Conférence sur la fracturation hydraulique et le risque
What Are the Real Risks in Hydraulic Fracturing?
Maurice B Dusseault, PEng
Earth and Environmental Sciences
University of Waterloo, Waterloo ON Canada
Salle 3370
Pavillon Adrien-Pouliot (PLT)
1065, avenue de la Médecine, Université Laval
Résumé
Proponents of shale gas and shale oil development tend to downplay and sometimes even deny associated risks. Conversely, opponents to development greatly exaggerate those risks. The talk will discuss the risks involved in drilling and fracturing large horizontal wellbores. Issues such as the possibility of fracturing fluids being forced to the surface, wellbore integrity and long-term gas seepage, treatment of fracturing flowback fluids, and induced seismicity will be presented and illustrated, focusing on the latest understanding of the actual risks involved.
To evaluate risk of an industrial activity, it is necessary to compare it broadly with other activities it may have replaced or affected. For example, few would disagree that the air pollution risks associated with coal-fired electrical power plants are greater than those associated with gas turbine power plants. Yet in Nova Scotia, where 56% of the electricity is generated with coal, widespread opposition to shale gas development led to a moratorium last August. In contrast, many persons in Nova Scotia seem comfortable with home heating by fuel oil and wood, both far greater polluters than natural gas furnaces.
The talk will explain the physical processes involved in hydraulic fracturing and well integrity, delineating the important pathways, and giving some insight into probability and consequences of environmental or safety risks. Shale gas and shale oil development are large-scale industrial activities, with well sites having 12 or more wells, all hydraulically fractured, that may be producing for 20 years, and may be re-stimulated during their lives using fracturing methods. This high local intensity increases local risk at sites, but reduces overall risk because sites are small and may be as infrequent as one per 8 km2. Issues such as fracture fluids flowback and induced seismicity will be briefly addressed.
Au sujet du conférencier
Maurice Dusseault carries out research in coupled problems in geomechanics including thermal and non-thermal oil production, wellbore integrity, deep disposal technologies for solid and liquid wastes, hydraulic fracture mechanics, CO2 sequestration in saline aquifers, shale gas and shale oil mechanics, and compressed air energy storage in salt caverns. He holds 10 patents and has co-authored two textbooks with John Franklin (former ISRM President, deceased 2012) as well as 520 full text conference and journal articles. Maurice works with governments and industry as an advisor and professional instructor in petroleum geomechanics. He was a Society of Petroleum Engineers Distinguished Lecturer in 2002-2003, visiting 19 countries and 28 separate SPE sections, speaking on New Oil Production Technologies. He teaches a number of professional short courses in subjects such as production approaches, petroleum geomechanics, waste disposal, and sand control, presented in over 23 different countries in the last 12 years.
Current projects are focused in these areas:
- Hydraulic fracturing of naturally fractured rock masses in differential stress states
- Work, energy and stress-strain responses of deep stressed rock masses (reservoirs, mines)
- Rock-cement-casing interaction and gas seepage along oil and gas wells
- THM coupling in naturally fractured rock masses
- Monitoring deformation in rock masses using surface and subsurface methods
- Storage of energy from stochastic renewable sources as compressed air in dissolved salt caverns
https://uwaterloo.ca/earth-environmental-sciences/people-profiles/maurice-b-dusseault
