Upper Cretaceous and Paleocene Shallow Water Carbonates along the Pontide Belt

Shallow water carbonates form a most important type of hydrocarbon reservoirs. In most hydrocarbon provinces of the world, as is the case in Turkey, shallow water carbonates trap much of oil and gas. Since the early days of onshore Pontide exploration in Turkey, Devonian and Jurassic aged carbonates were studied and targeted in some wildcat wells. The Upper Cretaceous-Paleocene aged Akveren Formation, although commonly present along the Pontide belt, was almost never considered as a viable exploration target because common outcrop facies is a series of marls, clayey limestones and thinly bedded calciturbiditic limestones. It also is at or near surface in most of the instances, causing maturation, migration, and seal concerns. During the onset of intensive exploration efforts in the Black Sea in 2003, all possible reservoir concepts were under scrutiny and the chance of any extension of rudist colonies encountered in Kefken area into offshore areas was seriously considered by TPAO Management and Earth Scientists. A sustained geological and geophysical data collection and interpretation study was undertaken by TPAO from 2004 onwards. These studies were partially complimented at certain brief intervals by the joint work of TPAO Partners Petrobras, ExxonMobil and Chevron. Within the scope of this work, many facies were defined, sections were measured, and maps and conceptual models were produced. Nearly 20000 km of 2D seismic and 5000 square kilometers of 3D seismic data collected to search for analogue reservoirs in buried underneath the deep waters of the Black Sea. Using the created models and trends, Ağva-1 (Water Depth: 86 m-2007), Sinop-1 (Water Depth: 2182 m-2010) and Yassıhöyük-1 (Water Depth: 2018 m-2010) offshore wells were drilled.