A Model for Predicting Injectivity Decline in Water-Injection Wells

TLDR

The study proposes a new method to predict injectivity decline in water‑injection wells. The method models both internal and external filtration, calculates a transition time using trapping efficiency from Stokesian dynamics, estimates damage‑zone radius and permeability with a deep‑bed filtration model, and derives equations that combine flow resistance in both filter cakes to compute overall injectivity decline.

Abstract

Summary We propose a new method to predict the injectivity decline for water-injection wells. Both internal and external filtration are considered in this method. A transition time from internal to external filtration is calculated by use of the trapping efficiency obtained from Stokesian dynamics simulations. The radius and the permeability of the damage zone are calculated by use of a deep-bed filtration model. Equations are derived that allow us to combine the flow resistance in the external and internal filter cakes to obtain the overall decline in injectivity.