Vertical and lateral fluid flow related to a large growth fault, South Eugene Island Block 330 field, offshore Louisiana
- Cornell Univ., Ithaca, NY (United States). Dept. of Geological Sciences
- Woods Hole Oceanographic Institution, MA (United States). Dept. of Marine Chemistry and Geochemistry
- Chevron Overseas Petroleum, Inc., San Ramon, CA (United States)
- Michigan Technological Univ., Houghton, MI (United States)
Data from sediments in and near a large growth fault adjacent to the giant South Eugene Island Block 330 field, offshore Louisiana, indicate that the fault has acted as a conduit for fluids whose flux has varied in space and time. Core and cuttings samples from two wells that penetrated the same fault about 300 m apart show markedly different thermal histories and evidence for mass flux. Sediments within and adjacent to the fault zone in the US Department of Energy-Pennzoil Pathfinder well at about 2200 m SSTVD (subsea true vertical depth) showed little paleothermal or geochemical evidence for through-going fluid flow. The sediments were characterized by low vitrinite reflectances (R{sub {omicron}}), averaging 0.3% R{sub {omicron}}, moderate to high {delta}{sup 18}O and {delta}{sup 13}C values, and little difference in major or trace element composition between deformed and undeformed sediments. In contrast, faulted sediments from the A6ST well, which intersects the A fault at 1993 m SSTVD, show evidence for a paleothermal anomaly (0.55% R{sub {omicron}}) and depleted {delta}{sup 18}O and {delta}{sup 13}C values. Overall, indicators of mass and heat flux indicate the main growth fault zone in South Eugene Island Block 330 has acted as a conduit for ascending fluids, although the cumulative fluxes vary along strike. This conclusion is corroborated by oil and gas distribution in downthrown sands in Blocks 330 and 331, which identify the fault system in northwestern Block 330 as a major feeder.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FC22-93BC14961
- OSTI ID:
- 343770
- Journal Information:
- AAPG Bulletin, Vol. 83, Issue 2; Other Information: PBD: Feb 1999
- Country of Publication:
- United States
- Language:
- English
Similar Records
Oil migration in a major growth fault: Structural analysis of the Pathfinder core, South Eugene Island Block 330, offshore Louisiana
Eugene Island Block 330 field-development and production history