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Title: Hydrogeological controls and indicators for oil deposits in rift grabens - An example from the Upper Rhine graben, France

Hydrogeological controls and indicators for oil deposits in rift grabens - An example from the Upper Rhine graben, France The Pechelbronn petroliferous region of northeast France is located on the west side of the Upper Rhine graben between the Vosges and Black Forest Mountains. Commercial oil occurs in Mesozoic and often Tertiary lenticular, faulted formations at various depths. In areas of oil fields and along fault zones, positive temperature anomalies at shallow and great depths (geothermal gradient: 10{degree}C/100 m), high salinities (TDS > 50,000 mg/L), and anomalously high Sr{sup {minus}}, Br{sup {minus}}, and I{sup {minus}} concentrations in shallow ground waters, flowing wells, and oil/gas seeps have been observed. These phenomena may be explained by topography-induced regionally ascending cross-formational groundwater flow. This interpretation is supported by the isotopic composition of the formation waters, suggesting a meteoric origin, relatively young {sup 14}c ages ({approx} 30,000 years), and calculated flow velocities of 0.30 m/year as well as numerical modeling. Ground-water recharges in the topographic highs, converges toward the Graben basin, and discharges under artesian conditions by vertically ascending flow, preferentially along conductive faults. Vertical migration of hydrocarons is also suggested by high methane concentrations in soils observed across faults with isotope ratios indicative of thermally mature hydrocarbon gases originating at depth. Consequently, a dynamic-genetic relationship appears to exist between basinal ground-water flow, more » hydrocarbon accumulations, and observed natural phenomena. This relationship may be used for hydrogeological-based exploration for hydrocarbons, complementing conventional methods. « less
Authors: ;
Publication Date:
OSTI Identifier:OSTI ID: 5627813
Report Number(s):CONF-8809346--
Journal ID: ISSN 0149-1423; CODEN: AABUD
Resource Type:Conference
Resource Relation:Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA); Journal Volume: 72:8; Conference: Mediterranean Basins conference and exhibition, Nice (France), 25-28 Sep 1988
Country of Publication:United States
Language:English
Subject: 02 PETROLEUM; 03 NATURAL GAS; FRANCE; NATURAL GAS DEPOSITS; PETROLEUM DEPOSITS; EXPLORATION; GEOLOGIC TRAPS; GROUND WATER; HYDROLOGY; MATHEMATICAL MODELS; ORIGIN; SEDIMENTARY BASINS; TERTIARY PERIOD; CENOZOIC ERA; EUROPE; GEOLOGIC AGES; GEOLOGIC DEPOSITS; GEOLOGIC STRUCTURES; HYDROGEN COMPOUNDS; MINERAL RESOURCES; OXYGEN COMPOUNDS; RESOURCES; WATER; WESTERN EUROPE 020200* -- Petroleum-- Reserves, Geology, & Exploration; 030200 -- Natural Gas-- Reserves, Geology, & Exploration