PetroNeft Resources PLC, Dublin, says drilling has confirmed potential identified by 3D seismic data of the northern half of Cheremshanskoye oil field on License 67 in the Tomsk Oblast of West Siberia.
The Cheremshanskoye No. 4 (C-4) well tested a combined 399 b/d of fluids from two horizons in the Upper Jurassic Bazhenov formation, exceeding expectations.
In the tertiary-objective J1-1 sandstone, the well encountered 1.6 m of net oil pay. Cores recovered oil-saturated sandstone with very good visual reservoir properties.
During a short open-hole test, the J1-1 produced 228 b/d of fluid, 84% of which was 35° gravity oil and the rest mud and filtrate.
Logs indicated the primary J1-3 interval, which also was cored, had 8.8 m of net oil pay. On a short flow test, the interval yielded 171 b/d of fluid, 70% of which was 35° gravity oil, with flow limited by formation damage.
PetroNeft said drilling was to resume for the secondary C-4 target in Lower Jurassic strata.
It said results so far indicate Upper Jurassic horizons might hold proved and probable reserves of 40 million bbl of oil.
PetroNeft is operator of the license with a 50% interest. Arawak Energy Ltd., London, holds the other 50%.
