Chain of Custody
Torkelson Geochemistry, Inc.
Torkelson Geochemistry, Inc. (TGI) specializes in providing laboratory
and consulting services in the areas of hydrocarbon fingerprinting
and physical properties of liquid petroleum products. TGI takes
pride in providing high quality data and consultation in a timely
fashion. TGI has been in business since 1995 and provides these
services to several major companies and many environmental service
companies, law firms and consultants.
Hydrocarbon fingerprinting or hydrocarbon characterization is used
in assessment, remediation and/or litigation related to petroleum
contaminated sites. Hydrocarbon fingerprinting provides information
as to the type, degree of weathering, age, and possible source of
spilled petroleum. The data used comes from high resolution capillary
gas chromatography analysis, a technique not available at most environmental
laboratories. High quality data combined with the expertise to interpret
the results provides the client with useable information to better
evaluate petroleum contaminated sites.
Determining the density, viscosity, surface tension, and interfacial
tension of a liquid petroleum provides the basic data for modeling
the recovery of petroleum spills. Environmental scientists have
been working on better methods for estimating the volume and recoverability
of free phase petroleum products in soil. These calculations require
accurate interfacial and surface tensions between petroleum products,
water, and air. It has been found that the interfacial and surface
tension values for petroleum products recovered from soil are significantly
different from literature values for the same petroleum product
fresh from the dispenser. The calculated volumes are sensitive to
these values and are significantly less than those obtained by "approximate"
TGI helped develop the use of the statistical technique “correlation
coefficients” to evaluate the results of hydrocarbon fingerprint
(gas chromatography) data. The method objectively compares and contrasts
the analytical results of two or more samples giving a single number
that indicates the degree of similarity between the samples. This
technique is especially useful for evaluating the data from large
sets of samples, providing an objective guide, but does not eliminate
the need expert interpretation of the data.
Bruce E. Torkelson
Bruce graduated in 1970 from Gustavus Adolphus College, St. Peter,
Minnesota with majors in geology and biology. He attended the University
of Tulsa where he received a Masters degree in geology. While employed
by Amoco Production Company for 21 years, Bruce took various short
courses and seminars related to organic geochemistry, petroleum
exploration, computing, and personal improvement.
Bruce was involved in various aspects of organic geochemistry while
working at the Amoco Production Company Research Center in Tulsa,
Oklahoma. As a technician in the lab he evaluated, installed, operated,
maintained, and modified a variety of instruments and procedures.
During 8 years experience doing technical service work he did routine
evaluation of source rock and oil samples, both foreign and domestic.
Bruce wrote reports, made presentations, helped plan sampling programs
and assisted explorationists in sampling on field trips. His research
experience at Amoco includes evaluating the technological needs
of the explorationists, planning projects, doing the research, overseeing
the work of others and delivering the results in the form of reports,
presentations and seminars.
Since 1995, Bruce has owned and operated Torkelson Geochemistry,
Inc. which specializes in providing laboratory and consulting services
in the areas of hydrocarbon fingerprinting and petroleum reservoir
continuity evaluation. Hydrocarbon fingerprinting is used for the
assessment, remediation and/or litigation related to petroleum contaminated
sites. Reservoir continuity evaluation is used to assess the compartmentalization
in an oil or gas reservoir or field providing a more complete picture
of the reservoir or field and how to more efficiently produce the
trapped petroleum. Both areas rely on high quality capillary gas
chromatography as the primary source of data and an experienced
scientist to interpret the results.
Bruce has published on a variety of topics in organic geochemistry
and more recently in the area of forensic geochemistry, more specifically
the interpretation and use of hydrocarbon fingerprinting (high resolution