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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 66 (1982)

Issue: 5. (May)

First Page: 646

Last Page: 646

Title: Shallow Thermal Anomaly Over San Sebastian Oil and Gas Field, Eastern Tierra del Fuego: ABSTRACT

Author(s): Gary W. Zielinski, Peter M. Bruchhausen

Article Type: Meeting abstract

Abstract:

Low thermal diffusivity of peat and soils overlying parts of the oil and gas province of the eastern Magellan basin has resulted in a small number of unusually shallow (< 2 m) relative heat-flow determinations. The values are in agreement with the single published heat-flow value for Tierra del Fuego of 2.3 HFU and with deep bottom-hole temperature measurements located in coincidence with the shallow determinations. They are furthermore consistent with local surface air-temperature measurements obtained for a period of 1 year prior to the field work. Compared with that for similar tectonic provinces (post-Precambrian, nonorogenic), the heat flow in eastern Tierra del Fuego appears to be about 0.5 HFU greater than might be expected. Maturation level estimates based on b rial history of sediments in the area suggest considerable lateral migration (> 100 km) of hydrocarbons from deeper in the Magellan basin. A model is explored whereby the same mechanism for transport of the hydrocarbons, namely, deep ground-water movement can also explain the heat-flow results. The dramatic 10-HFU decrease in relative surface heat flow observed across the southwestern edge of the San Sebastian oil and gas field is of similar magnitude as other thermal anomalies reported to be in close association with hydrocarbon accumulations.

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Copyright 1997 American Association of Petroleum Geologists