Petroleum Production Systems

Chapter 16. Carbonate Acidizing Design

16.1. Introduction

The acidizing process in carbonate formations is fundamentally different from that in sandstones. In a clastic formation, the surface reaction rates are slow and a relatively uniform acid front moves through the porous medium. In carbonates, surface reaction rates are very high, so mass transfer often limits the overall reaction rate, leading to highly nonuniform dissolution patterns. Often, a few large channels, called wormholes, are created, such as shown in Figure 16-1, caused by the nonuniform dissolution of limestone by HCl in a large block experiment (McDuff, Jackson, Schuchart, and Postl, 2010). The structure of these wormhole patterns depends on many factors, including (but not ...