CHAPTER2 DESCRIPTION OF THE RESOURCE The Department of Energy has defined Class 4 for the cost-shared oil recovery field demonstration program as strandplain/banier island reservoirs. This depositionally defied class of reservoirs represents a significant portion of the Nation's oil resource, as described in the DOE Tertiary O i l Recovery Information System (I'ORIS). The purpose of Chapter 2 is to present an overview of the reservoir, production, and geological characteristics of Class 4 reservoirs. Section 2.1 descriies the overall strandplain/banier island resource in the country based on an analysis of 330 Class 4 reservoirs listed in the TORIS database. Section 2.2 describes the general geological characteristics of strandplai4barrier island reservoirs based on a comprehensive review of the relevant geological literature. Section 2.3 presents an overview of the major Class 4 plays in the United States and includes summaries of the resource, reservoir, and production characteristics, as well as a summary of the recovery processes that have been used in these plays. The major plays are described in detail in Chapters 3 through 6. This facies, dong with the often overlying eolian facies, discussed below, constitutes the best reservoir rock associated with strandplainbarrier island systems.