塑性应变准则在油井出砂预测中的应用

APPLICATION OF PLASTIC STRAIN ON PREDICTION OF SAND PRODUCTION IN OIL WELL

用塑性应变准则建立了油井出砂预测的有限元力学模型 ,岩石的屈服应力准则用Drucker Prager准则。在某油田地层参数下 ,用该模型得到了不同井筒压差所对应井壁附近的塑性应力、应变变化结果 ,用这些结果可预测油井出砂情况。根据临界塑性应变 ,确定了井壁不出砂的临界生产压差 。

FEM Model of sand production in oil well was established with plastic strain criteria, the yield stress of the rock is the Drucker Prager criteria. According to the parameters of formation in some oilfield, the plastic stress strain results was obtained under the difference pressure with the model in the paper, the sand production can be predicted in light of the results. The criteria production pressure without sand production was determined according to the criteria plastic strain value. It provided the theoretical data for the normal production in oil well.