Multi-stage acid-proppant fracturing* has been used for the first time by Gazprom Neft, at well No. 1522 in the Eastern block of its Orenburgskoye oil and gas-condensate field. Well productivity under seven-stage fracking proved to be 57 percent higher than at similar wells subject to standard multi-stage acid fracturing.
The Eastern block of the Orenburgskoye oil and gas-condensate field is one of the most complex fields under development by Gazprom Neft subsidiary Gazpromneft-Orenburg, in which high-viscosity oil is embedded within low-temperature low-permeability carbonate reservoirs. Acid fracturing has been used for enhanced oil recovery (EOR) at the field since 2013.
Well No. 1522 is located in the western part of the field, where reserves are categorised as hard-to-recover. Analysis of similar wells, brought into production after acid fracturing in this area, have shown significant drops in production over their first year of operation. In searching for a solution to this problem Gazpromneft-Orenburg geologists applied a new EOR fracking technique using both acid and proppant, tested and utilised with the support of the Gazprom Neft Science and Technology Centre.