Naslov
The Hydrocarbon Occurrences of the Mrah Area in the Hayan Block-Syria

Autori
Stanković, Irenka ; Rumenjak, Ljubica ; Španić, Darko ; Troskot-Čorbić, Tamara ; Maričić, Marija ; Čuljak Veronika

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
ORGANIC GEOCHEMISTRY:CHALLENGES FOR THE 21st CENTURY VOL. 1 Book of Abstracts of the Communications presented to the 22nd nternational Meeting on Organic Geochemistry Seville – Spain / González-Vila, Francisco J. ; González-Pérez, Jose Antinio ; Almendros ; Gonzalo - Sevilla, 2005, 441-442

ISBN
84-689-3661-8

Skup
22nd International Meeting on Organic Geochemistry

Mjesto i datum
Sevilla, Španjolska, 12.09.2005. - 16.09.2005

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Hayan Block, Mrah area, Kurrachine Dolomite Formation

Sažetak
The Hayan concession block in central Syria belongs to the Palmyride region. Exploration activities of INA Naftaplin were focused on many prospects in the Hayan block. The aim of our interest is the Mrah area situated on the northern „Jihar“flank. Very little data are available on the presence of source rocks and hydrocarbons from this area. The main targets of exploration were the Kurrachine Dolomite Formation sediments, the prominent reservoir rocks in the area. In the studied area Mrah-1 and Mrah-2 exploration wells were drilled to total depths of 2490 m and 3043m respectively, terminating in the Kurrachine Dolomite Formation, which dates from the Middle Triassic period. Geochemical investigations of cuttings and cores have shown only limited quantities of organic matter. The average TOC ranges from 0.24 to 0.46%. The increased values of total organic carbon (TOC>0.3 %) are linked to claystone/shale layers within the sediments of the Middle Triassic age. In spite of this, the Rock Eval pyrolyses data (S2<2mgHC/g rock) show low petroleum generating capability along the whole well profile. The low hydrocarbon generation potential of the Middle Triassic sediments is the result of oxic to suboxic depositional conditions, which altered hydrogen rich organic matter into unfavourable organic facieses. The microscopic examination of kerogen has demonstrated the predominance of amorphous, unstructured organic matter with only sporadic traces of fusinite, liptodetrinite, vitrinite and reworked vitrinite. Considering all optical examinations and maturity parameters, organic matter has reached the high maturity stage of catagenesis (1.2 to 1.3 %Ro) (TAI from 3⎯to 4⎯) ([1], [3]). Low gas content was registered in shallower sediments but gas concentration increased with depth, especially within the Kurrachine Dolomite Formation. The gases are wet with significant content of high homologues, which indicates their thermal maturity and secondary, migrated origin ([3]). The presence of bitumen in the form of lamination and impregnation was also registered in both Mrah wells. The bitumen yields are rather high and varied from 368 to 1884 ppm. High EOM/TOC ratios (average 241mg HC/g TOC), and high content of the n-alkanes (77.7-91.9%) point to their secondary, migrated origin ([2], [3]). Fingerprint of bitumens shows differences in their molecular parameters and highlights the differences of organic matter type and their precursors, as well as environmental conditions and thermal maturity level. Dissimilar bitumen characteristics could be explained as the result of hydrocarbon migration processes, which took place during different geological periods. We hope that additional exploration activities will confirm economical hydrocarbon reserves in this area.

Izvorni jezik
Engleski

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