For many applications, standard trend data may not be adequate. Many of the factors affecting rock properties are incompletely ascertained.For example, acoustic velocities can be affected by numerous parameters, many of which cannot be measured.
To establish the basic relationships between physical properties and rock parameters, laboratory investigations are made.
Laboratory measurements of rock samples can provide controlled conditions and high data quality ("hard data").
In this chapter, we will tabulate important mineral and rock properties, and provide many of the mathematical models used to describe and predict properties.
Much of this summary is drawn upon the extensive work and compellations already available.
Although hydrocarbon reservoirs have been found in all three rock types, we will consider here primarily sedimentary rocks, by far the most common rocks associated with hydrocarbons.
Minerals are defined as naturally occurring solids: They have a definite structure, composition, and suite of properties that are either fixed or vary systematically within a definite range.
These relationships can be extended to a larger scale, or can even be made scaleless.
Typically, models and relations based on laboratory data are then applied to in-situ measurements to derive the parameters we actually need (say, permeability) from information we can actually collect (say, density and gamma ray radiation).
Most theoretical models are built on simplified physical concepts: what are the properties of an ideal porous media.