Pliocene Source Rocks, Miocene Reservoir Rocks and Origin of the Gas Accumulation of the Irma Field (Northern Adriatic, Croatia) Based on Wireline-Logging
| Autor: | Ivica Vulama |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Geologia Croatica Volume 50 Issue 1 Geologia Croatica, Vol 50, Iss 1, Pp 89-103 (2010) |
| ISSN: | 1333-4875 1330-030X |
| Popis: | The Pliocene source rocks of the Middle Adriatic ridge appearedto be thermally immature, according to the geophysical and the geochemicalanalyses, but they may have produced biogene gas. Wirelinelogging confirmed their broad extent. Correlation between geophysical and geochemical data indicated their distinguishing parameters:GR = 55 - 125 API, U238= 5 - 25 ppm, Rt = 1.5 - 4 Ohmm, ?? = 75-170 us/ft (x 0.306 us/m), Po = 1.6 - 1.9 g/cm3, ¢N = 33 - 39%, SP =-44(-) -56 mV, Corg. = 0.43 - 3.23%, V(%) = 0.47·0.66, K/Th = Illite.These organic matter have been classified as a kerogene type III-II.Characteristic geophysical parameters of the Miocene reservoir rocksare =$ = 22%, R = 0.18m = 1.8 Fr = 15.3, Ro = 2.75 Ohmm, K avg.= 2 1.4 x 10 3 um2. Favorable lithologic- tectonic conditions (overpressurezones, normal faulting) led to gas accumulation in Miocene calcarenites and sandstones. The Pliocene source rocks discordantlyoverlie Miocene reservoir rocks, separated by the Messinian unconformity. Statistical analyses show that, although the Pliocene shalesare thermally immature, they fit into the model of source rock recognition. |
| Databáze: | OpenAIRE |
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