Building confidence in CCS: From Sleipner to the Northern Lights Project
Authors: A.-K. Furre, R Meneguolo, P. Ringrose and S. Kassold
First Break: Vol 37, No 7, July 2019 pp 83-89
Equinor’s ambition is to be a leading company in CO2-efficient oil and gas production, and to offer new business opportunities within renewable energy (Figure 1). CO2 handling consequently provides both a challenge and an opportunity. Equinor has long experience with CO2 capture, transport, and storage as operator of TCM (Test Centre Mongstad), Sleipner and Snøhvit fields and also as partner in the In Salah field in Algeria. The Norwegian State is presently leading a new full-scale CCS project, aimed at capturing CO2 from industrial sources and storing it beneath the North Sea. Equinor, together with partners Shell and Total in the Northern Lights partnership, is responsible for FEED (Front-End Engineering Design) of the transport and storage part of this project. The Global CCS Institute defines a large-scale CCS facility to comprise at least 0.8 Mt CO2 annually for a coal-based power plant and at least 0.4 Mt CO2 for other emission-intensive industrial facilities. Globally, nearly 20 large-scale industry-scale CCS projects are in operation today, with development plans for more. Most of these projects are in onshore settings and focusing on enhanced oil recovery. In addition to Sleipner and Snøhvit, three other projects are injecting CO2 into saline aquifers: Quest (Alberta, Canada – operated by Shell), Decatur (Illinois, USA – operated by Midwest Geological Sequestration Consortium), and Boundary Dam (Alberta, Canada – operated by SaskPower) which uses both saline aquifer storage at the Aquistore site and CO2 EOR in the Weyburn-Midale oilfield.
Application of distributed fibre-optic sensing to geothermal reservoir characterization and monitoring
Authors: Michael Mondanos and Thomas Coleman
First Break: Vol 37, No 7, July 2019 pp. 51 - 56
Geothermal reservoirs offer unique characterization challenges due to the harsh environment that downhole tools are subject to and the discrete and spatially discontinuous hydrothermal features that make up the reservoir. Enhanced Geothermal Systems (EGS) offer great potential for dramatically expanding the use of geothermal energy by allowing development of traditionally inaccessible thermal resources; thus, offering the possibility to significantly reduce carbon emissions to combat anthropogenically induced climate change. However, EGS development offers an additional set of challenges as reservoir engineers have the burden of not only characterizing the existing reservoir, but to dynamically guide reservoir enhancement in heterogeneous media with a fine degree of resolution and accuracy. Developing EGS resources will require highly advanced and novel characterization and monitoring methods and technologies. Geophysical data can provide some of the most spatially extensive information about the subsurface and has a long and successful exploration role in the oil and gas industry. Continuous monitoring of the subsurface is of great importance especially in operations where the permeability is enhanced during hydro-shearing (expanding existing fractures) and hydraulic tensile fracturing (to create new fractures). Optimization of enhancement processes can be achieved through localization of the geologic structures (e.g. fracture zones), seismic monitoring during stimulation, and characterizing the resultant hydraulic connectivity between injection and production wells. Seismic methods, which utilize elastic waves provide incredibly detailed images of geologic formations and structures play an important role in monitoring changes in the subsurface. Time-lapse (4D) seismic imaging techniques have become commonplace for monitoring the movement of fluids in oil and gas reservoirs and carbon sequestration. They have also been applied to geothermal reservoir characterization. Detection and localization of microseismic events during reservoir stimulation can provide an indication of fracture development to guide stimulation efforts.