Trillion Energy has discovered light oil at the Çetinkaya-1 (C-1) well in south-east Türkiye, signalling a shift towards significant oil exploration efforts.
The discovery at the C-1 well, located in Block M47C3,C4 in Şırnak Province, confirmed the presence of 32.4° American Petroleum Institute (API) light oil in the Cretaceous Beloka and Mardin Group carbonates.
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Block M47C3,C4 is situated approximately 11km south-east of Türkiye’s largest onshore oil discovery, the Şehit Aybüke Yalçın field, which also draws oil from the Beloka and Mardin Group carbonate reservoirs.
According to Trillion Energy, the reservoir traits observed at C-1, such as oil gravity, porosity and fracture-induced flow, closely resemble those of nearby producing fields.
The company conducted a wireline logging programme involving gamma ray, dual laterolog resistivity and compensated density tools.
Analysis was carried out using Archie’s equation, tailored to the specific conditions of the C-1 formation.
The C-1 well, positioned on the eastern side of the North Lead structure close to the spill point, likely encountered only a small part of the hydrocarbon column.
A proposed sidetrack well, C-1ST, aims to reach the structural crest around 75–100m higher, where a larger oil column is anticipated.
Technical results revealed a fractured dolomitic reservoir with a gross interval of 76.6m and a net oil pay of 38m.
Fracture-adjusted measurements showed a gross pay of roughly 40.6m and a net pay between 36m and 38.5m.
The reservoir’s average effective porosity is reported at 5.5%, with potential permeability ranging from 5–50 millidarcies. Water saturation averages at 25%.
One highlighted reservoir interval of 7m demonstrated porosity up to 8.1% and water saturation as low as 8%, implying more than 90% oil saturation.
The reservoir mainly consists of dolomitic carbonate, aligning with regional productive analogues.
A hydrochloric acid stimulation confirmed fracture permeability, producing 32.4 API light oil with a final oil cut of 36%.
The well, however, intersected only a fraction of the intended 250–350m reservoir section due to a halt in drilling at 2,455m because of loss of circulation.
An additional reservoir of more than 160m remains unexplored.
Observations from the zone data indicate that Zone A, offering 13m of net pay, is yet to be tested, while the Near TD zone showed improved reservoir characteristics at depth. A planned sidetrack aims to explore these deeper sections further.
Several stacked pay zones across the Beloka and Derdere Formations highlight a multi-zone oil system.
In December 2024, Trillion Energy announced the recompletion of wells on the Akcakoca Platform in the SASB gas field in Türkiye.
