Characterization of solid bitumens originating from thermal chemical alteration and thermochemical sulfate reduction

The sulfur-isotopic compositions of benzothiophenes and dibenzothiophenes as a proxy for thermochemical sulfate reduction

“…A highly aromatic and sulfur-rich solid bitumen is also diagnostic for TSR, but is applicable mostly where severe TSR has occurred (Kelemen et al, 2008(Kelemen et al, , 2010. A promising approach to assess TSR has been developed in the last decade using sulfurized thiaadamantanes as molecular indicators (Hanin et al, 2002;Wei et al, 2007Wei et al, , 2012.…”

Formation and evolution of solid bitumen during oil cracking

“…In contrast, organic geochemists use the origin and geologic setting of solid bitumen to define this material as allochthonous organic material that was once mobile bitumen or petroleum fluid that migrated from source rocks as fluids but are now solids at surface or subsurface conditions. This bitumen may be produced by different processes, such as biodegradation and/or weathering, thermal cracking, gas deasphalting of bitumen or preexistent oil hydrocarbons, or by the precipitation of pre-existing oils within a reservoir (Curiale, 1986;Hwang et al, 1998;Schoenherr et al, 2007;Kelemen et al, 2010). This study focuses on insoluble solid bitumen formed during oil cracking and is also termed pyrobitumen, or coke.…”

Reprint of “Solid bitumen occurrences in the Arruda sub-basin (Lusitanian Basin, Portugal): Petrographic features”

“…Different processes like biodegradation and/or weathering, thermal cracking, gas deasphalting of bitumen or preexistent oil hydrocarbons, or precipitation of preexistent oil in a reservoir can lead to the production of solid bitumens (e.g., Curiale, 1986;Hwang et al, 1998;Kelemen et al, 2008Kelemen et al, , 2010Schoenherr et al, 2007). Geochemical studies are needed to permit the identification of the process that gave rise to the solid bitumen identified in the Arruda sub-basin (Lusitanian Basin).…”

“…Despite the different definitions, the use of petrographic and geochemical techniques allows a better understanding of this type of organic material. Many studies enable a better understanding on the origin of solid bitumen and using their characteristics to evaluate the thermal maturity (Curiale, 1986;Curiale et al, 1983;George et al, 2007;Huc et al, 2000;Hwang et al, 1998;Kelemen et al, 2008Kelemen et al, , 2010; and others also include petrographic analysis (e.g., Bertrand, 1990Bertrand, , 1993Bertrand and Héroux, 1987;Fowler et al, 1993;Gentzis and Goodarzi, 1990;Jacob, 1989;Landis and Castaño, 1995;Riediger, 1993;Schoenherr et al, 2007;Shalaby et al, 2012;Stasiuk, 1997).…”