10.5.6 Constant Composition Expansion

A constant composition expansion (CCE) is an isothermal test that establishes the pressure/volume relationship for a fluid system as it may be depleted in a reservoir. Measurements of this test include saturation pressure, relative volume, single-phase densities, and other details depending on fluid type, for example, compressibility (oil), deviation factors (gas), and liquid dropout (condensates) as a fluid sample is progressively allowed to expand with decreasing pressure without removing any of the sample.

Figure 10.5.6-1 Example of a hydrocarbon analysis model (constant composition expansion).