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A PRELIMINARY EVALUATION OF JURASSIC SOURCE ROCK POTENTIAL IN KUWAIT
Author(s) -
Abdullah F. H. A.
Publication year - 2001
Publication title -
journal of petroleum geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 42
eISSN - 1747-5457
pISSN - 0141-6421
DOI - 10.1111/j.1747-5457.2001.tb00679.x
Subject(s) - kerogen , geology , maturity (psychological) , source rock , oil shale , petrography , sedimentary rock , cretaceous , carbonate , organic matter , evaporite , geochemistry , paleontology , mineralogy , sterane , hopanoids , structural basin , psychology , developmental psychology , chemistry , materials science , organic chemistry , metallurgy
Jurassic sedimentary rocks in Kuwait are generally assigned to the Marrat, Dhruma, Sargelu and Najmah Formations (mainly limestones and calcareous shales) and the overlying Hith and Gotnia Formations which are composed of anhydrites and evaporites. This paper reports the results of organic‐geochemical analyses of Jurassic carbonate and shale samples recovered from ten wells in Kuwait. Analytical techniques included TOC analysis, elemental analyses of kerogen, density separation and petrographic analyses. The thermal history of Kuwait was modelled and calibrated with maturity indicators from the studied wells. The analytical results point to the presence of marine kerogen between Types II and III. Generally, the formations show amorphous rich sapropelic organic matter with high H/C ratios and low densities. Biodegradation of some samples resulted in elevated O/C ratios. The results of maturity studies indicate that most of the Jurassic Succession is mature, maturity differences being due to depth variations. Oil generation began in Late Cretaceous to Eocene time when structural traps had already been formed. Jurassic source rocks may therefore have supplied reservoir units in Kuwait. In particular, the Najmah Formation includes well‐preserved amorphous marine algal type organic matter. The high TOC values and thermal maturity of this formation make it one of the most important potential sources of oil in Kuwait.