Abstract: Tahe OilField is main oilproducing field of Sinopec in Western China. The field is characterized by ultradeep, ultraviscous and other features. Aimed at ultradeep and viscous oil reservoir′s feature in the Tahe OilField, combining blending light dropping viscosity evaluation, utilizing polyphone pipe flow calculation, on the basis of the study of high viscosity oil characteristic and deep well lifting technique, deep well highviscosity oil blending light dropping viscosity optimum design model is analyzed, the application of blending light dropping viscosity in the Tahe OilField is evaluated. Field operation indicates that blending light dropping viscosity technique is a kind of main oil recovery one and stimulation for fitting Tahe OilField ultradeep level heavy oil.

Key words: highviscosity oil, oil recovery technique, blending light dropping viscosity, multiphase flow, Tahe OilField