Abstract: Through the stress analysis，this paper discusses the relations of natrual stress，forma-tion pressure，hole angle and azimuthal angle to sand production of reservoir. It shows，asregards the say记production，the produdtion of oil veil 'shoed be controlled to obtain secure well production. The paper presents the conception of bottom-hole critical flowing pressure
and secure production of oil well. It is of practical significance for management of oil well.

Key words: Horizontal well Directional well well product