OREANDA-NEWS. September 30, 2011. The amount of 94,000 tons of extra-viscous oil (EVO) has been produced at Ashalchinskoye field of TATNEFT since the beginning of its development and it is expected to produce over 100 thousand tons of EVO by the end of 2011. Currently, 9 pairs of wells have been drilled with 7 of them put in operation, reported the press-centre of TATNEFT.

Pilot operations at Ashalchinskoye field have been carried out since 2006 with application of modified steam assisted drainage technologies through dual wellheads horizontal wells.

A specific feature of developing deposits of extra-viscous oil is a need for steam generation and injection into the reservoir. For further development of the field and increase of the EVO production experts of NGDU Nurlatneft are building a boiler station capable of generating 50 tons of steam per hour. Today the work on installation and piping of the process equipment are at the stage of completion, the process of the boiler station area vertical leveling is being completed and the above-ground part of the pipeline feeding gas to it being installed.

New technologies to limit the sand sloughing and to control the steam distribution along the wellbore have been introduced at the wells for the purpose of rational exploitation of the deposits.

Coiled tubing technologies and fiber optic cables are used at TATNEFT in order to control the bottomhole pressure and temperature.

The problem of preventing salt deposits in the pipelines and vessels due to mixing of sewage water of carboniferous and extra-viscous oil is solved through application of the technology of separated water injection into the reservoir pressure maintenance system.