Alberta EUB Bulletin GB 99-6 by H.O. Lillo, P.Eng April 6, 1999, Alberta Energy and Utilities Board
TO: All Oil and Gas Operators
APPLICATION OF STABLE CARBON ISOTOPE RATIO MEASUREMENTS TO THE
INVESTIGATIONS OF GAS MIGRATION AND SURFACE CASING VENT FLOW
SOURCE DETECTION
The Canadian Association of Petroleum Producers, Environment Canada, and participating
environmental services companies sponsored a study to develop and field validate a novel
method to determine the sources of surface vent flows and gas migration (SCVF/GM). The five
year research program, conducted by the University of Alberta, measured stable carbon isotope ratios of hydrocarbon gases, to establish “signatures” or “finger prints” that uniquely
characterize origin and transformation of the gases.
Use of stable carbon isotopic ratios in the investigation of SCVF/GM is considered a new field
technique currently under refinement. The protocol promises to enhance and complement other diagnostic methods for SCVF/GM investigation in current use. Therefore, the Alberta Energy and Utilities Board (EUB) and Saskatchewan Energy and Mines (SEM) are prepared to accept the use and validity of this method on a site specific basis.
Development and availability of high quality regional databases, containing interpreted
analytical and geological information, are necessary prerequisites to defensible, extrapolated
diagnoses for SCVF/GM problems. The need to involve qualified expertise is also necessary.
Technical questions pertaining to the application of stable carbon isotopic ratios should be
directed to CAPP at (403) 267-1100. For clarification of regulatory questions, contact
James Fujikawa at the EUB (403) 297-6952 or Todd Han at Saskatchewan Energy and Mines
(306) 787-2221, depending upon applicable jurisdiction.
<Original signed by>
H. O. Lillo, P.Eng.
Group Leader
Environment, Safety and Technical Services