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Abstract: The Drake Landing Solar Community in Okotoks, Alberta, Canada utilizes a solar thermal system with borehole seasonal storage to supply space heating to 52 detached energy-efficient homes through a district heating network. Systems of similar size and configuration have been constructed in Europe, however, this is the first system of this type designed to supply more than 90% of the space heating with solar energy and the first operating in such a cold climate (5200 degree C-days). Solar heat captured in 2293 m2 of flat-plate collectors, mounted on the roofs of detached garages, is stored in soil underground and later when needed for space heating, is extracted and distributed through a district system to each home in the subdivision. Independent solar domestic hot water systems installed on every house are designed to supply more than 50% of the water heating load. Annual greenhouse gas emission reductions from energy efficiency improvements and solar energy supply exceed 5 tonnes per house. The seasonal storage utilizes approximately 34,000 m3 of earth and a grid of 144 boreholes with single u-tube heat exchangers. The system is configured to maintain the centre of the field at the highest temperature to maximize heating capacity and the outer edges at the lowest temperature to minimize losses. A short -term thermal storage consisting of 240 m3 of water is used to interconnect the collection, distribution and seasonal heat storage subsystems. The system has undergone detailed monitoring since it was brought into service in July 2007 to characterize its performance and to improve the TRNSYS model employed in its design. A solar fraction of 97% in its fifth year of operation, convincingly confirms the design target, a solar fraction of more than 90% in year five, has been met. This paper describes the system and its operation, presents 5 years of measured performance and compares those results against the TRNSYS predicted performance for the same period. [Copyright &y& Elsevier]

Abstract: The province of Alberta is endowed with the second largest oil reserves in the world behind Saudi Arabia in the form of bitumen in oil sands, with established bitumen reserves of 27.0 109 m3 extracted from initial bitumen in place of 286.6 109 m3. This huge resource base presents enormous challenges to produce and upgrade bitumen in an environmentally responsible manner, related to potential greenhouse gas emissions. Extracting this bitumen from oil sands and thereafter upgrading it to synthetic crude oil requires extensive processing using either carbon rejection (coking) or hydrogen addition (hydrocracking). The production of hydrogen for hydrocracking necessitates emissions of CO2 into the atmosphere which contributes in a significant manner to Alberta’s greenhouse gas emissions. Enhance Energy Inc. and NorthWest Upgrading Inc., two privately funded Alberta based companies, are proposing a solution by constructing CO2 capture and a backbone CO2 gathering and distribution system from Alberta’s industrial heartland area, which is the site of current and proposed bitumen upgraders, to enhanced oil recovery fields in central and southern Alberta for ultimate sequestration of such CO2. This paper presents an overview of the project which is scheduled for operation in late 2013. [Copyright &y& Elsevier]

Abstract: The Heartland Area Redwater CO2 Storage Project (HARP) is a staged CO2 storage project located near Edmonton in the industrial heartland of Alberta, Canada. The project, being developed by ARC Resources Ltd. of Calgary, aims to store CO2 captured from diverse sources into the very large Redwater Leduc Fm. carbonate reef situated at depths between 922 and 1234 m and with a thickness of up to 275 m. In the first stage, a pilot operation will be implemented by the spring of 2011 that will inject between 200 and 300 t CO2/day. In the second stage, depending on the regulatory and economic environment, the pilot may be scaled up to a commercial-sized operation by 2015 that will inject at least 1 Mt CO2/year. Each stage of the project has several phases, with Stage I/Phase I having been completed in the summer of 2009. Work focused on the characterization of the storage unit: Namely, the Redwater reef, its caprock, and the immediately underlying and overlying aquifers. In Stage I/Phase II, injection and monitoring wells will be drilled and site-specific characterization and pilot design will be completed, while at the same time seeking regulatory approval and community acceptance for the pilot operation. In Stage I/Phase III, the pilot operation will be constructed. A multi-disciplinary, multi-organizational research program comprising major research organizations and universities in western Canada is being built around this CO2 storage project. This paper presents the results of Phase I of the project: Characterization of the storage unit and adjacent strata. [Copyright &y& Elsevier]

Abstract: This paper will present results of a numerical modelling study on CO2 migration through abandoned wells. Leakage of CO2 through plugged and abandoned wellbores is one of the major concerns for long-term safety and effectiveness of geologic CO2 sequestration. For risk assessment and mitigation, it is not only important to understand and characterize the potential for CO2 leakage through wellbores but also subsequent CO2 migration beyond the primary sequestration reservoir. Subsequent to the leak, CO2 may take a direct path towards the accessible environment or it may migrate in an indirect stair-stepping manner through wellbores/fractures across multiple, shallow permeable strata. In the later case, identification of leak source and application of mitigation strategies may become a challenge. For this study we use data from a site in Alberta, Canada which has reported natural gas leak at surface. Investigations on origin of the gas and potential gas migration path from the original source to the surface at the analog site show that the gas could be moving through multiple wells and across multiple formations. There are multiple wells at the site which were drilled and abandoned without production casing and are completely open between two hydrocarbon bearing zones creating cross-flow across zones through open wellbores. Our study focuses on the deeper formations and potential for leakage for CO2 injected in deeper formation. A complex numerical fluid-flow model is developed for the site in FEHM, LANL’s porous media fluid-flow simulator. The model explicitly accounts for wellbore details such as abandonment plugs, casing, annulus cement, etc. The model was used to perform long-term simulations of CO2 injection and potential migration through abandoned wells. Numerical simulation results show limited migration of CO2 through abandoned wells. Such detailed simulation would be valuable to develop effective abandonment practices as well as mitigation strategies at CO2 sequestration sites. [Copyright &y& Elsevier]