Part I: Characterization of Reservoir Rock for Formation Damage - Mineralogy, Texture, Petrographics, Petrophysics, and Instrumental Techniques

CHAPTER LIST

SUMMARY

The origin, mineralogy, and mineral sensitivity of petroleum-bearing formations are reviewed. The mechanisms and kinetics of mineral swelling, alteration, and fines generation are described. The models and rate equations for mineral-sensitive properties of rock, and the methods for interpretation and proper correlation of experimental data are presented. These models provide insight into the mechanism of the clay swelling process and a proper means of interpreting and analyzing the swelling-dependent characteristics of clayey formations. They allow for accurate determination of the swelling parameters of petroleum-bearing formations. They can be used to predict the conditions causing the well-bore stability problems and to alleviate the undesirable consequences of the swelling phenomenon in petroleum reservoirs.

2.1 INTRODUCTION

Among others, Ohen and Civan (1993) point out that fines migration and clay swelling are the primary reasons for formation damage measured as permeability impairment. Poorly lithified and tightly packed formations having large quantities of authigenic, pore-filling clays sensitive to aqueous solutions, such as kaolinite, illite, smectite, chlorite, and mixed-layer clay minerals, are especially susceptible to formation damage (Amaefule et al., 1988). Formation damage also occurs as a result...