Wednesday, February 27, 1:00pm

Dr Benjamin Rostron

Associate Professor, Dept. of Earth and Atmospheric Sciences, University of Alberta
 

Fingerprinting formation waters using stable isotopes: applications to petroleum exploration and production  
 

Abstract

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.