ÇAĞRILI KONUŞMALAR / KEYNOTES Invited Speeches ... - TPJD

Stratigraphy, Sedimentology and Geochemistry of Dadaş Formation as an
“Unconventional Reservoir”
Ayşe Güzel 1 , Hüsnü Çorbacıoğlu 1 , Nihat Bozdoğan 1 , Y. Haluk İztan 1 , Attila Aydemir 2 , Pelin Beşer 2
1 Turkish Petroleum Corporation,Research Center, Ankara
2 Turkish Petroleum Corporation, Exploration Department, Ankara
Shales bearing abundant amount of organic materials can generate oil and gas by the thermogenic
variations of the contained kerogen under the conditions of increasing burial pressure and heat.
Some of the generated fossil fuels are expelled from these source rocks but majority of them
are still confined. Those unexpelled hydrocarbons are considered as a new energy source and
being produced by the application of unconventional techniques recently developed in North
America. The shales being source rock may be a new energy resource for natural gas if overheated
(Ro>1.2) or for oil in existence of under-normal heat influence (Ro=1.2). Shales have
been considered as seal or source rocks up to date. However, they recently need to be analysed
and investigated with different techniques and new point of view, because they are accepted
another type of reservoirs as well, and they need to be studied for lithology, faciess distribution,
petrographic, minerological and geochemical composition, porosity & permeability parameters,
clay silica and carbonate contens and compositions and fraccability of them. In addition, new
rock mechanics analyses and extra lab-works are also demanded because plastic, elastic and
fraccability characteristics of shales directly involve to the operational success. Moreover,
distinguishing organic and litho-faciesses of the production intervals are also crucial for the
unconventional operations and horizontal drilling that becomes a standart for the unconventional
industry. Silurian Dadas Formation which has very vast extension (12.000 km2) in the SE Anatolia,
has been accepted as the main source rock for the “palaeozoic oil system” and the oil fields
around Diyarbakir, similar to the Middle East and North Africa. This study aims to investigate
the convenience for being an unconventional resource and evaluation of the Silurian deposits
(Dadas Formation) having thicknesses up to 400 m in the SE Anatolia. While investigating whole
Dadas section, potential intervals and their characteristics, their extension and propagation with
potential faciesses, palaeogeographic properties in the study area have also been described by
the help of lab results. In addition, prospective zones for shale gas and shale oil are aimed to
determine together with the descriptions given above.
Keywords : Unconventional, reservoirs, dadas, stratigraphy, geochemistry, sedimantology
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