Cheremshanskoye Oil Field

Cheremshanskoye New Field Discovery
Cheremshanskaya Correlation J14
Cheremshanskaya Correlation J1

In summary, the Cheremshanskaya No. 3 well discovered three separate oil pools and established the Cheremshanskoye oil field. These intervals were the J14, the J1-3 and the J1-1 + Bazhenov. The area of the field is very large encompassing almost 40 square kilometres and 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. The likely next step here is to acquire 3D seismic data over the field.

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 following fracture stimulation.

The next phase of testing focused on the primary Upper Jurassic J1-3 interval. The initial log interpretation indicated this interval to be water bearing, however, additional log and core interpretation indicated that it may contain up to 7.0 metres of net oil pay. The testing plan was to isolate the interval from the rest of the Upper Jurassic interval (J1-1 and J1-2) which were also interpreted to be oil bearing, and to get an independent test of the true saturation of this J1-3 interval.

Testing of the primary Upper Jurassic J1-3 interval was successfully completed in February 2011. 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.