Oymantepe (East Sadak)

East Sadak lease covers an area of 7,652 hectares near the city of Siirt. It is on the same structural trend of the most productive oil fields in the SE Anatolian Basin.

There two surface anticlines within the lease area. The one to the West (Oymantepe) drilled in 2014, and the lightest ever found in the country was discovered in East Sadak-1 well. Since then, the Oymantepe field has been developed with drilling 14 (of which 6 were sidetracked and one well was sidetracked twice) from 14 well pads. The other surface anticline to the SE corner has remained as undrilled structure which shares the same structural and stratigraphic features with the Oymantepe field.

The main reservoir units are Upper Cretaceous Beloka formation and Mardin Group carbonates, and Jurassic Cudi Group carbonates which is a deeper target and none of the East Sadak wells penetrated this reservoir yet. On the other hand, a new deep amplitude play concept has been developed to test Cudi Group reservoirs with drilling a well of 3,800m TD.

Beloka Formation is composed of fractured limestones, and dolomites; its low matrix porosity (4-6%) is enhanced by leaching and fracturing. Mardin Group carbonates has higher matrix porosity up to 15%. Starting with East Sadak-6 (2018), open-hole design has been used to complete both reservoirs to prevent formation damage.

Even though Garzan Formation is one of the main producing reservoirs in the region, it has not been a producing interval in the field. On the other hand, its behind-pipe potential has been studied to add it to the oil production pool.

During drilling the carbonate interval of the Paleocene age Upper Sinan formation, significant oil shows observed even though heavier drilling mud is used during drilling this upper section. AME has been also studying to test the HC potential of this reservoir with a shallow well design as a part of its field development plans.

In year 2022, ES9/ES9R and ES-15/15S wells were drilled. ES-15S (TD: 1,973m) could not cross a fault due to sloughing shales to enter the oil pool and therefore had to be abandoned. ES-9R (TD: 2,890m) tested oil, was put online with a pump but the pump failed before the well stabilized. Currently, it is waiting for a new pump installation.