Wednesday, February 27, 1:00pm
Dr Benjamin Rostron
Associate Professor, Dept. of Earth and Atmospheric Sciences, University of Alberta
During petroleum exploration and production operations the question often
arises 'Is the fluid recovered during well-testing pure formation-water or
contaminated with drilling fluid?' A variety of water chemical techniques
(e.g., 'stiff' diagrams) have historically been used to
answer this question. However, standard chemical fingerprinting techniques
can be problematic or ambiguous, especially when working in environments
with evaporites (hence brine formation-water), or in shallow (fresh
formation-water) settings. A new fingerprinting technique using stable
isotopes of hydrogen, oxygen and strontium in formation-waters has been
developed that overcomes many of the problems with previous methods.
Our on-going sampling program has collected more than 900 samples from producing wells and Drill-Stem-Tests in the Williston Basin (Canada-USA). These data have allowed us to create an isotopic database of formation-waters in the basin. This database has enabled the use of isotopic fingerprinting techniques in a variety of exploration and production operations, including: 1) During Drill-Stem-Testing and swabbing operations to determine if the recovered fluid is formation water. 2) As a production monitoring tool, to determine if produced fluids are originating in the perforated zone (versus 'leaking' into the wellbore from other formations). 3) As an aid to exploration, by enhancing understanding of reservoir continuity. These techniques are relatively fast and inexpensive, and have proven very useful to the petroleum industry.
Biography of the Speaker
Benjamin Rostron completed his B.A.Sc. in Geological Engineering at the
University of Waterloo in 1986, an M.Sc. in Geology in 1990 and a Ph.D. in
Geology in 1995 at the University of Alberta. He has worked as an
Assistant Professor at the University of Saskatchewan (1994-1997) and is
now Associate Professor at the University of Alberta, specialising in
regional scale fluid movement in basins.