Abstract: On the basis of rock mechanics, the effects of in-situ hori-zontal stresses and producing pressure drop on sand production in weakly-consolidated sand formations are analyzed, and tech-nique and measures of sand control for such formations are disc-cussed. It is shown that some areas around the borehole experi-ence shear failure and sand production much more easily than
others as a result of inhomogeneous in-situ horizontal stresses.Therefore, it would help sand control to avoid perforating such areas in selecting perforation sites. In addition, when borehole pressure is kept constant, the possibility of shear failure of per-foration holes and sand production increases with the depletion of reservoir pressure; when formation pressure is kept constant,the possibility of shear failure of perforation holes and sand pro-duction increases with the increase of producing pressure drop.

Key words: weak consolidation, sand formation, sand production, sand control