The Effect of Sand Production on Formation Porosity in Unconsolidated Oil Field

Formation porosity near the wellbore can be changed by massive sand production, so it is impractical to use the initial formation porosity in downhole operation design in unconsolidated sand reservoir. The numerical method for sand prediction is limited for its complicated calculation procedures. An analytical model for porosity variation calculation is developed by coupling the material balance equation with the critical fluid drag force. With the result of sand production simulated test, the model can quantify the relation between sand production rate and formation porosity variation. Application of the model in oil field shows that it is simple and practicable for field engineering design.