A new approach to interpreting relationship between Rock-Eval S2 and TOC data for source rock evaluation based on regression analyses

Document Type: Research Paper

Author

School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran

10.7508/GEOP.2015.01.001

Abstract

To evaluate the relationship between total organic carbon (TOC) and Rock-Eval S2 (petroleum potential) of petroleum source rocks, a
total of 180 outcrop samples from the black organic matter–rich facies of Mesozoic strata from a locality of southwest of Iran were
investigated using Rock-Eval VI pyrolysis and Leco Carbon Analyzer. The linear regression is applied to determine the correlation
between Leco TOC and Rock-Eval S1 and S2. The accuracy of the proposed model by this method has approximately 95% conformity
according to the Rock-Eval S2 and Leco TOC data (TOC = 0.492 + 0.174 S2). Then, by using the P value method, it was determined
that TOC is a function of S2 and S1 only causes the fluctuations. By means of sensitivity analysis of TOC with respect to S1 and S2, it
was shown that TOC has a linear relationship with S2 and does not have any noticeable correspondence to S1. The result of this study
can be used to evaluate petroleum potential (S2) of organic matter–rich facies by using TOC obtained by Leco Carbon Analyzer. For
the studied samples from the organic matter-rich facies, organic carbon richness is a quality and quantity index of petroleum potential.

Keywords


Bernie B. Bernard, Heather Bernard, and James M. Brooks., 2010. Determination of total carbon, total
organic carbon and inorganic carbon in sediments. College Station, Texas 77845.
Espitalié, J., Deroo, G., & Marquis, F. 1985a. La pyrolyse Rock-Eval et ses applications. Patrie I. Rev. Inst.
Fr. Pétrole, 40(5): 563-579.
Espitalié, J., Deroo, G., & Marquis, F. 1985b. La pyrolyse Rock-Eval et ses applications. Patrie II. Rev. Inst.
Fr. Pétrole, 40(6): 755-784.
Espitalié, J., Deroo, G., & Marquis, F. 1986. La pyrolyse Rock-Eval et ses applications. Patrie III. Rev. Inst.
Fr. Pétrole, 41(1): 73-89.
Hunt, John M., 1996. Petroleum Geochemistry and Geology, 2nd edition W.H. Freeman and Company. 743
pp.
Katz, B.J., 1983. Limitations of ‘Rock–Eval’ pyrolysis for typing organic matter. Org. Geochem. 4: 195–199.
Langford, F.F., Blanc-Valleron, M.M., 1990. Interpreting Rock-Eval pyrolysis data using of pyrolizable
hydrocarbons vs. total organic carbon. The American Association of Petroleum Geologists. AAPG Bull. 74
(6): 799–804.
Yalçın Erik, N., Özçelik O., Altunsoy, M., 2006. Interpreting Rock–Eval pyrolysis data using graphs of S2 vs.
TOC: Middle Triassic–Lower Jurassic units, eastern part of SE Turkey. Journal of Petroleum Science and
Engineering. 53: 34–46.