Cheremshanskoye Oil Field
Cheremshanskaya No. 3
The Cheremshanskaya No. 3 (C-3) well drilled by PetroNeft in 2011 discovered four separate hydrocarbon intervals and established the Cheremshanskoye oil field. These intervals were the J13, J14, the J1-3 and the J1-1 + Bazhenov. The area of the field is very large encompassing almost 40 square kilometres. Further delineation and pilot testing will be required to assess the true size of the field and ultimate development plan. There are large producing fields nearby with similar characteristics and the strong indications are that Cheremshanskoye will prove to be a substantial discovery upon further delineation.
Testing of the Lower Jurassic J14 interval which contains 8.6 metres of net pay was completed in December 2011. The well flowed naturally to the surface at a rate of 6 m3/d (38 bfpd), consisting of a light, high quality, low viscosity oil with an API gravity of 50 degrees, gas and water. This is understood to be the first natural flow ever achieved from this Lower Jurassic interval in the Tomsk Oblast. Sustained production has been achieved from this interval in other fields in this region only following fracture stimulation.
Testing of the primary Upper Jurassic J1-3 interval was successfully completed in February 2012. The J1-3 interval which was initially interpreted to be water bearing, proved to be oil bearing. Based on the cased hole testing the interval is interpreted to contain 6.5 m of net pay (4.7 m of oil saturation and 1.8 m of oil+water saturation). Average inflow was about 44 bfpd consisting of 20.3% oil and 79.7 % formation water. The oil is good quality with a 34 degrees API.
The J1-3 interval was then isolated with a cement packer and the J1-1 + Bazhenov interval was tested. This interval consisted of 1.2 m of net pay in the J1-1 plus 3 m of fractured shale at the base of the Bazhenov Formation. Average oil inflow from the J1-1 + Bazhenov was about 12.6 bopd of high quality oil with a 40 degrees API.
3D Seismic
In 2014, modern 3D seismic (95.16 sq. km.) was acquired over the Cheremshanskoye oil field in follow-up to the successful C-3 well. Interpretation of the 3D data indicates that there is a large area of the field structurally higher than existing wells that have tested oil.
Cheremshanskaya No. 4
The Cheremshanskaya No. 4 (C-4) delineation well will be drilled on the Cheremshanskoye oil field in 2018. The C-4 well is designed to further delineate and de-risk the Cheremshanskoye field in advance of field development. Three prior wells have been drilled on the field and oil has been identified and tested in 4 different intervals in the field: the Lower Jurassic J-14 and J-13 intervals and the Upper Jurassic J1-1 and J1-3 intervals. These initial wells were drilled without the benefit of modern 3D seismic data which was acquired in 2014. The C-4 well is designed to test a large portion of the field which is structurally higher than the previous wells based on this recently acquired 3D seismic data.
The primary reservoir target is the J1-3 interval which is approximately 10 m in thickness throughout the region and is the primary reservoir at the adjacent producing Lomovoye field operated by TomskNeft. The J1-3 interval tested 240 bopd of light oil (40°API) on natural flow in the adjacent Lomovoye No. 208 well.
The secondary reservoir target is the J14 interval which had a natural flow of 33 bopd of light oil (49°API) from 6.5 m of net pay in the 2011 Cheremshanskoye No. 3 well. The current Russian State (GKZ) registered reserves for this interval are about 16 million bbls gross recoverable C1+C2 reserves.
Tomsk Geophysical Company estimates the Russian C3 gross recoverable reserves for all 4 intervals at about 75 million bbls recoverable for the field, based on the 3D seismic and log evaluation of the existing wells.
Following a successful re entry of the well in 2020, the well was brought into production during Q1 2021 at a stabilised rate of approximately 300bopd.
