Page 158 - Reservoir Formation Damage

Chapter 8

Particulate Processes

in Porous Media

Summary
Physico-chemical, chemical, hydrodynamic, and mechanical processes
frequently lead to the mobilization, generation, migration and deposition
of fine particles, which in turn cause formation damage in petroleum
bearing formations.
This chapter is devoted to the review of the various types of internal
particulate processes that occur in porous media, and the factors and
forces affecting these processes.

Introduction
There are three primary sources of fine particles in petroleum bearing
formations:
1. Invasion of foreign particles carried with the fluids injected for
completion, workover, and improved recovery purposes,
2. Mobilization of in-situ formation particles due to the incompatibility
of the fluids injected into porous media and by various rock-fluid
interactions, and
3. Production of particulates by chemical reactions, and inorganic and
organic precipitation.
Fluids injected into petroleum reservoirs usually contain iron colloids
produced by oxidation and corrosion of surface equipment, pumps, steel
casing, and drill string (Wojtanowicz et al., 1987). Brine injected for
waterflooding may contain some fine sand and clay particles. Mud fines
can invade the formation during overbalanced drilling. These are some
examples of the externally introduced particles.
Petroleum bearing formation usually contains various types of clay and
other mineral species attached to the pore surface. These species can be

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