WCB-The Little Oil Patch That Could

Abstract

Introduction In terms of crude oil production, Canada is a relatively minor league player, ranking 14th among producing countries with 2.5% of the world total-Table 1(1). If considering the two largest producing provinces in the WCB (Western Canadian Basin) alone, Alberta would rank approximately 21st with less than 1.3% of the world's total. Saskatchewan produces roughly half that of Alberta, and would be on a par with Yemen (30th). Yet the WCB industry holds a globally dominant position in the key innovative exploitation technology (horizontal wells) and plays a major role in the related technical pursuits (UBD-Underbalanced Drilling, ERD- Extended Reach Drilling, coiled-tubing and multi-branch technology). Domination by Numbers In terms of scale of application of horizontal wells, the WCB is the world leader. Saskatchewan alone has in excess of 3,300 horizontal wells. Alberta, with over twice the resource base of Saskatchewan, has a 5,300+ horizontal well population. Collectively, the WCB claims a total approaching 10,000 wells, 40 - 60% of the world total(2). The world share can only be approximated since horizontal well statistics are not readily available from many of the major producing regions. Why is it that a region producing less than 2.5% of the world's crude would have a dominant position in the application of this advanced exploitation method? Outside observers might assume that the basin is characterized by one major reservoir type which is particularly conducive to horizontal well applications (e.g., the Austin Chalk of Texas). They may perceive that the application was championed by a large operator applying the technology to relatively huge fields (e.g., Statoil in Norway, or ADNOC in the UAE). On the contrary, the WCB is extremely diverse. Figure 1 provides a sample cross-section of horizontal wells drilled in the WCB in the period 1989 to 1993, the formative years of this technology in Canada. The TVD (true vertical depth) of these reservoirs varies from tens of metres to a number of kilometres. There is almost every conceivable type of hydrocarbon production (bitumen to deep sour gas), in many varied structures and lithologies. All the production processes are employed from primary through to the most advanced EOR (Enhanced Oil Recovery) methods, such as steam assisted gravity drainage (SAGD). In comparison to the world's major producing areas, the WCB would be described as a region of relatively thin, varied, depleted reservoirs of limited reserves and meagre profit margins. In Saskatchewan for example, pay zones frequently have net pay of less than five metres. Yet, in this marginal setting, oil production has increased over 90% in the last decade in large part due to the exponential growth of horizontal well applications(3). It is valid to state that, in general, the thinner the reservoir, the more attractive a horizontal well vs. a vertical well. However, it is simplified to suggest that a world technical dominance is solely resultant of a minor producing region having small, thin, depleted reserves in a very marginal profit setting.