Simple Mathematical Model for Estimating Mineral-Alkali Reactions in Alkaline Flooding: Topical Report

摘要

The problem of characterizing alkali-water-rock reactions in alkaline flooding is complicated because there are many mineral phases and aqueous species to include in a compositional model. The model presented in this report includes the following types of minerals: silicates, carbonates, sulfates, and oxides. Individual mineral reactions are arranged in order of increasing pH. Sulfate and carbonate minerals are converted to oxides and silicates at intermediate pH. Transformation of silicate minerals into zeolites occurs at high pH. The model predicts that calcium, magnesium, and carbonate ions are most important at neutral to intermediate pH and that silicate and aluminate ions become important at high pH. Results from bottle tests quantify the ability of minerals to consume alkaline agents. Studies on individual minerals, including kaolinite and dolomite, are reported. The effects of individual minerals in a mixture were found to be additive. The results described in this report show that an accurate determination of rock mineralogy is required for a reasonable prediction of alkali consumption in an oilfield. 42 refs., 14 figs., 13 tabs. (ERA citation 12:013165)