The Western Desert versus Nile Delta: A comparative molecular biomarker study

Diasty, W. Sh. El; Moldowan, J. Michael

doi:10.1016/j.marpetgeo.2013.07.003

Cited by 27 publications

(12 citation statements)

References 30 publications

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“…MCH is the most abundant alkane, indicating a high terrigenous input to the West Dikirnis oils, consistent with the elevated CPI values of 1.18-1.23 (Table 3) (Bray and Evans, 1961). The CPI values are consistent with those of oil from the Nile Delta (1.10-1.12), and differ from those of oil from the Western Desert (1.04-1.08) (El-Diasty and Moldowan, 2013), indicating that the Nile Delta oils are probably generated from terrigenous source rocks. Moreover, the high pristane/ phytane (Pr/Ph) ratio, low phytane/nC 18 (Table 3), low C 29 /C 30 hopane, very low C 35 homohopane index, high abundance of C 30 hopane and low dibenzothiphene/ phenanthrene (DBT/phen) (Table 4A, B), suggest that a shale-rich source rock generated the West Dikirnis oils.…”

Section: Source Rock Lithology and Depositional Environment Relevant supporting

confidence: 66%

“…A plot of oleanane index versus C 30 steranes (Peters et al, 1999) (Fig. 9A) indicates that the onshore West Dikirnis and El-Tamad oils, and the NW offshore Nile Delta Abu Qir condensates (El Diasty and Moldowan, 2013), are genetically related and are derived from a Late Cretaceous -Early Tertiary source rock. However, the offshore Wakar and Sidi Salem oils (El-Diasty and Moldowan, 2013) were generated by a Tertiary source rock.…”

Section: Age-relevant Biomarkersmentioning

confidence: 99%

“…The West Dikirnis field in the onshore delta was the first significant oil discovery to be made. The discovery encouraged exploration activity in the Nile Delta and as a result, the hydrocarbon prospectivity of this area become the subject of increased studies and fi eld investigations (Shaaban et al, 2006;Vandre et al, 2007;Kora et al, 2011;El-Diasty and Moldowan, 2013). However the nature of the source rocks and the controls on their maturity, hydrocarbon potential and organic matter type, as well as the timing of generation and migration, are still poorly understood.…”

Section: Introductionmentioning

confidence: 99%

“…Previous studies of the Nile Delta petroleum system (e.g. Halim et al, 1996;Kamel et al, 1998;Younes, 2001;Sharaf et al, 2003;Shaaban et al, 2006;Vandre et al, 2007;Kora et al, 2011;El-Diasty and Moldowan, 2013) have identifi ed various different source rocks. The Egyptian General Petroleum Corporation (EGPC, 1994) and Abd El- Halim (2001) proposed that prolifi c source rocks in the northern delta occur mainly in the Oligo-Miocene succession.…”

Section: Introductionmentioning

confidence: 99%

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Organic Geochemistry of Oil and Natural Gas in the West Dikirnis and El‐tamad Fields, Onshore Nile Delta, Egypt: Interpretation of Potential Source Rocks

Leila

Moscariello

2016

Journal of Petroleum Geology

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Crude oil in the West Dikirnis field in the northern onshore Nile Delta, Egypt, occurs in the poorly‐sorted Miocene sandstones of the Qawasim Formation. The geochemical composition and source of this oil is investigated in this paper. The reservoir sandstones are overlain by mudstones in the upper part of the Qawasim Formation and in the overlying Pliocene Kafr El‐Sheikh Formation. However TOC and Rock‐Eval analyses of these mudstones indicate that they have little potential to generate hydrocarbons, and mudstone extracts show little similarity in terms of biomarker compositions to the reservoired oils. The oils at West Dikirnis are interpreted to have been derived from an Upper Cretaceous – Lower Tertiary terrigenous, clay‐rich source rock, and to have migrated up along steeply‐dipping faults to the Qawasim sandstones reservoir. This interpretation is supported by the high C29/C27 sterane, diasterane/sterane, hopane/sterane and oleanane/C30 hopane ratios in the oils. Biomarker‐based maturity indicators (Ts/Tm, moretanes/hopanes and C32 homohopanes S/S+R) suggest that oil expulsion occurred before the source rock reached peak maturity. Previous studies have shown that the Upper Cretaceous – Lower Tertiary source rock is widely distributed throughout the on‐ and offshore Nile Delta. A wet gas sample from the Messinian sandstones at El‐Tamad field, located near to West Dikirnis, was analysed to determine its molecular and isotopic composition. The presence of isotopically heavy δ13 methane, ethane and propane indicates a thermogenic origin for the gas which was cracked directly from a humic kerogen. A preliminary burial and thermal history model suggests that wet gas window maturities in the study area occur within the Jurassic succession, and the gas at El‐Tamad may therefore be derived from a source rock of Jurassic age.

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Section: Source Rock Lithology and Depositional Environment Relevant supporting

confidence: 66%

Section: Age-relevant Biomarkersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Organic Geochemistry of Oil and Natural Gas in the West Dikirnis and El‐tamad Fields, Onshore Nile Delta, Egypt: Interpretation of Potential Source Rocks

Leila

Moscariello

2016

Journal of Petroleum Geology

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“…There is a long list of works that concludes Tertiary age of the source rock using high Oleanane index in the oil [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. However, till date, it has not been confirmed that oleanane in oil is migrated from the source rock.…”

Section: Introductionmentioning

confidence: 99%

Presence of Oleanane in Oil also as Evidence of Contamination

2015

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Presence of oleanane in crude oil is now considered as the age indicator of source deposition assuming the biomarker has been migrated with oil from the source rock. Possibility of contamination of the same biomarker in reservoir has so far been ignored. In this work, attempt has been made to see the possibility of reservoir contamination of 18α(H)-Oleanane in crude oil. A mixture of standard oleanane with saline water is first used to saturate a core, and then gasoline (free of oleanane) is used to displace the water in the core. Extracted gasoline from the core is then analyzed to check the presence of oleanane. Results show appreciable concentration in the extracted gasoline suggesting gasoline can be contaminated with oleanane if reservoir is deposited in oleanane-rich water.

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