Applied Petroleum Reservoir Engineering, 3rd Edition

Chapter 2. Review of Rock and Fluid Properties

2.1 Introduction

As fluid from a reservoir is produced and brought to the surface, the fluid remaining in the reservoir experiences changes in the reservoir conditions. The produced fluid also experiences changes as it is brought to the surface. The reservoir fluid typically sees only a decrease in pressure, while the produced fluid will experience decreases in pressure and in temperature. As the pressure decreases, it is common to observe gas that had been dissolved in the oil or water be liberated. Reservoir engineers use terms, such as the solution gas-oil ratio (R_so), to account for this. There are many variations on this term. R is generally used to denote any ratio, while the subscripts denote ...