Abstract: This paper presents the in-depth research of mechanism of enbancing heavy oil well productivity by sand-producing cold pro-duction and includes the increase of fluid flow by sand inflow; the formation of high permeability area; the formation of foaming oil and the decrease of skin effect. They may improve the understanding and recognition of the theoretical basis of sand-producing cold produc-tion in heavy oil well. In addition, the study indicates that the mechanism enhancing well productivity and factors controlling sand pro-duction are changing with time.

Key words: heavy oil, sand production, productivity, mechanismi