Suspended Solids Specifications for Water Injection from Coreflood Tests

Abstract

Abstract A method, which is based on the results of laboratory core-flood tests, is proposed for predicting the injectivity decline rate of water injectors. The method aims to provide design specifications for water treatment and injection facilities and procedures with which well injectivity behaviour can be analysed. A mathematical approach is outlined which describes impairment behaviour in terms of core plug filtration characteristics. The experimental procedure for isolating essential filter-cake properties required for the decline rate calculations consists of core flood tests at simulated inflow conditions done in conjunction with solids' characterisation via Coulter counter analysis of the injection water. When the extent and mechanism of plugging and also the filter-cake properties in terms of permeability and porosity have been established, it becomes possible to predict an injection well's half-life in relation to injection water quality. To illustrate the results that can be obtained with the proposed method, data from core-flood tests are used to construct injectivity decline rate curves for an arbitrary injection well.