OREANDA-NEWS. March 15, 2012. Record-breaking daily rate exceeding 500 tons oil was achieved on the Ilishevskoye oilfield in the Republic of Bashkortostan after JSOC Bashneft commissioned a horizontal oil well targeting Radaev-Bobrikov formation. It is the first time in over 20 years that such a flowrate is achieved at Bashkir oilfields.

"The results of drilling at the Ilishvskoye oilfield dispel the long-held notion that today there are only marginal wells left in Bashkortostan," commented Bashneft’s President Aleksander Korsik. "I’m convinced that this success is not an isolated instance. Undoubtedly, Bashkortostan’s subsoil resources are not exhausted, but in order to unlock their full potential we’ll need to conduct further surveys using state-of-the-art technology".

Oil well No. 7024h drilled in the Kadyrovsky area of the Ilishevskoye oilfield targets CVI layers of the Radaev-Bobrikov formation. The oilfield is developed by Chekmagushneft NGDU — a production unit of LLC Bashneft-Dobycha. The length of the horizontal wellbore passing through the sandstones of the CVI layer is 213 meters.

Well location and trajectory were designed using a 3D geotechnical model. Based on the modeling results, it was recommended to use horizontal wells, as they would ensure maximum productivity indices in the Radaev-Bobrikov formation.

"At the present stage in the development of most of the Company’s oilfields modeling of producing reservoirs and well design optimization are the promising tools for increasing production potential, which is confirmed by the results of drilling at the Ilishevskoye oilfield" said Mikhail Stavsky, First Vice President of Exploration and Production. "These techniques will be employed on the other Company’s oilfields as well."

Technical reference: After commissioning the fluid flow rate at horizontal well No. 7024h totaled 665 cubic meters per day with the water cut of 12% and pressure drawdown of 32 atm. The daily oil output totals 503.3 tons. The productivity index is 21 cubic meters/day/atm, which exceeds more than three times the productivity indices of directional wells No. 1649 and No. 7022 (6 cubic meters/d/atm), drilled earlier at the same deposit of the Ilishevskoye oilfield.

Bashneft’s specialists estimate potential output of oil well No. 7024г at 950 tons per day, which is significantly higher than the current production rate. In order to decide whether to exploit the well to its full potential, it is necessary to examine the trends in reservoir pressure depletion and perimeter aquifer support by hydrodynamic modeling.