Final answer:
Formation volume factors for gas or oil depend significantly on temperature and pressure, but not on formation porosity, which is related to storage capacity rather than fluid properties like volume factor.
Step-by-step explanation:
The formation volume factors for gas or oil depend on a variety of factors, primarily involved with the physical behavior of these fluids under different conditions. Factors such as temperature and pressure play significant roles in determining volume factors, as they directly affect the physical and chemical properties of the fluids. Temperature, for instance, can directly influence the thermal expansion or contraction of the fluid, while pressure has a profound effect on the compressibility and solubility of gases and liquids.
Porosity is a measure of the void space in a rock that can contain hydrocarbons. While it is crucial for understanding the storage capacity of a formation, it is not a direct factor in the calculation of the formation volume factor; rather, it influences the overall recoverable volume of hydrocarbons. Thus, formation porosity is NOT something that gas or oil formation volume factors depend on.
Fluid viscosity is another important parameter that influences the flow behavior or mobility of the fluid within the reservoir but does not directly impact the formation volume factor.