Geochemical Analysis for Determining Total Organic Carbon Content Based on ∆LogR Technique in the South Pars Field

Abstract

There is a recognized need for the determination of total organic carbon (TOC) as an essential factor in the evaluation of source rocks. In this study, the ∆LogR technique was coupled with logging curves of sonic, resistivity, spectral gamma-ray (SGR), and computed gamma-ray (CGR) to determine an accurate content of TOC in the Gadvan Formation. Multiple linear regression analysis was also applied to the ∆LogR technique. To this aim, 14 samples of the Gadvan Formation were taken from Wells B and C in the South Pars field and analyzed using Rock-Eval pyrolysis. Results from the ∆LogR technique and multiple linear regression analysis, well logs, and Rock-Eval were compared to calculate the accurate content of TOC in the Gadvan Formation. Geochemical data confirmed that the Gadvan Formation was a relatively poor source rock in the South Pars field, as average TOC and Tmax values of the samples were 0.79 and less than 430 °C, respectively. Also, the content of potassium (K < 0.1%) confirmed the origin of the source rock as a pure carbonate, whereas the low content of thorium (Th < 5 ppm) was indicative of the percentage of clays. There was a moderate content of uranium (U < 10 ppm), suggesting that the Gadvan Formation was not deposited in an excellent reducing environment to conserve the organic matter. Moreover, the results from the integration of the multiple linear regression model with SGR and CGR showed that the value of R2 was higher than the results obtained without SGR and CGR. Findings from this study could help the exploration and production team to determine the accurate content of TOC using the ∆LogR technique in association with logging curves.

Diverse Scale Data for Shale Gas Formation Description—Why Is Digital Shale Rock Model Construction Difficult? The Polish Silurian and Ordovician Rocks Case Study

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Application of X-ray Diffraction (XRD) and Rock–Eval Analysis for the Evaluation of Middle Eastern Petroleum Source Rock

“…Different techniques are applied and recognized for the determination of total organic carbon (TOC). One of the latest techniques is the Delta logR techniques applied in Gadvan formation in the south par field [28]. Apart from carbon, organic matter also includes oxygen, hydrogen, nitrogen, and sulfur.…”

Worthwhile Relevance of Infrared Spectroscopy in Characterization of Samples and Concept of Infrared Spectroscopy-Based Synchrotron Radiation

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