Evaluation model of two-stage gravel packing sand control well based on additional pressure drop

Abstract

Two-stage gravel pack sand control technology solves the problem of silt sand blockage in traditional high-pressure gravel pack, effectively improves the effective period and flow conductivity of the gravel pack. This technique has been widely used in the development of unconsolidated sandstone reservoirs, but the related studies still remain insufficient. In this paper, a sand control evaluation model based on additional pressure of the gravel packed layer is proposed for two-stage gravel packing sand control wells. Firstly, the complex mechanisms of sand plugging in gravel pack is divided into two types, horizontal and vertical, and the calculation model of dynamic permeability of the gravel pack is established. The finite element model of two-stage gravel packing sand control wells based on fluid-solid coupling is established by multi-physical coupling software COMSOL. The additional pressure drop of the sand control wells under various construction parameters is evaluated. Applying this method to evaluate a two-stage gravel packing well in Shengli Oilfield, it is concluded that after 200 days of production, the gravel pack’s additional pressure drop of the traditional packing increases to 2.5 MPa, while the overall additional pressure difference of two-stage gravel packing is stable at about 1.3 MPa. It is proved that two-stage gravel packing sand control technology can effectively reduce the additional pressure drop and improve the productivity of oil well after completion.