1.
n. [Formation Evaluation, Shale Gas]
Laboratory study of a sample of a
geologic formation, usually
reservoir rock, taken during or after drilling a well. Economic and efficient oil and gas
production is highly dependent on understanding key properties of reservoir rock, such as
porosity,
permeability, and
wettability. Geoscientists have developed a variety of approaches, including log and
core analysis techniques, to measure these properties. Core analysis is especially important in
shale reservoirs because of the vertical and
lateral heterogeneity of the rocks. Core analysis can include evaluation of
rock properties and
anisotropy; organic matter content,
maturity, and type; fluid content; fluid
sensitivity; and geomechanical properties. This information can be used to calibrate log and
seismic measurements and to help in well and
completion design, well placement, and other aspects of reservoir production.