Research on qualitative experimental dynamic sanding prediction considering the development performance

Sanding from the payzone is a dynamic developing process. It’s difficult to meet the needs of development for making a reliable qualitative experimental sanding prediction just by static logging data in the early development periods. Dynamic development data should be comprehensively considered for directing dynamic sanding prediction. First, the longitudinal wave velocities of unconsolidated sandstones which have different water saturations and pore pressures have been tested in simulated triaxial stress environment. The research shows that the longitudinal wave velocities speed up with the increasing of the water saturations; moreover the water saturation has much more significant effect on wave velocity when the sand consolidation is weaker. On the other hand, the longitudinal wave velocities increase with the decreasing of the formation pore pressure; and the stronger the consolidation, the weaker effect the pore pressure changes influence on the longitudinal wave velocities. Second, longitudinal wave velocity model which comprehensively influenced by water saturations and dimensionless pore pressure changes has been established by binary quadratic function fitting and principle of optimality. Depletion of reservoir pressure, water cut and lithology impact factor was introduced on the previous basis to develop the traditional combined modulus model and to establish the dynamic sanding prediction model. Last, the application in Obangue oil field shows that the dynamic sanding prediction model has well reliability and practicability.