Lineynoye and West Lineynoye Oil Fields
The Lineynoye Oil Field is located in the northwestern part of Licence 61. The Lineynoye No.1 well discovered oil within the structure in 1972. The well was drilled in the eastern part of the structure and tested oil from the Upper Jurassic ( J1 ) reservoir with a flow rate of 42 m3/day (264 bopd) on an 8 mm choke. The specific gravity of the oil is 0.835 g/cm3 or an API gravity of 38 degrees. Gas factor is 33 m3/m3. Reservoir pressure is 257 atmospheres. Russian C1 (proved) oil reserves totaling 45.75 million bbls/18.3 million bbls (in-place/recoverable) were approved by the State Committee for Reserves in 1972.
Detailed seismic surveys were carried out in 1985 - 1986, leading to structural reinterpretation of the field. The revised structural interpretation at that time broke the overall structure into several structural highs.
Since acquiring Licence 61, PetroNeft reprocessed the vintage seismic data over the Lineynoye structure and acquired an additional 515 line kms of new high resolution CDP seismic data over the Licence during the winter of 2005/2006. An additional 540 line kms of data was acquired during the winter of 2006/2007. Much of this new data has been acquired to further define the structural interpretation of the Lineynoye structure. The new interpretation, using previous drilling and new and vintage seismic, identified the West Lineynoye Prospect as potentially one oil bearing structure, above the known Oil Water Contact at -2,417 metres in the Lineynoye No. 5 well.
PetroNeft drilled the Lineynoye No. 6 well in 2007 to confirm the reservoir parameters and flow rates of the 1972 Lineynoye No. 1 discovery well. Lineynoye No. 6 penetrated 13.2 metres of net oil pay in the Upper Jurassic J1 interval and successfully tested at a stabilised flow of 100 bopd on a 1/8th inch choke. The well also lowered the oil water contact (owc) for the Lineynoye Field at least 10 metres which led to a reserve increase to 23.82 million bbls of proved and probable reserves. The Lineynoye No. 6 well was subsequently fitted with an Electric Submersible Pump (ESP) and put on long term test/pilot production during the first quarter of 2008 and 2009. The well has produced at a stabilised flow rate of around 250 bopd during the two test periods. This production data will assist in planning the optimal well fracture programme to stimulate production and enhance long-term recovery from the field.
In 2007 a second high impact exploration well, Lineynoye No. 7, was drilled in the West Lineynoye area. This well confirmed 1.5 metres of net oil pay and a 22 metre gross oil column in the J1 reservoir interval. The well initially flow tested at an inflow of 125 bopd (raising head methodology). The well was fitted with an ESP and was put on long term test/pilot production during the first quarter of 2008 and 2009.
In 2008 the Lineynoye No. 8 delineation well was drilled to further assess the West Lineynoye discovery. Lineynoye No. 8 encountered 4.0 metres of net pay in the J1 interval which tested at an inflow of 120 bopd without stimulation or pumping.
Ryder Scott estimates the proved and probable reserves for the West Lineynoye discovery at 23.30 million bbls. The combined Lineynoye and West Lineynoye fields have SPE 2P reserves of 47.12 million barrels of oil.
Russian experts consider the Lineynoye and West Lineynoye fields as one field. In December 2008 the Russian State Reserve Committee approved C1 + C2 reserves of 59.91 million barrels of oil for the combined field.
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