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Applications of Palynology for Hydrocarbon Exploration: Case Studies from Egypt, Eastern Tennessee (Usa) and the Gulf of Mexico

Zobaa, Mohamed K.1; Oboh-Ikuenobe, Francisca E.1; Zavada, Michael S.2
1 Department of Geological Sciences and Engineering, Missouri University of Science and Technology, Rolla, MO.
2 Department of Biological Sciences, East Tennessee State University, Johnson City, TN.

This study demonstrates the importance of palynological applications in the oil industry using case studies from Egypt, Eastern Tennessee, and the Gulf of Mexico. One hundred and ten rock samples, ranging in age from Jurassic to Miocene, were investigated. Samples were processed using the standard maceration techniques for palynological analyses. Spore/pollen coloration was used to interpret the degree of thermal maturity and thus, theoretically estimate other organic geochemical parameters such as Ro% and TOC. Some samples were analyzed for TOC and Rock-Eval Pyrolysis to confirm the palynofacies analysis and also to examine its degree of reliability.

The studied interval of the Sharib-1X well, north Western Desert, Egypt was classified into three palynofacies zones. From top to bottom: Palynofacies 1 (gas prone material), Palynofacies 2 (oil prone material), and Palynofacies 3 (inert material). Spore coloration showed increased color intensity with depth from immature through mature to overmature. Two palynological biozones ranging in age from Middle Jurassic to early Cenomanian were proposed. Paleoenvironmental reconstruction indicated deltaic to shallow marine conditions.

Kerogen type III to IV (gas prone material) was proposed for the GFS-1 core section, Eastern Tennessee. Pollen coloration indicated that these sediments are thermally immature and are not suitable for natural gas generation. TOC and Rock-Eval Pyrolysis subsequently confirmed conclusions drawn from kerogen composition. The proposed age for this section is Paleocene to Eocene.

Two distinctive palynofacies were recognized within the Middle Eocene to Early Miocene sequence of DSDP site 94, Gulf of Mexico. Palynofacies A (oil prone material) occurred in the upper part of the section, while Palynofacies B (gas prone material) occupied its lower part. Pollen coloration reflected fair to good thermal maturity indicating that each palynofacies is suitable for hydrocarbon generation.

In summary, palynology has facilitated the recognition of potential hydrocarbon source rock zones in the studied sequences. It also allowed the determination of the hydrocarbon type and degree of thermal maturity. Moreover, it showed an excellent degree of accuracy in predicting the possible results of some organic geochemical analyses. Palynology has also demonstrated its usefulness in constraining and interpreting the age, and paleoenvironmental and paleoclimatic conditions of the studied sections.


AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009