Fordoche oil field: formation waters and oils
South-central Louisiana, Pointe Coupee Parish, United States
Groundwater
- Type
- Groundwater
Oil and gas field in sandstones of the Wilcox Formation (Eocene), stacked reservoirs W-12, W-8 and Sparta B between 3500 and 4350 m, fed through a regional fault; source rock below the reservoirs (mudstone at 4334 m). Approximate coordinates of the village of Fordoche. Waters at 8 to 85 ppm B, +28 to +37 ‰, about 10 ‰ lighter in the deepest reservoir (W-12) excluding the gas well; oils at a few hundred ppb B.
δ11B in ‰ (per mil) Values of the same system
Standard : NIST SRM 951
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 36 ‰ | 36 / 36 ‰ | 2 | Sparta B reservoir formation water Mean and standard deviation recalculated from 2 analyses, +36 to +36 (John Green 1 +36; Andrews 2 +36). B: John Green 1 85.1 ppm; Andrews 2 29.3 ppm. Shallowest reservoir; John Green 1 closest to the fault (85.1 ppm B). | Williams et al. (2001), The influence of organic matter on the boron isotope geochemistry… |
| 35 ± 3 ‰ | 33 / 37 ‰ | 2 | W-8 reservoir formation water Mean and standard deviation recalculated from 2 analyses, +33 to +37 (Kent 1 +37; Smith 2 +33). B: Kent 1 14.6 ppm; Smith 2 15.6 ppm. Intermediate reservoir. For Smith 2 the published ratio (4.1514) gives +29 ‰ with the measured standard, and that of Smith 2D (4.1688) +33 ‰: the reverse of the printed δ11B (+33 and +29 ‰), kept here. | Williams et al. (2001), The influence of organic matter on the boron isotope geochemistry… |
| 28 ± 1 ‰ | 28 / 29 ‰ | 3 | W-12 reservoir formation water Mean and standard deviation recalculated from 3 analyses, +28 to +29 (Kent 1D +28; Smith 2D +29; Bomer 3 +28). B: Kent 1D 13.1 ppm; Smith 2D 8.3 ppm; Bomer 3 18.6 ppm. Deepest reservoir. See the remark on Smith 2 and Smith 2D in the W-8 reservoir row. | Williams et al. (2001), The influence of organic matter on the boron isotope geochemistry… |
| 37 ‰ | 1 | formation water from a gas well at the field edge (W-12 reservoir) Single analysis (El Plant 5). B 30.2 ppm. Value close to the upper reservoirs; preferential partitioning of 11B into the gas phase is discussed by the authors. | Williams et al. (2001), The influence of organic matter on the boron isotope geochemistry… | |
| 10 ± 6 ‰ | 5 / 17 ‰ | 3 | crude oil Mean and standard deviation recalculated from 3 analyses, +5 to +17 (Andrews 2 +17; Smith 2 +9; Smith 2D +5). Boron extracted by Parr bomb combustion with mannitol trapping; oils at 228 to 1527 ppb B. Oil-water difference in the same well of -19 to -24 ‰ (Andrews 2: +17 and +36; Smith 2: +9 and +33; Smith 2D: +5 and +29); the authors see it as incorporation of aqueous boron rather than equilibrium fractionation. | Williams et al. (2001), The influence of organic matter on the boron isotope geochemistry… |
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- Tungsten Queen mine waters United States
- Navajo Sandstone aquifer, Peabody (wells NAV9 and NAV6) United States
- Navajo Sandstone aquifer, Rocky Ridge (well PM2) United States
- Navajo Sandstone aquifer, Hotevilla (well SCH2) United States
- Navajo Sandstone aquifer, Shonto (wells PM4 and PM2) United States
- Vinto drinking water (DW1 to DW3) Bolivia
- Rosario River fan hot springs Argentina
Cite this page
IsoFind Atlas (2026). Fordoche oil field: formation waters and oils, isotope signatures. https://www.isofind.tech/isotopes/en/sites/champ-petrolier-de-fordoche-eaux-de-formation-et-huiles/ (accessed 2026-10-20).
@misc{isofind2026fordocheoilfieldformationwate,
title = {Fordoche oil field: formation waters and oils, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/sites/champ-petrolier-de-fordoche-eaux-de-formation-et-huiles/},
note = {Accessed 2026-10-20}
}Updated : 2026-10-20