CSPG Outreach Lecture - Petroleum systems & risk elements of the offshore Atlantic Canada


Petroleum systems & risk elements of the offshore Atlantic Canada


Professor Grant Wach 
Department of Earth Sciences, Dalhousie University

Canadian Society of Petroleum Geologists (CSPG) University Outreach Lecture Tour 2015


Thursday, November 19th, 2015
5:30 p.m.  

3120 HP
Carleton Universty



Source rock is a fundamental component of petroleum systems; coupled with reservoir distribution they are the two key risk elements in many basins offshore Eastern Canada (Figure 1). Significant issues in recent hydrocarbon exploration on this margin were accurate definition of the main source rock intervals and detection of reservoir rock. Existing models of deepwater sedimentation have underestimated the links between shelf and slope sedimentation, the roles of sea level, salt tectonism, and canyon formation, as controls on sediment transport pathways. Mass failure and along-slope sediment transport are also significant processes in passive continental margin development. The consequence of these sedimentary processes are the inherent complexities of shelf to slope sedimentation patterns and movement of potential reservoir rock to greater depths than previously anticipated.

Hydrocarbon exploration offshore Nova Scotia began in 1959; but the Scotian Basin remains unexplored with very few exploration wells (127 of 207), most concentrated in the Sable Subbasin. Exploration and production of gas and condensate focused on the 1) rollover anticlinal plays of the Mesozoic Sable delta, and 2) the carbonate platform. But the source and timing of hydrocarbon generation and migration pathways of these discrete petroleum systems are not fully understood (www.cnsopb.ns.ca). In comparison, the petroleum systems of the Newfoundland offshore margin (http://www.nr.gov.nl.ca) are better understood with over 1.3 billion barrels produced from one major source rock interval, the Kimmeridgian Egret Mb. of the Rankin Fm. However, the extensive Jurassic source rocks cropping out on the Western European and African conjugate margins (e.g. Duarte et al., 2010; Sachse et al., 2012) suggest that exploration for hydrocarbons can test alternative (and new) play concepts, improving chances of success.

The Basin and Reservoir Research Lab is a dedicated facility for petroleum geoscience research and training within the Department of Earth Sciences at Dalhousie University. The ongoing research have translation benefits to the offshore oil and gas sector through new insights developed from study of the offshore eastern Canada petroleum systems.



Professor Grant Wach began his geology career with Syncrude in the oil sands of Fort McMurray, Alberta. He stayed seven years, moving on to work worldwide for such oil and gas giants as Texaco and Exxon. He still works with the energy industry, but today, in his capacity as Professor of Petroleum Geoscience & Stratigraphy at Dalhousie University he now serves as a mentor, helping students become successful geoscientists. His research goal is to understand the entire petroleum system, particularly the reservoir component. Understanding the internal complexity of the reservoir isn’t easy; more than 50 per cent of the oil and gas is left in the ground and we must try and find more effective methods for recovering these resources. This is part of the path to sustainability. There is also a potential in the future to store CO2 in the reservoirs, serving two purposes – reducing Greenhouse gas emissions and recovering more oil by using the CO2 to push‐out the remaining gas trapped in the rocks.

Professor Wach studied at Western Ontario (Hons. B.A. Geog.); South Carolina (M.Sc. Geology) and the University of Oxford (D.Phil. Geology). He was the first recipient of the AAPG Foundation Professor of the Year Award in 2012.