Licence 61 (Tungolsky)
PetroNeft Resources wholly owned subsidiary «LLC Stimul-T» won the State Auction for the Tungolsky Licence No. 61 in the Tomsk Region of Western Siberia and acquired the Block in May 2005.
Highlights
- Tungolsky Licence 61 is located on the east side of the Ob River in the least explored oil bearing region of the Tomsk Oblast.
- The large 4,991 km² Licence contains 5 oil fields and over 25 identified prospects and leads.
- PetroNeft has thus far acquire 1,055 line kms of seismic data and drilled 7 exploration/delineation wells which exceeds the Licence work programme requirement and was completed ahead of schedule.
- Ryder Scott currently estimates the 2P reserves at 83 million bbls which includes 13.2 million bbls for the recent oil discovery at Arbuzovskoye
- The 2010 development plan including the construction of 9 development wells, central processing facilities and export pipeline was executed on time and on budget.
- Production commenced on schedule in Q3 2010 and reached 2,750 bopd by end 2010. Target rate at the end of Q1 2012 is 4,000 to 5,000 bopd.
- 2011 work programme consists of expanding the central process facility to 14,800 bpd, construction of 2 new pads, drilling of up to 17 development wells and three exploration/delineation wells.
- In August 2011 a sixth field was discovered at Sibkraevskaya. It is the largest single discovery made by PetroNeft to date.
Location
Licence No. 61 (Tungolsky) is located in the northern end of the Tomsk Region in Alexandrov administrative district. The climate is strongly continental, characterised by long cold (as low as −50°C) winters and short warm summers. Blizzards and heavy snowfalls persist from October till April. The average soil freezing depth is 1.2 m. The maximum frost penetration depth in swamps is 0.5 m. The snow cover reaches 1.5 m. The heating season lasts from
Seismic acquisition activities take place in the winter months. Drilling activities can take place year round provided the rig, supplies and heavy equipment have been moved to site during the winter months.
Brief History
Exploration on the Tungolsky Licence began in the 1960s with the acquisition of single trace analogue reflection seismic data. Common Depth Point (CDP) seismic data was acquired for the first time beginning in 1974. A total of 2,054 km of CDP data was acquired in the licence from 1974 to 1990. A total of 14 wells were drilled on Licence 61 during the Soviet era between 1970 and 1989. Two of these wells led to the discovery of the Lineynoye and Tungolskoye oil fields.
In 2005 PetroNeft engaged local consultants to reprocess and reinterpret all of the vintage seismic and well data on the Licence using modern technology. The combined reinterpretation of the 14 wells and seismic data allowed the Company to determine those structures with high potential for containing commercial quantities of oil.
The Company subsequently acquired 1,055 line km of high resolution CDP seismic data and drilled 9 exploration/delineation wells. As a result of these efforts the two Soviet era fields at Lineynoye and Tungolskoye have been successfully delineated and new oil fields have been discovered at West Lineynoye (2007), Kondrashevskoye (2008), Arbuzovskoye (2010) and Sibkrayevskoye (2011).
Ryder Scott currently estimates the 2P reserves for the Licence area at 83 million barrels including the field discovery at Arbuzovskoye but Sibkrayevskoye will only be included in the year end 2011 Ryder Scott report. The current Russian registered GKZ C1+C2 reserves are 105 million barrels which does not include the new field discovery at Sibkrayevskoye.
Source rocks are present in the Lower Jurassic Togur and Upper Jurassic Bazhenov formations. The fields discovered to date on the Licence area have been in Upper Jurassic sandstone reservoirs. However, wells have successfully tested oil in Middle Jurassic and Lower Cretaceous sandstones in the adjacent Licences to the east and west.
Licence and Work Programme
The Licence is a 25 year exploration and production licence that is valid until 2030. The minimum work commitments under the Licence were to acquire 1,000 km of new 2D seismic data within three years and drill six wells within six years. Production of hydrocarbons should commence within two years of approval of commercial reserves. These commitments have all been met.
In 2010 the Company started the development of the Lineynoye oil field with the construction of 9 development wells, central processing facilities and export pipeline. Production commenced on schedule in Q3 2010 and reached 2,750 bopd by end 2010.
The 2011 work programme consists of expanding the central process facility to 14,800 bpd, construction of 2 new pads, drilling of up to 17 development wells and three exploration/delineation wells (Kondrashevskoye No. 2, North Varyakhskaya No. 1 and Sibkrayevskaya No. 372). Target rate at the end of Q1 2012 is 4,000 to 5,000 bopd.
Lineynoye Development Status
The 9 wells drilled from Lineynoye Pad 1 in 2010 and the 17 planned wells for Pads 2 and 3 for 2011 are shown in Figure above.
The 9 wells drilled from Pad 1 in 2010 and the first 2 wells drilled from Pad 2 in 2011 all came in close to prognosis in terms of depth and the wells were normally high to progonosis. However, when well 203 was drilled the primary objective was encountered deeper than anticipated and close to the oil-water contact for the field. The well was then side-tracked up-dip to the planned 204 location. As a result of the information learned from well 203 the Company moved quickly to reprocess and re-evaluate all of the seismic data for the Lineynoye Field. The resulting new interpretation (see below) clearly connects Pads 1 and 2 to the West Lineynoye field to the north in the Lineynoye 5 area where previously it had been thought that Lineynoye and West Lineynoye were separate structures. While this has positive implications for reserve and production performance from these areas of the field, the new interpretation also showed that the western part of the structure was lower (at Pad 3) than previously mapped. All of the wells drilled since the new structural map was prepared have been close to prognosis in terms of depth and have thus far confirmed the new interpretation.
While the wells drilled from Pad 2 to the north have encountered thicker pay intervals than expected and extended the field to the north, the wells drilled to the west (203 sidetrack and 334 and 336) have encountered thinner than expected pay intervals. As a result additional wells will be added to the Pad 2 drilling programme and the Pad 3 drilling programme will be reduced (see below).
