Evaluation of organic matters, hydrocarbon potential and thermal maturity of source rocks based on geochemical and statistical methods: Case study of source rocks in Ras Gharib oilfield, central Gulf of Suez, Egypt

Abstract

In this study, we apply geochemical and statistical analyses for evaluating source rocks in Ras Gharib oilfield. The geochemical analysis includes pyrolysis data as total organic carbon (TOC%), generating source potential (S2), production index (PI), oxygen and hydrogen indices (OI, HI) and (Tmax). The results show that the Cretaceous source rocks are poor to good source rocks with kerogen of type III and have the capability of generating gas while, the Miocene source rocks are good to excellent source rocks with kerogen of type III-II and type II and have the capability of generating oil and gas. The analyzed data were treated statistically to find some factors, clusters, and relations concerning the evaluation of source rocks. These factors can be classified into organic richness and type of organic matter, hydrocarbon potentiality and thermal maturity. In addition, cluster analysis separated the source rocks in the study area into two major groups. (1) Source rocks characterized by HI >300 (mg/g), TOC from 0.76 to 11.63 wt%, S1 from 0.44 to 9.49 (mg/g) and S2 from 2.59 to 79.61 (mg/g) indicating good to excellent source rocks with kerogen of type III-II and type II and are capable of generating oil and gas. (2) Source rocks characterized by HI <300 (mg/g), TOC from 0.31 to 2.07 wt%, S1 from 0.17 to 1.29 (mg/g) and S2 from 0.31 to 3.34 (mg/g) indicating poor to good source rocks with kerogen of type III and are capable of generating gas. Moreover, Pearson's correlation coefficient shows a strong positive correlation between

High-Resolution Acoustic Mapping of Gas Charged Sediments and Living Benthic Foraminifera Assemblages From the Ne Region of the Guanabara Bay (Rj, Brazil)

“…The OI is a parameter that correlates with the O/C ratio, and so it is related to the amount of oxygen in organic compounds (El Nady et al, 2015). The OI is high for polysaccharide-rich remains of land plants and inert organic material (residual organic matter) encountered in marine sediments.…”

Hydrocarbon generation modeling and source rock characterization of the Cretaceous–Paleocene Taratu Formation, Great South Basin, New Zealand

“…The ratio between S 1 and PY makes up the PI, where it is the proportion of the amount of free hydrocarbons already generated to the total amount of hydrocarbon that the organic matter is capable of generating. This parameter can be used to measure source rock thermal maturity (Peters 1986;Shalaby et al 2011Shalaby et al , 2012aEl Nady et al 2015;Qadri et al 2016;Jumat et al 2018;Osli et al 2018). In this study, PI values range from 0.0642 to 0.117.…”

Numerical Simulation of Gas Production from Gas Shale Reservoirs—Influence of Gas Sorption Hysteresis

“…The mineralogical and geochemical properties of the samples are summarized in Tables 1 and 2, respectively. The parameters S1, S2 and S3 in Table 2 represent the amount of hydrocarbon and non-hydrocarbon compounds liberated during Rock-Eval 6 ® (a product of Vinci Technologies, France) pyrolysis of the shale samples [21][22][23]. S1 is the amount of free hydrocarbon released from the kerogen at 300 • C prior to thermal cracking [21][22][23] and it corresponds to the first peak detected by the flame ionizing detector (FID) in the Rock-Eval 6 ® equipment [22,23].…”

“…The parameters S1, S2 and S3 in Table 2 represent the amount of hydrocarbon and non-hydrocarbon compounds liberated during Rock-Eval 6 ® (a product of Vinci Technologies, France) pyrolysis of the shale samples [21][22][23]. S1 is the amount of free hydrocarbon released from the kerogen at 300 • C prior to thermal cracking [21][22][23] and it corresponds to the first peak detected by the flame ionizing detector (FID) in the Rock-Eval 6 ® equipment [22,23]. S2, the second peak detected by the FID at a temperature, T max , is the amount of hydrocarbon generated from the thermal cracking of the kerogen and heavy hydrocarbons present in the rock samples [21][22][23].…”

“…S1 is the amount of free hydrocarbon released from the kerogen at 300 • C prior to thermal cracking [21][22][23] and it corresponds to the first peak detected by the flame ionizing detector (FID) in the Rock-Eval 6 ® equipment [22,23]. S2, the second peak detected by the FID at a temperature, T max , is the amount of hydrocarbon generated from the thermal cracking of the kerogen and heavy hydrocarbons present in the rock samples [21][22][23]. S3, the third peak picked by the FID, is the volume of carbon dioxide generated from thermal cracking of kerogen at about 390 • C [21][22][23].…”