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.
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.
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 10 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), Sibkrayevskoye (2011) and North Varyakhskoye (2011).
Ryder Scott currently estimates the 2P reserves for the Licence area at 117.68 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. A 2008 study of vintage log data from old Soviet wells indicates potential missed pay in both Middle Jurassic and Cretaceous intervals in two wells in the southern part of the Licence area.
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 nine development wells, central processing facilities and 60 km export pipeline. Production commenced on schedule in late August 2010 and reached 3,000 bopd in Q1 2011 following fracture stimulation. Water injection for pressure maintenance commenced in June 2011.
The 2011 work programme consisted of expanding the Lineynoye central process facility to 14,800 bpd, construction of 2 new pads, drilling of 14 development/delineation wells. Ten of the Pad 2 wells were fracture stimulated in November 2011. The Pad 2 wells have not responded nearly as well as the Pad 1 wells to fracture stimulation and a number of studies are underway to see if we can better understand these differences and how to deal with them (see Lineynoye and West Lineynoye Field).
The Pilot Production Design for the Arbuzovskoye oil field was approved by the Russian State Central Development Committee in November 2011. A 10 km pipeline and utility line were constructed from the Lineynoye central processing facility to the Arbuzovskoye field in Q1 2012. Plans are to drill from 8 to 10 development wells at Arbuzovskoye in 2012.