Geology topics

Jerry L. Clayton

Publications and source records attributed to Jerry L. Clayton.

3 recordsLinked to original sources

USGS1994

Petroleum geochemistry of the Zala basin, Hungary

The Zala basin is a subbasin within the Pannonian basin of Hungary. Oil and smaller amounts of gas are produced from Upper Triassic through Miocene reservoirs. Our geochemical study of oils and rocks in the basin indicate that two, and possibly three, genetic oil types are present in the basin. Miocene source rocks, previously believed by explorationists to be the predominant source rock, have expelled minor amounts of hydrocarbons. The main source rock is the Upper Triassic (Rhaetian) Kossen Marl Formation or its stratigraphic equivalent. Oils derived from the Triassic source rock are recognizable by their isotopic and biological marker composition, and high content of metals. In other areas of Europe, Upper Triassic source rocks have been correlated with large oil accum lations (e.g., Molassa and Villafortuna fields, Po basin, and other fields in Italy) or are postulated to be good potential source rocks (e.g., Bristol Channel Trough). Knowledge of the geochemical characteristics of oils derived from these Upper Triassic source rocks and understanding of the source rock distribution and maturation history are important for recognizing Triassic oil-source bed relationships and for further exploration in other basins in Hungary and other parts of Europe where Triassic source rocks are present.

Zala basin↗

USGS1981

Organic geochemistry of the 9.6 km Bertha Rogers No. 1. well, Oklahoma

Organic geochemical analyses of fine-grained rocks from the 9.590 km Bertha Rogers No. 1 well have been carried out: total organic carbon, Soxhlet extraction and silica gel chromatography, C 15+ saturated and aromatic hydrocarbon gas chromatography and mass spectrometry, pyrolysis, kerogen analysis, X-ray diffraction and visual kerogen analysis. Rocks ranged in age from Permian to Ordovician; the well has an estimated bottom hole temperature of 225°C. Some data from this study are inconsistent with conventional theories concerning the generation and thermal destruction of hydrocarbons. For example, appreciable amounts of C 15+ gas-condensate-like hydrocarbons are present in very old rocks currently at temperatures where current theory predicts that only methane and graphite should remain. Also, substantial amounts of pyrolyzable C 15+ hydrocarbons remain on the kerogen in these deeply buried Paleozoic rocks. This suggests, at least in somes cases, that temperatures much higher than those predicted by current theory are required for generation and thermal destruction of hydrocarbons. The data from this well also suggest that original composition of organic matter and environment of deposition may have a much stronger influence on the organic geochemical characteristics of fine-grained sediments than has previously been ascribed to them. The results from this well, from other deep hot wells in which temperatures exceed 200°C, and from laboratory experiments, suggest that some of the basic concepts of the generation and maturation of petroleum hydrocarbons may be in error and perhaps should be reexamined.

Oklahoma↗

USGS1976

Source beds of petroleum in the Denver Basin

Crude oil and shale samples from the Denver basin of Colorado, Wyoming, and Nebraska were analyzed by organic geochemical techniques to determine the stratigraphic occurrence and regional distribution of petroleum source beds. The study demonstrates that the oils produced from Cretaceous Sussex, Shannon, ?D? and 'J' sandstone reservoirs are genetically related and have probably been derived from Cretaceous source beds in the Carlile, Greenhorn, Graneros, and Mowry interval. Oils produced from fractured Niobrara and Lower Pierre formations are geochemically dissimilar to other Cretaceous oils and may have been generated in place. The Permian Lyons oils distinctly different from all of the Cretaceous oils and its source has not been identified. Samples of the Cretaceous Carlile-Greenhorn-Graneros-Mowry interval that contain hydrocarbon distributions similar to the Cretaceous oils examined are restricted to the basin axis area between Denver and Fort Collins, Colo. This limited geographic distribution of effective source beds and the occurrence of petroleum in thermally immature areas of the basin suggest that extensive lateral migration has occurred. Organic geochemical studies can identify oil source-bed relationships and areas of favorable source-bed potential and can, therefore, provide valuable input to oil exploration decisions.

Open-File Report↗