Petroleum geochemistry has played an important role in many areas of e
xploration and production for fossil fuels. Many of the more recent de
velopments can be seen to have developed in parallel with developments
in analytical chemistry such as gas chromatography and gas chromatogr
aphy-mass spectrometry. For the past two decades such analytical techn
iques have been used to search for trace amounts of compounds known as
biomarkers present in oils and source rock extracts which can be used
to provide valuable information on the origin and history of the oil.
In the past two or three years much more effort has been placed on th
e development and utilization of such techniques as an aid to solving
reservoir and production problems. In this paper it is proposed to pro
vide an overview of major developments that have occurred in a number
of areas of geochemistry in recent years. This will include developmen
ts in reservoir geochemistry such as the use of high-resolution gas ch
romatography for reservoir continuity studies and high-temperature gas
chromatography for characterization of wax deposits. A brief overview
of recent developments in biomarker geochemistry will be provided in
the section on exploration geochemistry along wth a discussion on the
use of various pyrolysis techniques for the purposes of artificial mat
uration or characterization of the insoluble organic matter in source
rocks or asphaltenes in oils. While this paper is not intended for the
specialist in geochemistry, it is designed to provide the interested
reader with a broad overview of the areas of geochemistry where the si
gnificant developments have occurred and continue to occur. As our ana
lytical capabilities increase so do our abilities to obtain a far more
detailed and comprehensive picture on the origin of fossil fuels than
could ever have been imagined a mere two decades ago.