Scantland and Biegert 1996; Williams and Huntley 1998; Zatyagalova, Ivanov, and Golubov 2007). The study of hydrocarbon seepage in the Caspian Sea basin has a long history. In the beginning of the 1900s, onshore natural oil seeps were used by the explorers to identify petroleum fields and develop oil production in onshore areas. Later, during Soviet Union times, discovery of hydrocarbon seeps led to development of offshore production. As a result, the Caspian Sea is now one of the world’s most important production basins, with proven oil reserves of 20–30 billion barrels.