Horizontal Well Applications-Canadian Achievements

Abstract

Abstract Spectacular! It is the only word that can be used to describe the rapid growth in the advancement of horizontal well technology that has taken place over the past 14 years in the petroleum industry. This is the most exciting development that this industry has known. The history of horizontal drilling in North America, although brief, has been one filled with dramatic developments. Nearly 95% of all the horizontal wells drilled in the world are in Canada and the United States. The development of horizontal well technology in the US brought revolutionary advances to the drilling sector such as the development of poly-crystalline compact bits, downhole drilling motors, top-drive drilling rigs, logging-while-drilling, geo-monitoring with steerable drill systems, and re-entries from existing vertically cased wells with coiled tubing. These achievements were accomplished mainly in the Austin Chalk of Texas (1989) and the Bakken shales of North Dakota (1991). These tools brought a higher drilling rate, lower drilling cost, reduced rig time, better interpretation of the drilling bit position, and faster geological descriptions. In Canada, on the other hand, because of the larger variety of target reservoirs and geological settings, the synergistic interdisciplinary approach created unique solutions with significant qualitative improvements in implementation. The first Canadian well was drilled in 1978 and over 14,700 wells have been licensed to date. We never dreamt ten years ago that drilling would use tools which provide real time data about the reservoir with the aid of LWD (logging-while-drilling) or MWD (measurement-while-drilling) systems. Today, we use a rotary closed loop drilling system, which combines the performance of continuous rotary drilling with precise placement, all made possible by LWD sensors and automated downhole guidance systems; this enables the driller to find the right path in the reservoir. On the production side, there are a variety of multilateral well junctions in order to assure the functionality of multilateral horizontal wells with regard to the access for cleaning, sands/solids barrier, and isolation. Sperry Sun introduced the lateral tie back system (LTBS) that allows multilateral branches to be drilled and cased from a single horizontal wellbore, followed by innovative production techniques based on progressing cavity pumps. This new solution brought high handling efficiency and considerable savings in production costs. Canadian Western Natural Gas drilled the first underbalanced well with natural gas (not with air or nitrogen) in a gas storage, low pressure, and water sensitive reservoir. The use of natural gas, although it involves unprecedented high safety standards, it allows, at the same time, to minimize the formation damage that is essential in order to maintain demanding deliverability requirements. In low permeability gas reservoirs, several projects have been promising in reservoirs that could not have been exploited otherwise. In naturally fractured reservoirs, in the Midale carbonate beds in Weyburn, PanCanadian created an innovative solution by placing the wells parallel to the fractures rather than perpendicular to them, as had been routinely practised. The intent was to avoid water being drawn upwards from fractures that extend both vertically and laterally.